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Molecular Dynamics Simulation of Hydrate Decomposition Under Action of Alcohol Inhibitors

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Journal of Harbin Institute of Technology(New Series) 2023年第6期30卷 12-28页

作者： shuyan wang Xuqing Zha Baoli Shao Jing wang Xi Chen Jiawei Fan School of Petroleum Engineering Northeast Petroleum UniversityDaqing 163318HeilongjiangChina

The molecular dynamics method is used to investigate decomposition of methane hydrate at different temperatures,pressures and concentrations of *** analyzing the parameters of system conformation,mean square displacement and radial distribution function,the decomposition of hydrate in the presence of alcohol inhibitors ethylene glycol and glycerol is *** results show that the hydroxyl groups in alcohol molecules can destroy the cage structure of hydrate,and form hydrogen bonds with nearby water molecules to effectively prevent the reformation of ***,ethylene glycol and glycerol serve as inhibitors of methane hydrate,furthermore,in terms of inhibition effect,glycerol is better than ethylene glycol by comparing rate of hydrate decomposition.

关键词： methane hydrate alcohol inhibitors molecular dynamics simulation decompose

Differentially-grown cobalt regulators cooperatively involved in the tandem catalysis for high-yield production of second amines

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Nano Research 2024年第4期17卷 2444-2450页

作者： Jinhui Xu Xiao wang Ying wang Fei wang Lingling Zhang Wenjie Cui shuyan Song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry Tsinghua UniversityBeijing 100084China

One-pot tandem catalysis has been regarded as one of the most atomic economic ways to produce secondary amines,the important platform molecules for chemical synthesis and pharmaceutical manufacture,but it is facing serious issues in overall *** promotional effects are highly desired for boosting the activity and regulating the selectivity of conventional tandem *** this work,we report a high-performance tandem catalyst with maximized synergistic effect among each counterpart by preciously manipulating the spatial structure,which involves the active CeO_(2)/Pt component as kernel,the densely-coated N-doped C(NC)layer as selectivity controller,and the differentially-grown Co species as catalytic performance *** comprehensive investigations,the unique growth mechanism and the promotion effect of Co regulators are ***,the surface-landed Co clusters(Cocs)are crucial to selectivity by altering the adsorption configuration of benzylideneaniline ***,the inner Co particles(Cops)are essential for activity by denoting their electrons to neighboring *** from the unique promotion effect,a remarkably-improved catalytic efficiency(100%nitrobenzene conversion with 94%N-benzylaniline selectivity)is achieved at a relatively low temperature of 80℃,which is much better than that of CeO_(2)/Pt(100%nitrobenzene conversion with 12%N-benzylaniline selectivity)and CeO_(2)/Pt/NC(35%nitrobenzene conversion with 94%benzylideneaniline selectivity).

关键词： tandem catalysis CeO_(2) hierarchical structure heterogeneous catalyst dual-site materials

基于北斗VMS数据和DBSCAN算法的夏季海州湾中国毛虾资源分布

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上海海洋大学学报 2024年第2期33卷 444-451页

作者：李冬佳李国东熊瑛仲霞铭张琥顺宋大德杨帆康中杰吴晓睿王淑艳梁龙上海海洋大学海洋生物资源与管理学院上海201306 江苏省海洋水产研究所江苏南通226007 华东师范大学河口海岸国家重点实验室上海200241 上海海洋大学水产与生命学院上海201306

2020年我国伏季休渔期间中国毛虾限额捕捞试点在黄海海州湾实施,2021年该限额捕捞项目继续实施,在此背景下探究夏季海州湾中国毛虾资源分布对其限额捕捞精细化管理至关重要。首先基于2021年海州湾中国毛虾限额捕捞期间北斗渔船监控系统(... 详细信息

