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新屯煤矿综放工作面区段煤柱合理宽度优化研究

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煤 2024年第5期33卷 46-48页

作者：张子统冀中能源峰峰集团有限公司检测检验中心河北邯郸056201

为对新屯煤矿14282工作面的区段煤柱宽度进行优化,通过FLAC3D数值模拟软件分析了不同煤柱宽度下的垂直应力、围岩位移及塑性区分布特征,最终确定合理的区段煤柱宽度为25 m,并对巷道支护进行了设计。现场实践结果表明,在工作面回采期间,... 详细信息

为对新屯煤矿14282工作面的区段煤柱宽度进行优化,通过FLAC3D数值模拟软件分析了不同煤柱宽度下的垂直应力、围岩位移及塑性区分布特征,最终确定合理的区段煤柱宽度为25 m,并对巷道支护进行了设计。现场实践结果表明,在工作面回采期间,巷道顶底板最大移近量为348 mm,两帮最大移近量为470 mm,均在允许变形范围内,满足矿井安全高效的生产需求。

关键词：综放工作面区段煤柱合理宽度

Thermal smart materials with tunable thermal conductivity:Mechanisms, materials, and applications

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Science China(Physics,Mechanics & Astronomy) 2022年第11期65卷 18-35页

作者： zitong zhang BingYang Cao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

The demand for active and effective management of heat transfer is increasing in various modern application scenarios. The thermal conductivity of materials plays a key role in thermal management systems, and reversibly tunable thermal properties are one of the fundamental needs for materials. Thermal smart materials, whose thermal properties can be tuned with an external trigger, have attracted the attention of researchers. In this paper, we provide a brief review of current research advances in thermal smart materials in recent years in terms of fundamental physical mechanisms, thermal switching ratios, and their application value. We focus on typical thermal smart materials such as nanoparticle suspensions, phase change materials, polymers, layered materials tuned by electrochemistry and other materials tuned by a specific external field. After surveying the fundamental mechanisms, we present applications of thermal smart components and devices in temperature control, thermal circuits, phonon computers, thermal metamaterials, and so on. Finally, we discuss the limitations and challenges of thermal smart materials, as well as our predictions for future development.

关键词： thermal smart material thermal conductivity smart tuning thermal control system

小檗碱促进骨再生的机制、安全性及在骨组织工程中的应用

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中国组织工程研究 2024年第35期28卷 5702-5708页

作者：李昱林俞海鹏唐华菁张梓桐林兴南浙江中医药大学口腔医学院浙江省杭州市310000 长沙医学院临床医学院湖南省长沙市410000

背景:小檗碱具有诱导各种间充质干细胞在正常状态和高糖、感染及炎症等特殊状态下成骨分化的潜力,可替代生长因子诱导种子细胞成骨,是一种具有骨诱导潜力的天然小分子药物,在骨组织工程领域有着巨大的应用前景。目的:回顾和总结小檗碱... 详细信息

背景:小檗碱具有诱导各种间充质干细胞在正常状态和高糖、感染及炎症等特殊状态下成骨分化的潜力,可替代生长因子诱导种子细胞成骨,是一种具有骨诱导潜力的天然小分子药物,在骨组织工程领域有着巨大的应用前景。目的:回顾和总结小檗碱成骨机制及效能,尤其是在高糖、感染及炎症环境下的成骨潜力,以及小檗碱生物安全性方面的研究进展,为其在骨组织工程中的发展应用提供理论依据。方法:在PubMed、万方及中国知网数据库,以英文检索词“berberine,bone defects,bone repair,bone regeneration,osteoinductive,osteoporosis,osteoblast,osteoclast,bone tissue engineering,bone,high glucose,diabetes,inflam*,infect*”,中文检索词“黄连素,小檗碱,骨缺损,骨修复,骨再生,骨诱导,骨质疏松,成骨细胞,破骨细胞,骨组织工程,骨,高糖,糖尿病,炎症,感染”进行文献检索,最终筛选后纳入105篇文献进行综述。结果与结论:(1)小檗碱能用于治疗包括骨病在内的多种疾病,其具有促进骨再生作用,文章系统综述了小檗碱对骨再生作用机制及体内外研究。(2)研究表明小檗碱能够通过促骨生成、抑制破骨细胞形成及其活性、抗骨质疏松等方面发挥骨修复作用,主要通过参与Wnt/β-catenin,PI3K/AKT,EGFR/MEK/p38MAPK,cAMP/PKA/CREB和ERK等信号通路,表现出优异的成骨诱导分化潜力。(3)小檗碱还可以解除因高糖、感染及炎症引起的细胞成骨分化抑制,这为治疗患有糖尿病的骨缺损患者或骨缺损部位有感染及炎症的患者提供了更多可能。(4)小檗碱还具有毒性小、价格低廉和易于获取(目前已经能够人工合成)等优点,是较为理想的骨诱导潜力药物。(5)近年来应用小檗碱治疗骨缺损趋于局部使用,主要通过与骨组织工程技术结合改善生物利用度,在动物实验中表现出良好的骨修复作用和生物安全性,而且临床前实验表明,小檗碱在糖尿病、局部感染及炎症状态下仍然表现出优秀的骨再生潜力。(6)未来还需要更多的研究完整地揭示小檗碱的成骨机制和生物安全性等问题,并寻求最合适的控释载体制作出机械强度、疗效及生物安全性均佳的人工骨替代材料。

