• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Sustainability Evaluation of Different Systems for Sea Cucumber (Apostichopus japonicus) Farming Based on Emergy Theory

    2015-10-13 21:30:04WANGGuodongDONGShuanglinTIANXiangliGAOQinfengandWANGFang
    Journal of Ocean University of China 2015年3期

    WANG Guodong, DONG Shuanglin, TIAN Xiangli, GAO Qinfeng, and WANG Fang

    ?

    Sustainability Evaluation of Different Systems for Sea Cucumber () Farming Based on Emergy Theory

    WANG Guodong, DONG Shuanglin*, TIAN Xiangli, GAO Qinfeng, and WANG Fang

    ,,,266003,

    Emergy analysis is effective for analyzing ecological economic systems. However, the accuracy of the approach is affected by the diversity of economic level, meteorological and hydrological parameters in different regions. The present study evaluated the economic benefits, environmental impact, and sustainability of indoor, semi-intensive and extensive farming systems of sea cucumber () in the same region. The results showed thatindoor farming system was high in input and output (yield) whereas pond extensive farming system was low in input and output. The output/input ratio of indoor farming system was lower than that of pond extensive farming system, and the output/input ratio of semi-intensive farming system fell in between them. The environmental loading ratio ofextensive farming system was lower than that of indoor farming system. In addition, the emergy yield and emergy exchange ratios, and emergy sustainability and emergy indexes for sustainable development were higher in extensive farming system than those in indoor farming system. These results indicated that the current extensive farming system exerted fewer negative influences on the environment, made more efficient use of available resources, and met more sustainable development requirements than the indoor farming system.farming systems showed more emergy benefits than fish farming systems. The pond farming systems ofexploited more free local environmental resources for production, caused less potential pressure on the local environment, and achieved higher sustainability than indoor farming system.

    ; farming systems; emergy theory; sustainability

    1 Introduction

    Sea cucumber is an important mariculture echinoderm species in northeast Asia because of its nutritional and curative properties (Okorie., 2008). Natural resources ofhave declined over the past 20 years because of overexploitation (Conand, 2004).farming has been rapidly developed in recent years because of its high value. In 2010, the farming area ofreached 1.5billionm2and its total production reached 130000 tons, which brought about an annual value of 20 billion Chinese Yuan (CNY) in China (MOAC, 2011).

    At present,land-based farming systems include indoor, semi-intensive, and extensive systems. According to Li. (2013a, 2013b), the total organic carbon, total nitrogen, and total phosphorus contents in the outflow water are less than those in the inflow water ofextensive farming system. Therefore, the sea cucumber farming system is not only a production system of aquatic products but also an environment friendly system. To improve the yield of, many farmers adopt semi-intensive or indoor farming systems with artificial diets. As these patterns increase the inputs of supplemental energy and organic matter, the sustainability of such farming systems has attracted public attention (Ren., 2012a, 2012b).farming systems are semi-artificial ecosystems in which both ecological and economic processes play significant roles. Thus, the ecological and economic natures offarming systems are difficult to determine using only a single ecological or economic method.

    Using the principles of energy systems theory, Odum (1983) developed a comprehensive ecological economic evaluation method for evaluating different energies, materials, and monetary ?ows in terms of their ‘emergy’. Emergy is defined as an available energy used directly or indirectly to produce a product or service (Odum, 1996). Emergy is usually quanti?ed in solar energy equivalents and expressed as solar emjoules (sej) (Ulgiati and Brown, 2009), a conversion factor (transformity) that reflects the qualitative value of energy. By multiplying their respective transformities, the emergy of each resource, service, and corresponding product can be calculated. The resulting values can then be analyzed easily based on the same dimension.

    Following its development and application over the past 30 years, the emergy analysis approach has been proven to be an effective tool for measuring the efficiency and sustainability of a system (Brown and Ulgiati, 2004). Several studies on fish and shrimp farming systems have been reported, including those for(Brown., 1992),(Brown and Bardi, 2001),(Odum, 2001),(Vassallo., 2007),,,,(Li., 2011),,, and(Zhang., 2011). Qin(2009) analyzed the extensive farming system ofusing the emergy approach.

    Due to the differences in regional economic development levels, as well as meteorological, hydrological, and other natural conditions, the emergy of a production or service may be entirely different. Comparing the different data of different regions may obtain false or infeasible results without the exact emergy data of the production or service. In the present study, emergy analysis methods were applied to evaluate the indoor, semi-intensive, and extensive farming systems ofin the same region with similar economic development levels and meteorological and hydrological conditions to overcome the interference of inaccurate regional parameters. The systems were objectively evaluated in terms of their resource inputs, productivity, environmental impact, economic benefits and sustainability.

    2 Materials and Methods

    2.1 Location and Data Collection

    In the present study differentfarming systems in Qingdao, China were detected. The region had an average annual solar radiation of 4.8×109Jm?2(Wang., 2010), an average annual rainfall of 750mm (WSP, 2009), an average annual wind speed of 4.5ms?1(Wang, 2007), and an average annual tide range of 3.20m (Hu., 1989; Zhang., 2000) (Table 1).

    The indoor farming system studied was a greenhouse wherewere reared in 20 square concrete tanks (approximately 25m2in area, 1m in water depth) in a stocking density of about 1.5kgm?2.were fed twice a day with commercial fermentative feed. Polyethylene corrugated sheets were used as a substrate for. Aeration was provided continuously to maintain adequate dissolved oxygen. Adult(120– 150g) were captured once a year in October with the mortality rate of 20%, and fingerlings were complemented afterward.

