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β-Phase Crystallization of Poly(vinylidene fluoride) in Poly(vinylidene fluoride)/Poly(ethyl methacrylate) Blends

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Chinese Journal of Polymer Science 2019年第1期37卷 94-100,4-7页

作者： Zi-Jie Huang Jing Jiang Gi Xue dong-Shan zhou Department of Polymer Science and Engineering School of Chemistry and Chemical Engineering Key Laboratory of High Performance Polymer Materials and Technology and The State Key Laboratory of Coordination Chemistry Nanjing University School of Physical Science and Technology Xinjiang Key Laboratory and Phase Transitions and Microstructures in Condensed Matters Yili Normal University

The nature of the crystalline phase of poly(vinylidene fluoride)(PVDF) in compatible blends with poly(ethyl methacrylate)(PEMA) was investigated by using X-ray diffraction(XRD), infrared microscopy(IR) and differential scanning calorimetry(DSC). The βphase of PVDF was observed after quenching from the melt and further annealing above the glass transition temperature over a composition range. The PVDF/PEMA blend with weight ratio of 3:2 has formed higher content of PVDF β crystals than others. By taking advantage of fast cooling rate of ultrafast differential scanning calorimeter(UFDSC), the quenching process of blends was modeled and tested simultaneously, and the melting behavior of β crystals in all blends was investigated. Three types of crystallization behavior of βphase PVDF in blends were found after quenching-annealing at different temperatures.

关键词： β-Crystal of PVDF Mesophase PVDF/PEMA blend Ultra-fast scanning calorimetry

“霍山地震窗”小震检测及其在地震预测中的应用

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地震 2024年第2期44卷 135-146页

作者：汪小厉周冬瑞李玲利张炳柳建李军辉安徽省地震局安徽合肥230031 蒙城地球物理国家野外科学观测研究站安徽蒙城233500

安徽霍山地震窗作为地震预测效能评价较好的指标(R>R_(0),R=0.26,R_(0)=0.204),对安徽及邻区震情形势研判具有重要作用。历史震例总结显示,当霍山地震窗3个月内M_(L)≥1.0地震累计频次超过40次时,出现开窗异常,该异常对未来一年内地震... 详细信息

安徽霍山地震窗作为地震预测效能评价较好的指标(R>R_(0),R=0.26,R_(0)=0.204),对安徽及邻区震情形势研判具有重要作用。历史震例总结显示,当霍山地震窗3个月内M_(L)≥1.0地震累计频次超过40次时,出现开窗异常,该异常对未来一年内地震窗中心点周边100 km范围内的M_(S)3.5地震、 250 km范围内的M_(S)4.0地震、 500 km范围内的M_(S)5.0地震、 500 km以外的M_(S)6.0及以上地震具有预测意义。自1970年以来,使用该指标漏报地震7次,其中,在2018年河南固始M_(S)3.6地震与2019年湖北应城M_(S)4.9地震发震前,霍山地震窗区域内小震活动增强,并且3个月内ML≥1.0地震累计频次接近异常阈值。霍山地震窗区域内小震密集,可能存在小震波形相互交叠干扰而无法被识别的情况。本研究利用匹配定位(M&L)法对2017年4月与2019年4—9月霍山地震窗区域的小震进行检测,以获取更为完整的地震目录,并重新分析了霍山地震窗的预报效能。研究结果表明,基于小震检测后更为完整的地震目录,霍山地震窗开窗异常未漏报2018年河南固始M_(S)3.6地震与2019年湖北应城M_(S)4.9地震,计算得到R>R_(0)(R=0.30,R_(0)=0.196),该项异常对应地震优势发震时间为开窗后9个月内。本研究说明M&L法在霍山地震窗小震检测中具有实用性,可在后续霍山地震窗跟踪中作为一种常规的处理方法,以期获取更为完整的小震目录,为震情跟踪研判提供数据支撑。