2020年我国伏季休渔期间中国毛虾限额捕捞试点在黄海海州湾实施,2021年该限额捕捞项目继续实施,在此背景下探究夏季海州湾中国毛虾资源分布对其限额捕捞精细化管理至关重要。首先基于2021年海州湾中国毛虾限额捕捞期间北斗渔船监控系统(Vessel monitoring system,VMS)数据提取得到各毛虾张网渔船所有捕捞网位点及其捕捞努力量,然后运用具有噪声的密度聚类(Density-based spatial clustering of application with noise,DBSCAN)算法进一步识别含有捕捞产量的网位点,从而探究夏季海州湾中国毛虾资源分布格局。结果显示,含有产量的网位点识别率为97.18%,表明DBSCAN算法能精准识别含有产量的捕捞网位点。含有产量的网位点共有898个,空间上呈聚集性分布。依据捕捞努力量情况探究得到中国毛虾资源主要分布在120°00′E~120°15′E,34°43′N~34°48′N和119°47′E~119°53′E,34°36′N~34°43′N。本研究思路可作为其他渔业捕捞活动中运用VMS数据提取含产量捕捞网位点的科学参考。

关键词：中国毛虾渔船监控系统密度聚类限额捕捞海州湾

基于腺苷脱氨酶相关检测指标诊断恶性胸腔积液的临床研究

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中国呼吸与危重监护杂志 2024年第2期23卷 105-109页

作者：曾婷婷胡雪茹王淑妍李萍安娜尔申永春文富强四川大学华西医院呼吸与危重症医学科/生物治疗国家重点实验室呼吸病学研究室四川成都610041

目的探索年龄/胸腔积液腺苷脱氨酶(年龄/ADA)、血清乳酸脱氢酶/胸腔积液腺苷脱氨酶(Cancer Ratio,CR)诊断恶性胸腔积液(MPE)的临床价值。方法收集44例MPE和48例良性胸腔积液(BPE),比较两组研究对象年龄、性别、常规肿瘤标志物癌胚抗原(C... 详细信息

目的探索年龄/胸腔积液腺苷脱氨酶(年龄/ADA)、血清乳酸脱氢酶/胸腔积液腺苷脱氨酶(Cancer Ratio,CR)诊断恶性胸腔积液(MPE)的临床价值。方法收集44例MPE和48例良性胸腔积液(BPE),比较两组研究对象年龄、性别、常规肿瘤标志物癌胚抗原(CEA)、年龄/ADA和CR的差异;绘制受试者工作特征(ROC)曲线,计算CEA、年龄/ADA和CR的ROC曲线下面积(AUC)、敏感性和特异性,比较三者单独或联合诊断MPE的效能。结果CEA、年龄/ADA和CR在MPE组较BPE组显著升高(P<0.05);CEA、年龄/ADA和CR诊断MPE的AUC分别为0.768、0.837、0.866,敏感性分别为61.36%、88.64%、81.82%,特异性分别为85.42%、75.00%、83.33%;CEA+年龄/ADA、CEA+CR、年龄/ADA+CR、CEA+年龄/ADA+CR对应的AUC分别为0.892、0.911、0.837、0.907,敏感性分别为81.82%、86.36%、88.64%、90.91%,特异性分别为79.17%、79.17%、75.00%、77.08%。结论年龄/ADA和CR对于MPE具备良好的诊断效能,联合常规肿瘤标志物CEA可进一步提高诊断效能,未来还需要更多的研究去探索其诊断价值。

关键词：恶性胸腔积液胸腔积液腺苷脱氨酶诊断

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藜麦种质资源的茎秆性状评价

山西农业大学学报（自然科学版） 2024年第4期44卷 1-9页

作者：张永康王树彦张锦豪李佳娜邢路虹刘瑞香郭占斌内蒙古农业大学农学院内蒙古呼和浩特010019 内蒙古农业大学沙漠治理学院内蒙古呼和浩特010011 内蒙古益稷生物科技有限公司内蒙古呼和浩特010011

