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Effect of VO4^3- Substitution on the Electrochemical Properties of a LiSn2（PO4）3 Anode Material

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Chemical Research in Chinese Universities 2018年第3期34卷 444-450页

作者： FENG Xiaojing HE Jun WANG Xiaoran WANG Gongkai WANG Xin peng huifen School of Material Science & Engineering Hebei University of Technology Tianjin 300130 P. R. China Research Institute for Energy Equipment Materials Hebei University of Technology Tianjin 300130 P. R. China Tianjin Key Laboratory of Materials Laminating Fabrication & Interface Control Teehnologyo Hebei University of Technology Tianjin 300130 P. R. China

VO4^3- anion was used to partially substitute for PO43 in the Nasicon compound of LiSn2（PO4）3 via a sol-gel method. XRD analysis revealed that the VO4^3-substituted samples did not have a single LiSn2（PO4）3 phase, and some secondary phases like SnO2 and SnP2O7 appeared. Introduction of the VO4^3- anion did not prevent the LiSn2（PO4）3 compound from decomposing during the initial lithiation; however the VO4^3- anion substitution remarkably enhanced the rate capability and cycling performance of the products because they reduced the charge transfer hnpedance, increased the lithium ion diffusion, and strengthened the role of the Li3PQ matrix due to the precipitation of the Li3V04 phase, Of the substituted samples, the sample with a nominal composition of LiSn2（PO4）2.5（VO4）0.5 delivered a capacity of 449.2 mA-h/g at a rate of 0.25 C after 25 cycles and 373.8 mA.h/g at 2 C rate. Those values surpassed some previous reports on LiSn2（PO4）3 and the LiSnz（PO4）3/C composites. Accordingly, the partial substitution of phosphorus by vanadium in LiSn2（PO4）3 is a feasible technique to remarkably improve its electrochemical properties.

关键词： Sn-based material Anode material LiSn2(PO4)3 VO43- substitution Electrochemical property

Improved electrochemical properties in the Li_3Fe_2(PO_4)_3 by titanium and vanadium doping

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Chinese Chemical Letters 2019年第3期30卷 792-796页

作者： Zhengshen Hua Xin Zhang Xiaojing Feng Xiaoran Wang Jun He Xin Wang huifen peng School of Material Science & Engineering Hebei University of Technology Research Institute for Energy Equipment Materials Hebei University of Technology Tianjin Key Laboratory of Laminating Fabrication & Interface Control Technology for Advanced Materials

The nominal Li_(3-x)Fe_(2-x)Ti_x(PO_4)_(2.55)(VO_4)_(0.45)(x=0～0.3) compounds were synthesized by a sol-gel *** from the single V043 doping, further introduction of Ti^(4+) ion was easy to result in precipitation of a little secondary phases, besides the main NASICON products. The simultaneous substitution of Ti^(4+)and VO_4~3 for Fe^(3+) and PO_4~3,respectively, in the Li_3 Fe_2(PO_4)_3 resulted in a net improvement in the rate capability and cycling performance, as compared with the single Ti^(4+) or VO_4~3-substituted *** sample with x=0.2 presented a high initial discharging capacity of 125.4 mAh/g at the rate of 0.5 C,about 25% higher than the Ti^(4+)-substituted Li_(2.8)Fe_(1.8)Ti_(0.2)(PO_4)_3, and 102.6 mAh/g after 60 cycles at 2 C,about 12% higher than the single VO_4~3-substituted one. The high rate performance between 0.5 C to 10 C suggested that this sample had a good stability and reversibility. These results proved that the combination of the Ti^(4+) substitution for Fe^(3+) with the V043 substitution for PO_4~3 was a promising method of improving electrochemical performance of the studied Li_3 Fe_2(PO_4)_3 cathode material.

