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Defined organic-octamolybdate crystalline superstructures derived Mo_(2)C@C as efficient hydrogen evolution electrocatalysts

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Chinese Chemical Letters 2024年第6期35卷 201-205页

作者： Jiao li Chenyang Zhang Chuhan Wu Yan liu xuejian Zhang Xiao li Yongtao li Jing Sun Zhongmin Su School of Materials Science and Engineering Jilin Jianzhu UniversityChangchun 130018China School of Chemical and Environmental Engineering Changchun University of Science and TechnologyChangchun 130022China

Hydrogen evolution electrocatalysts derived from metal-organic crystalline frameworks can inherit the merits of ordered and adjustable structures with high surface area.In this paper,organic-octamolybdate crystalline superstructures(OOCS)with a fixed stoichiometric ratio of Mo_(8)(L)_(2) and high Mo content(>40 wt%)were synthesized using flexible ligands with controllable lengths(named as OOCS-1-3).Then,molybdenum carbides coated with carbon layers as electrocatalysts(Mo_(2)C@C-1-3)can be obtained directly from a one-step high-temperature carbonization process using OOCS-1-3 as precursors.As a typical example,Mo_(2)C@C-3 exhibits satisfactory hydrogen evolution activity with a low overpotential of 151 m V(1.0 mol/L KOH)at 10 m A/cm^(2) and stability for 24 h.The electrocatalytic activity is mainly from the synergistic interactions between the carbon layers and molybdenum carbide species.Furthermore,compared with the initial content of C,N,Mo in OOCS and Mo_(2)C@C,the catalytic activity increases with the N amount.This work makes organic-octamolybdate crystalline superstructures used as general precursors to product high Mo content electrocatalysts applied in energy storage and conversion fields.

关键词： Molybdenum carbides Electrocatalysts Organic-octamolybdate crystalline superstructures Synergistic interactions Hydrogen evolution reaction(HER)

scEpiTools: a database to comprehensively interrogate analytic tools for single-cell epigenomic data

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Journal of Genetics and Genomics 2024年第4期51卷 462-465页

作者： Zijing Gao Xiaoyang Chen Zhen li xuejian Cui Qun Jiang Keyi li Shengquan Chen Rui Jiang Ministry of Education Key Laboratory of Bioinformatics Bioinformatics Division at the Beijing National Research Center for Information Science and TechnologyCenter for Synthetic and Systems BiologyDepartment of AutomationTsinghua UniversityBeijing 100084China School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071China

Recent advances in single-cell sequencing technologies provide significant implications for understanding cellular heterogeneity,developmental biology,and disease mechanisms.To fully exploit the potential of these data,numerous tools have been proposed for upstream and downstream analyses.In the the single-cell RNA sequencing(scRNA-seq)community,scRNA-tools(Zappia et al.,2018)was proposed to help researchers navigate the plethora of tools by category.Since its inception,scRNA-tools has been widely used and its updated version further reveals trends in the field with over 1000 collected tools(Zappia and Theis,2021),providing a valuable guidance in selecting tools for analyses.

关键词： analytic selecting Tools

Direct conversion of CO_(2)to graphene via vapor–liquid reaction for magnesium matrix composites with structural and functional properties

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Journal of Magnesium and Alloys 2023年第4期11卷 1206-1212页

作者： xuejian li Xiaojun Wang Xiaoshi Hu Chao Xu Wenzhu Shao Kun Wu State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001PR China National Key Laboratory of Precision Hot Processing of Metal Harbin Institute of TechnologyHarbin 150001PR China

Converting CO_(2)to valuable materials is attractive in environmental protection and resource utilization.In this study,a vapor-liquid interface reaction system for mass production of high-quality graphene is reported.The graphene obtained has high crystallinity and few defects during the reaction of CO_(2)and Mg melt.The growth mechanism of graphene is demonstrated in vapor-liquid interface area by combining the CO_(2)bubbles as a soft template to guide growth with the confinement effect of dense MgO nanoparticles.The quality of the graphene is verified by epoxy composites with high electromagnetic shielding effectiveness.Additionally,the V-L reaction method ingeniously solves the dispersion of graphene in metal,providing a preparation strategy of Mg matrix composites with structure and function integration.