    The ponds of the semi-intensive farming system were confined mainly to intertidal zone. The water area of each pond was about 40000m2with an average water depth of 1.5m. The ponds relied on the tides as a means of water exchange. Farmers obtained land use rights through a contract with the local government, paying ‘rent’ during the contract. Stones, tiles or polyethylene cages were used as substrates of. The producers of the semi- intensive farming system relied on the tides and sediment accumulation to provide most of the food for, and supplemented nutrition with formulated feed. The stocking density was about 0.054kgm?2. Aeration was used discontinuously to provide adequate oxygen forin the semi-natural farming system. Adult(120–150g) were harvested twice a year, in March and November, with the mortality rate of 10%, and fingerlings were supplemented into the ponds in spring and autumn.

    The extensive farming system featured characteristics similar to those of the semi-intensive system but operated without artificial feeding and aerators. The stocking density of this system was about 0.046kgm?2.

    During the investigation period in 2012, 3 indoor farming systems (amount to 200 tanks approximately), 4 semi-intensive farming systems and 3 extensive farming systems (amount to 80 ponds approximately) were investigated. All local renewable resource inputs and purchased resource inputs considered in the production systems were provided by farmers working in the three systems, and converted to annual ?ows.

    Among the purchased resource inputs, the energy of the fingerlings was measured with a calorimeter (PARR Instrument Company, USA). The emergy of electricity and coal was calculated by multiplication coefficients of 3.6×106J(kWh)?1and 2.3×1010Jt?1(EC, 2007), respectively. Purchased resource inputs, including direct labor, rent, maintenance, pesticide, feed, and capture, were reported in monetary terms (Odum, 1996).

    2.2 Methods of Emergy Analysis and Evaluation

    Emergy resources included local renewable resource inputs and purchased resource inputs. The former included solar radiation, wind, rain, tides, and sediment accumulation, while the latter comprised fingerlings, electricity, coal, direct labor, rent, maintenance, pesticide, and feed (Table 1). The ‘Maintenance’ included depreciation period of boiler (3 years), substrate (4 years), roof (3 years) and aeration equipment (2 years) in indoor farming system and substrate (4 years), ponds clean (3 years) and aeration equipment (2 years) in semi-intensive and extensive farming systems.

    The total emergy () flow offarming system was calculated using the following equation:

    whereis local renewable resource input,is the renewable fraction of the purchased resource inputs, andnis the non-renewable fraction of the purchased resource inputs. The emergy yield ratio (), an indicator of the production efficiency of a system or process for exploiting local resources, is calculated as follows (Odum, 1996):

    .

    The environmental loading ratio (), an index of the potential pressure on the local environment or system stress due to production activity, is calculated as follows (Odum, 1996):

    The emergy sustainability index (), a ratio that measures the contribution of a resource or process to the economy per unit of environmental loading, is calculated as follows (Brown and Ulgiati, 1997):

    .

    The emergy exchange ratio (), an indicator of the emergy benefits or losses from the sale of products, is calculated as follows (Odum, 1996; Lu., 2009):

    ,

    where (income·(sej/CNY)) is the emergy embodied in the received money. The emergy index for sustainable development (), an indicator of the sustainability of the system considering the effects of market exchange on the emergy yield, is calculated as follows (Lu., 2009):

    Table 1 Annual emergy accounting and analysis table for the three farming systems of A. japonicus

    Notes:a, Wang., 2010;b, Wang, 2007;c, WSP (Weather of Shandong Province), 2009;d, Hu., 1989;e, Zhang., 2000;f, Qin., 2009;g, EC (Energy of Coal), 2007.

    3 Results and Discussion

    3.1 Emergy Flows inFarming Systems

    Aggregated system diagrams of the three farming systems ofwere shown in Figs.1 and 2 according to Odum (1996). The diagrams illustrated the boundaries, main components, interactions, and emergy driving sources for the systems. Pathways indicated casual interactions, showed material cycles or carry information, and were always created with some energy. Energy system diagrams included pathways for all energy inflows that might be stored, or flow out as exports, or be drained away through ‘heat sink’, representing used energy (without available energy to do work). Symbols for sources and components in the energy system diagrams were arranged from left to right in increasing order of transformity (Odum and Peterson, 1996).

    No feed, electricity or maintenance costs were noted in the extensive farming system comparing with the semi- intensive farming system. Pesticide and coal were used to maintain the health and fast growth ofin the indoor farming system, but no local renewable resources (., solar radiation, wind, rain and tides) were determined comparing with the semi-intensive and extensive farming systems.

    Fig.1 Summary diagram of the emergy flows in the indoor system for A. japonicus farming.

    Fig.2Summary diagram of the emergy flows in the semi- intensive system forfarming.

    3.2 Economic Accounting and Analysis ofFarming Systems

    Annual economic accounting and analysis table for the three farming systems ofwere presented in Table 2. The indoor farming system had a high input (6530000CNY) and high yield (8000000CNY) features, whereas the extensive farming system had a low input (110000CNY) and low output (181000CNY) features. The output/input ratio of the extensive farming system (1.64) was higher than that of the indoor farming system (1.23). The ratio of the semi-intensive farming system (1.61) was between those of the other two systems.

    Table 2Annual economic accounting and analysis of three farming systems of A. japonicus

    3.3 Emergy Accounting and Analysis ofFarming Systems

    Fig.3 shows the main resource inputs for thesefarming systems. The emergy structures (., the types of supporting emergy sources) each production system were detailed in this figure. The total emergy flows of the indoor, semi-intensive and extensive farming systems were 8.32×1018, 1.91×1017and 1.59×1017sej/annual, respectively.

    Fig.3Structure of detailed emergy inputs into the three farming systems of.

    Table 3 Annual emergy accounting and analysis of the indoor farming system of A. japonicus

    Notes: The data sources area, Odum, 1988;b, Odum, 1996;c, Jiang., 2008;d, Cavalett., 2006.

