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Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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Petroleum Science 2024年第1期21卷 551-566页

作者： Li-Li Yang Ze-Yu Liu Shi-bo Wang Xian-bo he Guan-Cheng Jiang Jie Zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore *** this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite *** suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of *** viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same *** multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of *** sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was ***,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection *** work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

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New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

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Science China Chemistry 2024年第3期67卷 945-952页

作者： Jia-Lu Zhang Wen-bo he Xiu-Qin Hu Peng-Fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China State Key Laboratory of Veterinary Etiological Biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

关键词： enantioselective photocatalysis asymmetric organocatalytic/photocatalysis relay catalysis five consecutive chiral centers chirality-induced strategy chirality vicinal amino alcohols

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Corrosion evaluation and resistance study of alloys in chloride salts for concentrating solar power plants

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Rare Metals 2024年第3期43卷 1222-1233页

作者： Dong-Mei Han Yong Shuai Bachirou Guene Lougou bo-Xi Geng Xi-bo he Tian-Tian Yan Jia-Meng Song School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

Thermal energy storage(TES)systems based on molten salt are widely used in concentrating solar power(CSP)*** investigation of the corrosion behavior of alloy materials in molten salt is crucial for the correct selection of alloy materials and the design of TES *** this study,the corrosion behavior of 304,310S,316,and In625 alloys in molten chloride salts(27 mol%NaCl-22 mol%KCl-51 mol%MgCl,)was *** evolution of mass loss of the alloy samples with corrosion time and temperature and the analysis of the experimental results by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)revealed the corrosion mechanism of the alloy samples in molten chloride *** main factors affecting the corrosion of the alloy samples were further *** was found that the loose multi-layer corrosion was formed on the surface of the corroded alloy samples with the increase in corrosion ***,the experimental *** that Mo played a positive role in improving the corrosion resistance of the alloy samples because the presence of Mo could inhibit the outward diffusion of alloying element *** work enriches the molten salt corrosion database and provides a reference for the selection of alloy materials for TES systems with potential application in CSP plants.

关键词： Thermal energy storage Molten chloride salt Alloy materials Corrosion mechanism Corrosion resistance

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Consensus-based Optimal Control Strategy for Multi-microgrid Systems with Battery Degradation Consideration

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 1911-1924页

作者： Tonghe Wang Hong Liang bo he Haochen Hua Yuchao Qin Junwei Cao Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China Meihua Holdings Group Co. Ltd.Langfang 065001China. Department of Astronautical Science and Technology Space Engineering UniversityBeijing 101416China College of Energy and Electrical Engineering Hohai UniversityNanjing211100China Department of Applied Mathematics and Theoretical Physics University of CambridgeCambridgeCB30WAUK. Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Consensus has been widely used in distributed control,where distributed individuals need to share their states with their neighbors through communication links to achieve a common ***,the objectives of existing consensus-based control strategies for energy systems seldom address battery degradation cost,which is an important performance indicator to assess the performance and sustainability of battery energy storage(BES)*** this paper,we propose a consensusbased optimal control strategy for multi-microgrid systems,aiming at multiple control objectives including minimizing battery degradation *** consensus is used to synchronize the ratio of BES output power to BES state-of-charge(SoC)among all microgrids while each microgrid is trying to reach its individual *** order to reduce the pressure of communication links and prevent excessive exposure of local information,this ratio is the only state variable shared between *** our complex nonlinear problem might be difficult to solve by traditional methods,we design a compressive sensing-based gradient descent(CSGD)method to solve the control *** simulation results show that our control strategy results in a 74.24%reduction in battery degradation cost on average compared to the control method without considering battery *** addition,the compressive sensing method causes an 89.12%reduction in computation time cost compared to the traditional Monte Carlo(MC)method in solving the control problem.

关键词： Battery degradation compressive sensing consensus distributed control multi-microgrid

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Numerical Simulations of the Flow Field around a Cylindrical Lightning Rod

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Structural Durability & health Monitoring 2024年第1期18卷 19-35页

作者： Wei Guo Yanliang Liu Xuqiang Wang Jiazheng Meng Mengqin Hu bo he State Grid Ningxia Ultra High Voltage Co. Ltd.Yinchuan750000China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China