[目的]藜麦种子具有全谷物高营养的品质,但倒伏是制约藜麦产量的重要因素之一,明确藜麦作物茎秆的抗倒伏特性,有利于筛选具有不同倒伏能力的藜麦品种(系),为藜麦抗倒伏育种鉴定、评价和创新提供理论依据。[方法]本研究根据株高、籽粒大... 详细信息

[目的]藜麦种子具有全谷物高营养的品质,但倒伏是制约藜麦产量的重要因素之一,明确藜麦作物茎秆的抗倒伏特性,有利于筛选具有不同倒伏能力的藜麦品种(系),为藜麦抗倒伏育种鉴定、评价和创新提供理论依据。[方法]本研究根据株高、籽粒大小、倒伏特性和生育期长短选取22份供试藜麦品种(系)并对其生育期、茎秆表型性状、茎秆机械强度和生理特征共16个指标进行测定和分析。[结果]22份藜麦品种(系)具有较高度的遗传变异,14个性状的变异系数为12.39%~81.08%,倒伏指数的变异系数最大,纤维素含量的变异系数最小。多因素方差分析得出作物倒伏特性与品种(系)、生育期、机械强度指标三者具有显著互作关系。相关性分析发现弯曲力矩、倒伏指数与茎秆表型性状、机械强度指标具有显著或极显著相关关系。基于13个茎秆特性指标以及隶属函数均值进行聚类分析可将22份藜麦品种(系)划分为3个类群,第Ⅰ类为抗倒伏组,第Ⅱ、Ⅲ类群为易倒伏组。多元线性回归分析得出,11个茎秆特性指标与倒伏指数和倒伏率做回归,R2均大于0.85。22份藜麦品种(系)的隶属函数均值为2.21~1.47,倒伏率范围为18.13%~91.83%,倒伏等级为2~5级。[结论]22份藜麦品种(系)农艺性状遗传多样性较为丰富,可为藜麦种质资源的创造提供参考。倒伏指数和弯曲力矩对作物倒伏能力评价具有重要作用。综合分析后推测K157、W120为抗倒伏品系,Y4、W26为易倒伏品系。

关键词：倒伏性茎秆特性倒伏指数弯曲力矩

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富锌农产品及检测方法的研究进展

耕作与栽培 2024年第2期44卷 53-56,60页

作者：马明王书言黄向东王晓波邢一进王艳丽洛阳市农业技术推广服务中心河南洛阳471000 洛阳市产品质量检验检测中心河南洛阳471000 洛阳理工学院环境工程与化学学院河南洛阳471023

锌对人体生长发育、代谢、免疫、生殖等都具有重要作用。人体对富锌农产品中锌的吸收利用率高,对药品和添加强化食品中锌的吸收利用率低且不安全。富锌农产品的检测方法有紫外可见分光光度法、原子吸收法、电感耦合等,但多为全量检测,... 详细信息

锌对人体生长发育、代谢、免疫、生殖等都具有重要作用。人体对富锌农产品中锌的吸收利用率高,对药品和添加强化食品中锌的吸收利用率低且不安全。富锌农产品的检测方法有紫外可见分光光度法、原子吸收法、电感耦合等,但多为全量检测,锌形态检测方法不多。本文就锌的作用、形态和标准进行了介绍,并对锌现有的检测方法进行了概括分析,对未来的检测方法进行了展望,提出了多元螯合提取,液相色谱-火焰原子吸收光谱(LC-FAAS)联用检测的设想。

关键词：锌富锌农产品形态分析多元螯合提取

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基于DEFORM-3D的X型号压裂泵用连杆模锻件预制坯优化

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铝加工 2024年第2期 38-42,46页

作者：许开春曾庆华樊勇王姝俨白倩倩西南铝业(集团)有限责任公司重庆401326 北京星航机电装备有限公司北京100071

针对X型号压裂泵用连杆模锻件的形状特点,结合实际生产提出了一套成形工艺方案。利用有限元数值模拟软件DEFORM3D分析了预制坯形状对成形结果的影响,设计了3种预制坯方案,模拟终锻成形过程。通过对比不同方案成形过程中的填充情况、等... 详细信息

