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甲烷裂解——中国南方寒武系页岩含气量低的一个重要原因

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天然气地球科学 2024年第5期35卷 902-916页

作者：米敬奎帅燕华姜林马行陟提高石油采收率国家实验室北京100083 中国石油勘探开发研究院北京100083

对中国南方页岩气地球化学特征统计分析结果表明,寒武系筇竹寺组页岩气除了具有与志留系龙马溪组页岩气相似的干燥系数极高(>98.9%)、碳同位素倒转的地球化学特征外,还具有N_(2)含量高,页岩含气量低的特征。在对目前各种高过成熟阶段天... 详细信息

对中国南方页岩气地球化学特征统计分析结果表明,寒武系筇竹寺组页岩气除了具有与志留系龙马溪组页岩气相似的干燥系数极高(>98.9%)、碳同位素倒转的地球化学特征外,还具有N_(2)含量高,页岩含气量低的特征。在对目前各种高过成熟阶段天然气碳同位素倒转成因理论分析的基础上,提出甲烷裂解过程的聚合作用是高过成熟阶段天然气碳同位素倒转的重要原因。这一观点得到了CH_(4)+N_(2)混合气体及碳同位素正序天然气裂解模拟实验验证。不同条件下CH_(4)+N_(2)混合气体裂解模拟实验结果证明,甲烷大量裂解时氮气也不会分解,且页岩对甲烷的裂解具有催化作用。结合有机质结构及页岩储层导电性能随成熟度的演化、不同结构烃类分子裂解键能的对比,认为有机质在生气结束后(甲基完全脱落)的强烈石墨化作用会导致页岩电阻率明显降低,并伴随着甲烷的裂解。相关模拟实验结果表明有机质演化过程中氮气生成虽主要发生在烃类气体生成将近结束阶段之后(R_(0)>3.0%),但氮气生成量与有机质整个演化过程烃类气体的生成量相比非常少。寒武系页岩气地球化学特征、生烃模拟实验结果、甲烷与天然气的裂解模拟实验、寒武系页岩含气量与页岩储层物性及页岩成熟度综合研究结果表明,除了地质保存条件外,甲烷裂解应是寒武系(特别是R_(0)>3.0%区域)页岩气低产及高含N_(2)的另一个重要因素。

关键词：寒武系页岩气氮气含量成熟度演化甲烷裂解

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用于红外和雷达波隐身的水泥基复合材料

材料导报 2024年第5期38卷 22-30页

作者：马超解帅王永超冀志江吴子豪王静中国建筑材料科学研究总院有限公司绿色建筑材料国家重点实验室北京100024

红外和雷达波隐身主要是通过降低目标的红外辐射信号和雷达回波信号来提高目标的隐蔽性。将相变材料与炭黑封装为相变单元,并将其与膨胀珍珠岩-磁粉/水泥复合材料结合,研制出一种兼具红外和雷达波隐身的双功能水泥基复合材料,对其吸波... 详细信息

红外和雷达波隐身主要是通过降低目标的红外辐射信号和雷达回波信号来提高目标的隐蔽性。将相变材料与炭黑封装为相变单元,并将其与膨胀珍珠岩-磁粉/水泥复合材料结合,研制出一种兼具红外和雷达波隐身的双功能水泥基复合材料,对其吸波性能和热性能进行试验与仿真研究。结果表明:炭黑对相变材料相变温度的影响较小,潜热仅降低了约1.9%;500次冷热循环后,相变材料的潜热留存率为78.3%,循环稳定性较好。相变单元和膨胀珍珠岩均可以提高水泥基复合材料的吸波能力,且反射损耗在-5~-15 dB可调。相变单元通过吸收大量热量来降低目标外表面温度,削弱红外辐射。相变材料的加入会增加水泥基复合材料的热导率,但相变材料高储热密度和珍珠岩低热导率的共同作用使得水泥基复合材料的隔热效应更加显著,从而降低目标的红外辐射信号。仿真结果表明:磁损耗仅出现在水泥基体中,相变单元通过电阻损耗来影响水泥基复合材料的吸波性能。热量传递在相变单元处受阻,传导热通量在相变单元边缘处的传输过程出现弯曲。当相变材料相变完成后,热量趋于均匀分布。因此,水泥基复合材料可通过损耗电磁波来降低雷达回波信号,通过相变材料吸收目标的热量来降低红外辐射,从而实现不同复杂环境下建筑材料的红外和雷达波等多波段隐身。

