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柱前衍生化液质联用法测定氯乙酰氯试剂中的乙酰氯和二氯乙酰氯

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化学试剂 2024年第4期46卷 102-107页

作者：邵方娴何燕琳芦丽黄朝瑜王晨严菲江苏省食品药品监督检验研究院江苏南京210019 中国药科大学药物分析教研室江苏南京210009 国家药品监督管理局化学药杂质谱重点实验室江苏南京210019

建立了柱前衍生化超高效液相色谱-三重四级杆联用(UPLC-MS/MS)法同时测定酰化试剂氯乙酰氯中的杂质乙酰氯和二氯乙酰氯的含量。以苯胺作衍生化试剂,采用Poroshell 120 Aq-C18(150 mm×2.1 mm, 2.7μm)为色谱柱,0.1%(V/V)甲酸水和乙腈为... 详细信息

建立了柱前衍生化超高效液相色谱-三重四级杆联用(UPLC-MS/MS)法同时测定酰化试剂氯乙酰氯中的杂质乙酰氯和二氯乙酰氯的含量。以苯胺作衍生化试剂,采用Poroshell 120 Aq-C18(150 mm×2.1 mm, 2.7μm)为色谱柱,0.1%(V/V)甲酸水和乙腈为流动相,梯度洗脱,流速为0.3 mL/min。在电喷雾离子源(ESI),正离子监测下,采用多反应监测扫描(MRM)模式。乙酰氯和二氯乙酰氯分别在0.5~50 ng/mL和5~500 ng/mL范围内线性关系良好(R^(2)≥0.998 6),定量限为0.5和5 ng/mL,检出限为0.2和2 ng/mL;回收率(n=3)为90.8%~103.1%和92.5%~108.7%,RSD为1.4%~6.6%和0.9%~3.8%。衍生化产物室温放置24 h内稳定。方法准确可靠,简便高效,可用于氯乙酰氯中乙酰氯和二氯乙酰氯的同时检测。

关键词：氯乙酰氯杂质检测乙酰氯二氯乙酰氯柱前衍生化超高效液相色谱-串联质谱法(UPLC-MS/MS)

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肿瘤医院中心静脉导管相关血流感染病原菌耐药性及其危险因素

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中华医院感染学杂志 2024年第12期34卷 1806-1810页

作者：杨兴肖田建兵李锦锦王媛何艳凛刘志广孔洁羽王翯童邢亚威河北医科大学第四医院感染管理科河北石家庄050011

目的探讨肿瘤医院中心静脉置管患者导管相关血流感染(CRBSI)病原菌耐药情况及其危险因素.方法收集2019年1月-2022年12月河北医科大学第四医院299例中心静脉置管患者资料,观察留置中心静脉导管患者的CRBSI病原菌及药物敏感结果,并对危险... 详细信息

目的探讨肿瘤医院中心静脉置管患者导管相关血流感染(CRBSI)病原菌耐药情况及其危险因素.方法收集2019年1月-2022年12月河北医科大学第四医院299例中心静脉置管患者资料,观察留置中心静脉导管患者的CRBSI病原菌及药物敏感结果,并对危险因素进行分析.结果调查发现84例患者发生了CRB-SI,千日感染率为0.08‰;感染居首位的科室为ICU;共培养分离病原菌88株,其中革兰阴性菌51株占57.95%,革兰阳性菌31株占35.23%,检出率前5位的菌株为肺炎克雷伯菌、铜绿假单胞菌、人葡萄球菌、表皮葡萄球菌、阴沟肠杆菌,主要病原菌对青霉素、头孢菌素、红霉素、喹诺酮类等抗菌药物有较高的耐药率;置管时间、糖尿病是CRBSI的危险因素,而白蛋白是CRBS1的保护因素(P<0.05).结论引起CRBSI发生的病原菌主要为革兰阴性菌,且耐药率较高,临床应提高警惕,同时对于存在高危因素的患者应采取有效防控措施,以预防CRBSI的发生.

关键词：中心静脉置管导管相关血流感染病原菌耐药性危险因素肿瘤医院

Large eddy simulation study of 3D wind field in a complex mountainous area under different boundary conditions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 541-556页

作者： yan LI Lei yan Xuhui he School of Civil Engineering Central South UniversityChangsha410075China National Engineering Research Center for High-speed Railway Construction Changsha410075China Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structures Changsha410075China

Large eddy simulations generally are used to predict 3D wind field characteristics in complex mountainous *** simulation boundary conditions,such as the height and length of the computational domain or the characteristics of inflow turbulence,can significantly impact the quality of *** this study,we examined these boundary conditions within the context of the mountainous terrain around a long-span cable-stayed bridge using a wind tunnel *** sizes of computational domains and turbulent incoming wind velocities were used in large eddy *** results show that when the height of the computational domain is five times greater than the height of the terrain model,there is minimal influence from the top wall on the wind field characteristics in this complex mountainous *** the length of the wake region of the computational domain has negligible effects on the wind *** in the inlet boundary reduces the length of the wake region on a leeward hill with a low slope,but has less impact on the mean wind velocity of steep hills.