关键词：霍山地震窗小震检测累计频次地震预测

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联邦忘却学习研究综述

计算机学报 2024年第2期47卷 396-422页

作者：王鹏飞魏宗正周东生宋威肖蕴明孙庚于硕张强大连理工大学计算机科学与技术学院大连理工大学社会计算与认知智能教育部重点实验室大连大学先进设计与智能计算教育部重点实验室美国西北大学计算机科学系吉林大学计算机科学与技术学院吉林大学符号计算与知识工程教育部重点实验室

数据已经成为与土地、劳动力、资本、技术等并列的重要生产要素之一.利用数据分析挖掘数据的潜在价值，有助于推动产业创新、技术升级和区域经济发展.然而，在数据使用过程中，隐私泄露等风险限制了数据的流通和共享.因此，如何在数据... 详细信息

数据已经成为与土地、劳动力、资本、技术等并列的重要生产要素之一.利用数据分析挖掘数据的潜在价值，有助于推动产业创新、技术升级和区域经济发展.然而，在数据使用过程中，隐私泄露等风险限制了数据的流通和共享.因此，如何在数据流通和共享过程中保护数据隐私已成为研究热点.联邦忘却学习（Federated Unlearning）撤销用户数据对联邦学习模型的训练更新，可以进一步保护联邦学习用户的数据安全.本文综述了联邦忘却学习的研究工作，首先简要阐述了联邦学习架构，并引出忘却学习和联邦忘却学习的概念和定义;其次，根据修正对象的不同将联邦忘却学习算法分为面向全局模型和面向局部模型两类，并详细分析各类算法的实现细节以及优缺点;然后，本文还详述联邦忘却学习中常用评价指标，将评价指标划分为模型表现指标、遗忘效果指标和隐私保护指标三类，并分析不同类型评价指标的优缺点;最后，本文对联邦忘却学习未来的研究方向进行展望.

关键词：联邦学习联邦忘却学习数字经济隐私保护边缘智能

抗N-甲基-D-天冬氨酸受体脑炎急性期严重程度及短期预后影响因素分析

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中国现代神经疾病杂志 2024年第5期24卷 331-339页

作者：叶睿曦蔡林君孔雪莹李劲梅周东洪桢四川大学华西医院神经内科成都610041

目的探究抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎患者急性期严重程度及短期预后的影响因素。方法纳入2020年1月至2023年7月四川大学华西医院收治的60例抗NMDAR脑炎患者,根据急性期改良Rankin量表(mRS)评分分为轻症组(mRS≤3分,25例)和重... 详细信息

目的探究抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎患者急性期严重程度及短期预后的影响因素。方法纳入2020年1月至2023年7月四川大学华西医院收治的60例抗NMDAR脑炎患者,根据急性期改良Rankin量表(mRS)评分分为轻症组(mRS≤3分,25例)和重症组(mRS> 3分,35例),根据我院治疗1个月后mRS评分分为短期预后良好组(mRS≤3分,32例)和短期预后不良组(mRS> 3分,28例),采用单因素和多因素Logistic回归分析筛查抗NMDAR脑炎患者急性期病情严重及短期预后不良的危险因素。结果存在意识障碍(OR=8.975,95%CI:2.048~39.327;P=0.004)及高中性粒细胞百分比/白蛋白比值(NPAR;OR=5.004,95%CI:1.138~22.011,P=0.033)是抗NMDAR脑炎急性期病情严重的危险因素,高血清IgE水平是其急性期病情较轻的保护因素(OR=0.994,95%CI:0.989~0.999;P=0.026);女性(OR=4.380,95%CI:1.205~15.929;P=0.025)、存在意识障碍(OR=5.493,95%CI:1.535~19.657;P=0.009)及高NPAR(OR=2.949,95%CI:1.010~8.612;P=0.048)是抗NMDAR脑炎患者短期预后不良的危险因素。结论存在意识障碍、低血清IgE水平及高NPAR是抗NMDAR脑炎患者急性期病情严重的危险因素,女性、存在意识障碍及高NPAR是其短期预后不良的危险因素。NPAR是潜在的评估抗NMDAR脑炎患者急性期严重程度及预测其短期预后的生物学指标。

