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741.
本文对大学生就业存在的自身问题、高校办学专业设置和培养模式问题、用人单位的误区问题以及现今的社会问题等进行了理性分析,并提出了加强对大学生的就业指导,引导大学生树立科学理性的就业观,广泛疏通就业途径和集聚多方力量鼓励大学生自主创业的对策。  相似文献   
742.
具有γ放射性的~(110m)Ag是核电站放射性废液中的主要核素之一,半衰期长,并且可以通过食物链在海洋生物中富集,研究其高效去除技术具有重要的意义.核电站化学去污过程加入的络合剂(如柠檬酸)对~(110m)Ag的化学形态和吸附性能有重要的影响.因此,本文首先模拟核电站水化学环境,研究了柠檬酸对~(110m)Ag化学形态的影响规律,其次研究了不同形态的~(110m)Ag物种在几种优选材料上的吸附性能.结果表明,由于核电站放射性废液的来源不同,柠檬酸与~(110m)Ag同时形成离子态络合物和~(110m)Ag0/柠檬酸纳米金属复合物;采用过氧化氢与紫外线联合高级氧化的方法能够破坏柠檬酸络合离子及~(110m)Ag0/柠檬酸复合物结构,形成单独的离子态~(110m)Ag+,从而有效地提高了~(110m)Ag物种的吸附去除性能.  相似文献   
743.
China has won the name of the world factory being famous for exporting a great deal of and various kinds of low-price merchandise. However, most of Chinese exports are primary goods or manufactured products that create heavy pollution and require intensive use of resources. Chinese products go abroad, but their following harms stay behind. The article analyzes many obvious low-price facts in China and their concomitant terrible environmental results in detail, and points out that there are huge hidden troubles in the way of China's sustainable development behind her seemingly flourishing economy.  相似文献   
744.
酸雨和SO2对蔬菜生长和产量的影响   总被引:10,自引:0,他引:10       下载免费PDF全文
应用开顶式熏气装置,以油菜和白菜为材料,分别将其暴露于模拟酸雨(pH2.8—5.6)和模拟酸雨与0.1ppmSO_2环境中,测定单独污染与复合污染对蔬菜生长反应和产量的影响。结果表明,酸雨(pH2.8)和酸雨(pH4.6)与0.1ppmSO_2复合处理均对LAR有明显抑制,LAR最多可减少37.5%。模拟酸雨(pH2.8,3.6)使蔬菜减产1.4—8.7%,而模拟酸雨与SO_2复合污染可使蔬菜产量减少7.9—28.9%(P<0.05)。  相似文献   
745.
四湖流域水环境污染现状空间分布和污染源分析   总被引:3,自引:0,他引:3  
四湖流域水环境恶化已影响到当地生产和群众生活,亟待对四湖流域的水环境污染现状进行调查与评估。于2010年春季在四湖流域的主要湖泊以及四湖总干渠进行了水质现场监测和水样采集,共采集了84个样点,每个样点测定了12项水质指标,并对测定结果中四湖流域总氮、总磷、高锰酸钾指数等水质指标的空间分布进行了分析。分析结果表明:四湖流域的两个主要湖泊,长湖和洪湖均受到不同程度的污染,长湖为重度污染,洪湖为轻度污染,从长湖流入总干渠中的水质多为中性或略偏碱性,总磷、总氮含量超标几倍到几十倍,在靠近长湖的总干渠上游段为重度污染,靠近洪湖的总干渠下游段为轻度污染。各水质指标浓度总体趋势上,长湖的要大于总干渠,总干渠的大于西干渠,西干渠的大于洪湖。  相似文献   
746.
