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131.
The structure and evolution of populations of Squilla mantis (Crustacea: Stomatopoda) have been studied, and the statistical techniques used are discussed. Population studies were performed by multivariate analysis. Thirty-three monthly samples comprising 20 length classes of males and females were examined. Males and females display evolutionary cycles: each cycle begins in June/July and proceeds through a succession of evolution and eventual regression, the later being particularly marked every 2 years. 相似文献
132.
本文报道了以黄铁矿和还原铁粉或其代用品为原料,制备含砷废水净化剂-硫化亚铁的方法。原料配比为100:35,粒度≤100目,反应温度为200~350℃是制备的最佳条件。本法原料广,工艺简单,成本低,具有良好的开发应用前景。 相似文献
133.
134.
The sol–gel method was used to synthesize a series of metal oxides-supported activated carbon fiber (ACF) and the simultaneous catalytic hydrolysis activity of carbonyl sulfide (COS) and carbon disulfide (CS2) at relatively low temperatures of 60°C was tested. The effects of preparation conditions on the catalyst properties were investigated, including the kinds and amount of metal oxides and calcination temperatures. The activity tests indicated that catalysts with 5 wt.% Ni after calcining at 400°C (Ni(5)/ACF(400)) had the best performance for the simultaneous catalytic hydrolysis of COS and CS2. The surface and structure properties of prepared ACF were characterized by scanning electron microscope-energy disperse spectroscopy (SEM-EDS), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), carbon dioxide-temperature programmed desorption (CO2-TPD) and diffuse reflectance Fourier transform infrared reflection (DRFTIR). And the metal cation defects were researched by electron paramagnetic resonance (EPR) method. The characterization results showed that the supporting of Ni on the ACF made the ACF catalyst show alkaline and increased the specific surface area and the number of micropores, then improved catalytic hydrolysis activity. The DRFTIR results revealed that -OH species could facilitate the hydrolysis of COS and CS2; -COO and -C–O species could facilitate the oxidation of catalytic hydrolysate H2S. And the EPR results showed that high calcination temperature conditions provide more active reaction center for the COS and CS2 adsorption. 相似文献
135.
随着社会的进步,传统环境监控日渐式微,存在效率低问题。针对这个问题,基于Web环境监控查询系统成为近几年研究的焦点。综合国内外相关研究资料,设计一个基于Web的环境监控数据查询系统。该系统实现了通过网络共享远程终端数据对环境的实时监控,推动环保工作的现代化管理。为验证其有效性,系统在设计完成后在某地进行了为期6个月的投入实验。基于Web的环境监控数据查询系统较传统监控系统效率更高,满足了人们的需求,对未来相似系统设计有一定的借鉴意义。 相似文献
136.
Nanoscale zero-valent iron(nZVI) assembled on graphene oxide(GO)(rGO-nZVI) composites were synthesized by reduction of GO and ferrous ions with potassium borohydride,for use in Cr(VI) removal from aqueous solution.The results showed that the two-dimensional structure of GO could provide a skeleton support for Fe~0,thus overcoming the bottleneck of aggregation for nZVI.Also,rGO-nZVI would form a ferric-carbon micro-electrolysis system in Cr(VI)-contaminated aquifers,enhancing and accelerating electron transfer,exhibiting high rate and capacity for Cr(VI) removal.The optimum dosage of the applied r GO-nZVI was linearly correlated with the initial Cr(VI) concentration.Characterization of rGO-nZVI before and after reaction with Cr(VI) revealed the process of Cr(VI) removal:r GO-nZVI firstly transferred electrons from Fe~0 cores via their Fe(II)/Fe(III) shells to the GO sheet;there,negatively charged Cr(VI) received electrons and changed into positively charged Cr(III),which was adsorbed by the negatively charged GO sheet,avoiding the capping and passivating of nZVI.rGO-nZVI formed a good electrically conductive network,and thus had long-term electron releasing properties,which was important for groundwater remediation. 相似文献
137.
Kin-Che Lam Weichun Ma Pak Kin Chan Wing Chi Hui King Lam Chung Yi-tak Teresa Chung Chun Yin Wong Hui Lin 《Environmental monitoring and assessment》2013,185(12):9683-9695
This paper reports on a study which explored the possible relationship between road traffic noisescape and urban form in Hong Kong. A total of 212 residential complexes from 11 contrasting urban forms were sampled, and their noise levels assessed both at dwelling and neighbourhood scales by noise mapping. Its findings indicate that residential complexes with different urban forms have significantly different noisescape attributes. There is a strong correlation between the noise characteristics and morphological indicators at the dwelling scale. A less obstreperous noisescape is associated with urban forms with lower road and building densities, and with building arrangements which provide self-noise screening. These findings suggest that urban form is an influential determinant of the noisescape in the urban environment, and they point to the need to rethink the conventional approach to managing the urban acoustic environment. 相似文献
138.
在地震灾难频发及网络媒体迅速发展的背景下,"青龙奇迹"引起了公众的广泛关注和争议,其社会舆论影响不容忽视.以此为切入点,笔者一行利用2010年暑期社会实践在河北省青龙县、抚宁县进行了实地调研走访,结合学者论述、新闻报道,从灾难社会学和传播学角度,分析"青龙奇迹"传播现象,并对其准确度进行了探讨. 相似文献
139.
Fast transformation of roxarsone into toxic arsenic species with ferrous iron and tetrapolyphosphate
Chen Na Wan Yichao Ai Zhihui Jia Falong Zhang Lizhi 《Environmental Chemistry Letters》2019,17(2):1077-1084
Environmental Chemistry Letters - Organoarsenic compounds have been widely used as feed additives in livestock and poultry breeding. They are excreted in manure and thus cause environmental... 相似文献
140.