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31.
红外光度法测定石油类和动植物油常见问题探讨   总被引:2,自引:0,他引:2  
根据石油类在波数为2930cm-1、2960 cm-1、3030 cm-1全部或部分谱带处有物征吸收的原理,采用红外光度测油仪和水样絮凝富集技术测定石油类、动植物油。  相似文献   
32.
The Ethical Contract as a Tool in Organic Animal Husbandry   总被引:1,自引:3,他引:1  
This article explores what an ethicfor organic animal husbandry might look like,departing from the assumption that organicfarming is substantially based in ecocentricethics. We argue that farm animals arenecessary functional partners in sustainableagroecosystems. This opens up additional waysto argue for their moral standing. We suggestan ethical contract to be used as acomplementary to the ecocentric framework. Weexpound the content of the contract and end bysuggesting how to apply this contract inpractice. The contract enjoins us to share thewealth created in the agroecosystem (by ourjoint contributions) by enjoining us to carefor the welfare and needs of the individualanimal, and to protect them from exploitation(just as human co-workers should not beexploited). The contract makes promoting goodanimal welfare a necessary condition forbenefiting farm animals. Animals for their partare guaranteed coverage under the contract solong as they continue to contribute to thesystem with products and services.  相似文献   
33.
Few moral arguments have been made against vegetarian diets. One exception is the “Logic of the Larder:” We do animals a favor by purchasing their meat, eggs, and milk, for if we did not purchase these products, fewer animals would exist. This argument fails because many farm animals have lives that are probably not worth living, while others prevent a significant number of wild animals from existing. Even if this were not so, the purchase of animal products uses resources that could otherwise be used to bring a much greater number of animals into existence.  相似文献   
34.
The solution chemistry of forested streams primarily in western North America is explained by considering the major factors that influence this chemistry — geological weathering; atmospheric precipitation and climate; precipitation acidity; terrestrial biological processes; physical/chemical reactions in the soil; and physical, chemical, and biological processes within streams. Due to the complexity of all these processes and their varying importance for different chemicals, stream water chemistry has exhibited considerable geographic and temporal variation and is difficult to model accurately. The impacts of forest harvesting on stream water chemistry were reviewed by considering the effects of harvesting on each of the important factors controlling this chemistry, as well as other factors influencing these impacts ‐ extent of the watershed harvested, presence of buffer strips between streams and harvested areas, nature of post‐harvesting site preparation, revegetation rate following harvesting, pre‐harvesting soil fertility, and soil buffering capacity. These effects have sometimes reinforced one another but have sometimes been counterbalancing or slight so that harvesting impacts on stream water chemistry have been highly variable. Eight major knowledge gaps were identified, two of which — a scarcity of detailed stream chemical budgets and knowledge of longitudinal variation in stream chemistry — relate to undisturbed streams, while the remainder relate to forest harvesting effects.  相似文献   
35.
The need for scientifically defensible water quality standards for nonpoint source pollution control continues to be a pressing environmental issue. The probability of impact at differing levels of nonpoint source pollution was determined using the biological response of instream organisms empirically obtained from a statistical survey. A conditional probability analysis was used to calculate a biological threshold of impact as a function of the likelihood of exceeding a given value of pollution metric for a specified geographic area. Uncertainty and natural variability were inherently incorporated into the analysis through the use of data from a probabilistic survey. Data from wadable streams in the mid‐Atlantic area of the U.S. were used to demonstrate the approach. Benthic macroinvertebrate community index values (EPT taxa richness) were used to identify impacted stream communities. Percent fines in substrate (silt/clay fraction, > 0.06 mm) were used as a surrogate indicator for sedimentation. Thresholds of impact due to sedimentation were identified by three different techniques, and were in the range of 12 to 15 percent fines. These values were consistent with existing literature from laboratory and field studies on the impact of sediments on aquatic life in freshwater streams. All results were different from values determined from current regulatory guidance. Finally, it was illustrated how these thresholds could be used to develop criterion for protection of aquatic life in streams.  相似文献   
36.
A systematic understanding of dynamic animal extinction trajectories for different regions in a nation like China is critically important to developing practical conservation strategies. We explored historical and contemporary changes in terrestrial mammalian diversity to determine how diversity in each of the 5 regions in China has changed over time and to examine the conservation potential of these regions. We used records from databases on Pleistocene mammalian fossils and historical distribution records (1175–2020) for Primates (as a case study) to reconstruct evolutionary and historical distribution trajectories of the 11 orders of terrestrial mammals and to predict their prospective survival based on the national conservation strategy applied. The results indicated that since the Pleistocene, 4–5 mammalian orders have been lost in the northeast, 3 in central China, 2 along the coast, and 1 in the northwest. In the southwest, all 11 orders were maintained. Contemporarily, the coast and southwest had the highest and second-highest species densities. The southwest region and southeastern sections of the northwest region were the most historically and contemporarily diverse areas, which suggests that they should be the first priority for protected area (PA) designation. The central and coastal areas should be secondarily prioritized. In these 2 regions, conservation should focus on human coexistence with nature. Less attention should be paid to the PA in the northeast and western northwest because in these areas ecosystems are depauperate and the climate is harsh. Conservation in these areas should focus principally on avoiding further human encroachment on natural areas. Article impact statement: Historical and contemporary patterns of extinction can be a basis for mammalian conservation strategies.  相似文献   
37.