As an important lightning protection device in substations,lightning rods are susceptible to vibration and potential structural damage under wind *** order to understand their vibration mechanism,it is necessary to conduct flow *** this study,numerical simulations of the flow field around a 330 kV cylindrical lightning rod with different diameters were performed using the SST k-ω*** flow patterns in different segments of the lightning rod at the same reference wind speed(wind speed at a height of 10 m)and the flow patterns in the same segment at different reference wind speeds were *** variations of lift coefficient,drag coefficient,and vorticity distribution were *** results showed that vortex shedding phenomena occurred in all segments of the lightning rod,and the strength of vortex shedding increased with decreasing *** vorticity magnitude and the root mean square magnitudes of the lift coefficient and drag coefficient also increased *** time history curves of the lift coefficient and drag coefficient on the surface of the lightning rod exhibited sinusoidal patterns with a single dominant *** the same segment,as the wind speed increased in a certain range,the root mean square values of the lift coefficient and drag coefficient decreased,while their dominant frequencies ***,there was a proportional relationship between the dominant frequencies of the lift coefficient and drag *** findings of this study can provide valuable insights for the refined design of lightning rods with similar structures.

关键词： Lightning rod flow around circular tubes numerical simulation vortex shedding phenomenon

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Natural rubber latex as a potential additive for water-based drilling fluids

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Petroleum Science 2024年第4期21卷 2677-2687页

作者： Jun Yang Guan-Cheng Jiang Jing-Tian Yi Yin-bo he Li-Li Yang Teng-Fei Dong Guo-Shuai Wang College of Petroleum Engineering China University of Petroleum (Beijing) National Engineering Research Center of Oil & Gas Drilling and Completion Technology Changqing Drilling General Company CNPC Chuanqing Drilling Engineering Company Limited

The environmental hazards and "carbon footprint" of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals. This paper explored for the first time the interaction mechanism between natural rubber latex(NRL) and bentonite suspensions(BTs) through a series of characterization experiments, as well as the potential applications in water-based drilling fluids(WBDF). The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k) and flow index(n) of BTs, and enhance the shear thinning performance of BTs as pseudo-plastic fluids. In addition, 0.5 w/v% NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles, but also facilitated the compatibility of pressure loss and flow efficiency. The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles, and optimize the particle size distribution and flow resistance of WBDF under the "intercalation-exfoliation-encapsulation" synergistic interaction. Moreover, NRL can improve the rheological properties of WBDF at high temperatures(he pores and cracks of the filter cake, which ultimately reduces the permeability of the cake and the filtration loss of WBDF.

关键词： Natural materials Water-based drilling fluids Natural rubber latex Bentonite suspensions Filtration loss

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Bidirectional position attention lightweight network for massive MIMO CSI feedback

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The Journal of China Universities of Posts and Telecommunications 2024年

作者： Li Jun Wang Yukai Zhang Zhichen he bo Zheng Wenjing Lin Fei School of Information Science and Engineering， Shandong University School of Information and Automation， Qilu University of Technology (Shandong Academy of Sciences)

In frequency-division duplex massive multiple-input multiple-output (MIMO) systems， a bidirectional positional attention network (BPANet) is proposed to address the high computational complexity and low accuracy of existing deep learning-based channel state information (CSI) feedback methods. Specifically， a bidirectional position attention module (BPAM) is designed in the proposed BPANet to improve the network performance. The BPAM captures the distribution characteristics of the CSI matrix by integrating channel and spatial dimension information， thereby enhancing the feature representation of the CSI matrix. Furthermore， channel attention is decomposed into two one-dimensional feature encoding processes， which effectively reduce computational costs. Simulation results demonstrate that， compared with the existing representative method CLNet， BPANet reduces computational complexity by an average of 19.4% and improves accuracy by an average of 7.1%. Additionally， it performs better in terms of running time delay and cosine similarity.

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Correlation between abdominal computed tomography signs and postoperative prognosis for patients with colorectal cancer

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World Journal of Gastrointestinal Surgery 2024年第7期16卷 2145-2156页

作者： Shao-Min Yang Jie-Mei Liu Rui-Ping Wen Yu-Dong Qian Jing-bo he Jing-Song Sun Department of Radiology Xingtan Hospital Affiliated to Shunde Hospital of Southern Medical UniversityFoshan 528315Guangdong ProvinceChina Department of Rehabilitation Medicine Shunde HospitalSouthern Medical UniversityFoshan 528399Guangdong ProvinceChina Department of Radiology Lecong Hospital of ShundeFoshan 528315Guangdong ProvinceChina Department of Ultrasound Lecong Hospital of ShundeFoshan 528315Guangdong ProvinceChina