关键词： Graphene Vapor-liquid interface Magnesiothermic reaction Dispersion Shielding effectiveness

U肋全熔透焊接正交异性板构造疲劳性能试验研究

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世界桥梁 2024年第3期52卷 104-110页

作者：汪金辉李雪健中铁大桥勘测设计院集团有限公司湖北武汉430056 合肥工业大学土木与水利工程学院安徽合肥230009

为研究U肋与钢桥面不同焊接工艺接头的疲劳性能,以主跨408 m的中承式连续钢桁拱桥——武汉汉江湾桥主桥为背景,在传统单面埋弧焊基础上,提出一种先平位内焊再船位外焊的双面埋弧全熔透焊接技术,制作不同焊接工艺U肋与钢面板试件,开展丁... 详细信息

为研究U肋与钢桥面不同焊接工艺接头的疲劳性能,以主跨408 m的中承式连续钢桁拱桥——武汉汉江湾桥主桥为背景,在传统单面埋弧焊基础上,提出一种先平位内焊再船位外焊的双面埋弧全熔透焊接技术,制作不同焊接工艺U肋与钢面板试件,开展丁字接头弯曲疲劳试验、焊接接头拉伸疲劳试验及3种典型构造细节疲劳试验,分析U肋与钢面板构造细节疲劳性能。结果表明:不同焊接方式下U肋与钢面板的疲劳强度差异明显,埋弧焊丁字接头的疲劳强度较高,大于342 MPa。U肋与钢面板双面埋弧熔透焊试件轴向拉伸状态下最低疲劳强度121.6 MPa,在-50~50 MPa拉-压循环应力幅和100 MPa拉应力幅下试件均未开裂;在120 MPa拉应力幅下,疲劳开裂加载次数均大于200万次,顶板内侧焊缝焊趾发生疲劳开裂。U肋与钢面板双面埋弧全熔透焊接构造细节疲劳性能优于单面焊及不开坡口的双面焊部分熔透构造细节,可以提高结构的耐久性和使用寿命。

关键词：钢桥正交异性钢桥面板 U肋与钢面板构造细节双面埋弧全熔透焊接疲劳性能疲劳试验

Diurnal and seasonal variations in carbon fluxes in bamboo forests during the growing season in Zhejiang province, China

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Journal of Forestry Research 2019年第2期30卷 657-668页

作者： liang Chen Yuli liu Guomo Zhou Fangjie Mao Huaqiang Du Xiaojun Xu Pingheng li xuejian li State Key Laboratory of Subtropical Silviculture Zhejiang A & F University Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A & F University School of Environmental and Resources Science Zhejiang A & F University

Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bamboo shoots and their correlation with environment factors are poorly understood. We measured carbon dioxide exchange and climate variables using open-path eddy covariance methods during the 2011 growing season in a Moso bamboo forest(MB, Phyllostchys edulis) and a Lei bamboo forest(LB, Phyllostachys violascens) in Zhejiang province,China. The bamboo forests were carbon sinks during the growing season. The minimum diurnal net ecosystem exchange(NEE) at MB and LB sites were-0.64 and-0.66 mg C m^(-2) s^(-1), respectively. The minimum monthly NEE, ecosystem respiration(RE), and gross ecosystem exchange(GEE) were-99.3 ± 4.03, 76.2 ±2.46, and^(-1)91.5 ± 4.98 g C m^(-2) month^(-1), respectively,at MB site, compared with-31.8 ± 3.44, 70.4 ± 1.41,and^(-1)57.9 ± 4.86 g C m^(-2) month^(-1), respectively, at LB site. Maximum RE was 92.1 ± 1.32 g C m^(-2) month^(-1) at MB site and 151.0 ± 2.38 g C m^(-2) month^(-1) at LB site.Key control factors varied by month during the growing season, but across the whole growing season, NEE and GEE at both sites showed similar trends in sensitivities to photosynthetic active radiation and vapor pressure deficit,and air temperature had the strongest correlation with RE at both sites. Carbon fluxes at LB site were more sensitive to soil water content compared to those at MB site. Both onyear(years when many new shoots are produced) and offyear(years when none or few new shoots are produced)should be studied in bamboo forests to better understand their role in global carbon cycling.