关键词： Li3Fe2(PO4)3 Lithium ion battery Cathode Doping Electrochemical property

Effect of Al on Microstructures and Mechanical Properties of the Ultrahigh Carbon Steels

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Journal of Materials Science & Technology 2004年第5期20卷 567-570页

作者： huifen peng, Baoqi WANG, Jianjun ZHANG, Xiaoyan SONG, Xiaoli MA and Nanju GUSchool of Materials Science & Engineering, Hebei University of Techonology, Tianjin 300130, China Sch. of Mat. Sci. and Eng. Hebei Univ. of Technol. Tianjin 300130 China

In this research, we tried to find a simple processing method to break up the network carbides in ultrahigh carbon steels (UHCS). Our results revealed that Al addition was favorable to the decrease in the proeutectoid carbides, the pearlite-colony size and the pearlitic interlamellar spacing of the forged microstructures, and that a fully-pearlitic structure was obtained in the UHCS containing 1.6 wt pct Al. The quenching-and-tempering process resulted in fine microstructure in those steels. On the other hand, the strength of the UHCSs increased with the increase of the Al content, and the highest strength was obtained at the UHCS with 1.6 wt pct Al. The UHCSs with Al contents higher than 1.3 wt pct showed a high tensile strength of more than δb=1000 MPa and good ductility of higher than δ5=10% at ambient temperature.

关键词： Ultrahigh-carbon steel Al Spheroidization

Direct Preparation of the Nanocrystalline MnZn Ferrites by Using Oxalate as Precipitant

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Journal of Materials Science and Chemical Engineering 2015年第12期3卷 23-29页

作者： Fei Hua Cuicui Yin Huanque Zhang Qiangqiang Suo Xin Wang huifen peng School of Materials Science & Engineering Hebei University of Technology Tianjin China Department of Fire Protection Engineering Chinese People’s Armed Police Force Academy Langfang China School of Chemical Engineering Hebei University of Technology Tianjin China

Oxalate was generally used as a precipitant for synthesis of MnZn ferrites during the co-precipitation process. However, the MnZn ferrite couldn’t be directly obtained and a calcination process was needed. In this research, we reported a direct preparation of the MnZn ferrite nanoparticles by using co-precipitation method, together with refluxing process. XRD measurements proved that crystallite size of the obtained samples increased with an increase in pH value of the co-precipitation solution, and that the crystallite size of about 25 nm was obtained for the sample at a pH of 13. This sample showed the maximum Ms of 58.6 emu/g, which was about one times larger than that of 12 (pH value). Calcination to the obtained samples result in an enlargement in their crystal size and an improvement in their magnetic properties with an increase in temperatures. The samples calcinated in CO2 + H2 atmosphere presented good stability, and the maximum Ms value of 188.2 emu/g was obtained for the 1100。C-heated sample. Unfortunately, precipitation of some Fe2O3 at 800。C suggested poor stability of the nanocrystalline MnZn ferrite in N2 atmosphere.

关键词： Magnetic Material MnZn Ferrite Co-Precipitation Process Nanocrystalline Material

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再制造抽油杆纵向共振模糊可靠性分析

石油学报 2017年第4期38卷 468-474页

作者：宋玉杰彭惠芬夏晔东北石油大学机械科学与工程学院黑龙江大庆163318

针对再制造抽油杆设计参数的离散性和共振准则的模糊性,所导致的再制造抽油杆疲劳强度设计偏于危险的缺陷,将模糊可靠性理论引入再制造抽油杆疲劳强度设计中,根据再制造抽油杆实际工况,从实验出发,研究再制造抽油杆弹性变形应力刚化对... 详细信息