    As shown in Table 3, in the indoor farming system, the emergies of direct labor, rent and feed showed the same order of magnitude and were higher than those of other purchased resource inputs. To clean the tanks, a large amount of direct labor was needed to movewith substrates from one tank to the neighboring tank every several days. Sediment accumulation was the maximum local renewable resource input in the semi- intensive and extensive farming systems. Rent was the largest purchased emergy input for all the three farming systems (Fig.3).

    The renewable and purchased resource inputs in the three systems were multiplied by their corresponding renewability factors in order to divide them into renewable and non-renewable fractions (Zhang., 2011). The results were showed in Tables 3, 4 and 5.

    Table 4Annual emergy accounting and analysis of the semi-intensive farming system of A. japonicus

    Notes: The data sources area, Odum., 2000;b, Brown and Bardi, 2011;c, Qin., 2009;d, Odum, 1988;e, Odum, 1996;f, Jiang., 2008;g, Cavalett., 2006.

    Table 5Annual emergy accounting and analysis of the extensive farming system of A. japonicus

    Notes: The data sources are the same as in Table 4.

    3.4 Comparison of Emergy and Economic Benefits Among ThreeFarming Systems

    The emergy analysis approach was an effective tool for measuring ecological economic systems. However, accurate parameters of economic, meteorological, and hydrological conditions were difficult to obtain. Thus, conducting an ecological economic efficiency analysis among large scale regions was unrealistic. The present study focused on the three farming systems in the same region, Qingdao, to overcome the interference of inaccurate regional parameters. Thus, the systems might be objectively evaluated in terms of their economic benefits, environmental impact, and sustainability.

    Comparison and evaluation of emergy and economic indices for the three farming systems were shown in Table 6. The emergy yield ratio () was the ratio of total emergy to the purchased nonrenewable inputs and showed how efficiently the system uses the available local resources (Vassallo., 2007). According to Table 6, the extensive farming system obtained the highest(2.06), followed by the semi-intensive farming system (1.90) and the indoor farming system (1.18). The conversion efficiency of renewable resource decreased with increasing intensification offarming pattern. Theof the indoor farming system was close to 1, which indicates that the system typically exploits few natural resources and relied on the import of high purchased emergy inputs. In a way, the indoor farming system operated more like an industrial process than as a traditional agricultural one, which was characterized by high ecological efficiency (Zhang., 2011).

    Table 6Comparison and evaluation of emergy and economic indices for the three farming systems of A. japonicus

    If the environmental input ?ows didn’t take economic input flows into account, optimum use of resources could not be achieved, and management decisions would be based on incomplete analyses (Ulgiati., 1994). The emergy exchange ratio () was an indicator and the ratio of emergy exchanged in a trade or purchase (what was received to what was given). The trading partner that received more emergy would receive greater real wealth and greater economic stimulation because of the trade. In the present study the EERs of the indoor system (=1.85), semi-intensive system (2.11), and extensive system (2.17) showed 85%, 111%, and 117% emergy benefits from the market exchange, respectively. The extensive farming system showed more emergy benefit than the indoor and semi-intensive farming systems (Table 6).

    Therevealed the pressure on the environment for evaluating environmental services (Vassallo., 2007). ELR was directly related to the fraction of renewable resources, and was considered a measure of ecosystem stress due to production (Ulgiati and Brown, 2009). A largerusually suggested a higher level of environmental stress. Theof the indoor farming system (=5.50) was about five times greater than those of the extensive farming (0.94) and semi-intensive farming (1.12) systems. The results indicated that the pressure exerted by the indoor farming system on local environment was significantly greater than those exerted by the extensive and semi-intensive farming systems.

    The emergy sustainability index () was a composite ratio that indicated the process trade-off between the emergy advantage and its environmental pressure (Brown and Ulgiati, 1997; Lu., 2009). In other words, theindicated whether a process or a system provided sustainable contribution to the user with low environmental pressure. Thetook both ecological and economic compatibility into account. A largerusually means a higher sustainability of a process or a system. The order of the ESIs in the present study was as follows: extensive farming system (=2.18)>semi-intensive farming system (1.70)>indoor farming system (0.21). These results indicated that the extensive farming system was relatively sustainable whereas the indoor or industrialized farming system was not sustainable relatively.

    After considering the effects of market exchange on output, coupling ofand the emergy index for sustainable development () might be an appropriate approach for measuring sustainability characterized by complex time and spatial scales (Vassallo., 2007). In the present study, the EISDs obtained indicated that the extensive (=4.74) and semi-intensive (3.58) farming systems were more sustainable than the indoor farming system (0.40).

    3.5 Comparison BetweenFarming Systems and Other Aquaculture Systems

    Previous studies showed that the EERs of,, andrange from 0.46 to 0.52 (Zhang., 2011), and the EERs of,,ranged from 0.61 to 1.48 (Li., 2011). The EERs of the present farming systems were in the range of 1.85–2.17, which indicates that thefarming systems had more emergy benefits than other fish farming systems.

    Previous studies showed that the EYRs of(Vassallo., 2007),(Odum, 2001), and(Brown., 1992) were 1.20, 1.23 and 1.02, respectively, which were similar to that of the indoor farming system (=1.18) but lower than those of the semi-intensive farming (1.86) and extensive farming (2.06) systems in present study. The ELRs of the mentioned fish farming systems were 5.00, 4.24 and 46.52, respectively, which were also similar to that of the indoor farming system (=5.50) but higher than those of the semi-intensive farming (1.12) and extensive farming (0.94) systems in the present study. ESIs also exhibited similar patterns, which indicated that investment in pond farming systems ofexploited more free local environmental resources, caused less potential pressure on the local environment, and achieved higher sustainability than the fish farming systems. Previous studies showed that total organic carbon, total nitrogen, and total phosphorus contents of the inflow water in the extensive farming system ofwere greater than those of the outflow water (Zheng., 2009; Li., 2013a, 2013b). Thus, theextensive farming system was an environment-friendly farming system.

