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71.
To restore China’s degraded ecological environment, the government has launched an environmental restoration project named the “Grain for Green Project” (GGP) in 1999. From 1999 to 2010, the government will spend 40 billion dollars to convert 147 million ha of croplands and 173 million ha of wastelands into forestlands and grasslands in 25 provinces, municipalities and autonomous regions. A primary goal is to replace cropping and livestock grazing in fragile areas with trees and grass. Given the tremendous scale and great number of participants in the project, the attitudes of the affected farmers and the future development in the area where GGP is implemented have a direct influence on the success of the project. To gain a clear idea about the farmers’ attitudes towards the project and put forward the development models for the forestlands converted from croplands, two case sites in the mountain-gorge region in Nujiang River are selected as the study areas, and the methods of field survey and semi-structured interview are adopted to make interviews with more than 100 households in 2002 and 2003 in order to quantify the farmers’ opinions about the GGP and how it has affected their livelihood, socio-cultural and industrial structures, etc. The results are as follows: 1) the project has a certain influence on the farmers with better economic basis and exerts greater influence on the farmers living in the low-elevation regions than on those living in the regions with middle-high elevation; 2) the production models of the local farmers has changed from cultivation and animal husbandry to forestry and sidelines due to the project and the income structure has changed from animal husbandry as main income source to state subsidy and sideline as main income sources; 3) the reduction in the grain income and decrease in the quantity of livestock because of the project have led to the diminution in the total income of the farmers; 4) the project has resulted in changes in the lifestyles and architecture styles of the local farmers, and the traditional “huotang” culture has gone away after the implementation of the project; 5) energy utilization has changed from firewood to methane and electricity in the wake of the implementation of the project. The above-mentioned study results have indicated that the GGP has truly exerted influence on the livelihood and production of the local farmers. Therefore, it is very necessary to make a research into the development models in the forestlands converted from croplands to resolve the problems of the farmers’ livelihood and production. The study results will provide some references for the sustainable development of the mountain-gorge regions.  相似文献   
72.
Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene (COI) was used to identifing five sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.  相似文献   
73.
Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.  相似文献   
74.
新疆克拉玛依强下坡风暴的机理研究   总被引:1,自引:0,他引:1  
卢冰  史永强  王光辉  岳斌 《气象学报》2014,72(6):1218-1230
利用美国中尺度数值模式 WRF 对2013年3月7—8日克拉玛依强风进行了模拟,对下坡风发生、发展和结束3个阶段的三维结构特征进行了分析,并由此提出克拉玛依强下坡风的形成机制模型:上游地区出现中高层西南风、低层西北风并伴有强冷平流的配置,当风速不断增大时,气流能够翻越加依尔山在背风坡侧形成重力波,重力波相位向气流上游方向倾斜产生非线性效应,促进了波不稳定区域的形成并导致波破碎,形成湍流活跃层,不断把上层的能量向下传播;克拉玛依中低层形成三层夹心的大气层结稳定度分布,出现明显的过渡气流带从而导致强下坡风的形成;南北风分量在低层和中层符号相反,形成了临界层,不断吸收上层波能量并向地面传送,强下坡风暴不断维持发展。最后利用2006—2012年克拉玛依33个强下坡风过程中的探空观测资料对提出的形成机制进行了验证。  相似文献   
75.
The Huanghebei Coalfield, one of the coal production bases in North China, was considered as a coalfield without coal‐bed methane (CBM) during past decades. In recent years, however, CBM has been discovered in coal‐bearing successions. In order to understand the CBM geological characteristics and accumulation process in this area, fifteen coal samples were collected and analyzed with respect to coal maceral and reflectance. The result shows that the gas distribution is uneven and the content varies in different areas even for the same coal bed. The storage of CBM is affected by geological factors such as burial depth, geological structures, and magmatic intrusion, among which the former two are more important in the formation of CBM. Deep burial of coal beds with the presence of cap‐rock mudstone can seal CBM. The CBM is also accumulated and preserved at the place where normal faults are distributed. Magmatic intrusion causes contact metamorphism and controls the CBM formation by heating the coal‐bearing successions. The obtained data indicate the geological conditions in northeastern Zhaoguan Mine are preferable for CBM formation and conservation; recent exploration estimates the CBM geological reserves up to 282.16 Mm3 and average of reserve abundance at 0.1662 × 108 m3 km?2. The Changqing Mine is a potential prospect in terms of CBM exploration since its geological conditions (structures and burial depth) are similar to the Zhaoguan Mine and its cap rock is even better.  相似文献   
76.