关键词：小檗碱中药有效成分骨缺损骨再生支架材料骨组织工程糖尿病感染炎症

硫化脂肪酸酯的合成及其在高温高压钻井液中的应用

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钻井液与完井液 2024年第3期41卷 344-349页

作者：夏小春邹洋王志永张紫铜宋钰戴媛静中海油田服务股份有限公司油田化学研究院河北三河065201 润滑技术研究所·清华大学天津高端装备研究院天津300300 高端装备界面科学与技术全国重点实验室·清华大学北京100084

大位移井高温储层水基钻井液在高负荷、高盐度、高温条件下,液体润滑剂的润滑性能不足,导致憋钻具、卡钻和钻具磨损等问题,实验室合成了一种硫化脂肪酸酯,将其与润滑剂复配后得到复合硫剂(QT311),添加至HTFlow高温高压水基钻井液中,能... 详细信息

大位移井高温储层水基钻井液在高负荷、高盐度、高温条件下,液体润滑剂的润滑性能不足,导致憋钻具、卡钻和钻具磨损等问题,实验室合成了一种硫化脂肪酸酯,将其与润滑剂复配后得到复合硫剂(QT311),添加至HTFlow高温高压水基钻井液中,能够提升钻井液的润滑性能。通过四球试验机测试可知,添加1%QT311后,其COF能够下降64%,磨斑直径降低43%,润滑性能优于几款常用市售钻井液用润滑剂。通过电镜分析摩擦副表面,发现硫剂在摩擦过程中发生摩擦化学反应生成硫-铁极压膜,从而提升钻井液的减摩性能,且该剂在HTFlow钻井液体系中表现出优异的配伍性、抗水解性能、抗盐及抗温性能。试验结果为钻井液用润滑剂的进一步研究提供参考。

关键词：大位移井硫化脂肪酸酯抗磨减摩配伍性

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一种高精度宽范围共模输入的电流检测电路

微电子学与计算机 2024年第7期41卷 56-63页

作者：张子同江月艳李珂徐叶中国电子科技集团第五十八研究所江苏无锡214035

基于0.18μm HV SOI CMOS工艺,设计实现了一种应用于电流保护系统中的高精度宽范围共模输入的电流检测电路。该电路通过检测采样电阻上的压降来获取电流值变化量;同时基于包含了LDMOS管的保护电路单元实现了宽的共模电压变化范围。此外... 详细信息

基于0.18μm HV SOI CMOS工艺,设计实现了一种应用于电流保护系统中的高精度宽范围共模输入的电流检测电路。该电路通过检测采样电阻上的压降来获取电流值变化量;同时基于包含了LDMOS管的保护电路单元实现了宽的共模电压变化范围。此外,通过电路内置的逻辑控制单元实现输入正负压状态下高低侧运放的切换使用,降低了功耗;利用差分放大器以及跨阻放大器对获取的信号值进行处理,提高了检测精度。测试结果表明,在25℃温度下电路总输出误差<0.67%,在-55℃~125℃温度范围内电路可承受-18V~80 V宽范围共模输入且带宽大于200 kHz,当输入电压在-18V~80 V范围内变化时,输出电压的变化小于40 mV。

关键词：电流检测宽范围高精度逻辑控制

Deep Reinforcement Learning Based Bi-layer Optimal Scheduling for Microgrids Considering Flexible Load Control

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CSEE Journal of Power and Energy Systems 2023年第3期9卷 949-962页

作者： zitong zhang Jing Shi Wangwang Yang Zhaofang Song Zexu Chen Dengquan Lin the State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In this paper,the bi-layer scheduling method for microgrids,based on deep reinforcement learning,is proposed to achieve economic and environmentally friendly ***,considering the uncertainty of renewable energy,the framework of day-ahead and intra-day scheduling is established,and the implementation scheme for both price-based and incentive-based demand response(DR)for the flexible load is ***,comprehensively considering the operating characteristics of the microgrid in the day-ahead and intra-day time scales,a bi-layer scheduling model of the microgrid is *** terms of algorithms,since day-ahead scheduling has no strict requirement for dispatching time,the particle swarm optimization(PSO)algorithm is used to optimize the time-of-use electricity price and distributed power output for the next *** the environmental fluctuations and requirements for rapidity of intra-day online scheduling,the deep reinforcement learning(DRL)algorithm is adopted for ***,based on the data from the actual microgrid,the rationality and effectiveness of the proposed scheduling method is *** results show that the proposed bi-layer scheduling based on the PSO and DRL algorithms achieves the optimization of scheduling cost and calculation speed,and is suitable for microgrid online scheduling.

关键词： Bi-layer optimal scheduling demand response deep reinforcement learning microgrid scheduling

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Pedosphere 2003年第1期13卷 11-22页

作者： GONG zitong, zhang GANLIN, ZHAO WENJUN, ZHAO YUGUO and CHEN ZHICHENGInstitute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008

During the past half century, the land utilization of Hainan Island has undergone a rapid development,but in the meanwhile, soil degradation occurs. Analysis on some basic data of the soil series collected frommore than 100 soil profiles at the end of the 1990s and beginning of this century, in combination with dataavailable, showed that soils there suffered significant decline in organic matter, experienced P and K deficiencywith soil K going on losing and undergone acidification with continuing trend. The current situation calls forstrategies to build up Hainan into an important province of sound ecology by restoring forests, to improvefood quality by implementing K supplement projects, to combat soil acidification by ameliorating the soils andgrowing leguminous crops and to ensure health of the people by developing dairy production and increasingthe daily Ca uptake by the people.

关键词： hainan island land use soil changes

Highly efficient labelling of extracellular vesicles for enhanced detection on a microfluidic platform

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Chinese Chemical Letters 2024年第2期35卷 441-445页

作者： Shi Hu Rui Hao zitong Yu Huitao zhang Hui Yang Bionic Sensing and Intelligence Center Institute of Biomedical and Health EngineeringShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Developing precise extracellular vesicles(EVs)labelling techniques with minimal disturbance is of great importance to the follow-up EVs detection and ***,currently available methods such as using probes to conjugate phospholipids or membrane proteins have certain limitations due to EV steric hindrance,dye aggregation,***,we present a microfluidic platform to enhance EVs’labelling efficiency and improve their *** platform provides excellent sample throughput and high-efficiency EV labelling at lower label concentrations with an optimized flowing *** cytometry analysis(FCM)and cellular uptake results show that EV labelling by utilizing this platform possesses the merits of a higher labelling efficiency with 64.1%relative improvement than conventional co-incubation method and a lower background ***,this technique maintains EVs’size,morphology and biological *** the recipient cells uptake the EVs treated by the microfluidic platform,the spatial and temporal distribution of EVs in the cells are clearly *** results demonstrate that our method holds great potential in efficient labelling of EVs,which is essential to subsequent EV quantification and analysis.

关键词： Microfluidic platform Extracellular vesicles Labelling PKH dye Flow cytometry

Character of Convective Systems Producing Short-Term Heavy Precipitation in Central China Revealed by Kilometer and Minute Interval Observations

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Journal of Meteorological Research 2024年第3期38卷 530-541页

作者： zitong CHEN Yunying LI Zhiwei zhang Jing SUN Chengzhi YE Anyuan XIONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha410073China High Impact Weather Key Laboratory of China Meteorological Administration Changsha410073China Unit No.92192 of Chinese People’s Liberation Army Ningbo315000China Hubei Key Research Laboratory for Heavy Rain Monitoring and Warning Institute of Heavy RainChina Meteorological AdministrationWuhan430223China Institute of Meteorological Sciences of Hunan Province Hunan Meteorological BureauChangsha410118China National Meteorological Information Centre China Meteorological AdministrationBeijing100081China

Accurate forecasting of heavy precipitation in central China is still a challenge,within which a key issue is our still incomplete understanding of the convective systems(CSs)responsible for such *** this study,through use of an iterative rain-cell tracking algorithm,the macroscale characteristics(scale,intensity,duration,etc.)of the CSs that produced 595 short-term heavy precipitation events in Hunan Province,central China,are quantitatively analyzed,based on radar reflectivity,echo top,and rainfall observations at 1-km and 6-min intervals in April-September of *** results show that CSs present significant seasonal and diurnal *** CSs usually cover a larger echo area with stronger convective cores and thus generate more precipitation than summer CSs,though summer CSs develop more vigorously and *** initiated at 1400-1600 local time are characterized by the strongest convection and a smaller spatiotemporal scale,causing violent and transient showers with typical areal precipitation of 0.5-1 mm km^(−2),but less total *** analyses of the relationships among the scale,intensity,duration,and total precipitation of CSs reveal that the convective intensity is linearly correlated to the spatiotemporal scale of CSs,with the duration increasing on average by 0.0372 h dBZ^(−1);the echo area is significantly correlated to the total precipitation,and the duration and rainfall amount are connected with the area expansion rate(AER)of CSs:when the AER exceeds 50%,CSs expand rapidly with increasing total precipitation,but the duration is *** findings provide a helpful reference for the forecasting of short-term heavy precipitation induced by CSs in central China.

关键词： convective system radar reflectivity factor total precipitation iterative rain-cell tracking