    4 Conclusions and Suggestion

    indoor farming system was high in input and output whereas pond extensive farming system was low in input and output (Table 2). These characteristics might be a driving force for farmers preferring indoor farming systems under the condition of limited land resources. However, the output/input ratio of the indoor farming system was lower than that of the extensive farming system. The output/input ratio of the semi-inten- sive farming systems was in between them, which might explain why the semi-intensive farming system was generally adopted by farmers.

    The results of emergy analysis demonstrated that theof theextensive farming system was lower than that of the indoor farming system. In addition,,,andwere all higher in the extensive farming system than those in the indoor farming system (Table 6). These results indicated that the current extensive farming system had fewer negative influences on the environment, made more efficient use of available resources, and met more sustainable development requirements.

    farming systems obtained more emergy benefits than other mentioned fish farming systems did. The results of this study indicated that pond farming systems ofexploited more free local environmental resources for production, caused less potential pressure on the local environment, and achieved higher sustainability than indoor farming system.

    Acknowledgements

    This work is supported by the Key R & D Program (2011BAD13B03), the National Marine Public Welfare Project of China (200905020), and the program for Excellent Youth Foundation of Shandong province (Grant No. JQ201009).

    Brown, M. T., and Bardi, E., 2001.,. Center for Environmental Policy, Environmental Engineering Sciences, University of Florida, Gainesville.

    Brown, M. T., Green, P., Gonzalez, A., and Venegas, J., 1992.. Center for Wetlands, University of Florida, Gainesville, FL, 1-405.

    Brown, M. T., and Ulgiati, S., 1997. Emergy-based indices and ratios to evaluate sustainability: Monitoring economies and technology toward environmentally sound innovation., 9: 51-69.

    Brown, M. T., and Ulgiati, S., 2004. Energy quality, emergy, and transformity: H. T. Odum’s contributions to quantifying and understanding systems., 178: 201-213.

    Cavalett, O., Queiroz, J. F. D., and Ortega, E., 2006. Emergy assessment of integrated product ion systems of grains, Pig and fish in small farms in the south Brazil., 193: 205-224.

    Conand, C., 2004. Present status of world sea cucumber resources and utilization: An international overview. In:Lovatelli, A.,, eds., FAO, Rome, 13-23.

    Hu, F. X., and Gu, G. C., 1989. Seasonal changes of the mean tidal range along the Chinese coasts., 20: 401-411.

    Jiang, M. M., Zhou, J. B., Chen, B., and Chen, G. Q., 2008. Emergy-based ecological account for the Chinese economy in 2004., 13: 2337-2356.

    Li, J. W., Dong, S. L., and Gao, Q. F., 2013a. Nitrogen and phosphorus budget of integrated aquaculture system of sea cucumber, jellyfishand shrimp., 13: 503-508.

    Li, J. W., Dong, S. L., Gao, Q. F., Wang, F., Tian, X. L., and Zhang, S. S., 2013b. Total organic carbon budget of integrated aquaculture system of sea cucumber, jellyfishand shrimp., 45: 1825-1831.

    Li, L. J., Lu, H. F., Ren, H., Kang, W. L., and Chen, F. P., 2011. Emergy evaluations of three aquaculture system on wetlands surrounding the Pearl River estuary, China., 11: 526-534.

    Lu, H. F., Kang, W. L., Campbell, D. E., Ren, H., Tan, Y. W., Feng, R. X., Luo, J. T., and Chen, F. P., 2009. Emergy and economic evaluations of four fruit production systems on reclaimed wetlands surrounding the Pearl River Estuary, China., 35: 1743-1757.

    MOAC (Ministry of Agriculture, China), 2011.. China Agriculture Publisher, Beijing, 1-129.

    Odum, H. T., 1983.. Wiley, New York, 1-644.

    Odum, H. T., 1988. Self-organization, transformity, and information., 242: 1132-1139.

    Odum, H. T., 1996.. John Wiley and Sons, New York, 1-370.

    Odum, H. T., 2001.. University of Florida Press, 1-9.

    Odum, H. T., Brown, M. T., and Brandt-Williams, S., 2000.Center for Environmental Policy, Environmental Engineering Sciences. University of Florida, Gainesville, 1-16.

    Odum, H. T., and Peterson, N., 1996. Simulation and evaluation with energy systems blocks., 93: 155- 173.

    Okorie, O. E., Ko, S. H., Go, S., Lee, S., Bae, J. Y., Han, K., and Bal, S. C., 2008. Preliminary study of the optimum dietary ascorbic acid level in sea cucumber,(Selenka)., 39: 758- 765.

    Qin, C. X., Dong, S. L., Wang, F., and Tian, X. L., 2009. Sustainability analysis of sea cucumber () culturing in earthen ponds China using the emergy approach., 55: 319-323.

    Ren, Y. C., Dong, S. L., Qin, C. X., Wang, F., Gao, Q. F., and Tian, X. L., 2012a. Ecological effects of co-culturing sea cucumber(Selenka) with scallopin earthen ponds., 30: 71-79.

    Ren, Y. C., Dong, S. L., Wang, X. B., Gao, Q. F., and Jiang, S. H., 2012b. Beneficial co-culture of jellyfish(Kishinouye) and sea cucumber(Selenka): Implications for pelagic-benthic coupling., 45: 177-187.

    Ulgiati, S., and Brown, M. T., 2009. Emergy and ecosystem complexity., 14: 310-321.

    Ulgiati, S., Odum, H. T., and Bastianoni, S., 1994. Emergy use, environmental loading and sustainability: An emergy analysis of Italy., 73: 215-268.