关键词： Bamboo forest Eddy covariance Carbon fluxes Carbon sequestration

SiO_(2)气凝胶/硅溶胶复合材料的制备及传热机理研究

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化工新型材料 2024年第7期52卷 234-238,244页

作者：孔哲黄冬梅李德何森张雪键中国计量大学质量与安全工程学院杭州310018

由于纳米SiO_(2)与玻璃纤维制备的复合材料表面会出现碎屑,在材料中加入硅溶胶,制备了一种新型SiO_(2)气凝胶/硅溶胶复合材料,通过热重分析仪和傅里叶变换红外光谱仪研究了SiO_(2)气凝胶含量对复合材料热性能和微观结构的影响。结果表明... 详细信息

由于纳米SiO_(2)与玻璃纤维制备的复合材料表面会出现碎屑,在材料中加入硅溶胶,制备了一种新型SiO_(2)气凝胶/硅溶胶复合材料,通过热重分析仪和傅里叶变换红外光谱仪研究了SiO_(2)气凝胶含量对复合材料热性能和微观结构的影响。结果表明:随着SiO_(2)气凝胶含量的增加,复合材料热导率没有下降,而是出现上升趋势,这与复合材料的密度和固体热导率密切相关;SiO_(2)气凝胶的加入使得复合材料产生了硅氧键,但不影响复合材料的物理结构,由于硅氧键的存在,材料的物理性能更好;SiO_(2)气凝胶含量为9%(质量分数)时,复合材料的性能最佳。

关键词： SiO_(2)气凝胶硅溶胶复合材料热导率传热模式

黄河故道区夏玉米农田水热传输特征及对环境因子的响应

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应用生态学报 2024年第6期35卷 1635-1644页

作者：任晓娟李国栋张曼丁圣彦孙雪健王靖钰李鹏飞黄河中下游数字地理技术教育部重点实验室(河南大学)/河南大学地理与环境学院河南开封475004 河南大别山森林生态系统国家野外科学观测研究站郑州450046 信阳生态研究院河南信阳464000

精确评估地-气之间物质和能量交换对于有效管理水资源和促进农业可持续发展至关重要。为揭示黄河故道区玉米农田生态系统的能量分配特征和水热分量动态变化过程及其对气象因子的变化响应,本研究基于涡度相关系统和全要素自动气象站,对2... 详细信息

精确评估地-气之间物质和能量交换对于有效管理水资源和促进农业可持续发展至关重要。为揭示黄河故道区玉米农田生态系统的能量分配特征和水热分量动态变化过程及其对气象因子的变化响应,本研究基于涡度相关系统和全要素自动气象站,对2019—2020年黄河故道区典型夏玉米农田生态系统的能量通量以及常规气象要素进行不间断观测,分析夏玉米农田各能量通量的变化特征以及与气温、降水、风速等环境因子的相关关系,并计算夏玉米生育时期的能量闭合率和能量分配比率。结果表明:研究区夏玉米净辐射、显热通量和潜热通量的峰值出现在11:00—14:00,土壤热通量的峰值发生在14:00—15:00。在能量分配上,夏玉米农田全生育期的能量分配以潜热通量和显热通量为主,播种-出苗期能量主要被显热通量消耗,占净辐射的37.1%,其余生育周期的能量均以潜热通量消耗为主。全生育期能量闭合率较好,决定系数为0.83,其中,白天闭合率较高,晚上较低。降水对潜热通量和显热通量都有明显影响,潜热通量对降水的反应更敏感,生育后期潜热通量在降雨后与降雨前的增幅比生育前期低。在夏玉米全生育期内,太阳辐射是水热通量最主要的气象因子,其次为饱和水汽压差。温度和饱和水汽压差对潜热通量的贡献度明显高于显热通量,风速、相对湿度和太阳辐射对潜热通量的解释率低于显热通量,叶面积指数和植被覆盖度与潜热通量呈显著正相关、与显热通量呈显著负相关。本研究的定量化结果可以深化对黄河故道区夏玉米农田水热传输规律的认识,为作物高效用水提供理论依据。

