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排序方式: 共有272条查询结果,搜索用时 15 毫秒
61.
Abstract

In aquatic toxicology, QSAR models are generally designed for chemicals presenting the same mode of toxic action. Their proper use provides good simulation results. Problems arise when the mechanism of toxicity of a chemical is not clearly identified. Indeed, in that case, the inappropriate application of a specific QSAR model can lead to a dramatic error in the toxicity estimation. With the advent of powerful computers and easy access to them, and the introduction of soft modeling and artificial intelligence in SAR and QSAR, radically different models, designed from large non-congeneric sets of chemicals have been proposed. Some of these new QSAR models are reviewed and their originality, advantages, and limitations are stressed.  相似文献   
62.
浙江省是全国岛屿最多的省份,海岛为全省实现“海洋经济大省”起着重要作用。本文在分析浙江省海岛土地利用现状及其特点的基础上,指出开发利用中存在的主要问题,提出了合理开发利用的战略对策。  相似文献   
63.
The dangerous chemicals are special chemicals. They are very important to human being though they are dangerous generally. In this paper, we will vividly introduce the family of dangerous chemicals and classification so that readers can better understand them.  相似文献   
64.
近年来,国内外不断发生的化学恐怖袭击和化学事故仍然是当今人类生存、国家安全所面临的重大威胁。化学侦检是防化应急处置与救援的眼睛,熟练掌握和正确使用侦检装备是应对化学威胁、降低损失和伤亡的关键因素。基于化学传感等技术的侦检装备具有响应快速、智能便携的特点,并且在远程监测和实时值守等方面具有优势。该文针对涵盖电化学传感器、质量敏感型传感器、红外传感器、拉曼传感器、离子迁移谱仪、火焰光度检测器、光致电离检测器、远程遥测传感装备等在内的现场侦检装备,从原理、性能、优势和不足等方面进行了概述,重点阐述了侦检装备在应对化学威胁方面的最新进展,并对其发展趋势、应用前景进行了展望,以期为化学侦检装备在应对化学威胁中的深入研究与应用提供参考。  相似文献   
65.
Summary In-silico screening of flexible ligands against flexible ligand binding pockets (LBP) is an emerging approach in structure-based drug discovery. Here, we describe a molecular dynamics (MD) based docking approach to investigate the influence on the high-throughput in-silico screening of small molecules against flexible ligand binding pockets. In our approach, an ensemble of 51 energetically favorable structures of the LBP of human estrogen receptor α (hERα) were collected from 3 ns MD simulations. In-silico screening of 3500 endocrine disrupting compounds against these flexible ligand binding pockets resulted in thousands of ER–ligand complexes of which 582 compounds were unique. Detailed analysis of MD generated structures showed that only 17 of the LBP residues significantly contribute to the overall binding pocket flexibility. Using the flexible LBP conformations generated, we have identified 32 compounds that bind better to the flexible ligand-binding pockets compared to the crystal structure. These compounds, though chemically divergent, are structurally similar to the natural hormone. Our MD-based approach in conjunction with grid–based distributed computing could be applied routinely for in-silico screening of large databases against any given target.  相似文献   
66.
《印度化学会志》2023,100(9):101072
The most crucial and demanding universal issue lies in the enrichment of sustainable drive technology. As traditional resource, petrochemical becomes increasingly scarce in the future; mankind must turn to renewable alternatives to yield liquefied fuels and valuable commodities through sustainable process. It has been reported that furan compounds serve as an excellent platform molecule derived from defatted rice bran. The current work aims at the synthesis of copper ferrite nano catalyst by microwave assisted solution incineration approach. The catalytic properties stood verified by X-ray diffraction, SEM, EDAX and BET techniques. The catalytic performance of the copper ferrite catalyst were reinforced through in-situ microwave assisted acetalization reaction of furfural with discrete solvents like methanol, ethanol, and 1-propanol at optimum reaction conditions for the preparation of wide range of commodity chemicals such as carboxylic acids, alkyl esters, di alkyl acetals, di ketones which are of commercial importance. The comparative study of relative yield of the products with different solvents is reported. The formation of the value-added products were confirmed by GC-MS, FT-IR technique. The catalysts from the reaction mixture are recovered by magnetic field.  相似文献   
67.
Herein, an improved method for detecting the endocrine-disrupting chemicals in milk is presented, which is based on high performance liquid chromatography tandem mass spectrometry, coupled with a quick, effective, and safe method. The linearity of the proposed method was in the range of 0.05–100 μg/L, and all correlation coefficients were ≥0.9973. At three concentration levels, the spiked recoveries ranged from 77.7 to 107.5%, relative standard deviations ranged from 0.2 to 14.6%, limits of quantitation ranged from 0.1 to 40 μg/kg, limits of detection ranged from 0.03 to 13.3 μg/kg. The proposed method for the identification and quantitation of 26 endocrine disruptors present in milk is not only easy, fast, and cost-efficient but also provides a reference for the detection of various endocrine disruptors in milk and other dairy products.  相似文献   
68.
由于高校实验室危险化学品重大事故时有发生,对危险化学品的管理已成为高校实验室安全管理的重要问题。本文以郑州大学为例,从危险化学品的采购、存储、配送、使用、危废收集全过程,梳理和分析实验室危险化学品管理存在的问题,针对危险化学品的安全管理体系建设进行了探索,介绍了危险化学品采购管理一体化平台的建设思路和具体措施,有效实现了危险化学品全生命周期管理,保障学校教学科研安全运行。  相似文献   
69.
目前高校化学教学实验室小型试剂库(暂存库)存在较多安全隐患,但一般体量较小,容易被相关管理者忽视,可能会造成实验室安全事故的发生。本文结合国家级实验教学示范中心(中国科学技术大学)化学实验教学实验室的实际情况,阐述了化学教学实验室小型试剂库改造的实践经验,为其他高校实验室试剂库的改造提供符合法律法规和国家标准要求的、适应面广、操作性强的可借鉴经验。  相似文献   
70.
树脂吸附法处理有毒有机化工废水及其资源化研究   总被引:19,自引:0,他引:19  
介绍了大孔树脂的发展及在有机化工废水处理及资源化领域的应用,包括大孔树脂的合成、吸附作用的基本原理以及在具体化工废水处理项目(如2,3-酸、对硝基酚等)的应用。  相似文献   
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