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Ecological effects of atmospheric nitrogen deposition on soil enzyme activity

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Journal of Forestry Research 2013年第1期24卷 109-114页

作者： WANG Cong-yan Lv yan-na liu xue-yan WANG Lei School of Environmental Sciences Jiangsu University School of Life Sciences Nantong University School of Life Sciences Nanjing University

The continuing increase in human activities is causing global changes such as increased deposition of atmospheric nitrogen. There is considerable interest in understanding the effects of increasing atmospheric nitrogen deposition on soil enzyme activities, specifically in terms of global nitrogen cycling and its potential future contribution to global climate change. This paper summarizes the ecological effects of atmospheric nitrogen deposition on soil enzyme activities, including size-effects, stage-effects, site-effects, and the effects of different levels and forms of atmospheric nitrogen deposition. We discuss needs for further research on the relationship between atmospheric nitrogen deposition and soil enzymes.

关键词： global change nitrogen deposition soil enzyme activities

Numerical simulation of orthotropic steel deck bridges with two membrane layers systems

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交通运输工程学报 2013年第3期13卷 1-8页

作者： LI Jin-long liu xue-yan SCARPAS Tom TZIMIRIS George Faculty of Civil Engineering and Geosciences Delft University of Technology

The finite element system CAPA-3D was utilized as the numerical simulation platform,two structural FE models of orthotropic steel bridge decks were set up,the static and dynamic FE simulations under different loading conditions were carried out,the special attention was given to identify the critical wheel load location,and the maximum tensile stress distribution and the variation of strain rate inside membrane layers.Simulation result shows that the FE models are capable of simulating the realistic behavior of orthotropic steel bridge.The distributions of strains and stresses inside the surfacing materials depend highly on wheel load level,wheel load frequency,wheel position,membrane bonding strength as well as the thicknesses and characteristics of surfacing layers.The maximum tensile stress of membrane layers is found around 0.4MPa,which coincides with the minimum requirement for the adhesive bonding strength of membrane material proposed by the standards NF P98-282and TP-BEL-B.The maximum membrane strain rate is found around 0.1,which is an important information that can be utilized for the characterization of membrane products.1tab,28figs,7refs.

关键词：交通运输公路运输桥梁工程工程设计

Insights into seasonal variation of litter decomposition and related soil degradative enzyme activities in subtropical forest in China

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Journal of Forestry Research 2013年第4期24卷 683-689页

作者： WANG Cong-yan Lü yan-na WANG Lei liu xue-yan TIAN Xingjun School of Life Sciences Nanjing University School of Environmental Sciences Jiangsu University

We used a litterbag method to investigate litter decomposition and related soil degradative enzyme activities across four seasons in a broad-leaved forest and a coniferous forest on Zijin Mountain in sub-tropical China. Across four seasons, we quantified litter mass losses, soil pH values, and related soil degradative enzyme activities. Litter decomposition rates differed significantly by season. Litter decomposi- tion rates of broadleaf forest leaves were higher than for coniferous for- ests needles across four seasons, and maximal differences in litter de- composition rates between the two litter types were found in spring.

关键词： broad-leaved forest coniferous forest litter decomposition soil degradative enzyme

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减载伸长路径下棕榈纤维加筋砂力学响应

科学技术与工程 2024年第18期24卷 7792-7803页

作者：刘昆钰唐玉肖刘问刘学彦魏少伟刘睿迪云南省建设投资控股集团有限公司昆明650000 北京林业大学水土保持学院北京100083 中国铁道科学研究院集团有限公司铁道建筑研究所北京100081 北京铁科特种工程技术有限公司北京100081

为探究棕榈纤维对石英砂力学性能的增强作用,采用减载三轴伸长试验方法测试了饱和状态下棕榈纤维加筋石英砂的剪切力学性能,计算了棕榈纤维加筋石英砂在不同纤维长度和掺量下的应力-应变曲线、初始弹性模量和割线模量,基于摩尔库伦准则... 详细信息