BACKGROUND Patients with different stages of colorectal cancer(CRC)exhibit different abdominal computed tomography(CT)***,the influence of CT signs on CRC prognosis must be *** To observe abdominal CT signs in patients with CRC and analyze the correlation between the CT signs and postoperative *** The clinical history and CT imaging results of 88 patients with CRC who underwent radical surgery at Xingtan Hospital Affiliated to Shunde Hospital of Southern Medical University were retrospectively *** and multivariate Cox regression analyses were used to explore the independent risk factors for postoperative death in patients with *** three-year survival rate was analyzed using the Kaplan-Meier curve,and the correlation between postoperative survival time and abdominal CT signs in patients with CRC was analyzed using Spearman correlation *** For patients with CRC,the three-year survival rate was 73.86%.The death group exhibited more severe characteristics than the survival group.A multivariate Cox regression model analysis showed that body mass index(BMI),degree of periintestinal infiltration,tumor size,and lymph node CT value were independent factors influencing postoperative death(Phe death group had a low three-year survival rate(log-rankχ2=66.487,11.346,12.500,and 27.672,respectively,Phe survival time of CRC patients was negatively correlated with BMI,degree of periintestinal infiltration,tumor size,lymph node CT value,mean tumor long-axis diameter,and mean tumor short-axis diameter(r=-0.559,0.679,-0.430,-0.585,-0.425,and-0.385,respectively,Phe degree of periintestinal invasion,lymph node CT value,and mean tumor short-axis diameter(r=0.303,0.431,and 0.437,respectively,Phe degree of periintestinal infiltration,tumor size,and lymph node CT value are c

关键词： Colorectal cancer Abdominal Computed tomography signs Radical surgery Prognosis Correlation

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High-efficiency gene editing in Anopheles sinensis using ReMOT control

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Insect Science 2024年第1期31卷 307-312页

作者： Xiao-lin Yang Xia Ling Quan Sun Pin-pin Qiu Kai Xiang Jun-feng Hong Shu-lin he Jie Chen Xin Ding Hai Hu Zheng-bo he Cao Zhou Bin Chen Liang Qiao Chongqing Key Laboratory of Vector Insects Institute of Entomology and Molecular BiologyCollege of Life SciencesChongqing Normal UniversityChongqingChina Xunjian Life Science&Technology Co.Ltd. ChongqingChina State Key Laboratory of Resource Insects Southwest UniversityChongqingChina

Dear editor,Functional genomics studies of mosquito vectors are crucial for understanding their physiological behavior,pathogen transmission,and evolution,and for providing essential molecular targets for genetic control(Severson&Behura,201l;Alphey,2014;Ruzzante et al.,2019;Hong et al.,2022).The main methods involve clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)gene editing via embryo microinjection(Criscione et al.,2015;Kistler et al.,2015).

关键词： editor editing injection

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论中国未成年人网络保护法律制度体系的改进

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法律科学（西北政法大学学报） 2024年第2期42卷 94-109页

作者：何波中国信息通信研究院互联网法律研究中心北京100191

2023年9月,国务院审议通过《未成年人网络保护条例》,对网络保护制度进行了体系化的再造,中国未成年人网络保护法律制度体系基本形成。从内在结构看,该体系由纵向体系的三大法律层级和横向体系的四大制度单元精巧衔接、有机耦合而成,未... 详细信息

2023年9月,国务院审议通过《未成年人网络保护条例》,对网络保护制度进行了体系化的再造,中国未成年人网络保护法律制度体系基本形成。从内在结构看,该体系由纵向体系的三大法律层级和横向体系的四大制度单元精巧衔接、有机耦合而成,未成年人网络素养促进等制度单元基本涵盖了未成年人网络保护的主要领域。在生成机理上,该体系以化解网络风险为逻辑起点,以最有利于保护未成年人为主要原则,坚持自然亲权与国家亲权相协调,最大化发挥技术治理手段的保护功能,并以网络平台为重心,推动侵害未成年人权益的网络问题的多方共治。中国未成年人网络保护法律制度体系在施行中取得了显著的保护成效,实现了以体系化法律制度应对体系化网络风险的目标,但仍未臻完善,主要体现在法律规范衔接互动还存在不足,部分制度施行存在效果偏差等方面。中国未成年人网络保护法律制度体系的完善,应强化保护理念,完善配套法规,调试制度适用,寻求未成年人网络保护最优的处理方案。

关键词：网络保护纵向体系国家亲权横向体系

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