关键词：水泥基复合材料红外隐身雷达波隐身相变材料有限元法

Mitigating the Reconstruction of Metal Sulfides for Ultrastable Oxygen Evolution at High Current Density

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CCS Chemistry 2024年第1期6卷 137-148页

作者： shuai Niu Tang Tang Yuanju Qu Yuyun Chen Hao Luo Hui Pan Wen-Jie Jiang Jianan Zhang Jin-Song Hu Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Nanostructure and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190 Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoMacao SAR 999078 Department of Chemical Engineering University of MelbourneParkvilleVictoria 3010 College of materials Science and Engineering Zhengzhou UniversityZhengzhou 450001 School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049 Dalian National Laboratory for Clean Energy Dalian 116023

Metal sulfides are emerging highly active electrocatalysts for the oxygen evolution reaction(OER),but still suffer from the instability caused by their inevitable reconstruction,especially at industrial-level current density.Here,it is discovered that Fe-incorporated Ni3S2 nanowires can deliver extraordinary durability with an ultralow potential degradation rate of 0.006 mV/h in alkaline electrolytes made with fresh water and seawater at a benchmark of 500 ma cm^(-2) while meeting the industrial activity requirement for overpotential less than 300 mV(290 mV).Systematic experiments and theoretical simulations suggest that after forming the S-doped NiFeOOH shell to boost intrinsic activity,Fe incorporation effectivelymitigates the reconstruction of the Ni_(3)S_(2) nanowire core by restraining Ni oxidation and S dissolution,justifying the performance.This work highlights the significance of circumventing reconstruction and provides a strategy to explore practical chalcogenides-based OER electrocatalysts.

关键词： oxygen evolution reaction sulfur-doped NiFeOOH NiFe sulfides nanowire ultrastable high current density

Robust Artificial Noise-Aided Beamforming for A Secure MISO-NOma Visible Light Communication System

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China Communications 2020年第11期17卷 42-53页

作者： Xiaodong Liu Zezong Chen Yuhao Wang Fuhui Zhou shuai ma School of Electronic Information Wuhan UniversityWuhan 430072China School of Information Engineering Nanchang UniversityNanchang 330031China College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210000China School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China Shanxi Key Laboratory of Information Communication Network and Security Xi’an University of Posts&TelecommunicationsXi’an 710121China

Visible light communication(VLC)and non-orthogonal multiple access(NOma)have been deemed two promising techniques in the next wireless communication networks.In this paper,secure communications in the presence of potential eavesdropper are investigated for a multiple-input single-output VLC system with NOma.The artificial noise jamming and beamforming technologies are applied to improve secure performance.A robust resource allocation scheme is proposed to minimize the total transmit power taking into account the constraints on the quality of service requirement of the desired users and the maximum tolerable data rate of the eavesdropper,and the practical imperfect channel state information of both the desired users and the eavesdropper.The formulated non-convex optimization problem is tackled based onS-Procedure and semi-definite programming relaxation.Simulation results illustrate that our proposed resource allocation scheme can effectively guarantee communication security and achieve transmit power saving.Moreover,the height and number of LED can significantly affect system performance and the optimum LED height can be obtained for different LED numbers.

关键词： artificial noise non-orthogonal multiple access physical-layer secrecy robust resource allocation visible light communication

The mass,fake news,and cognition security

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Frontiers of Computer Science 2021年第3期15卷 1-13页

作者： Bin GUO Yasan DING Yueheng SUN shuai ma Ke LI Zhiwen YU School of Computer Science Northwestern Polytechnical UniversityXi'an 710072China School of Cyber Security Tianjin UniversityTianjin 300350China School of Computer Science and Engineering Beihang UniversityBeijing 100191China

The widespread fake news in social networks is posing threats to social stability,economic development,and political democracy,etc.Numerous studies have explored the effective detection approaches of online fake news,while few works study the intrinsic propagation and cognition mechanisms of fake news.Since the development of cognitive science paves a promising way for the prevention of fake news,we present a new research area called Cognition Security(CogSec),which studies the potential impacts of fake news on human cognition,ranging from misperception,untrusted knowledge acquisition,targeted opinion/attitude formation,to biased decision making,and investigates the effective ways for fake news debunking.CogSec is a multidisciplinary research field that leverages the knowledge from social science,psychology,cognition science,neuroscience,AI and computer science.We first propose related definitions to characterize CogSec and review the literature history.We further investigate the key research challenges and techniques of CogSec,including human-content cognition mechanism,social influence and opinion dif-fusion,fake news detection,and malicious bot detection.Finally,we summarize the open issues and future research directions,such as the cognition mechanism of fake news,influence maximization of fact-checking information,early detection of fake news,fast refutation of fake news,and so on.