As wildlife habitat is in constant evolution, periodic monitoring is essential to assess its quality. In this study, the change to the red-crowned crane habitat in the Yellow River Delta Nature Reserve was detected from multi-temporal remote sensing data from 1992 to 2008 in a geographic information system. Habitat fragmentation was derived from both physical constraints and human disturbance. The changing habitat quality was assessed against five landscape indices. The results obtained from Landsat TM images indicate that potential habitat shrank 37.9 % during 1992–2001, but recovered 99.4 % by 2008. Suitable habitat shrank by 4,329 ha to a level below that of 1992 despite an increase of 4,747 ha in potential habitat due to an increase of 9,075 ha in fragmented areas. Both landscape indices and the red-crowned crane population reveal that suitable habitat was the most fragmented in 2001, but the least fragmented in 1992. Therefore, it is inadequate to just restore wetland through artificial diversion of channel flow to the Reserve to preserve the crane habitat. Commensurate efforts should also be directed at improving habitat quality by minimizing human activities and spatially juxtaposing water and reed marshes harmoniously inside the Reserve.  相似文献   
747.
Abstract

China has won the name of the world factory being famous for exporting a great deal of and various kinds of low-price merchandise. However, most of Chinese exports are primary goods or manufactured products that create heavy pollution and require intensive use of resources. Chinese products go abroad, but their following harms stay behind. The article analyzes many obvious low-price facts in China and their concomitant terrible environmental results in detail, and points out that there are huge hidden troubles in the way of China's sustainable development behind her seemingly flourishing economy.  相似文献   
748.
Abstract

From the perspective of tourism competitiveness, the paper takes 12 island counties of China as the research object, and applies the method of factor analysis to study their competitiveness. The result shows that Putuo and Dinghai are more competitive while Pingtan and Nan’ao are less competitive. Finally, the 12 island counties are divided into four styles: first-class competitive county (Putuo), seond-class competitive counties (Dinghai,Yuhuan), third-class competitive counties (Chongming, Daishan, Changdao, Changhai and Shengsi), fourth-class competitive counties (Dongshan, Dongtou, Pingtan and Nan’ao) by cluster analysis. The classification of island counties is to clear their relative position, then to promote their development.  相似文献   
749.
Persistent organochlorine pesticides pollutants (OCPs) have been reported to occur at relatively high concentrations in some Chinese waters. In order to map the distribution of organochlorine pesticides in the surface water throughout China, samples were collected from over 600 sites in seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative organochlorine pesticides contaminants including lindane (gamma-HCH), p,p'-DDT and heptachlor epoxide. In general, the most frequently detected compound was lindane, being detected in 83.9% of samples (mean=31.3 ng/l; range <0.17-860 ng/l), and the highest concentration was present in the Yellow River basin. p,p'-DDT was detected in 63.1% of the samples collected (mean=14.6 ng/l; range <0.14-368 ng/l) with the highest concentration present in the Huaihe River basin. Heptachlor epoxide was detected in only 9.3% of water samples (range <0.11-10 ng/l). Measured concentrations for the three compounds were low and rarely exceed the environment quality standard for surface water of China. Lindane was more frequently detected at much higher concentrations in the rivers of northern China compared with those of southern China. The sites with higher concentration of lindane and p,p'-DDT mainly occurred in the Yellow River and Huaihe River basins, so the results of this investigation indicate that the organochlorine pesticide contamination of Yellow River and Huaihe River basins should be of particular concern relative to the other basins. When compared with other regions of the world, it appears that the Chinese surface water is moderately polluted by lindane and p,p'-DDT.  相似文献   
750.
面向可持续发展的技术创新:从技术预见到战略选择   总被引:1,自引:0,他引:1  
本文研究了技术预见、关键技术选择和技术创新之间的关系,从方法学、科学技术观的角度分析了技术预见、关键技术选择在技术创新战略中的地位和作用,提出技术预见和关键技术选择是制订和实施技术创新战略的重要手段和基础,应当成为国家创新体系的重要组成部分。建立面向可持续发展的技术创新体系,对落实全面、协调、可持续的科学发展观,实现社会和谐发展具有战略意义。本文分析了传统的技术创新与可持续发展的差异,提出适应当今经济社会发展方向的技术创新应追求经济、社会和环境效益的统一。本文还探讨了在我国开展技术预见和关键技术选择的方法和应遵循的原则,提出应从战略视角把握关键技术选择,进一步指出在技术预见的基础上促进面向可持续发展的技术创新体系建设对实现我国可持续发展战略目标具有重大意义。  相似文献   
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