关键词：玉米农田潜热通量显热通量能量平衡特征环境因子黄河故道区

四川新龙地区中酸性侵入岩年代学、地球化学及对甘孜-理塘洋演化过程的制约

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地质通报 2024年第2期43卷 401-415页

作者：严松涛吴青松代雪健李虎辛重阳朱利东中国地质调查局军民融合地质调查中心四川成都610036 成都理工大学沉积地质研究院四川成都610059 成都理工大学地球科学学院四川成都610059

基于详细的野外调查,对四川新龙地区不同类型侵入岩进行了岩石学、地球化学和锆石U-Pb同位素测年,探讨其岩石成因及构造背景。研究表明,古隆巴花岗闪长岩和日果闪长岩同属准铝质系列,具有低硅碱、高铁镁特征,中等的稀土元素总量及明显... 详细信息

基于详细的野外调查,对四川新龙地区不同类型侵入岩进行了岩石学、地球化学和锆石U-Pb同位素测年,探讨其岩石成因及构造背景。研究表明,古隆巴花岗闪长岩和日果闪长岩同属准铝质系列,具有低硅碱、高铁镁特征,中等的稀土元素总量及明显的Nb、Ta负异常,属于I型花岗岩,为俯冲期岩浆活动产物,获得日果闪长岩锆石U-Pb年龄为217.1±0.8 Ma,形成时代为晚三叠世。日里隆巴花岗闪长岩和花岗岩属于过铝质系列,具有高硅碱、低铁镁及弱的Nb、Ta负异常,均属于S型花岗岩,但后者经历了更高程度的分异,分别为碰撞期和后碰撞期岩浆活动的产物,获得日里隆巴花岗闪长岩锆石U-Pb年龄为203.6±0.5 Ma,形成时代为晚三叠世末。结合区域资料认为,晚三叠世甘孜-理塘洋盆大规模向西俯冲,少量的弧岩浆岩就位于被动大陆边缘雅江残余盆地;晚三叠世末期,由于洋板块的消亡发生弧-陆碰撞,地壳发生部分熔融,形成强过铝质花岗岩。

关键词：新龙地区雅江残余盆地花岗岩锆石U-Pb测年地球化学地质调查工程四川

滇中祥云盆地构造应力场孕灾机制及其应对措施研究

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自然灾害学报 2024年第3期33卷 152-166页

作者：张元陈爱兵邵东桥李可可张文纶董雪健昆明理工大学国土资源工程学院云南昆明650093 甘肃省地质矿产勘查开发局第三地质矿产勘查院甘肃兰州730050

亚欧板块和印度板块相互挤压碰撞导致青藏高原强烈隆升,地壳物质向云南滇西北及滇中西部地区挤入,地质构造活动剧烈,地质灾害频发。为探讨构造应力场特征对地质灾害发生的影响,利用区域构造解析法、节理分析法、共轭剪节理法和水系折线... 详细信息

亚欧板块和印度板块相互挤压碰撞导致青藏高原强烈隆升,地壳物质向云南滇西北及滇中西部地区挤入,地质构造活动剧烈,地质灾害频发。为探讨构造应力场特征对地质灾害发生的影响,利用区域构造解析法、节理分析法、共轭剪节理法和水系折线图法对研究区构造应力场进行反演,探究各类地质构造对地质灾害的控制作用,并针对构造诱发的地质灾害,提出相应的应对措施。研究结果表明,祥云盆地周缘发育北东、北西、近东西向断裂和节理构造,通过断层及节理的交切关系以及水系折线图法判断,研究区至少经历3次构造应力场作用,最大主应力σ1先后从北东向、北西向、近东西向转换。断裂构造通过控制水系演化间接诱发地质灾害,区内三岔河、苴力河等河流多沿断裂带发育,滑坡、崩塌等地质灾害多沿河流两岸边坡分布;地质构造多期次活动增强岩土体断裂网络系统的密集程度,致使岩土体透水能力增强,稳定性变差,导致滑坡、崩塌和泥石流等地质灾害发育。对于构造诱发的地质灾害防治,工程治理效果较差,文中提出优化建设区选址,搬迁避让和群测群防的应对措施。

关键词：节理构造应力场地质灾害水系祥云盆地