    Vassallo, P., Bastianoni, S., Beiso, I., Ridolfi, R., and Fabiano, M. 2007. Emergy analysis for the environmental sustainability of an inshore fish farming system., 7: 290-298.

    Wang, J. X., 2007. The analysis and calculation of the wind Energy resources in Shandong province. Master’s thesis. Lanzhou University, 1-74.

    Wang, J. Y., Zhao, Y. J., Chen, Y. C., and Feng, J. S., 2010. Evaluation on solar radiation resource and photosynthetic and thermal potential productivity in Shandong province., 11: 150-154.

    Zhang, J. W., and Du, B. L., 2000. The trend of tidal range enlarging along the coast of Yellow Sea of China., 19: 1-9.

    Zhang, L. X., Ulgiati S., Yang, Z. F., and Chen, B., 2011. Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area, China., 92: 683-694.

    Zheng, Z. M., Dong, S. L., Tian, X. L., Wang, F., Gao, Q. F., and Bai, P. F., 2009. Sediment-water fluxes of nutrients and dissolved organic carbon in extensiveculture ponds., 37: 218-224.

    Weather of Shandong Province (WSP), 2009. http://sd.weather. com.cn/sdqh/11/88004.shtml.

    Energy of Coal (EC), 2007. http://iask.sina.com.cn/b/7868133. html.

    (Edited by Qiu Yantao)

    10.1007/s11802-015-2453-z

    (August 10, 2013; revised October 10, 2013; accepted February 8, 2015)

    . Tel: 0086-532-66782799 E-mail: dongsl@ouc.edu.cn

    ISSN 1672-5182, 2015 14 (3): 503-510

    ? Ocean University of China, Science Press and Spring-Verlag Berlin Heidelberg 2015