关键词：抗N-甲基-D-门冬氨酸受体脑炎健康状况指标预后危险因素 Logistic模型

Influence of Chain Architectures on Crystallization Behaviors of PLLA Block in PEG/PLLA Block Copolymers

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Chinese Journal of Polymer Science 2019年第3期37卷 258-267页

作者： Sheng Xiang dong-dong zhou Li-dong Feng Xin-Chao Bian Gao Li Xue-Si Chen Tian-Chang Wang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Sciences Jilin Biomedical Polymers Engineering Laboratory University of Chinese Academy of Sciences South China Advanced Institute for Soft Matter Science and Technology South China University of Technology

The effect of the architecture of poly(ethylene glycol)/poly(L-lactide)(PEG/PLLA) block copolymers on the non-isothermal crystallization behaviors of PLLA blocks was investigated by differential scanning calorimetry(DSC) and wide angle X-ray diffraction(WAXD). 1-Arm MPEG-b-PLLA and 4-arm PEG-b-PLLA(4PEG-b-PLLA) were synthesized by the ring-opening polymerization of Llactide in the presence of poly(ethylene glycol) methyl ether(MPEG) and 4-arm poly(ethylene glycol)(4PEG). 4-Arm PLLA-b-MPEG(4PLLA-b-PEG) was synthesized by coupling 4-arm PLLA and MPEG. The WAXD results indicated that the crystalline structure of PLLA blocks did not alter due to the different chain architectures. The average values of Avrami index(ˉn) were all above 4, which indicated that the nucleation mechanism of PLLA blocks was heterogeneous nucleation, regardless of the architectures. The overall crystallization rates were decreased markedly as following: MPEG-b-PLLA > 4PEG-b-PLLA > 4PLLA-b-PEG, ascribed to the different confinement by PEG blocks and to the steric hindrance of chain architectures. Therefore, the crystallization of PLLA blocks became more difficult and the crystallization activation energy of the PLLA blocks increased due to the confinement of chain architectures.

关键词： Poly(L-lactide) Poly(ethylene glycol)/poly(L-lactide)block copolymer Non-isothermal crystallization Chain architecture

Analysis of the Microstructure and Macroscopic Fluid-Dynamics Behavior of Soft Soil after Seepage Consolidation

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Fluid Dynamics & Materials Processing 2022年第2期18卷 285-302页

作者： Fang Jin dong zhou Liying Zhu Institute of Civil Engineering Huanghe S&T UniversityZhengzhou450063China

The purpose is to study the microstructure and macroscopic fluid-dynamic behavior of soft soil after it has been subjected to a seepage consolidation ***,the microscopic pore structure of soft clay is quantitatively studied by a scanning electron microscope ***,the average contact area rate of soil particles is obtained employing statistical analysis applied to microscopic images of soft soil,and the macroscopic porosity of soft clay is determined through an indoor geotechnical ***,mathematical relationships are introduced by fitting the results of the *** results show that the unmodified empirical equation for the permeability coefficient of coarse-grained soil produces large errors in calculations related to cohesive *** contrast,the permeability coefficient calculated by the empirical equation modified by the average contact area ratio theory is in good agreement with the measured average value of the indoor test.

关键词： Seepage consolidation soil structure microstructure macro-mechanics

Leaching of Copper and Zinc in a Garden Soil Receiving Poultry and Livestock Manures from Intensive Farming

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Pedosphere 2008年第1期18卷 69-76页

作者： HAO Xiu-Zhen zhou dong-Mei CHEN Huai-Man dong Yuan-Hua State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) Graduate School of the Chinese Academy of Sciences Beijing 100049 (China)

