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61.
本文应用主成分分析方法(PCA)对赣江流域丘陵山区县级系统的资源经济结构梯度进行了分析。根据35个县市资源和经济结构变量资料分析表明,各县市之间的系统差异主要由气候条件、土壤成分、农业集约化经营水平及城市化程度所决定;这些决定因素在地理空间分布上存在着一定的连续性,并呈梯度变化:即资源结构以吉泰盆地为中心向南、西、北方向辐射;地形和地势由河谷平原向低丘、高丘、低山和中山过渡;生产经济结构类型也由盆地的单纯种植业型向农牧型、农牧副型、多种经营型和山地林业型变化。据此可把该流域丘陵山区分为上游山区和上游南部丘陵区、中游南部丘陵区和西部山区、北部丘陵区及下游丘陵区6大区。最后根据资源经济结构梯度和分区结果提出本流域丘陵山区的资源开发战略方向为以浙赣铁路线上的下游丘陵区和以赣州市为依托的上游北部丘陵区为中心向中游的吉泰盆地和西部山区及上游的南部山区定向开发。  相似文献   
62.
全面调查了呼市无害化处理场垃圾处理的现状,讨论了垃圾前处理、渗漏液处理、气体收集等方面存在的问题,并根据实际情况提出了相应的建议。  相似文献   
63.
The sorption of selenium (Se) on humic acid (HA) was investigated in order to better understand the fate of stable and radioactive Se in soils and sediments. An ultrafiltration technique was used to determine size distributions of HA-sorbed-Se when increasing Se concentration and solid/liquid ratio. The results showed that the Se sorption onto HA followed the Freundlich isotherm. No solid/liquid ratio-dependence was observed especially when <3 kDa molecular size fraction was used from solid/liquid separation. The Freundlich isotherm parameters K(F) and n obtained using the <3 kDa molecular size fraction for solid/liquid separation were 3.7 x 10(2) and 0.82, respectively. In addition, since dissolved HA increased with decreased ionic strength in the HA suspension, ionic strength could promote aggregation of HA. The conformational change of HA could affect the sorption behavior of Se on HA.  相似文献   
64.
When trimethylarsine oxide (TMAO) was administered orally to hamsters once only, 86.9±11.1% of the administered dose of the compound was exreted in the urine during the following 24 hours: TMAO proved to be an arsenic compound eliminated extremely rapidly. The unchanged form of TMAO was the one and only trimethylarsenic compound (TMA) detected in the urine: in othe words, TMAO proved neither to be demethylated nor to be converted to arsenobetaine. It was shown, on the other hand, that TMAO is partly reduced in vivo and that only trimethylarsine was detected in expired air.  相似文献   
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论述了在香港提供消防与安全工程研究生教育的必要性,为了培养高质量人才,消防与安全工程高等教育的科目应当包括消防工程学和安全工程学(如火灾动力学),用于建筑设计的计算机火灾模拟,消防工程系统,火灾安全管理立法因素,用于火灾安全管理的设计事项,建造的安全因素,职业安全和人类工程学,事故防范、危害评估和控制,安全管理系统和安全审核。而这些重要课程的质量提高都强烈依赖于相关研究的进展。  相似文献   
67.
The concentration and geochemical fractionation of six trace metals related with environmental quality assessment, namely Cd, Cr, Cu, Ni, Pb, and Zn, in 30 surface sediments from both inshore and offshore areas of the Taiwan Strait were measured to investigate their distribution characteristics, evaluate their potential mobility, and assess their pollution status. The geoaccumulation index results indicated that, on average, the studied metals presented an order of Cd?>?Pb?>?Ni?>?Zn?>?Cu?>?Cr and were practically in uncontaminated status except Cd. The results of the sequential extraction analysis indicated that, on average, the studied metals were mostly accumulated in residual fraction except Cd whose concentration was the highest in the acid soluble fraction presenting a high risk to the environment, and their mobility decreased in the sequence of Cd?>?Pb?>?Ni?>?Cu?>?Zn?>?Cr. Based on the mean probable effect level quotients, the combination of the studied metals had an 8 % probability of being toxic at two sampling sites and had a 21 % probability of being toxic at the rest of sites. The spatial distribution of the studied metals in total concentrations and different geochemical fractions corroborated the previous findings about the possible sediment transportation routes in and around the Taiwan Strait.  相似文献   
68.
Immunoassay methods are generally used for measuring of allergenic substances. However, they need special facilities, skilled handling, and time-consuming procedure. In this work, a fiber-optic immunoassay system which could measure allergen by fluorescent intensities of immune complexes formed by allergens and fluorescently labeled antibodies was established. Immune complexes absorbed on the optical fiber probe surface, and excitation light was injected into the probe, then evanescent field is created in the proximity of the probe. The fluorophores were excited by the evanescent light, and fluorescence was detected by a photo diode. The target allergen detected by our system was Der f1 derived from Dermatophagoides farinae that is one of the house dust mite and major source of inhaled allergens. The fluorophore used labeling on detecting antibody was cyanine 5. The system enabled to detect and quantitatively determine of Der f1. The measurement range was from 0.24 to 250?ng/ml, and the result competes with ELISA. The measurement time was 16?min/sample. The immunoassay system was applied to measurement of Der f1 from actual dust samples. Calculated values of Der f1 showed good correlations between the fiber-optic fluoroimmunoassay and ELISA.  相似文献   
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70.
We conducted an event study on the concealment of the blending ratio of waste paper with virgin pulp in Japan. By investigating 10 companies in the paper industry between May 30, 2007 and January 18, 2008, we clearly show that stock prices of the relevant companies were affected by the news on the concealment of the blending ratio of waste paper. In addition, the impact of the second event was found to be greater than that of the first event. Therefore, the concealment of major companies negatively affects the stock prices of non-major companies, which did not conceal information during this period. Thus, bad news is negatively assessed by the market, and this influence has spread in the paper industry in general.  相似文献   
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