    一卡2卡三卡四卡精品乱码亚洲| 老汉色av国产亚洲站长工具| 久久久久久久精品吃奶| 欧美3d第一页| 一本综合久久免费| 女人高潮潮喷娇喘18禁视频| 一二三四社区在线视频社区8| 国产精品 国内视频| aaaaa片日本免费| 成人欧美大片| 我的老师免费观看完整版| 久久中文看片网| 母亲3免费完整高清在线观看| 国产成人欧美在线观看| 亚洲一区二区三区不卡视频| 国产亚洲精品第一综合不卡| 欧美日韩亚洲综合一区二区三区_| 一进一出抽搐动态| 中文字幕av在线有码专区| 一区二区三区高清视频在线| 国产亚洲欧美在线一区二区| 国产真实乱freesex| 久久热在线av| 欧美日韩黄片免| 国产精品一及| 又大又爽又粗| 观看免费一级毛片| 精品少妇一区二区三区视频日本电影| 久久99热这里只有精品18| а√天堂www在线а√下载| 成年免费大片在线观看| 不卡av一区二区三区| 免费看a级黄色片| 女生性感内裤真人,穿戴方法视频| 毛片女人毛片| 成人欧美大片| 国产精品久久久久久亚洲av鲁大| 亚洲性夜色夜夜综合| 18禁黄网站禁片午夜丰满| 久久久久久久久免费视频了| 亚洲 欧美 日韩 在线 免费| 免费高清视频大片| 狂野欧美白嫩少妇大欣赏| 欧美一级a爱片免费观看看 | 欧美黄色淫秽网站| 亚洲av五月六月丁香网| 精品国产美女av久久久久小说| 欧美成人性av电影在线观看| 亚洲avbb在线观看| 波多野结衣巨乳人妻| 在线a可以看的网站| 草草在线视频免费看| 亚洲黑人精品在线| 国产aⅴ精品一区二区三区波| 婷婷精品国产亚洲av| 在线观看一区二区三区| www.www免费av| 亚洲欧洲精品一区二区精品久久久| 老司机在亚洲福利影院| 欧美午夜高清在线| 在线观看午夜福利视频| 一级毛片女人18水好多| 亚洲 国产 在线| 国产精品九九99| 久久香蕉激情| 亚洲成av人片在线播放无| 嫩草影视91久久| 亚洲精品国产精品久久久不卡| 久9热在线精品视频| 高潮久久久久久久久久久不卡| 国产精品久久久久久久电影 | 美女午夜性视频免费| 国产黄色小视频在线观看| 女人被狂操c到高潮| 免费在线观看视频国产中文字幕亚洲| 国产一区二区在线观看日韩 | 国内揄拍国产精品人妻在线| 18禁裸乳无遮挡免费网站照片| 中文在线观看免费www的网站 | 亚洲成a人片在线一区二区| 波多野结衣巨乳人妻| 午夜福利在线在线| 少妇裸体淫交视频免费看高清 | 男人舔女人的私密视频| 91av网站免费观看| 国产精品 欧美亚洲| 国产视频一区二区在线看| 18禁国产床啪视频网站| av福利片在线| 老司机深夜福利视频在线观看| 国产在线观看jvid| 18美女黄网站色大片免费观看| 在线播放国产精品三级| 变态另类成人亚洲欧美熟女| 长腿黑丝高跟| av片东京热男人的天堂| 精品福利观看| 日韩三级视频一区二区三区| 国产精品美女特级片免费视频播放器 | 91老司机精品| 国产精品久久久久久亚洲av鲁大| 啪啪无遮挡十八禁网站| 精品久久久久久久久久久久久| 国产视频一区二区在线看| 日本精品一区二区三区蜜桃| 国产视频内射| 日本成人三级电影网站| 久久精品综合一区二区三区| 91麻豆av在线| 成人特级黄色片久久久久久久| 99精品欧美一区二区三区四区| 成人av在线播放网站| 欧美高清成人免费视频www| 亚洲乱码一区二区免费版| 亚洲七黄色美女视频| 亚洲精品国产一区二区精华液| 国产精品98久久久久久宅男小说| 麻豆国产97在线/欧美 | 久久久久亚洲av毛片大全| 亚洲九九香蕉| svipshipincom国产片| 精品一区二区三区视频在线观看免费| 欧美一区二区国产精品久久精品 | 麻豆久久精品国产亚洲av| 亚洲精品粉嫩美女一区| 中出人妻视频一区二区| 精品福利观看| 色综合站精品国产| 亚洲男人的天堂狠狠| 国产亚洲av高清不卡| 日本精品一区二区三区蜜桃| 国产单亲对白刺激| 欧美绝顶高潮抽搐喷水| ponron亚洲| 久久这里只有精品中国| 久久久精品欧美日韩精品| 久久精品国产99精品国产亚洲性色| 精品福利观看| 长腿黑丝高跟| 热99re8久久精品国产| 欧美乱码精品一区二区三区| 国产不卡一卡二| 免费看十八禁软件| 久久久久久久久中文| 巨乳人妻的诱惑在线观看| 18禁裸乳无遮挡免费网站照片| 国产99久久九九免费精品| av天堂在线播放| 51午夜福利影视在线观看| 午夜久久久久精精品| 黄色 视频免费看| 一个人免费在线观看的高清视频| 国产精品永久免费网站| 18禁观看日本| 在线观看午夜福利视频| 可以在线观看毛片的网站| 亚洲成人精品中文字幕电影| 午夜精品在线福利| 日本熟妇午夜| 久久99热这里只有精品18| 亚洲一卡2卡3卡4卡5卡精品中文| 亚洲一区中文字幕在线| 久久久久久国产a免费观看| 国产69精品久久久久777片 | 一二三四社区在线视频社区8| x7x7x7水蜜桃| 国产视频一区二区在线看| av有码第一页| 国产精品永久免费网站| 国产亚洲精品第一综合不卡| 欧美色视频一区免费| 91九色精品人成在线观看| 草草在线视频免费看| 别揉我奶头~嗯~啊~动态视频| 99久久99久久久精品蜜桃| 国产一区二区在线观看日韩 | 日韩三级视频一区二区三区| 欧美国产日韩亚洲一区| 国产三级在线视频| 毛片女人毛片| 亚洲色图av天堂| 亚洲熟妇中文字幕五十中出| 欧美中文综合在线视频| 亚洲av成人不卡在线观看播放网| 这个男人来自地球电影免费观看| 两性午夜刺激爽爽歪歪视频在线观看 | 大型av网站在线播放| 制服人妻中文乱码| 国产真人三级小视频在线观看| 18美女黄网站色大片免费观看| 人妻丰满熟妇av一区二区三区| 国产男靠女视频免费网站| 啪啪无遮挡十八禁网站| 在线观看舔阴道视频| 草草在线视频免费看| 一进一出抽搐动态| 日本黄色视频三级网站网址| 亚洲人成77777在线视频| 欧美日韩亚洲国产一区二区在线观看| 久久精品人妻少妇| 国产精华一区二区三区| 