针对再制造抽油杆设计参数的离散性和共振准则的模糊性,所导致的再制造抽油杆疲劳强度设计偏于危险的缺陷,将模糊可靠性理论引入再制造抽油杆疲劳强度设计中,根据再制造抽油杆实际工况,从实验出发,研究再制造抽油杆弹性变形应力刚化对其振动特性的影响,并以实验为基础,建立并验证再制造抽油杆纵向振动数值模型;基于随机有限元理论,采用一次二阶矩法推导了再制造抽油杆固有频率的均值及方差;利用正态型隶属函数描述再制造抽油杆共振边界的模糊性,推导了具有多阶固有频率再制造抽油杆模糊可靠度计算公式,数值算例验证了该方法的有效性和可行性。在此基础上,研究了变异系数和隶属度对再制造抽油杆振动模糊可靠度的影响,分析了不同阻尼比下再制造抽油杆共振产生的悬点处附加动反力和纵向位移响应特性曲线,为再制造抽油杆合理疲劳强度设计提供理论基础。

关键词：再制造抽油杆模糊可靠性纵向共振变异系数隶属度

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基于小波内聚力模型的界面裂纹扩展

复合材料学报 2016年第8期33卷 1830-1837页

作者：彭惠芬夏晔周立明东北石油大学机械科学与工程学院大庆163318 吉林大学机械科学与工程学院长春130022

利用区间B样条小波良好的局部化性能,将内聚力模型(CZM)引入小波有限元法(WFEM)数值分析中,以区间B样条小波尺度函数作为插值函数,构造小波内聚力界面单元,推导了小波内聚力界面单元刚度矩阵,基于虚拟裂纹闭合技术(VCCT)计算界面裂纹应... 详细信息

利用区间B样条小波良好的局部化性能,将内聚力模型(CZM)引入小波有限元法(WFEM)数值分析中,以区间B样条小波尺度函数作为插值函数,构造小波内聚力界面单元,推导了小波内聚力界面单元刚度矩阵,基于虚拟裂纹闭合技术(VCCT)计算界面裂纹应变能释放率(SERR),采用β-Κ断裂准则,实现界面裂纹扩展准静态分析。将WFEM和传统有限元法(CFEM)的SERR数值分析结果与理论解进行比较,结果表明:采用WFEM和CFEM计算的SERR分别为96.60J/m2和101.43J/m2,2种方法的SERR数值解与理论解相对误差分别为1.85%和3.06%,这明确表明WFEM在计算界面裂纹扩展方面能用较少单元和节点数获得较高的计算精度和效率。在此基础上,探讨了界面裂纹初始长度和双材料弹性模量比对界面裂纹扩展的影响,分析结果表明:界面裂纹尖端等效应力随界面裂纹初始长度的增加而增加;双材料弹性模量比相差越大,界面裂纹越易于扩展,且裂纹扩展长度也越大,因此可通过调节双材料弹性模量比来延缓界面裂纹扩展。

关键词：内聚力模型小波有限元界面裂纹扩展虚拟裂纹闭合技术应变能释放率

Effect of aging on microstructures and properties of the Mo-alloyed Fe-36Ni Invar alloy

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Effect of aging on microstructures and properties of the Mo-...

“第十届中国钢铁年会”暨“第六届宝钢学术年会”

作者： Zhonghua Sun Jianxin Li Jinbao Chang Yunfei Zhang huifen peng Hebei Iron and Steel Technology Research Institute Hebei Iron and Steel Group School of Materials Science and Engineering Hebei University of Technology

The Mo-alloyed invar alloy is prepared by the vacuum induction melting *** investigations of mechanical properties,phase constitutions,microstructures,thermal expansion features are *** was found that precipitation of the Mo2C secondary phase could be tailored by adjusting the aging processes,and that the highest strength of 820 MPa and good elongation of 35%,together with a low CTE value of 3.37×10-6/℃were obtained when solution treating at 1050℃for 1h and than aging at 525℃for *** in the aging time resulted in the Mo2C phase to aggregate and grow at the grain or sub-grain boundaries of the austenite,concomitant with a deterioration in strength and thermal expansion of the materials.