The leaching characteristics of a garden soil may be greatly affected by application of poultry and livestock manures from intensive farming. Packed soil columns of a garden soil （CK） and the soils after respectively receiving 2% pig manure （PM）, chicken manure （CM）, and commercial organic manure （OM） were leached with 0.05 mol L^-1 Ca（NO3）2 and 0.01 mol L 1 EDTA solutions. The leachate EC （electric conductivity） values gradually increased at the beginning and then reached a stable value when the soil columns were leached with 0.05 mol L^-1 Ca（NO3）2 solution. The leachate EC values showed a peak-shape when leached with 0.01 mol L^-1 EDTA solution. In all the soil columns, the pH values of the leachates decreased with increase of displacement volumes when the Ca（NO3）2 solution was used. The total amounts of Cu and Zn eluted from the four soil columns were significantly correlated with the extracted soil Cu and Zn concentrations by 1.0 mol L^-1 NH4NO3, but were not correlated with the leachate dissolved organic carbon （DOC） contents. The Zn concentration in the leachate of the PM-treated soil column with 0.05 mol L^-1 Ca（NO3）2 solution was above the Quality Standard III for Ground Water of China （GB/T 14848-93, Zn 〈 1.0 mg L^-1）. When compared with 0.05 mol L^-1 Ca（NO3）2, the EDTA solution significantly accelerated Cu and Zn elutions in the manure-treated columns. This suggested that applying poultry and livestock manures from intensive farming to farmland might pose a threat to the groundwater quality.

关键词： copper garden soil leaching manures zinc

Study of （2＋1）-Dimensional Higher-Order Broer-Kaup System

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Communications in Theoretical Physics 2007年第3期47卷 403-408页

作者： WANG Ling LIU Xi-Qiang dong Zhong-zhou School of Mathematical Sciences Liaocheng University Liaocheng 252059 China Department of Mathematics Chizhou Teacher＇s College Chizhou 247000 China

Painleve property and infinite symmetries of the （2＋1）-dimensional higher-order Broer-Kaup （HBK） system are studied in this paper. Using the modified direct method, we derive the theorem of general symmetry *** to （2＋1）-dimensional HBK system. Based on our theorem, some new forms of solutions are obtained. We also find infinite number of conservation laws of the （2＋1）-dimensional HBK system.

关键词： (2+1)-dimensional HBK system Painleve property symmetries exact solution conservation laws

Zinc phosphate dissolution by bacteria isolated from an oligotrophic karst cave in central China

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Frontiers of Earth Science 2013年第3期7卷 375-383页

作者： Hongmei WANG Qiang dong Jianping zhou Xing XIANG State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China

Biogeochemical processes are fundamental to sustain the ecosystem in subsurface caves, but to date they are still far from well understood. To investigate micro-bially mediated phosphorus and zinc cycles, we isolated three bacterial strains from the dripping water in Heshang cave, central China, identified as Exiguobacterium aurantiacum E11, Pseudomonas fluorescens P35, and Pseu- domonas poae P41, respectively. Microbial capabilities in the dissolution of phosphorus-containing minerals were tested with zinc phosphate （Zn3（PO4）2） in batch culture at 30~C. A spectrophotometer, atomic absorption spectrum, and scanning electronic microscopy were used to measure the microbial growth, soluble Zn（II） concentration, and to observe the morphology of Zn3（PO4）2 before and after microbial dissolution. P. fluorescens and P. poae, the well- known phosphorus solubilizing bacteria （PSB）, are observed to solubilize Zn3（PO4）2 with an efficiency of 16.7% and 17.6%, respectively. To our knowledge, E. aurantiacum is firstly reported in this study to dissolve phosphorous-containing minerals with a higher efficiency of 39.7%, expanding our understanding about the ubiquitous occurrence of PSB in natural environments. Aqueous Zn（II） concentration positively correlates with H＋ activity, confirming the presence of acidification mechanisms widely exploited by PSB. Few itching pits were observed on the surface of Zn3（PO4）2 after microbial dissolution, inferring that microbial dissolution is not always associated with the direct contact with minerals. Even though the soluble Zn（II） concentration reached up to 370 mg/L in the system inoculated with E. aurantiacum Ell, inhibition of microbial growth was not detected by spectrophotometer. Our laboratory data revealed the importance of microbially-mediated P and Zn cycles in the subsurface ecosystem.

关键词： karst cave phosphate solubilizing bacteria (PSB) zinc toxicity biogeochemical process subsurface biosphere