为探究棕榈纤维对石英砂力学性能的增强作用,采用减载三轴伸长试验方法测试了饱和状态下棕榈纤维加筋石英砂的剪切力学性能,计算了棕榈纤维加筋石英砂在不同纤维长度和掺量下的应力-应变曲线、初始弹性模量和割线模量,基于摩尔库伦准则分析了棕榈纤维加筋石英砂剪切强度随纤维配比的变化规律,通过对比素砂和加筋砂在剪切过程中的体积应变及孔隙得出了棕榈纤维对石英砂力学性能的增强作用。结果表明:纤维加筋会增强石英砂在伸长破坏中的应力应变强度,对石英砂峰值应力和残余应力提升效果最佳的纤维掺量和长度为0.9%和12 mm;棕榈纤维加筋石英砂的初始弹性模量和峰值割线模量均随有效围压的增大而增大,整体刚度与有效围压呈正相关关系;纤维对石英砂剪切强度的增强效果只能在低围压状态时显现;在石英砂中添加棕榈纤维减小了石英砂的临界孔隙比及剪胀性。研究结果有助于促进纤维加筋砂的工程应用并提供相应理论参考。

关键词：棕榈纤维加筋砂减载伸长剪切强度孔隙比

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基于数值模拟的建筑设计优化研究综述

科学技术与工程 2024年第8期24卷 3054-3062页

作者：于水李思尧刘雪研姚钰锋沈阳建筑大学市政与环境工程学院沈阳110168

在双碳目标的背景下,对建筑物进行优化设计是实现节能减排的一个新途径;计算机技术的飞速发展,更使得建筑优化设计的效率有了很大的提升。为了更加全面地掌握基于数值模拟的优化技术在实际建筑中的应用现状,对优化研究的主要阶段进行了... 详细信息

在双碳目标的背景下,对建筑物进行优化设计是实现节能减排的一个新途径;计算机技术的飞速发展,更使得建筑优化设计的效率有了很大的提升。为了更加全面地掌握基于数值模拟的优化技术在实际建筑中的应用现状,对优化研究的主要阶段进行了概括,归类分析了各类优化平台的优缺点,总结对比了各类优化算法的性能。分析发现,优化阶段主要分为预处理、优化、后处理3个阶段;优化工具根据开发目的分为三大类;常用的优化算法有:进化算法、无导数搜索算法、混合算法;并且当下的优化研究还有很大的空间值得探索与改进。

关键词：数值模拟建筑优化优化算法优化工具

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新疆五家渠灌区渠系优化配水研究

中国农村水利水电 2024年第4期 169-174页

作者：李旭乔长录刘延雪胡永旭邵珠林石河子大学水利建筑工程学院新疆石河子832000 寒旱区生态水利工程兵团重点实验室新疆石河子832000 第六师水利工程管理服务中心新疆五家渠831300

通过建立多目标渠系优化配水模型,优化渠系配水过程,为新疆农业节水灌溉提供科学依据。以新疆五家渠灌区新东干渠作为研究对象,采用多目标粒子群优化算法以配水渠道的渗漏损失量最小,水流稳定为优化目标,建立多目标渠系优化配水模型,并... 详细信息

通过建立多目标渠系优化配水模型,优化渠系配水过程,为新疆农业节水灌溉提供科学依据。以新疆五家渠灌区新东干渠作为研究对象,采用多目标粒子群优化算法以配水渠道的渗漏损失量最小,水流稳定为优化目标,建立多目标渠系优化配水模型,并与回溯搜索算法就配水时间和渗漏损失量进行比较。研究表明,多目标渠系优化配水模型能将配水时间从15 d缩短至约11 d,渠系配水量为71.58万m^(3),与回溯搜索算法相比,配水时间从14 d缩短至11 d,渗漏量减少了8.39万m^(3)。采用多目标粒子群优化算法对新疆五家渠灌区新东干渠进行配水过程优化,不但满足了优化目标,减少了渠系渗漏,缩短了配水时间,且比回溯算法更具有实用性。

关键词：五家渠灌区多目标粒子群算法优化配水渠系优化

基于全气化顶空气相色谱技术测定香精油中甲醇含量

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现代化工 2024年第1期44卷 239-242页

作者：刘学琰李欢朱洪悦于康罗迎春戴毅王浩贵州民族大学化学工程学院贵州贵阳550025 云南中烟工业有限责任公司技术中心云南昆明650231

提出了一种全气化顶空气相色谱法测定香精油中甲醇含量的方法,并考察了时间､温度､样品量对测定结果的影响。结果表明,在105℃和2 min条件下,<80μL的样品接近全气化。该方法具有良好的精密度(RSD<3.89%)和准确度(加标回收率在97.8%~101... 详细信息

