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Annealing Induced Microstructure and Mechanical Property Changes of Impact Resistant Polypropylene Copolymer

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Chinese Journal of Polymer Science 2015年第9期33卷 1211-1211,1212-1224页

作者： jing-wei chen Jian Dai jing-hui Yang Nan Zhang Ting Huang 王勇 Chao-liang Zhang Key Laboratory of Advanced Technologies of Materials (Ministry of Education) School of Materials Science & Engineering Southwest Jiaotong University State Key Laboratory of Oral Diseases Sichuan University

The effects of annealing on microstructure and mechanical properties of an impact resistant polypropylene copolymer （IPC） were investigated. Different annealing temperatures ranging from 80 ℃ to 160 ℃ were selected. The phase reorganization of IPC during annealing process was studied through morphological characterization technologies, including scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The crystalline structure changes in the IPC sample, including the iPP matrix and PE component, were investigated using wide angle X-ray diffraction （WAXD） and differential scanning calorimetry （DSC）. Dynamic mechanical analysis （DMA） was used to analyze the relaxation extent of 1PC before and after annealing. The results showed that annealing induced phase reorganization in IPC and the degree of phase reorganization depended on annealing temperature. The annealed IPC samples exhibited largely increased crystallinity compared with the unannealed one. Intensified damping peak with increased molecular chain mobility was achieved for the annealed IPC samples. At an appropriate annealing tem. perature （140 ℃）, largely enhanced impact strength was achieved for the annealed IPC sample. The toughening mechanisms were analyzed based on the phase reorganization and relaxation behavior.

关键词： Impact resistant polypropylene copolymer Annealing Microstructure Mechanical properties.

Carbon cathode with heteroatom doping and ultrahigh surface area enabling enhanced capacitive behavior for potassium-ion hybrid capacitors

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Rare Metals 2024年第5期43卷 2136-2149页

作者： Yan Xiong Ya-Fei Zhang Chun-Liu Zhu Lei Yang Huan-Yu Liang jing Shi jing-wei chen wei-QianTian Shuai Liu Zhi Li jing-Yi Wu Huan-Lei Wang School of Materials Science and Engineering Ocean University of ChinaQingdao 266100China Department of Chemical and Materials Engineering University of AlbertaEdmontonAB T6G 2V4Canada

Potassium-ion hybrid capacitors(PIHCs)are widely regarded as highly promising energy storage devices,due to their exceptional energy density,impressive power density,and abundant potassium ***,restricted by the inherent capacitive storage mechanism,the carbon cathodes possess a much lower specific capacity than battery-type ***,designing high-performance carbon cathodes is extremely urgent for the development of ***,N,O codoped porous carbon(NOPC)was fabricated through the NaCl hard template method and combined KOH/melamine chemical activation technique,displaying the characteristics of abundant N/O content(4.7 at%/16.9 at%),ultrahigh specific surface area(3092 m^(2)g^(-1))and hierarchical pore *** designed NOPC cathode delivers a high specific capacity(164.4 mAh.g^(-1)at 0.05 A.g^(-1))and superior cyclability(95.1%retention ratio at 2 A·g^(-1)over 2500 cycles).Notably,the adjustable ratio of micropores to mesopores facilitates the achievement of the optimal bal-ance between capacity and rate ***,the pseudocapacitance can be further augmented through the incorporation of N/O functional *** expected,the graphite//NOPC based PIHC possesses a high energy density of 113 Wh·kg-at 747 W·kg^(-1)and excellent capacity retention of 84.4% fter 400 cycles at 1.0 A·g^(-1).This work introduces a novel strategy for designing carbon cathodes that enhances the electrochemical performance of PIHCs.