关键词： Large eddy simulation(LES) Spectral representation method Recycling method High mountainous canyon Wind characteristics Atmospheric boundary layer Computational domain

Prediction of solar activities:Sunspot numbers and solar magnetic synoptic maps

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Science China Earth Sciences 2024年第8期67卷 2460-2477页

作者： Rui ZHUO Jiansen he Die DUAN Rong lin Ziqi WU Limei yan Yong WEI School of Earth and Space Sciences Peking UniversityBeijing 100091China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Centre for Mathematical Plasma Astrophysics Department of MathematicsKU LeuvenLeuven 3001Belgium Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The evolution of solar magnetic fields is significant for understanding and predicting solar *** our knowledge of solar magnetic fields largely depends on the photospheric magnetic *** this paper,based on the spherical harmonic expansion of the photospheric magnetic field observed by Wilcox Solar Observatory,we analyze the time series of spherical harmonic coefficients and predict Sunspot Number as well as synoptic maps for Solar Cycle *** find that solar maximum years have complex short-period disturbances,and the time series of coefficient g_(7)~0 is nearly in-phase with Sunspot Number,which may be related to solar meridional *** Long Short-Term Memory networks(LSTM),our prediction suggests that the maximum of Solar Cycle 25 is likely to occur in June 2024 with an error of 8 months,the peak sunspot number may be 166.9±22.6,and the next solar minimum may occur around January *** incorporating Empirical Mode Decomposition,we enhance our forecast of synoptic maps truncated to Order 5,validating their relative *** prediction not only addresses a gap in forecasting the global distribution of the solar magnetic field but also holds potential reference value for forthcoming solar observation plans.

关键词： Solar activity prediction Solar magnetic field Spherical harmonic expansion Long-Short Term Memory(LSTM) Empirical Mode Decomposition(EMD)

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Hybrid Hierarchical Particle Swarm Optimization with Evolutionary Artificial Bee Colony Algorithm for Task Scheduling in Cloud Computing

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Computers, Materials & Continua 2024年第1期78卷 1135-1156页

作者： Shasha Zhao Huanwen yan Qifeng lin Xiangnan Feng he Chen Dengyin Zhang College of Internet of Things Nanjing University of Posts and TelecommunicationsNanjing210003China Jiangsu Key Laboratory of Broadband Wireless Communication and Internet of Things Nanjing University of Posts and TelecommunicationsNanjing210003China Tongding Interconnection Information Co. Ltd.Suzhou215000China

Task scheduling plays a key role in effectively managing and allocating computing resources to meet various computing tasks in a cloud computing *** execution time and low load imbalance may be the challenges for some algorithms in resource scheduling *** this work,the Hierarchical Particle Swarm Optimization-Evolutionary Artificial Bee Colony Algorithm(HPSO-EABC)has been proposed,which hybrids our presented Evolutionary Artificial Bee Colony(EABC),and Hierarchical Particle Swarm Optimization(HPSO)*** HPSO-EABC algorithm incorporates both the advantages of the HPSO and the EABC *** testing including evaluations of algorithm convergence speed,resource execution time,load balancing,and operational costs has been *** results indicate that the EABC algorithm exhibits greater parallelism compared to the Artificial Bee Colony *** with the Particle Swarm Optimization algorithm,the HPSO algorithmnot only improves the global search capability but also effectively mitigates getting stuck in local *** a result,the hybrid HPSO-EABC algorithm demonstrates significant improvements in terms of stability and convergence ***,it exhibits enhanced resource scheduling performance in both homogeneous and heterogeneous environments,effectively reducing execution time and cost,which also is verified by the ablation experimental.

关键词： Cloud computing distributed processing evolutionary artificial bee colony algorithm hierarchical particle swarm optimization load balancing

Fully Nonlinear Equations of Krylov Type on Riemannian Manifolds with Totally Geodesic Boundary

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1293-1307页

作者： Li CheN yan he Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied MathematicsHubei UniversityWuhan 430000P.R.China

In this paper,we study fully nonlinear equations of Krylov type in conformal geometry on compact smooth Riemannian manifolds with totally geodesic *** prove the a priori estimates for solutions to these equations and ... 详细信息

关键词： The modified Schouten tensor k-convex hessian type equation

Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： Zhi-lin Shen Jian-Jun he Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)he,^(4)he,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)he,d(d,p)t,d(p,γ)^(3)he,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) he *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

The Minimum Centroid Branch Spanning Tree Problem

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Journal of the Operations Research Society of China 2024年第2期12卷 528-539页

作者： Hao lin Cheng he School of Science Henan University of TechnologyZhengzhou450001HenanChina

For a spanning tree T of graph G,the centroid of T is a vertex v for which the largest component of T-v has as few vertices as *** number of vertices of this component is called the centroid branch weight of *** minimum centroid branch spanning tree problem is to find a spanning tree T of G such that the centroid branch weight is *** application to design of communication networks,the loads of all branches leading from the switch center should be as balanced as *** this paper,we prove that the problem is strongly NP-hard even for bipartite ***,the problem is shown to be polynomially solvable for split graphs,and exact formulae for special graph familis,say Kn_(1),n_(2),...,n_(k)and P_(m)×P_(n),are presented.

关键词： Spanning tree optimization Centroid branch-NP-hardness Polynomial-time algorithm

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

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Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： Cheng he Shiqi yan Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science1nd EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science1nd Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory