mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
腰椎斜外侧椎间融合术后交感神经链损伤的临床特征分析

目的:分析腰椎斜外侧椎间融合术(oblique lumbar interbody fusion,OLIF)后交感神经链损伤(sympathetic chain injury)的临床特征,并统计其发生率。方法:回顾性分析2016年4月~2017年12月在我院骨科行OLIF的54例腰椎退行性疾病患者,其中男性10例,女性44例;年龄37~80岁(58.4±10.9岁)。腰椎滑脱症18例,腰椎不稳12例,腰椎间盘突出症8例,腰椎退变性侧凸14例,腰椎间盘突出症术后复发2例。单节段OLIF 39例,多节段OLIF 15例。左侧入路52例,右侧入路2例。术前采用电子感应体温仪测量双小腿及双足背体表温度,术后次日采用同样方法测量双小腿及双足背体表温度,将双小腿或足背温度差≥0.5℃定义为双下肢温度不等,并诊断为腰交感神经链损伤,记录所有患者术后下肢症状,术后1周、6周、6个月、2年随访时采用Likert五分量表法评价患者对交感神经链损伤引起的不适体验。结果:54例患者术前双下肢体表温度差异不具有统计学意义(P>0.05)。术后16例(29.6%)存在双下肢体表温度温度差≥0.5℃,诊断为交感神经链损伤。其中女性15例(34.1%),男性1例(10%),女性患者较男性患者发生率高,但差异无统计学意义(P>0.05);腰椎滑脱4例(4/18,22.2%),腰椎不稳4例(4/12,33.3%),腰椎间盘突出症(3/8,37.5%),腰椎退变性侧凸(5/14,35.7%),差异无统计学意义(P>0.05);单节段OLIF 10例(24%),多节段6例(46%),多节段患者的发生率显著性高于单节段患者(P<0.05)。术后8例(14.8%)自我感觉双下肢皮温不等,12例(22.2%)患者出现大腿前方疼痛、麻木感、股四头肌乏力,二者在有交感神经链损伤患者和无交感神经链损伤患者的分布无统计学差异(P> 0.05)。16例交感神经链损伤患者术前左小腿温度为36.1±0.2℃,右小腿36.1±0.3℃,左足温度为36.0±0.2℃,右足35.9±0.3℃,术后左小腿温度为36.7±0.3℃,右小腿36.1±0.3℃,左足温度为36.7±0.3℃,右足35.8±0.4℃,术后第一天双小腿温差0.6±0.1℃,足部温差0.9±0.3℃,足部温差较小腿明显;温差不等持续1.5~12个月。术后1周主观体验Likert五分量表法评定:差2例(12.5%),中等14例(87.5%);6周时2例改善,6个月时6例改善,其中1例差改善为中等,至术后2年随访,2例由差改善至中等,7例由中等改善至良好。结论:电子感应体温仪测量双下肢体表温度可协助诊断,多节段OLIF患者的交感神经链损伤发生率高于单节段OLIF,大部分患者对双下肢温度不等的主观体验为中等不适。
基于LSTM神经网络的短期轨道预报

针对基于动力学模型的轨道预报方法对卫星自主轨道预报与大量非合作目标轨道预报中存在建模成本过高和缺少目标空间环境信息的问题,提出一种基于误差数据驱动的神经网络轨道预报方法。该方法在解析法动力学模型的基础上,使用长短期记忆神经网络对历史轨道预报的误差进行学习,预测未来短期动力学模型的预报误差,以此对预报结果进行修正。选用Ajisai卫星轨道数据和SGP4(simplified general perturbations)动力学模型对所提模型的有效性和性能进行仿真验证。实验结果表明,所提方法对地心惯性坐标系下3个轴一天的预报误差分别下降到原来的16.87%、17.66%、19.58%,显著提升了轨道预报精度。
我国Natech事件分布规律及涉水Natech事件致因分析

为弥补我国自然-技术事件(Natech事件)案例研究空白,基于多种数据挖掘方法对近20 a公开报道的自然灾害诱发的技术事故案例进行收集整理,建立了Natech事件数据库。对该类事件时空分布、行业分布进行交叉分析后发现:Natech事件季节特征明显,暴雨和大风是主要肇因,建筑业和交通运输业脆弱性较强。在引入不利气象情景对涉水Natech事件造成死亡失踪人数进行相关分析后发现:多种行业组合下的涉水Natech事件导致的死亡失踪人数与事件发生前4 ~ 5 d的降水量变化率(PSPD)存在显著相关关系(r >0.3,p <0.01),该相关关系对于研判和防范连续降水时Natech事件风险具有重要参考价值。
基于SCS-CN与GIS耦合模型的闽三角城市群承灾空间淹没风险研究

以闽三角城市群为研究对象,创新水文SCS-CN算法与GIS耦合技术,计算出不同暴雨重现期(5 a,10 a,50 a一遇)下的淹没范围,构建闽三角城市群内涝淹没风险评估体系。通过地理探测器进一步探究淹没风险与社会生态系统空间分布规律,为闽三角城镇群的生态安全保障与可持续发展提供技术支撑。研究表明:闽三角城市群内涝淹没区空间上呈现沿河道向入海口与海岸线聚集的状态,其风险性由海岸向内陆逐步递减。淹没区等级一类,二类,三类风险区占研究区面积的10.2%,14.6%,27.4%。厦、漳、泉市的淹没面积分别为135.67 km~2、304.10 km~2、572.09 km~2。其中一类风险区占比分别为84%,78%,62%,进一步确定研究范围内高频发淹没地段的具体位置。最终通过分析八类主要的社会生态因子与淹没区的空间异质关系,在区域层面提出兼顾城市开发强度的内涝防控分区。
弹性波法测试火灾后混凝土动弹性模量应用研究

混凝土动弹性模量是混凝土构件在动荷载作用下应力与应变的比值,是混凝土建筑物承受动荷载(包括地震荷载、冲击、爆炸)作用及灾害影响(火灾、酸雨侵蚀等)后,分析结构力学特性的一个重要参数,同时也是评价混凝土耐久性安全性的一个关键指标。该文对比介绍了基于冲击弹性波的动弹性模量测试方法、原理,并给出相关验证实例及对比材料。通过对比研究表明基于冲击弹性波的混凝土弹性模量测试具有较高的测试精度,可推广运用于火灾影响后混凝土实体结构动弹性模量检测。
基于双重同步内移相的DAB回流功率简化控制

针对目前双有源桥(DAB)变换器存在的回流功率控制策略设计复杂的问题,通过同步调节初、次级桥臂的内移相角来简化回流功率的控制过程,建立了传输功率、回流功率与内移相角的数学模型,利用同步移相角使变换器在全工况下实现零功率回流。最后,通过实验样机验证了控制策略的有效性。
基于功率反馈控制的四并联DC/DC变换器的研制

设计了一种用于沈抚有轨电车的四并联双向DC/DC变换器系统。DC/DC变换器可以通过信号检测系统识别有无接触网来调整工作模式。在有接触网区,变换器为充电模式对超级电容进行充电;在无接触网区,变换器工作模式转换为放电模式释放超级电容储存的电能用于牵引系统和整车使用。在无输出电流传感器的情况下,采样电压反馈控制作为外环,功率反馈控制作为内环,对整个并联系统进行并联均流控制。最后通过仿真和实验验证了该方案的可行性。
具有电压前馈的两级式逆变器的稳定性分析

针对两级式逆变器因负载突变引起的电压不稳定问题,提出了带有电压前馈和有效值反馈比例积分(PI)补偿器控制两级式逆变器运行。前级变换器采用有源超前滞后补偿器的电压环控制直流母线电压稳定。基于小信号数学模型,给出了前级变换器闭环输出阻抗和后级变换器闭环输入阻抗,并引入Dr. Feng判据分析了两级式逆变器在空载和满载下的稳定性。根据Dr. Feng判据的分析结果,推出在电压前馈和有效值反馈PI补偿器控制下,两级式逆变器可实现空载和满载切换运行。最后,通过仿真和实验结果的分析,充分证明了该控制方式的可行性和有效性。
拓扑优化中压级联多电平变换器及MPC设计

级联H桥多电平变换器在中压大功率应用场景需配合使用具有多个二次绕组的移相变压器为每个H桥模块提供独立的直流源,从而存在系统成本较高的问题,对此,提出了一种拓扑优化中压级联多电平变换器及其模型预测控制(MPC)。新型级联多电平变换拓扑每相只需一个独立直流源,故所需二次绕组数量大为减少,同时每相使用中点箝位(NPC)三电平模块,可将整个系统的复杂度和成本降至最低。进一步,建立了新变换器的离散时间域数学模型,并引入了MPC完成了直流侧电容电压和输出电流的多目标控制。利用小功率变换器样机进行了实际测试,实验结果验证了新型级联多电平变换拓扑的优势以及MPC的效果。
机柜式静止无功补偿装置结构设计

静止无功补偿装置,又称静止无功发生器(SVG),主要用于无功功率补偿,提高功率因数,优化电能质量。此处首先对SVG系统工作原理进行了介绍;然后在输入电压为AC 10 kV的基础上,结合绝缘配合要求进行机柜的结构设计,结合仿真进行结构与热设计校核;最后,通过对功率柜进行满功率拷机、工频耐压、雷电冲击试验分析,验证了其性能。
基于比例前馈积分反馈的虚拟惯性控制策略

在直流系统中配置储能可以平抑直流电压波动,为系统提供惯性支撑,提高系统稳定性。针对储能系统现有虚拟惯性控制策略存在的问题,提出了一种基于比例前馈积分反馈的新型惯性控制策略。该控制策略通过比例前馈系数、积分反馈系数、积分系数实现了对虚拟惯性的多维度控制。新型虚拟惯性控制策略中,比例前馈系数控制功率初始值给定,积分反馈系数控制稳态输出功率,积分系数控制动态响应能力,提高了控制策略的适应性。最后,储能系统以采用不共地式三电平双向DC/DC变换器为例,开展相关实验,实验结果验证了所提新型虚拟惯性控制策略的有效性。
降低整流管电压应力的宽输入LLC参数优化方法

为了提高宽电压范围输入LLC谐振变换器的可靠性,针对宽输入LLC谐振变换器在寄生参数的影响下整流管电压产生高频振荡导致电压应力过大的问题,分状态建立等效模型和状态方程。根据整流管电压应力随工作频率的变化规律,分析应力最大区域并提出能降低整流管电压应力的参数优化设计方法。在该方法下,整个工作区间在避开应力最大区域的同时保证了增益宽度。搭建2.5倍输入范围的600 W全桥LLC平台,开展实验验证。实验结果表明,相比传统的宽电压范围输入LLC参数设计方法,该方法显著降低了工作范围内的整流管最大电压应力值,提高了电路的安全稳定性。
解读2021年诺贝尔物理学奖:浅谈Klaus Hasselmann的科学贡献

2021年诺贝尔物理学奖授予了对理解复杂物理系统作出突出贡献的三位科学家,其中包括两位气象学家,分别是德国马克斯普朗克气象研究所的Klaus Hasselmann和美国普林斯顿大学的Syukuro Manabe[1].主要是为了表彰他们对模拟地球气候、定量气候变率和准确预测全球变暖而做出的突出贡献.这是气象学家历史上首次获得诺贝尔物理学奖,也是自1995年气象学家因臭氧空洞的发现而获得诺贝尔化学奖之后,时隔26年再次斩获诺贝尔科学类奖项.鉴于此次获奖对于气象人的巨大鼓舞,本文对Klaus Hasselmann的科学贡献进行了一些简要解读并就对我们科研工作的启示谈一些个人的看法.关于Manabe的学术贡献可参见胡永云教授的解读[2].
三维氧化石墨烯气凝胶高效吸附与可见光光催化去除六价铬

三维气凝胶材料由于具有大比表面积和优异的光学、电学等性能,近年来引起研究者的关注.本研究以氧化石墨烯(graphene oxide, GO)为前驱体,结合交联法与超临界CO_2萃取法制备了三维多孔和易于回收的氧化石墨烯气凝胶(graphene oxide aerosol,GOA).采用扫描电子显微镜、X-射线衍射仪、拉曼光谱和氮气吸附法对其理化性质进行了表征,考察了其对于六价铬(Cr(VI))的吸附和可见光下的光催化还原性能.GOA制备过程中GO被水热还原且基面产生了较多缺陷,三聚氰胺与三聚氰酸作为交联剂增大层间距的同时使GOA拥有大比表面积和丰富的多孔结构.GO、三聚氰胺、三聚氰酸质量比为3:3:3且GO浓度为6 mg L~(-1)时,获得的样品GOA_(333-6)的比表面积和缺陷密度最大,且展现出对Cr(VI)最优的吸附能力和可见光光催化效率.GOA对Cr(VI)的吸附行为符合拟二阶动力学模型和Langmuir吸附等温模型,说明该吸附过程为单层的化学吸附,其中初始吸附阶段颗粒内扩散是限速步骤.本研究结合了吸附和光催化技术,制备出的GOA样品对于提高污染物去除效率和GO样品的开发利用都具有参考意义.
Mapping high resolution National Soil Information Grids of China

Soil spatial information has traditionally been presented as polygon maps at coarse scales.Solving global and local issues,including food security,water regulation,land degradation,and climate change requires higher quality,more consistent and detailed soil information.Accurate prediction of soil variation over large and complex areas with limited samples remains a challenge,which is especially significant for China due to its vast land area which contains the most diverse soil landscapes in the world.Here,we integrated predictive soil mapping paradigm with adaptive depth function fitting,state-of-the-art ensemble machine learning and high-resolution soil-forming environment characterization in a highperformance parallel computing environment to generate 90-m resolution national gridded maps of nine soil properties (pH,organic carbon,nitrogen,phosphorus,potassium,cation exchange capacity,bulk density,coarse fragments,and thickness) at multiple depths across China.This was based on approximately 5000 representative soil profiles collected in a recent national soil survey and a suite of detailed covariates to characterize soil-forming environments.The predictive accuracy ranged from very good to moderate (Model Efficiency Coefficients from 0.71 to 0.36) at 0-5 cm.The predictive accuracy for most soil properties declined with depth.Compared with previous soil maps,we achieved significantly more detailed and accurate predictions which could well represent soil variations across the territory and are a significant contribution to the GlobalSoilMap.net project.The relative importance of soil-forming factors in the predictions varied by specific soil property and depth,suggesting the complexity and non-stationarity of comprehensive multi-factor interactions in the process of soil development.
Asymmetrical response of summer rainfall in East Asia to CO_2 forcing

Understanding the regional hydrological response to varying CO_2 concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future.To characterize summer monsoon rainfall change in East Asia in a changing CO_2 pathway,we used the Community Earth System Model (CESM) with 28 ensemble members in which the CO_2 concentration increases at a rate of 1% per year until its quadrupling peak,i.e.,1468 ppm (ramp-up period),followed by a decrease of 1% per year until the present-day climate conditions,i.e.,367 ppm (ramp-down period).Although the CO_2 concentration change is symmetric in time,the amount of summer rainfall anomaly in East Asia is increased 42% during a rampdown period than that during a ramp-up period when the two periods of the same CO_2 concentration are compared.This asymmetrical rainfall response is mainly due to an enhanced El Nino-like warming pattern as well as its associated increase in the sea surface temperature in the western North Pacific during a ramp-down period.These sea surface temperature patterns enhance the atmospheric teleconnections and the local meridional circulations around East Asia,resulting in more rainfall over East Asia during a ramp-down period.This result implies that the removal of CO_2 does not guarantee the return of regional rainfall to the previous climate state with the same CO_2 concentration.
Revealing the dust transport processes of the 2021 mega dust storm event in northern China

The dust cycle is an important component of the Earth system,and dust storms are a severe environmental issue affecting many countries around the world.East Asia,the most populous territory on Earth,has been frequently affected by dust storms in the past 500 years.Both the scientific community and the public are deeply interested in identifying initial sources,transport pathways,and depositional processes of Asian dust.Understanding these processes is essential for accurately interpreting windborne dust in paleoclimatic archives (e.g.,ice core,loess,and lake sediments) and for finding effective solutions to mitigate the hazards brought by dust storms.High temporal resolution remote sensing data,such as Moderate Resolution Imaging Spectroradiometer (MODIS),Cloud Aerosol Lidar Infrared Pathfinder Satellite Observation (CALIPSO) data,and Fengyun series (e.g.,
Confining ultrafine SnS nanoparticles in hollow multichannel carbon nanofibers for boosting potassium storage properties

SnS has been extensively investigated as a potential anode material in potassium-ion batteries (PIBs) for its high theoretical capacity.Nonetheless,it suffers a limited cyclic lifespan owing to its poor electronic conductivity and huge volume expansion.This work proposed a facile approach where SnS nanocrystals are confined in the walls of hollow multichannel carbon nanofibers (denoted SnS@HMCFs) to tackle the issues above.In contrast to previous studies,impregnated ultrafine SnS nanocrystals in HMCFs compactly can increase the SnS loading number per unit area of the carbon matrix.Furthermore,the unique hollow multichannel carbon nanofibers are used as a robust carrier to uniformly distribute the SnS nanocrystals.This can significantly accelerate K~+/electron transport,resulting in large specific capacity,outstanding rate performance,and steady cycling property for PIBs.High reversible capacities of 415.5 mAh g~(-1) at 0.1 A g~(-1) after 300 cycles and 245.5 mAh g~(-1) at 1 A g~(-1) after 1000 cycles are retained,suggesting great potential of SnS@HMCFs as a negative electrode material for PIBs.Additionally,when the SnS@HMCF anode is assembled with the KVPO_4F cathode,the obtained full cell shows a large discharge capacity of 165.3 mAh g~(-1) after 200 cycles at 0.1 A g~(-1).
Non-spreading Bessel spatiotemporal optical vortices

Non-spreading nature of Bessel spatiotemporal wavepackets is theoretically and experimentally investigated and orders of magnitude improvement in the spatiotemporal spreading has been demonstrated.The spatiotemporal confinement provided by the Bessel spatiotemporal wavepacket is further exploited to transport transverse orbital angular momentum through embedding spatiotemporal optical vortex into the Bessel spatiotemporal wavepacket,constructing a new type of wavepacket:Bessel spatiotemporal optical vortex.Both numerical and experimental results demonstrate that spatiotemporal vortex structure can be well maintained and confined through much longer propagation.High order spatiotemporal optical vortices can also be better confined in the spatiotemporal domain and prevented from further breaking up,overcoming a potential major obstacle for future applications of spatiotemporal vortex.
Structural architectures of polymer proton exchange membranes suitable for high-temperature fuel cell applications

High-temperature proton exchange membrane (HT-PEM) fuel cells offer more advantages than low-temperature PEM fuel cells. The ideal characteristics of HT-PEMs are high conductivities, low-humidity operation conditions, adequate mechanical properties, and competitive costs. Various molecular moieties, such as benzimidazole, benzothiazole, imide, and ether ether ketone, have been introduced to polymer chain backbones to satisfy the application requirements for HT-PEMs. The most common sulfonated polymers based on the main chain backbones have been employed to improve the rties. Side group/chain engineering, including the introduction of SO3 – on the side chain, grafting, branching, and crosslinking, has been widely applied to HTPEMs to further improve their proton conductivity, thermal stability, and mechanical properties. Currently, phosphoric acid-doped polybenzimidazole is the most successful polymer material for application in HT-PEMs. The compositing/blending modification methods of polymers are effective in obtaining high PA-doping levels and superior mechanical properties. In this review, the current progress of various membrane materials used for HT-PEMs is summarized. The synthesis and performance characteristics of polymers containing specific moieties in the chain backbones applied to HT-PEMs are discussed systemically. Various modification approaches and their deficiencies associated with HT-PEMs are analyzed and clarified. Prospects and future challenges are also presented.
Polarized upconversion luminescence from a single LiLuF_4:Yb~(3+)/Er~(3+) microcrystal for orientation tracking

Polarized upconversion luminescence (UCL) of lanthanide-doped micro/nano-crystals has shown great promise in single-particle tracking and super-resolution bioimaging. However, because of the spectral line broadening and multiple sites of lanthanide in upconversion particles (UCPs), the crystal-field (CF) polarization components of UCL are usually undistinguishable. Herein, we report the linearly polarized UCL in LiLuF_4:Yb~(3+)/Er~(3+) single microcrystals with resolvable CF transition lines and a polarization degree up to 0.82. The CF levels and CF transition lines of Er~(3+), as well as their emission polarization anisotropy, are unraveled for the first time through low-temperature and high-resolution photoluminescence (PL) and UCL spectroscopies. By taking advantage of the well-resolved and highly-polarized CF transition lines of Er~(3+), we demonstrate the application of LiLuF_4:Yb~(3+)/Er~(3+) single microcrystals as anisotropic UCL probes for orientation tracking. These findings provide fundamental insights into the polarization anisotropy of UCL in lanthanide-doped single particles, thus laying a foundation for the future design of anisotropic luminescent probes towards versatile applications.
Porous carbon matrix-encapsulated MnO in situ derived from metalorganic frameworks as advanced anode materials for Li-ion capacitors

Conversion-type anode materials hold great potential for Li~+ storage applications owing to their high specific capacity, while large volume expansion and poor electrical conductivity limit their rate and cycling performances. Herein, a bimetal ZnMn-based metal-organic framework (ZnMn-MOF) is engineered for in situ conversion of MnO-encapsulated porous carbon (MnO/PC) composite. The templating and activation effects of coordinated Zn endow the converted PC matrix with a highly porous structure. This enhances the compatibility of PC matrix with MnO particles, resulting in the full encapsulation of MnO particles in the PC matrix. More significantly, the PC matrix provides enough void space to buffer the volume change, which fully wraps the MnO without crack or fracture during repeated cycling. As a result, MnO/PC shows high charge storage capability, extraordinary rate performance, and long-term cycling stability at the same time. Thus MnO/PC exhibits high delithiation capacities of 768mAh g~(–1) at 0.1Ag~(–1) and 487mAh g~(–1) at a high rate of 0.7Ag~(–1), combined with an unattenuated cycling performance after 500 cycles at 0.3Ag~(–1). More significantly, MnO/PC demonstrates a well-matched performance with the capacitive activated carbon electrode in a Li-ion capacitor (LIC) full cell. LIC demonstrates a high specific energy of 153.6Wh kg~(–1) at 210Wkg~(–1), combined with a specific energy of 71.8Wh kg~(–1) at a high specific power of 63.0kWkg~(–1).
Recent advances in materials and device technologies for aqueous hybrid supercapacitors

Aqueous hybrid supercapacitors (AHSCs) offer potential safety and eco-friendliness compared with conventional electrochemical energy storage devices that use toxic and flammable organic electrolytes. They can serve as the bridge between aqueous batteries and aqueous supercapacitors by combining the advantages of high energy of the battery electrode and high power as well as long lifespan of the capacitive electrode. Over the past few decades, extensive research efforts have been devoted to developing advanced materials and fascinating device architectures for AHSCs. However, further development related to the compatibilities between the battery-type electrode and capacitive electrode remains stagnant mainly due to discrepancy encountered in terms of reaction kinetics and capacity. This review focuses on the recent progress made in the field of AHSCs via elucidating the main concepts on the design of battery and capacitive electrodes and emerging electrolytes. In particular, ingenious AHSCs that possess either better flexibility toward materials selection or better device functionality such as those with “dual-ion” energy storage mechanism and non-polarity feature are also discussed. Recent advances and unresolved issues in multivalent ion hybrid devices (in particular, zinc-ion AHSCs) are further outlined. Finally, future research directions and challenges for AHSCs are presented, which are anticipated to deliver higher energy and demonstrate greater multifunctionalities for more breakthrough technology applications.
Effect of graphitization degree of fuel cell gas diffusion layers on their heat management: Modeling and experiments

Serving as gas diffusion layers (GDLs), the thermal conductivity of carbon paper (CP) plays a significant role in the heat transfer management in fuel cells. In the present study, the effect of graphitization degree of CP on its throughplane thermal conductivity and in-plane thermal conductivity is investigated. The relationship between heat treatment temperatures (1800, 2000, 2200, 2400 and 2500 ℃) and graphitization degree is also investigated by SEM, XRD and Raman measurements. A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix carbon. The experimental and simulation results are compared. The results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and inplane thermal conductivity.
Effective recovery of chalcopyrite at low temperatures using modified ester collector

The effect of a modified ester collector named as BL on the flotation of chalcopyrite at low temperatures was investigated by micro-flotation tests, contact angle measurements, adsorption experiments, laser particle size analysis, cryogenic transmission electron microscopy (Cryo-TEM) and Fourier transform infrared (FTIR) analyses. Micro-flotation tests proved that the collecting ability of BL for chalcopyrite was significantly better than that of N,N-diethyl dithiocarbamate propiononitrile ester (ester-105) at low temperatures. Combined with laser particle size, Cryo-TEM and FTIR analyses, it was found that the particle size of BL in water was smaller than that of ester-105, and the distributed density of BL was higher than that of ester-105 at low temperatures, indicating that BL dispersed well at low temperatures. Therefore, BL was more easily adsorbed on the chalcopyrite surface and improved the surface hydrophobic degree of chalcopyrite, which were also confirmed by the contact angle measurements and adsorption experiments.
Effect of ECAP processing on distribution of second phase particles, hardness and electrical conductivity of Cu-0.81Cr-0.07Zr alloy

The effect of equal-channel angular pressing (ECAP) processing at room temperature and 300 °C on the distribution of the second phase particles and its influence on hardness and electrical conductivity of the commercial Cu-0.81Cr-0.07Zr alloy were investigated. Microstructural characterization indicated that the area fraction of coarse Cr-rich particles decreased after ECAP processing. This reduction was attributed to the Cr dissolution induced by plastic deformation. The electrical conductivity of the alloy decreased by 12% after 4 ECAP passes at room temperature due to the increase of electrons scattering caused by higher Cr content in solid solution and higher density of defects in the matrix. These results were supported by the reduction of the Cu lattice parameter and by the exothermic reactions, during differential scanning calorimetry (DSC) analysis, observed only in the samples subjected to ECAP processing. Aging heat treatment after ECAP processing promoted an additional hardening effect and the complete recuperation of the electrical conductivity, caused by the re-precipitation of the partially dissolved particles. The better combination of hardness (191 HV) and electrical conductivity (83.5%(IACS)) was obtained after 4 ECAP passes at room temperature and subsequent aging at 380 °C for 1 h.
Deep metallogenic mechanism in southeastern China based on receiver function data

Crustal deformation and deep metallogenic mechanisms in southeastern (SE) China are still debated. In this study, we applied the receiver function method to measure crustal thickness and Poisson’s ratio for crustal rock using teleseismic data recorded at 207 seismic stations from China Earthquake Administration Network. The results showed that crustal thickness varied from ~27 km in the eastern part to ~43 km in the western part of the study area, with an average crustal thickness of 31 km. The crust is thick in the west and thin in the east. The observed Poisson’s ratio for crustal rock was relatively high in the southern Cathaysia Block (CB), with an average of 0.295, while in the Qinling— Dabie terrane, it was relatively low, with an average of 0.257. In the middle of the Yangtze craton and central east of the CB, Poisson’s ratio for crustal rock varied from 0.257 to 0.286. By comparing Poisson’s ratio of the intrusive deposits with that of igneous rocks in volcanic complexes, we deduced that the metallic mineral system might be associated with orogenic and hydrothermal deposits. These results indicated that multistage magma and mineralization in the study area might be attributed to the tectonic-magma-thermal event. The high Poisson’s ratio for crustal rock in the southeastern margin of the CB and northeastern Upper Yangtze Craton might be related to Mesozoic lower crustal mafic partial melt, which provides an important environment for various magmatic intrusions and metallogenies.
利用同震和震后位移数据联合反演2011年日本M_w9.0地震同震断层滑动

基于黏弹性球体位错理论,联合陆地和海底同震GPS数据以及日本本岛330个陆地GPS站点5~10年的震后数据,反演了日本M_w9.0地震的断层滑动模型,提升了断层滑动分布在细节上的合理性。首先,基于日本本岛330个陆地GPS站点震前2年和震后10年的连续观测数据,获取了日本M_w9.0地震震后5~10年的年平均位移,该时段的位移几乎完全由地幔黏弹性松弛效应引起;接着,利用黏弹性球体位错理论对震后5~10年的位移进行反复拟合,确定了日本M_w9.0地震震源及周边地区的地幔黏滞性系数最优解(9.0×1018 Pa · s)。然后,联合同震和震后位移数据,引入黏弹性位错格林函数,反演了2011年日本M_w9.0地震的断层滑动分布。结果表明,该地震同震破裂的最大值达到了62.72 m.同震滑动的总地震矩为4.48× 1022 Nm,相应的矩震级为M_w9.03。由于黏弹性松弛效应引起的震后位移中包含了同震破裂的信息,基于黏弹性球体地震位错理论,联合同震和震后位移数据反演断层同震破裂,有效提高了日本M_w9.0地震断层滑动分布的可靠性。最后,本文提出的反演方法为同震观测结果缺乏的大地震震后科考提供了理论支撑:在大地震发生之后,即使在同震期间没有足够的观测数据,也可以在震后通过对震源区的加密观测积累的震后数据,使用本文提出的反演方法优化同震断层滑动模型。
2020年云南巧家M5.0地震震源机制解与震源区应力场研究

基于国家测震台网数据中心提供的波形资料,采用gCAP方法反演2020年5月18日云南巧家M5.0地震及研究区域51次地震震源机制解,并收集研究区域震源机制解50个。采用网格捜索法反演区域构造应力场,并对研究区域采用不同划分进行应力场反演。获得以下结论:①主震震源机制解节面I的走向、倾角和滑动角分别为175°、67°和- 19°,节面II的走向、倾角和滑动角分别为273°、73°和- 156°,矩震级为4.97,矩心深度为8.8 km。表明主震属于兼具逆冲分量的走滑型地震;②震后区域应力场主压应力轴方位为NWW,倾角接近水平,主张应力轴方位为NNE,倾角接近水平,属于走滑型应力状态,与周边地质构造运动状态相吻合;③对研究区域采用不同划分所得应力场结果相差不大,表明该区域应力场比较稳定,受深大断裂带和震源机制解类型影响较小。