基于ABAQUS的钢管活性粉末混凝土短柱轴压受力性能研究

基于ABAQUS工作平台,建立已完成的钢管活性粉末混凝土(RPC)短柱试验试件的有限元模型,对其轴压荷载作用下的受力性能进行分析,将数值计算所得破坏形态、荷载—应变曲线、极限承载力与试验结果进行对比,两者吻合较好。基于此,进一步对钢管和RPC应力—应变曲线进行分析,探讨钢材强度、含钢率和RPC强度对柱轴压性能的影响。结果表明:随着钢材强度和含钢率增加,短柱的极限承载力和残余承载力提高,延性性能改善;RPC强度增加时,试件的极限承载力提高而残余承载力变化不大。最后,根据极限平衡理论建立短柱轴压承载力计算公式,其在0.18ξ2.62范围内适用性较好,可为工程设计提供参考。     

NLRP3 inflammasome is involved in the mechanism of mitigative effect of selenium on lead-induced inflammatory damage in chicken kidneys

Environmental Science and Pollution Research - Lead (Pb) is a kind of widespread toxic environmental pollutant which can cause harm to organisms. Selenium (Se) has the property of mitigating Pb...     

Does green finance improve the industrial eco-efficiency in China?

Environmental Science and Pollution Research - Improving industrial eco-efficiency is of great significance for building a beautiful China and achieving its carbon peak and neutrality targets....     

Isolation and characterization of hydrophilic dissolved organic matter in waters by ion exchange solid phase extraction followed by high resolution mass spectrometry

Environmental Chemistry Letters - Dissolved organic matter (DOM) is a complex substance occurring in marine and freshwater environments. DOM has many functions that modify physical, chemical and...     

Ammonia volatilization,N2O and CO2 emissions from landfill leachate-irrigated soils

Effects of leachate addition on ammonia volatilization and N₂O and CO₂ emissions from two different soils were investigated using the 10-day laboratory incubation method at two levels of moisture content. Ammonia volatilization was dominated by soil pH and only occurred in alkaline clay soil, where 0.26–0.32% of soil ammonia could be lost. The N₂O emission from the alkaline clay soil was one order of magnitude greater than that from the acidic sandy soil, when either water or leachate was irrigated. Increasing the moisture content from 46% water-filled pore space (WFPS) to 70% WFPS in the alkaline clay soil or the acidic sandy soil by either water or leachate irrigation increased the N₂O emission by over twofold. The CO₂ emission from each soil sample at the two WFPSs was almost the same. The CO₂ emission from the alkaline clay soil with leachate addition was 72% lower than that from the acidic sandy soil with leachate addition, and 6.7 times higher than that from the alkaline clay soil with distilled water addition. Ammonia volatilization and N₂O emission under leachate irrigation could be minimized by avoiding the excessively wet condition and by selecting the acidic sandy soil with low organic carbon and total nitrogen content.     

Dissipation behavior and risk assessment of butralin in soybean and soil under field conditions

Dissipation behavior, final residue, and risk assessment of butralin in soybean, green soybean, plant, and soil were investigated. Butralin residues were extracted with acetonitrile and then soybean samples were detected with gas chromatography-mass spectrometer (GC-MS) and soil samples were determined with GC with nitrogen phosphorous detector (GC-NPD). The limit of quantification (LOQ) of the method was 0.01 mg/kg for soybean, green soybean, plant, and soil. Average recoveries ranged from 90.4 ~ 98.2% for green soybean, 86.2 ~ 86.6% for soybean, 86.0 ~ 98.8% for plant, and 85.0 ~ 106.8% for soil. The relative standard deviations (RSDs) were 2.0 ~ 7.2% for green soybean, 2.0 ~ 3.0% for soybean, 3.1 ~ 8.1% for plant, and 1.8 ~ 6.6% for soil. Half-lives of butralin in soil samples varied in the range of 11–22 days. At harvest time, final residues of butralin in soybean and green soybean were lower than LOQ. Risk assessment demonstrated that, at recommended dosage and frequency, butralin would not induce significant harm on humans. The study could be used as a quantitative basis for application of butralin on soybean.     

地区发展差异与湖北省可持续发展战略

湖北省的经济发展水平与全国其它地区存在着较大的差异，从全国范围看，湖北省多年一直处在中等偏下的水平，而在长江流域，近年湖北省一下游省市的差距在迅速扩大；在中心地区各省中，湖北则相对领先。     

防震减灾 任重道远

中华人民共和国已经度过了60年光辉岁月，中国大地发生了沧桑巨变；特别是改革开放的30年．给中华民族带来了蓬勃发展的生机：国家走向繁荣昌盛的强国之路，人民实现了安居乐业的梦想。对于从事防震减灾工作的人们来说，我们更是深切地体会到国家的防震减灾事业得到了长足的进展，增强了我国城乡防震减灾的能力。当然，也许有人会问，你们不是说地震预报没有过关吗？唐山地震和汶川地震都没能预报，造成了巨大的损失，