关键词： cyberspace cognition security fake news crowd computing human-content interaction

Structure-based design of pan-coronavirus inhibitors targeting host cathepsin L and calpain-1

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1651-1664页

作者： Xiong Xie Qiaoshuai Lan Jinyi Zhao Sulin Zhang Lu Liu Yumin Zhang Wei Xu maolin Shao Jingjing Peng shuai Xia Yan Zhu Keke Zhang Xianglei Zhang Ruxue Zhang jian Li Wenhao Dai Zhen Ge Shulei Hu Changyue Yu Jiang Wang Dakota ma Mingyue Zheng Haitao Yang Gengfu Xiao Zihe Rao Lu Lu Leike Zhang Fang Bai Yao Zhao Shibo Jiang Hong Liu Drug Discovery and Design Center State Key Laboratory of Drug ResearchCAS Key Laboratory of Receptor ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Medical Molecular Virology(MOE/NHC/CAMS) School of Basic Medical SciencesShanghai Institute of Infectious Disease and BiosecurityFudan UniversityShanghai 200032China Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan 430071China School of Chinese materia Medica Nanjing University of Chinese Medicine138 Xian Lin RoadJiangsu 210023 NanjingChina School of Pharmaceutical Science and Technology Hangzhou Institute for Advanced StudyUCASHangzhou 310024China National Clinical Research Center for Infectious Disease Shenzhen Third People's HospitalShenzhen 518112China

Respiratory disease caused by coronavirus infection remains a global health crisis.Although several SARS-CoV-2-specific vaccines and direct-acting antivirals are available,their effcacy on emerging coronaviruses in the future,including SARS-CoV-2 variants,might be compromised.Host-targeting antivirals provide preventive and therapeutic strategies to overcome resistance and manage future outbreak of emerging coronaviruses.Cathepsin L(CTSL)and calpain-1(CAPN1)are host cysteine proteases which play crucial roles in coronaviral entrance into cells and infection-related immune response.Here,two peptidomimetic a-ketoamide compounds,14a and 14b,were identified as potent dual target inhibitors against CTSL and CAPN1.The X-ray crystal structures of human CTSL and CAPN1 in complex with 14a and 14b revealed the covalent binding of a-ketoamide groups of 14a and 14b to C25 of CTSL and C115 of CAPN1.Both showed potent and broad-spectrum anticoronaviral activities in vitro,and it is worth noting that they exhibited low nanomolar potency against SARS-CoV-2 and its variants of concern(VOCs)with ECso values ranging from 0.80 to 161.7 nM in various cells.Preliminary mechanistic exploration indicated that they exhibited anticoronaviral activity through blocking viral entrance.Moreover,14a and 14b exhibited good oral pharmacokinetic properties in mice,rats and dogs,and favorable safety in mice.In addition,both 14a and 14b treatments demonstrated potent antiviral potency against SARS-CoV-2 XBB 1.16 variant infection in a K18-hACE2 transgenic mouse model.And 14b also showed effective antiviral activity against HCoV-OC43 infection in a mouse model with a final survival rate of 60%.Further evaluation showed that 14a and 14b exhibited excellent antiinflammatory effects in Raw 264.7 mouse macrophages and in mice with acute pneumonia.Taken together,these results suggested that 14a and 14b are promising drug candidates,providing novel insight into developing pan-coronavirus inhibitors with antiviral and anti-inflammatory properties.