Xuanwei and Fuyuan, two counties located in southwest China, are areas with exceptionally high lung cancer incidence since the 1970s. In this study, questionnaires from a total of 18 communes, and 28 administrative villages (consisting of 280 small villages) in the two counties were fulfilled and collected. The sampling sites were randomly chosen in consideration of the incidence rate of lung cancer and the types of coal used. The sampling sites were divided into high lung cancer occurrence areas and low lung cancer occurrence areas. Industrial and environmental information was investigated and finally analyzed for the possible relationship to the lung cancer. It indicated that 78.1 % of the villages in high lung cancer incidence areas had been found using smoky coal or coking coals in people’s everyday lives; 43.4 % of these villages located near the coking factories, 31.1 % near the iron-zinc smelters and 11.8 % near the chemical industries. In the low lung cancer incidence areas, 78.8 % of the villages had been found using non-smoky coals (anthracite) in people’s everyday lives; 26.9 % of these villages are near the coking factories, 23.1 % near the iron-zinc smelters and 5.8 % near the chemical industries. Logistic regression analysis indicated that the coal type used was a foremost risk factor related to incidence of lung cancer [β > 0, Exp (β) >1, P < 0.05]. The use of smoky coals and coking coals seemed to be a hazardous factor for lung cancer generation, while non-smoky coals seemed to have no significant relationship to the lung cancer incidence. The results in this study added basic and important data and should be helpful for the future study on the etiology of lung cancer.  相似文献   
77.
Yu  Shiwei  Hou  Jindong  Lv  Jun  Ba  Guizhi 《Natural Hazards》2014,75(2):219-231

The completion and operation of the Three Gorges Reservoir in China have increased the frequency of geo-hazards and dangers in the area. To monitor and to warn of geo-hazards effectively, the Chinese government has invested billions of funds for constructing a monitoring and warning engineering system. Similar to other social infrastructure investments, a reasonable assessment of investment returns is necessary. Therefore, this study proposes an economic benefit assessment model, which considers both the expected and the actual values. The economic benefit of the geo-hazard monitoring and warning engineering in the Three Gorges Reservoir areas is evaluated. Based on the engineering characteristics, the model reasonably defines the frontier of the input and output and adds the casualties and the losses of ecological environment into the economic benefit evaluation index system. A case study on the Zhangjiawan landslide in Guojiaba Town, Zigui County, was conducted. The evaluation results show that (1) land has the largest benefit in direct reductional loss (total of 56.7 %), while the largest indirect reductional losses of the hazard-bearing bodies are in agricultural production and ecological environment (total of 97.6 %); (2) the costs-to-expected return ratio of landslide monitoring and warning engineering is 1:280, whereas the cost-to-actual benefit ratio is 1:30; (3) the accumulation of relevant information and the public knowledge of geological disasters should be strengthened.

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78.
植被覆盖度是衡量地表植被覆盖的一个重要指标。根据Worldview II影像计算归一化植被指数,利用像元二分模型得到某区域的植被覆盖度图,为水土流失监测评价提供重要的基础数据。  相似文献   
79.
为了验证程家村航磁异常圈闭,对该异常圈闭进行了查证工作,针对该区域铁矿体均呈深部隐伏的赋存状态,以"物探先行,钻探验证"的工作方法开展工作,利用地面高精度磁测扫面确定磁异常圈闭平面形态及位置;对高精度磁测剖面数据进行切线法剖面反演,确定强磁性地质体位置和埋深,再结合重磁剖面联合反演方法,推断强磁性地质体的赋存状态,从而给钻探验证提供依据。通过上述工作,取得了良好的找矿效果,表明重磁方法是深部隐伏磁铁矿勘查中的重要工作手段。  相似文献   
80.
Irrigation is the major water supply for crop production in water‐limited regions. However, this important water component is usually neglected or simplified in hydrological modelling primarily because information concerning irrigation is notably difficult to collect. To assess real effects of irrigation on the simulation of evapotranspiration (ET) in water‐limited region, the Community Land Model version 4 was established over a typical semi‐humid agricultural basin in the northern China – the Haihe River basin. In the irrigated cropland, incorporating an irrigation scheme can enhance the simulated ET and improve the simulation of spatial variability of soil moisture content. We found that different configurations in the irrigation scheme do not cause significant differences in the simulated annual ET. However, simulated ET with simulated irrigation differs clearly from that with observed irrigation in mean annual magnitude, long‐term trend and spatial distribution. Once the irrigation scheme is well‐calibrated against observations, it reasonably reproduces the interannual variability of annual irrigation, when irrigation water management is relatively stable. More importantly, parameter calibration should be consistent with the configuration of the source of irrigation water. However, an irrigation scheme with a constant parameter value cannot capture the trend in the annual irrigation amount caused by abrupt changes in agricultural water management. Compared with different remotely sensed ET products, the enhancement in the simulated ET by irrigation is smaller than the differences among these products, and the trend in simulated ET with the observed irrigation cannot be captured correctly by the remotely sensed ET. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
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