关键词： Template method N/O co-doping High specific surface area Carbon cathode Potassium-ion capacitors

Evaluation on a 400 Wh kg^(-1)lithium-sulfur pouch cell

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Journal of Energy Chemistry 2022年第3期31卷 24-29,I0002页

作者： Ge Ye Meng Zhao Li-Peng Hou wei-jing chen Xue-Qiang Zhang Bo-Quan Li Jia-Qi Huang School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing 100083China

Lithium–sulfur(Li–S)batteries are highly regarded as next-generation energy storage devices due to their ultrahigh theoretical energy density of 2600 Wh kg^(−1).However,practical high-energy-density Li–S pouch cells suffer from limited cycling lifespan with rapid loss of active ***,systematic evaluation on a 400 Wh kg^(−1)Li–S pouch cell is carried out to reveal the working and failure mechanism of Li–S batteries under practical *** morphology,spatial distribution and species analysis of sulfur,and capacity retention of electrodes are respectively evaluated after the first cycle of discharge or *** lithium polysulfides are found in electrolyte even at the end of discharge or charge,where the sulfur redox reactions are reversible with high capacity ***,severe morphology change is identified on lithium metal anode,yet there remains substantial active lithium to support the following *** work not only demonstrates unique behaviors of Li–S batteries under practical conditions,which is essential for promoting the progress of Li–S pouch cells,but also affords a systematic evaluation methodology to guide further investigation on high-energy-density Li–S batteries.

关键词： Lithium-sulfur batteries Pouch cell High energy density Failure analysis

Large-scale doping-engineering enables boron/nitrogen dual-doped porous carbon for high-performance zinc ion capacitors

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Rare Metals 2022年第7期41卷 2505-2516页

作者： Chun-Liu Zhu Huan-Lei Wang Wen-Jie Fan Sheng-Li Zhai Xing-Jie Wang jing Shi Ming-Hua Huang Shuai Liu Zhi Li jing-wei chen School of Materials Science and Engineering Ocean University of ChinaQingdao 266100China Department of Chemical and Materials Engineering University of AlbertaEdmonton AB T6G 2V4Canada

Zinc ion capacitors(ZICs)have drawn increas-ing interest in energy storage devices because of their economic benefits,high safety,and long cycling ***,the lack of high-performance cathodes for ZICs remains a key ***,we fabricated B,N co-doped porous carbon(BN-C)via a salt template *** aqueous ZICs assembled from BN-C cathode delivered a high capacity of 190.2 mAh·g^(-1)and a remarkable energy density of 105.1 Wh·kg^(-1).Moreover,systematic charac-terization verifies that B/N dual-doping promotes the physical adsorption/desorption kinetics of anion and the chemical absorption/desorption kinetics of Zn^(2+),thus improving the electrochemical performance of *** addition,the quasi-solid-state pouch-type battery exhibited excellent electrochemical durability and mechanical flexi-bility,demonstrating its vast application potential as a flexible power ***,this research not only pre-sents a reasonable approach to the large-scale production of carbon cathode materials with excellent electrochemical performance but also strengthens the essential recognition of the charge storage mechanism of heteroatoms-doped carbon materials.

关键词： Heteroatom doping Porous carbon Zinc ion capacitor High energy density Charge storage mechanism

Assessment Method for the Reliability of Power Transformer Based on Fault-tree Analysis

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高电压技术 2009年第3期35卷 514-520页

作者： WANG You-yuan ZHOU jing-jing chen wei-gen DU Lin chen Ren-gang State Key Laboratory of Power Transmission Equipment & System Security and New Technology Department of High Voltage and Insulation Engineering College of Electrical Engineering Chongqing University Chongqing 400030 China

Accurate assessment of system reliability with limited or insufficient statistical data is difficult. At present, to assess the reliability of the transformers primarily depend on the statistics data, and the result of the assessment does not accurately reflect the reliability of a transformer. Fault tree is a powerful tool for depicting the logical relationships between the faults system. However, for a sophisticated reliability system, like power transformer, fault analysis is hard or infeasible because of the complexities of the equipment configuration and its faults. This paper presents a method which overcomes the drawbacks of traditional fault-tree analysis (FTA) by using FTA based on fault probability and equivalent calculation of each failure mode. Based on the further analysis of typical failure modes and influences of power transformer, the fault-tree of transformer is set up by using FTA techniques and the assessment method for the reliability of transformer is put forward, combined with the index of the importance and the method of improved analytic hierarchy process(IAHP). The assessment examples show the method can deduct the failure modes of transformer clearly, meanwhile, find out the weaknesses in time during the operation and get better assessment results. The method is helpful for the reliability analysis of a sophisticated system.