关键词： Invar alloy Mo alloying Strengthening Thermal expansion Aging

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镍掺杂对黄铁矿型二硫化铁电化学性能的影响

硅酸盐学报 2014年第10期42卷 1303-1308页

作者：丁玮何珺王新彭会芬彭智君董斌河北工业大学材料科学与工程学院天津300131 天津轻工职业技术学院电子信息与自动化系天津300350 秦皇岛市特种设备监督检验所河北秦皇岛066000

利用溶剂热方法合成了纯的Ni掺杂FeS2,Ni掺杂减小了FeS2的颗粒尺寸,并使FeS2由不规则的颗粒转变为均匀的球状。充放电测试结果表明:Ni掺杂FeS2在90mA/g电流密度下的首次放电容量为904mAh/g,远高于同样条件下未掺杂的FeS2。450mA/g电流... 详细信息

利用溶剂热方法合成了纯的Ni掺杂FeS2,Ni掺杂减小了FeS2的颗粒尺寸,并使FeS2由不规则的颗粒转变为均匀的球状。充放电测试结果表明:Ni掺杂FeS2在90mA/g电流密度下的首次放电容量为904mAh/g,远高于同样条件下未掺杂的FeS2。450mA/g电流密度下的首次放电容量为480mAh/g,20次循环后放电容量仍大于150mAh/g。电导率与阻抗谱测试结果表明,Ni掺杂能提高FeS2的电导率,减小FeS2电极的内阻。

关键词：锂电池正极材料黄铁矿型二硫化铁掺杂电化学性能

低分子肝素应用于妊娠期羊水过少对产后胎盘的病理影响

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齐齐哈尔医学院学报 2023年第21期44卷 2022-2026页

作者：彭惠芬康高杨彭莹翟丽丽齐齐哈尔市第一医院产科黑龙江齐齐哈尔161005 齐齐哈尔市第一医院病理科黑龙江齐齐哈尔161005

目的探讨低分子肝素应用于妊娠晚期临界性羊水过少的孕妇在免疫因素的影响下对胎盘的临床作用价值。方法选择2022年1—12月本院收治的164例妊娠晚期临界性羊水过少的孕妇作为研究对象,按照其免疫指标结果分为免疫指标阳性者和免疫指... 详细信息

目的探讨低分子肝素应用于妊娠晚期临界性羊水过少的孕妇在免疫因素的影响下对胎盘的临床作用价值。方法选择2022年1—12月本院收治的164例妊娠晚期临界性羊水过少的孕妇作为研究对象,按照其免疫指标结果分为免疫指标阳性者和免疫指标阴性者,其中免疫指标阳性者分为观察组Ⅰ和对照组Ⅰ,免疫指标阴性者分为观察组Ⅱ和对照组Ⅱ。对照组均采用水化疗法,观察组在对照组基础上联合应用低分子肝素。产后胎盘送病理,在显微镜下观察胎盘梗死灶范围及钙化区域(S),分为三个级别:胎盘梗死和/或散在钙化(S≤5%)、胎盘梗死和/或钙化(5%10%)。结果观察组Ⅰ和对照组Ⅰ(免疫指标阳性者)产后胎盘梗死灶范围及钙化区域(S)的差异有统计学意义(P=0.0061);观察组Ⅱ和对照组Ⅱ(免疫指标阴性者)产后胎盘梗死灶范围及钙化区域(S)的差异有统计学意义(P=0.0092);观察组Ⅰ和观察组Ⅱ(采用低分子肝素治疗联合水化疗法)产后胎盘梗死灶范围及钙化区域(S)的差异没有统计学意义(P=1.0000)。结论对于妊娠晚期临界性羊水过少的孕妇,不论免疫指标性质如何,应用低分子肝素后,产后的胎盘病理显示梗死灶范围和/或钙化区域较未应用低分子肝素的明显减小,说明应用低分子肝素后能通过影响母体凝血途径、调节胎盘细胞因子等途径改善胎盘循环功能,而羊水过少受多因素多通路影响,低分子肝素对胎盘和对免疫性疾病所致的羊水过少的影响有可能是通过不同的途径来起作用的。

关键词：低分子肝素胎盘病理胎盘梗死羊水过少免疫因素抗凝治疗水化疗法