关键词： calpain overcome entrance

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战略联盟与企业风险承担

经济体制改革 2024年第1期 105-114页

作者：赵欣侯德帅马海云郑州航空工业管理学院商学院河南郑州450046 首都经济贸易大学会计学院北京100070 中国人民大学商学院北京100086

基于风险承担视角,研究战略联盟合作的经济效果,发现参与战略联盟的公司其整体风险承担水平显著提升。机制检验表明,战略联盟通过降低企业代理成本和企业运营成本提高企业风险承担水平。异质性分析发现,对于非国有企业、高行业竞争度企... 详细信息

基于风险承担视角,研究战略联盟合作的经济效果,发现参与战略联盟的公司其整体风险承担水平显著提升。机制检验表明,战略联盟通过降低企业代理成本和企业运营成本提高企业风险承担水平。异质性分析发现,对于非国有企业、高行业竞争度企业及处于市场化水平较低区域的企业,战略联盟对企业风险承担的提升效应更大。拓展性研究表明,股权式合作模式、双边契约形式,区域商业合作文化显著增加了战略联盟对企业风险承担的提升作用。战略联盟对企业风险承担的影响具体表现为债务融资规模的扩大、资本性支出水平的提升和研发投入的增加。鉴于此,企业应积极寻求建立有效的战略联盟,监管机构应激励和支持企业构建战略联盟,以提升企业的风险承担能力,增强企业竞争优势,助推企业高质量发展。

关键词：战略联盟风险承担资本支出企业合作

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高马赫数球状气泡动力学理论研究

哈尔滨工程大学学报（英文版） 2024年第1期23卷 39-48页

作者：韩泠西颜帅李帅 College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China

The compressibility of fluids has a profound influence on oscillating bubble dynamics,as characterized by the mach number.However,current theoretical frameworks for bubbles,whether at the first or second order of the mach number,are primarily confined to scenarios characterized by weak compressibility.Thus,a critical need to elucidate the precise range of applicability for both first-and second-order bubble theories arises.Herein,we investigate the suitability and constraints of bubble theories with different orders through a comparative analysis involving experimental data and numerical simulations.The focal point of our investigation encompasses theories such as the Rayleigh–Plesset,Keller,Herring,and second-order bubble equations.Furthermore,the impact of parameters inherent in the second-order equations is examined.For spherical oscillating bubble dynamics in a free field,our findings reveal that the first-and second-order bubble theories are applicable when ma≤0.3 and 0.4,respectively.For a single sonoluminescence bubble,we define an instantaneous mach number,mai.The second-order theory shows abnormal sensibility when mai is high,which is negligible when mai≤0.4.The results of this study can serve as a valuable reference for studying compressible bubble dynamics.

关键词： Bubble dynamics Spherical bubble Cavitation Compressibility mach number

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聚β-环糊精修饰电极零流电位法检测氯吡脲

分析试验室 2024年第1期43卷 64-69页

作者：马明明何成毅史帅崔淑慧刘佳西安工程大学环境与化学工程学院西安710048 西安市农产品质量安全检验监测中心西安710077

采用电聚合方法,在多壁碳纳米管修饰的铅笔芯电极(MWCNT-PEC)表面制备聚β-环糊精-氯吡脲(CPPU)复合材料(P-β-CD-CPPU),并对其结构和形貌进行表征。结果表明,含有CPPU分子残留活性点的P-β-CD-CPPU拥有较大筒腔结构,能重新包合识别CPP... 详细信息

采用电聚合方法,在多壁碳纳米管修饰的铅笔芯电极(MWCNT-PEC)表面制备聚β-环糊精-氯吡脲(CPPU)复合材料(P-β-CD-CPPU),并对其结构和形貌进行表征。结果表明,含有CPPU分子残留活性点的P-β-CD-CPPU拥有较大筒腔结构,能重新包合识别CPPU分子,据此建立了P-β-CD-CPPU修饰电极零流电位法检测CPPU的新方法。考察了影响P-β-CD-CPPU重新包合CPPU前后零流电位差值变化的条件。在优化条件下,修饰电极的零流电位与CPPU浓度在0.5~50μmol/L范围内成正比,CPPU的检出限为21.4 nmol/L。CPPU体系可能共存的有机物及金属离子均不干扰测定;同一根修饰电极对同一浓度CPPU零流电位测定值在14 d内的相对标准偏差(RSD)为2.0%;5根不同批次修饰电极的零流电位测定值的RSD为1.7%。应用本方法检测实际猕猴桃样品中CPPU残留浓度,平均回收率为102.7%~109.1%,与液相色谱-质谱联用法检测结果基本一致。

关键词：氯吡脲零流电位法 β-环糊精电聚合超分子识别