关键词：电力变压器供电系统故障树分析失效模式

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Efficacy and safety of non-pharmacological interventions for irritable bowel syndrome in adults

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World Journal of Gastroenterology 2020年第41期26卷 6488-6509页

作者： Yun-Kai Dai Yun-Bo Wu Ru-Liu Li wei-jing chen Chun-Zhi Tang Li-Ming Lu Ling Hu Institute of Gastroenterology Science and Technology Innovation CenterGuangzhou University of Chinese MedicineGuangzhou 510405Guangdong ProvinceChina Medical College of Acu-Moxi and Rehabilitation Guangzhou University of Chinese MedicineGuangzhou 510000Guangdong ProvinceChina

BACKGROUND Although nonpharmacological interventions(NPI) for irritable bowel syndrome(IBS) have been applied clinically, their relative efficacy and safety are poorly *** To compare and rank different NPI in the treatment of *** Five electronic databases were searched from their inception to January 12, 2020. Data of included publications were analyzed using network meta-analysis(NMA). Quality of endpoints were assessed by tools of the Cochrane Handbook and the GRADEpro software. Pooled relative risk or standardized mean difference with their corresponding 95% confidence intervals were used for statistical analysis. Surface under the cumulative ranking curve(SUCRA) probability value was conducted to rank the examined interventions. Sensitivity analysis was performed to verify the robustness of results and test the source of *** Forty randomized controlled trials with 4196 participants were included in this NMA. Compared with routine pharmacotherapies and placebo, acupuncture and cognitive behavioral therapy(CBT) had better efficacy in relieving IBS symptoms. Based on the SUCRA values, acupuncture ranked first in improving overall clinical efficacy and avoiding adverse effects. CBT ranked first in lowering the scores of IBS symptom severity scale, self-rating anxiety scale and self-rating depression *** This study confirmed the efficacy and safety of NPI for improving IBS symptoms, which to some extent recommended several interventions for clinical practice.

关键词： Nonpharmacological interventions Irritable bowel syndrome Network meta-analysis Randomized controlled trials Adults Clinical practice

A Mixed Ether Electrolyte for Lithium Metal Anode Protection in Working Lithium-Sulfur Batteries

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Energy & Environmental Materials 2020年第2期3卷 160-165页

作者： wei-jing chen Chang-Xin Zhao Bo-Quan Li Qi Jin Xue-Qiang Zhang Tong-Qi Yuan Xitian Zhang Zhehui Jin Stefan Kaskel Qiang Zhang Beijing Advanced Innovation Center for Tree Breeding by Molecular Design Beijing Forestry UniversityBeijing 100083China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025HeilongjiangChina School of Mining and Petroleum Engineering Department of Civil and Environmental EngineeringUniversity of AlbertaEdmonton AB T6G 1H9Canada Department of Inorganic Chemistry Dresden University of TechnologyBergstrasse 66Dresden 01069Germany Fraunhofer Institute for Material and Beam Technology Winterbergstrafie 28Dresden 01277Germany