针对X型号压裂泵用连杆模锻件的形状特点,结合实际生产提出了一套成形工艺方案。利用有限元数值模拟软件DEFORM3D分析了预制坯形状对成形结果的影响,设计了3种预制坯方案,模拟终锻成形过程。通过对比不同方案成形过程中的填充情况、等效应变云图、等效应力云图、截面金属流速分布等,得出了合理的预制坯形状及成形工艺参数,消除了产生缺陷的风险,提高了锻件的一次成形率,通过生产试制,有效验证了研究结果。

关键词：数值模拟预制坯成形情况

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Nitrogen‑Doped Magnetic‑Dielectric‑Carbon Aerogel for High‑Efficiency Electromagnetic Wave Absorption

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Nano-Micro Letters 2024年第1期16卷 313-327页

作者： Shijie wang Xue Zhang shuyan Hao Jing Qiao Zhou wang Lili Wu Jiurong Liu Fenglong wang Key Laboratory for Liquid‑Solid Structural Evolution and Processing of Materials Ministry of Education Shandong UniversityJinan 250061People’s Republic of China School of Mechanical Engineering Shandong UniversityJinan 250061People’s Republic of China Shenzhen Research Institute of Shandong University Shenzhen 518057GuangdongPeople’s Republic of China

Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and ***,developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption(EWA)materials with a broad effective absorption bandwidth(EAB)and strong absorption yet hits some ***,the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment,homogeneous and abundant nickel(Ni)and manganese oxide(MnO)particles in situ grew on the carbon *** to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels,the nitrogen-doped magnetic-dielectric-carbon aerogel(Ni/MnO-CA)suggests a praiseworthy EWA performance,with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss(RLmin)of−64.09 dB,while achieving a specific reflection loss of−253.32 dB mm−***,the aerogel reveals excellent radar stealth,infrared stealth,and thermal management ***,the high-performance,easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection,electronic devices and aerospace.

关键词： Electromagnetic wave absorption Wide bandwidth Dielectric-magnetic synergy Multifunction

Endosulfan residues and farmers’replacement behaviors of endosulfan in the north-west inland cotton region

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Frontiers of Environmental Science & Engineering 2024年第4期18卷 35-47页

作者： shuyan Zhou Yang Zhang Jingjing wang Shikun Cheng Fuyan Zhuo Yun Hong School of Energy and Environmental Engineering University of Science and Technology Beijing 100083China Foreign Environmental Cooperation Center Ministry of Ecology and Environment of the People’s Republic of ChinaBeijing 100035China United Nations Development Programme in China Beijing 100600China National Agro-Tech Extension and Service Center Beijing 100125China

We assessed the situation of endosulfan residues in cotton fields after the endosulfan ban came into effect and the current knowledge,attitude,and practice(KAP)of cotton farmers on the phase-out of endosulfan and the application of alternative *** samples(n=91)of cotton fields were collected from the major cotton-producing areas in China,namely the north-west inland cotton region,and the endosulfan residues were analyzed.A KAP survey was carried out for cotton farmers,and 291 questionnaires were *** influences of gender,age,education background,cotton planting years,publicity and training,income sources,and other factors on cotton farmers’KAP were *** results showed that endosulfan sulfate was the main endosulfan residue in the soil,followed byβ-endosulfan andα-endosulfan,the average residual contents were 0.569,0.139,and 0.060μg/kg,*** results of the KAP study showed that cotton farmers scored low on knowledge about the phase-out of endosulfan and the application of alternative technologies but high on attitude and *** number of family members,years of cotton planting,age,and the cottonplanting area had different degrees of influence on KAP *** training could significantly improve the KAP scores of cotton farmers;training should be more targeted and designed reasonably for key groups,such as men and the population under 30,followed by training them to use pesticides *** large-scale cotton growers,training should focus on green prevention and control technologies.

关键词： Cotton fields Endosulfan residues Farmers KAP survey Replacement behaviours