International trade in exotic pets is an important and increasing driver of biodiversity loss and often compromises the standards required for good animal welfare. We systematically reviewed the scientific and gray literature and used the United Nations Environment Programme ‐ World Conservation Monitoring Centre (UNEP‐WCMC) Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) trade database to establish temporal and geographical trade patterns of live exotic birds, mammals, and reptiles and to describe trends in research, taxonomic representation, and level of threat and legal protection of species traded. Birds were the most species‐rich and abundant class reported in trade; reptiles were second most abundant but unusually the most studied in this context; and mammals were least abundant in trade. Mammalian and reptilian species traded as pets were more likely to be threatened than expected by random. There have been a substantial number of Appendix I listed captive‐bred mammals and birds and wild‐caught birds and reptiles reported in trade to CITES. We identified the Middle East's emerging role as a driver of demand for exotic pets of all taxa alongside the well‐established and increasing role of South America and Southeast Asia in the market. Europe, North America, and the Middle East featured most heavily in trade reports to CITES, whereas trade involving South America and Southeast Asia were given most emphasis in the literature. For effective monitoring of and appropriate response to the international exotic pet trade, it is imperative that the reliability and detail of CITES trade reports improve and that scientific research be directed toward those taxa and locations that are most vulnerable. El Mercado Global de Mascotas Exóticas 2006‐2012  相似文献   
38.
为改善生物有机肥性质,提高生物有机肥质量,采取在生物有机肥中添加外源氨基酸水解液以提升生物有机肥中功能微生物的数量.以病死猪酸解制得氨基酸水解液为生物有机肥外加原料,研究了氨基酸水解液添加量、有机肥种类(鸡粪、牛粪、中药渣)、发酵时间对功能菌株SQR9数量的影响.结果表明:当氨基酸水解液添加量为20%时固体发酵效果优于其他接种量,预发酵3 d后接种SQR9的功能菌数量明显高于未预发酵直接接菌,预发酵中肥料(以干质量计,下同)的最高功能菌数量可达4×108 CFU/g,而第0天接菌时肥料的最高功能菌数量仅为1.2×108 CFU/g.以腐熟鸡粪、牛粪、中药渣堆肥为载体,添加酸解氨基酸研制生物有机肥的最优接菌量分别为10.0%、7.5%、10.0%;SQR9菌株生长的最佳含水量为40%.此外,氨基酸水解液的添加可提高生物有机肥的w(TN).研究显示,氨基酸水解液的添加能有效促进固态发酵过程中功能菌株数量的增加.   相似文献   
39.
以典型三环多环芳烃菲为代表,选取11种典型纳米颗粒对水中不同浓度的菲进行吸附实验,探究水体中的纳米颗粒对菲的吸附特征.结果表明,Freundlich模型对所有样品的拟合结果最好.logKFr值显示,有机膨润土及3种炭黑对菲的吸附作用最强,且远远大于其他纳米颗粒.有机膨润土对菲的吸附表现为线性吸附(n=1.08),而3种炭黑均表现出显著的非线性特征(n<0.5),且非线性特征随吸附能力的增强而增强,其他几种纳米颗粒均表现出非线性吸附特征(n<0.9).水中所有的纳米颗粒在与菲作用的过程中,吸附的强弱与颗粒表面电位、粒径及比表面积均无显著相关性,即对于所有纳米颗粒来说,这几种性质并不是决定吸附作用的最主要因素,而吸附剂的化学组成及结构特性可能是引起吸附作用差异的主要原因.  相似文献   
40.
东北三省畜禽养殖类固醇激素排放及其潜在污染风险   总被引:4,自引:0,他引:4  
以东北三省畜禽养殖数量统计数据和养殖结构分析为基础,对黑龙江、吉林和辽宁省畜禽养殖类固醇激素排放量进行了估算,并初步探讨了畜禽粪便中类固醇激素对当地水体的潜在污染风险.结果表明,由于养殖数量的增加,东北三省畜禽粪便所排放的类固醇激素量均持续增大.在1998~2008年的10 a间,辽宁、吉林和黑龙江三省的类固醇激素排放量分别增长了2 272.7、1 951.1和1 634.8 kg,并且省会城市沈阳、长春和哈尔滨的增长最为明显.东北三省各城市中畜禽粪便类固醇雌激素排放量最大的是长春,达到874.7 kg;哈尔滨和沈阳的排放量在各自省份中也是最大,分别为652.7 kg和603.1 kg·辽宁省的畜禽类固醇激素排放总量在东北三省为最多,所排放类固醇雌激素的雌二醇等当量浓度EEQs预测值也最高,达到17.1ng·L-1.如果以英国环保署(Environment Agency,United Kingdom)建议的最低可观测效应浓度10 ng·L-1为参考依据,辽宁省在目前的畜禽养殖规模和结构下,所排放的粪便类固醇雌激素极有可能会对地表水体中的水生生物产生内分泌干扰效应.  相似文献   
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