Lithium-sulfur(Li-S) battery is considered as a promising energy storage system to realize high energy ***,unstable lithium metal anode emerges as the bottleneck toward practical applications,especially with limited anode excess required in a working full *** this contribution,a mixed diisopropyl ether-based(mixed-DIPE) electrolyte was proposed to effectively protect lithium metal anode in Li-S batteries with sulfurized polyacrylonitrile(SPAN) *** mixed-DIPE electrolyte improves the compatibility to lithium metal and suppresses the dissolution of lithium polysulfides,rendering significantly improved cycling ***,Li | Cu half-cells with the mixed-DIPE electrolyte cycled stably for 120 cycles,which is nearly five times longer than that with routine carbonate-based ***,the mixedDIPE electrolyte contributed to a doubled life span of 156 cycles at 0.5 C in Li | SPAN full cells with ultrathin 50 μm Li metal anodes compared with the routine *** contribution affords an effective electrolyte formula for Li metal anode protection and is expected to propel the practical applications of high-energy-density Li-S batteries.

关键词： full cells lithium anode protection lithium-sulfur batteries mixed diisopropyl ether-based electrolyte sulfurized polyacrylonitrile cathode

基于局域重加权的智能配电网多源分布式协调优化算法

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电力系统自动化 2016年第21期40卷 146-153页

作者：李静沈忱韦巍戴文战浙江工商大学信息与电子工程学院浙江省杭州市310018 浙江大学电气工程学院浙江省杭州市310027

为了实现大量间歇式新能源的充分消纳,提出了一种含高密度分布式电源的智能配电网有功和无功资源的区域分布式协调优化算法。该方法首先建立多时间段线性锥最优潮流模型,其次利用辅助变量增广Lagrangian乘子法分裂节点以实现各区域子系... 详细信息

为了实现大量间歇式新能源的充分消纳,提出了一种含高密度分布式电源的智能配电网有功和无功资源的区域分布式协调优化算法。该方法首先建立多时间段线性锥最优潮流模型,其次利用辅助变量增广Lagrangian乘子法分裂节点以实现各区域子系统潮流的空间解耦,最后提出了基于局域重加权Lagrangian的分布式优化算法,实施全网有功和无功资源的协调优化。算法上,各区域子系统无需全局协调可独立并行迭代优化,通过邻域子系统间少量的部分信息交互达到全网优化。该算法降低了通信复杂度,最大限度地保留了各子系统的独立性。算例验证结果表明,所提算法计算效率较高且收敛特性良好。

关键词：分布式电源智能配电网分布式优化最优潮流线性锥规划

Sweet sorghum for phytoremediation and bioethanol production

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Journal of Leather Science and Engineering 2021年第1期3卷 360-382页

作者： Ming‑Zhao Xiao Qian Sun Si Hong wei‑jing chen Bo Pang Zhi‑Yan Du Wen‑Bin Yang Zhuohua Sun Tong‑Qi Yuan Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing 100083China Yuan Longping High‑Tech Agriculture Co. LtdChangsha 410000China Inner Mongolia Lignicell Bio‑Refining Co. LtdBaotou 014000China

As an energy crop,sweet sorghum(Sorghum bicolor(L.)Moench)receives increasing attention for phytoremedia‑tion and biofuels production due to its good stress tolerance and high biomass with low input *** sorghum possesses wide adaptability,which also has high tolerances to poor soil conditions and *** rapid growth with the large storage of fermentable saccharides in the stalks offers considerable scope for bioethanol pro‑***,sweet sorghum has heavy metal tolerance and the ability to remove cadmium(Cd)in ***,sweet sorghum has great potential to build a sustainable phytoremediation system for Cd‑polluted soil remediation and simultaneous ethanol *** implement this strategy,further efforts are in demand for sweet sorghum in terms of screening superior varieties,improving phytoremediation capacity,and efficient bioetha‑nol *** this review,current research advances of sweet sorghum including agronomic requirements,phytoremediation of Cd pollution,bioethanol production,and breeding are ***,crucial problems for future utilization of sweet sorghum stalks after phytoremediation are combed.

关键词： Sweet sorghum Bioenergy crop Phytoremediation Cadmium,Bioethanol Pretreatment