少妇熟女aⅴ在线视频| 五月玫瑰六月丁香| 亚洲欧美精品综合久久99| 日本黄色视频三级网站网址| 成人午夜高清在线视频| 免费一级毛片在线播放高清视频| 91麻豆精品激情在线观看国产| 欧美色视频一区免费| 日韩国内少妇激情av| 深夜精品福利| 99热这里只有精品一区 | 美女午夜性视频免费| 国产熟女午夜一区二区三区| 成年版毛片免费区| 在线观看美女被高潮喷水网站 | 国产一区二区在线观看日韩 | 女生性感内裤真人,穿戴方法视频| 欧美日韩亚洲国产一区二区在线观看| av中文乱码字幕在线| 18美女黄网站色大片免费观看| 久久久久久久久中文| 国产精品久久久人人做人人爽| 国产成人av教育| 亚洲色图av天堂| 亚洲av日韩精品久久久久久密| 午夜成年电影在线免费观看| 亚洲国产精品999在线| 成年人黄色毛片网站| 天天一区二区日本电影三级| 久久久精品欧美日韩精品| 亚洲天堂国产精品一区在线| 在线观看一区二区三区| 国产精品亚洲av一区麻豆| 999久久久精品免费观看国产| 国产亚洲精品久久久久5区| 亚洲欧美日韩高清在线视频| 香蕉av资源在线| 国产精品亚洲av一区麻豆| 亚洲一区二区三区色噜噜| 搡老妇女老女人老熟妇| 欧美日本视频| 哪里可以看免费的av片| 久久热在线av| 日韩欧美一区二区三区在线观看| 精品欧美一区二区三区在线| 男人舔奶头视频| 又大又爽又粗| 国产精品一区二区精品视频观看| 制服丝袜大香蕉在线| 午夜精品一区二区三区免费看| 97人妻精品一区二区三区麻豆| 国产av又大| 亚洲av五月六月丁香网| 一夜夜www| 免费观看精品视频网站| 免费电影在线观看免费观看| 丰满人妻熟妇乱又伦精品不卡| 欧美日本亚洲视频在线播放| 99热6这里只有精品| 亚洲电影在线观看av| av视频在线观看入口| 窝窝影院91人妻| 色综合亚洲欧美另类图片| 欧美中文日本在线观看视频| 精品人妻1区二区| 国产精品久久视频播放| 国内精品一区二区在线观看| 欧美性猛交╳xxx乱大交人| 男女那种视频在线观看| 在线永久观看黄色视频| 亚洲avbb在线观看| 中文字幕人成人乱码亚洲影| www国产在线视频色| 国产精品综合久久久久久久免费| 十八禁人妻一区二区| 欧美绝顶高潮抽搐喷水| 日韩欧美免费精品| 午夜日韩欧美国产| 19禁男女啪啪无遮挡网站| 国产精品永久免费网站| 亚洲精品久久成人aⅴ小说| 成年免费大片在线观看| 99国产极品粉嫩在线观看| 后天国语完整版免费观看| 国产精品1区2区在线观看.| 俄罗斯特黄特色一大片| 国产亚洲精品av在线| 国产欧美日韩精品亚洲av| 黄色丝袜av网址大全| 天天躁狠狠躁夜夜躁狠狠躁| av片东京热男人的天堂| 国内少妇人妻偷人精品xxx网站 | 日日爽夜夜爽网站| 久久久久久久久久黄片| 久久热在线av| 久久久久久久久久黄片| 男女那种视频在线观看| 在线免费观看的www视频| 99热这里只有精品一区 | 精品乱码久久久久久99久播| 国产成人啪精品午夜网站| 女人高潮潮喷娇喘18禁视频| 欧美色欧美亚洲另类二区| 国产一区二区三区视频了| 久久精品成人免费网站| 又黄又爽又免费观看的视频| 搡老妇女老女人老熟妇| 天天一区二区日本电影三级| 免费看美女性在线毛片视频| 9191精品国产免费久久| 亚洲性夜色夜夜综合| 免费一级毛片在线播放高清视频| 19禁男女啪啪无遮挡网站| 亚洲av成人精品一区久久| 日本 av在线| 首页视频小说图片口味搜索| 精品久久久久久,| 精品无人区乱码1区二区| 三级国产精品欧美在线观看 | xxx96com| 宅男免费午夜| 亚洲天堂国产精品一区在线| 18禁国产床啪视频网站| 成人18禁高潮啪啪吃奶动态图| 一区福利在线观看| 熟女少妇亚洲综合色aaa.| 日韩成人在线观看一区二区三区| 国产亚洲欧美98| 波多野结衣高清无吗| 亚洲成人久久爱视频| 每晚都被弄得嗷嗷叫到高潮| 国产av又大| 欧美三级亚洲精品| 国产精华一区二区三区| 亚洲中文字幕一区二区三区有码在线看 | 精品欧美国产一区二区三| 在线观看免费视频日本深夜| 久久精品成人免费网站| 亚洲成人免费电影在线观看| 久久亚洲真实| 婷婷精品国产亚洲av| 日韩av在线大香蕉| 午夜激情av网站| cao死你这个sao货| 日韩国内少妇激情av| 制服丝袜大香蕉在线| 亚洲一区二区三区不卡视频| 精品免费久久久久久久清纯| 成人国产综合亚洲| 最近最新免费中文字幕在线| 午夜激情av网站| 久久久国产欧美日韩av| 久久久久久亚洲精品国产蜜桃av| 午夜影院日韩av| x7x7x7水蜜桃| 久久久国产欧美日韩av| 婷婷丁香在线五月| 国产又色又爽无遮挡免费看| 欧美国产日韩亚洲一区| 黄片小视频在线播放| 成人18禁高潮啪啪吃奶动态图| 国产精品一及| 欧美一级a爱片免费观看看 | 亚洲一区中文字幕在线| 国产精品久久视频播放| 日本黄色视频三级网站网址| 国产欧美日韩一区二区精品| 一进一出抽搐gif免费好疼| 久久久国产成人免费| 亚洲中文字幕一区二区三区有码在线看 | 国产成人av教育| 伊人久久大香线蕉亚洲五| 精品熟女少妇八av免费久了| 欧美又色又爽又黄视频| 欧美中文日本在线观看视频| 在线观看一区二区三区| 中文字幕最新亚洲高清| 丰满人妻一区二区三区视频av | 国产亚洲av嫩草精品影院| 日本黄色视频三级网站网址| 成人手机av| 色哟哟哟哟哟哟| 麻豆成人午夜福利视频| 999久久久精品免费观看国产| 国产av又大| 99久久久亚洲精品蜜臀av| 欧美日韩一级在线毛片| av天堂在线播放| 夜夜夜夜夜久久久久| 亚洲成人精品中文字幕电影| 熟女少妇亚洲综合色aaa.