提出了一种全气化顶空气相色谱法测定香精油中甲醇含量的方法,并考察了时间､温度､样品量对测定结果的影响。结果表明,在105℃和2 min条件下,<80μL的样品接近全气化。该方法具有良好的精密度(RSD<3.89%)和准确度(加标回收率在97.8%~101%之间)。与传统方法相比,本方法操作简单,可批量检测液体香精香料中残留的甲醇。

关键词：甲醇香精油顶空分析气相色谱

Comparison of Rotating Stall Warning by Different Methods for Variable Speed Configurations in a Contra-Rotating Compressor

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Journal of Thermal Science 2024年第4期33卷 1379-1393页

作者： xue Fei WANG yan'gang liu Qian WU Tong liu Hanru School of Power and Energy Northwestern Polytechnical University

Stall in compressors can cause performance degradation and even lead to disasters.These unacceptable consequences can be avoided by timely monitoring stall inception and taking effective measures.This paper focused on the rotating stall warning in a low-speed axial contra-rotating compressor.Firstly,the stall disturbance characteristics under different speed configurations were analyzed.The results showed that as the speed ratio(RR)increased,the stall disturbance propagation speed based on the rear rotor speed gradually decreased.Subsequently,the standard deviation(SD) method,the cross-correlation(CC) method,and the discrete wavelet transform(DWT)method were employed to obtain the stall initiation moments of three different speed configurations.It was found that the SD and CC methods did not achieve significant stall warning results in all three speed configurations.Besides,the stall initiation moment obtained by the DWT method at RR=1.125 was one period after the stall had fully developed,which was unacceptable.Therefore,a stall warning method was developed in the present work based on the long short-term memory(LSTM) regression model.By applying the LSTM model,the predicted stall initiation moments of three speed configurations were at the 557th,518th,and 333rd revolution,which were44,2,and 74 revolutions ahead of stall onset moments,respectively.Furthermore,in scenarios where a minor disturbance preceded the stall,the stall warning effect of the LSTM was greatly improved in comparison with the aforementioned three methods.In contrast,when the pressure fluctuation before the stall was relatively small,the differences between the stall initiation moments predicted by these four methods were not significant.

关键词： contra-rotating compressor stall disturbance stall initiation moment long short-term memory (LSTM) stall warning

Risk Factors of Depression Screened by Two-Sample Mendelian Randomization Analysis:A Systematic Review

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Biomedical and Environmental Sciences 2024年第1期37卷 85-95页

作者： WANG Han Lin xue yan Feng CUI Bao Qiu liu Hong SHEN Xin Xin Shandong Provincial Research Center for Bioinformatic Engineering and Technique School of Life SciencesShandong University of TechnologyZibo 255049ShandongChina Shanxi Province Cancer Hospital/Shanxi Hospital Affiliated to Cancer Hospital Chinese Academy of Medical Sciences/Cancer Hospital Affiliated to Shanxi Medical UniversityTaiyuan 030013ShanxiChina State Key Laboratory of Infectious Disease Prevention and Control National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China

Objective This study explored the potentially modifiable factors for depression and major depressive disorder(MDD)from the MR-Base database and further evaluated the associations between drug targets with MDD.Methods We analyzed two-sample of Mendelian randomization(2SMR)using genetic variant depression(n=113,154)and MDD(n=208,811)from Genome-Wide Association Studies(GWAS).Separate calculations were performed with modifiable risk factors from MR-Base for 1,001 genomes.The MR analysis was performed by screening drug targets with MDD in the DrugBank database to explore the therapeutic targets for MDD.Inverse variance weighted(IVW),fixed-effect inverse variance weighted(FE-IVW),MR-Egger,weighted median,and weighted mode were used for complementary calculation.Results The potential causal relationship between modifiable risk factors and depression contained 459 results for depression and 424 for MDD.Also,the associations between drug targets and MDD showed that SLC6A4,GRIN2A,GRIN2C,SCN10A,and IL1B expression are associated with an increased risk of depression.In contrast,ADRB1,CHRNA3,HTR3A,GSTP1,and GABRG2 genes are candidate protective factors against depression.Conclusion This study identified the risk factors causally associated with depression and MDD,and estimated 10 drug targets with significant impact on MDD,providing essential information for formulating strategies to prevent and treat depression.

关键词： Risk factors Drug targets Depression Major depressive disorder Two-sample Mendelian randomization