| 国产高清激情床上av| 亚洲国产中文字幕在线视频| 免费av毛片视频| 国产人伦9x9x在线观看| 亚洲精品美女久久av网站| 久久 成人 亚洲| 国产精品日韩av在线免费观看| 丁香六月欧美| 亚洲人成77777在线视频| 好看av亚洲va欧美ⅴa在| 一个人免费在线观看电影 | 欧美黑人精品巨大| 两个人看的免费小视频| 黄色视频不卡| 久久久久免费精品人妻一区二区| 久久久久久久精品吃奶| 国产亚洲精品久久久久久毛片| 午夜福利视频1000在线观看| 亚洲成人久久性| 国产成人一区二区三区免费视频网站| 午夜免费成人在线视频| 成人三级做爰电影| 香蕉av资源在线| 精品一区二区三区av网在线观看| 久久香蕉国产精品| 欧美乱色亚洲激情| 亚洲欧美一区二区三区黑人| 精品少妇一区二区三区视频日本电影| 最近在线观看免费完整版| 亚洲中文字幕日韩| 国产高清有码在线观看视频 | 国产三级在线视频| 非洲黑人性xxxx精品又粗又长| av天堂在线播放| 精品久久蜜臀av无| 久久精品国产清高在天天线| 免费在线观看日本一区| 99国产综合亚洲精品| 欧美不卡视频在线免费观看 | 亚洲av中文字字幕乱码综合| 琪琪午夜伦伦电影理论片6080| 中文资源天堂在线| 一个人观看的视频www高清免费观看 | 日本熟妇午夜| 18禁裸乳无遮挡免费网站照片| 国产精品99久久99久久久不卡| 亚洲欧美一区二区三区黑人| 中文资源天堂在线| 久久久久久久午夜电影| 91老司机精品| 国产精品一及| 日日摸夜夜添夜夜添小说| 国产精品自产拍在线观看55亚洲| 又黄又爽又免费观看的视频| 国产亚洲av嫩草精品影院| 精品电影一区二区在线| 欧美丝袜亚洲另类 | 两个人视频免费观看高清| 成年版毛片免费区| 亚洲欧美日韩高清专用| 午夜福利在线在线| 国产激情久久老熟女| 亚洲激情在线av| 亚洲欧美日韩高清在线视频| 叶爱在线成人免费视频播放| 精品福利观看| 久久久国产成人免费| 免费看a级黄色片| 午夜福利成人在线免费观看| 深夜精品福利| 91九色精品人成在线观看| 99国产精品一区二区蜜桃av| 国产99白浆流出| 免费在线观看亚洲国产| 日本 av在线| 亚洲欧美日韩高清在线视频| 久久中文字幕一级| 久久国产精品影院| 一进一出抽搐动态| 国产又色又爽无遮挡免费看| 久久久精品大字幕| 国内毛片毛片毛片毛片毛片| 国产精品98久久久久久宅男小说| 国产真实乱freesex| 村上凉子中文字幕在线| 中文字幕最新亚洲高清| 久久久国产精品麻豆| 欧美日韩瑟瑟在线播放| 午夜免费激情av| www.自偷自拍.com| 人妻久久中文字幕网| 88av欧美| 欧美日本视频| 国模一区二区三区四区视频 | av有码第一页| 国内精品一区二区在线观看| 成年人黄色毛片网站| 国产男靠女视频免费网站| 国产精品 欧美亚洲| 变态另类丝袜制服| 国内精品一区二区在线观看| 制服诱惑二区| 丁香欧美五月| 黄色a级毛片大全视频| 俄罗斯特黄特色一大片| 在线观看免费视频日本深夜| 久久这里只有精品19| 男人舔女人下体高潮全视频| 久久久精品大字幕| 一个人免费在线观看电影 | 国产成年人精品一区二区| 男男h啪啪无遮挡| 两个人视频免费观看高清| 妹子高潮喷水视频| 久久精品国产99精品国产亚洲性色| 午夜免费观看网址| 中文字幕av在线有码专区| 啪啪无遮挡十八禁网站| 999久久久国产精品视频| 精品午夜福利视频在线观看一区| 欧美黑人欧美精品刺激| 中文资源天堂在线| a在线观看视频网站| av天堂在线播放| 亚洲第一电影网av| 久久久国产精品麻豆| 午夜激情av网站| 亚洲成人久久爱视频| 男女下面进入的视频免费午夜| 国产探花在线观看一区二区| av视频在线观看入口| 两个人的视频大全免费| 成年女人毛片免费观看观看9| 88av欧美| 欧美性长视频在线观看| 欧美色视频一区免费| 丁香欧美五月| 看免费av毛片| 国产成人精品无人区| 国产高清视频在线播放一区| 午夜福利成人在线免费观看| 国产一区二区在线av高清观看| 日韩国内少妇激情av| 制服诱惑二区| 国产又色又爽无遮挡免费看| 国产精品野战在线观看| 亚洲五月天丁香| 日本免费一区二区三区高清不卡| 亚洲男人的天堂狠狠| 琪琪午夜伦伦电影理论片6080| 国产精品99久久99久久久不卡| 国产麻豆成人av免费视频| 亚洲国产看品久久| 精品久久久久久久人妻蜜臀av| 日韩av在线大香蕉| 嫩草影视91久久| 国产片内射在线| 淫秽高清视频在线观看| 欧美成人午夜精品| 亚洲一区高清亚洲精品| 18禁国产床啪视频网站| 亚洲专区字幕在线| 久久性视频一级片| 日韩欧美精品v在线| 亚洲欧美日韩高清在线视频| cao死你这个sao货| 色综合欧美亚洲国产小说| 老汉色av国产亚洲站长工具| 亚洲午夜精品一区,二区,三区| 1024手机看黄色片| 一区福利在线观看| 99久久99久久久精品蜜桃| 男插女下体视频免费在线播放| 天天躁狠狠躁夜夜躁狠狠躁| 脱女人内裤的视频| 欧美黑人巨大hd| 国产精品影院久久| 欧美久久黑人一区二区| av视频在线观看入口| 男人舔女人的私密视频| 日韩欧美国产在线观看| 久久中文字幕人妻熟女| 不卡一级毛片| 成人亚洲精品av一区二区| 亚洲精品粉嫩美女一区| 在线观看66精品国产| 欧美丝袜亚洲另类 | 久99久视频精品免费| 久久精品aⅴ一区二区三区四区| 麻豆一二三区av精品| 国产精品 国内视频| 亚洲精品一区av在线观看| 精品一区二区三区av网在线观看| 国产成人精品无人区| 日韩精品青青久久久久久| 久久人妻av系列| av视频在线观看入口| 国产三级中文精品| 日韩欧美国产在线观看| 一夜夜www| 亚洲 国产 在线| 久久国产精品人妻蜜桃| 一个人免费在线观看电影 | 久久久久久大精品| 黑人巨大精品欧美一区二区mp4| 国产单亲对白刺激| 亚洲中文av在线| 一级黄色大片毛片| 免费看日本二区| 久久久久久国产a免费观看| 中文亚洲av片在线观看爽| 性欧美人与动物交配| 久久香蕉国产精品| 欧美不卡视频在线免费观看 | 欧美黑人精品巨大| 国产亚洲精品一区二区www| 久久久国产成人免费| 丰满的人妻完整版| 无限看片的www在线观看| 国产成人aa在线观看| 日韩欧美三级三区| 亚洲色图av天堂| 性欧美人与动物交配|