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lightweight Si_(3)N_(4)@SiO_(2) ceramic foam for thermal insulation and electromagnetic wave transparency

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Nano Research 2024年第5期17卷 4298-4306页

作者： Zongwei Tong Xiangjie Yan Yuexiang Wang kexun li Weihai Ma China-Blarus Belt and Road Joint Laboratory on Electromagnetic Environment Effect the 33rd Research Institute of ChinaElectronics Technology Group CorporationTaiyuan 030032China Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education School of Material Science and EngineeringTianjin UniversityTianjin 300072China Department of Materials Science and Engineering Jinzhong UniversityJinzhong 030619China

Increasing porosity is one of the most direct ways to improve the thermal insulation and dielectric properties of materials.Until now,many wet methods for preparing Si_(3)N_(4) ceramic foams usually face the problems of complex rheology,long period,and expensive cost,and the reported pore sizes of Si_(3)N_(4) ceramic foams are typically micron-grade,resulting in a lack of competitiveness in thermal insulation and wave-transparent applications.In this paper,the Si_(3)N_(4)@SiO_(2) ceramic foams were prepared using an efficient dry-method,which combined three processes of low temperature chemical vapor deposition(LTCVD),template,and isostatic pressing.The method has the advantages of simple operation and short preparation period,and can realize near-net size molding and mass production.In addition,the evolution mechanisms of honeycomb microstructure and composition of Si_(3)N_(4)@SiO_(2) ceramic foam during sintering were studied by chemical reaction thermodynamics.The as-prepared Si_(3)N_(4)@SiO_(2) ceramic foam possesses low density(0.377 g·cm^(-3)),high compressive strength(7.5 MPa),low thermal conductivity(0.0808 W·m^(-1)·K^(-1)),and excellent dielectric properties(εlied in the interlayer of Si_(3)N_(4) ceramic radome to improve its thermal insulation and electromagnetic wave transparency performances.

关键词： silicon nitride ceramic foam honeycomb microstructure dielectric properties thermal insulation

In-situ construction of abundant active centers on hierarchically porous carbon electrode toward high-performance phosphate electrosorption: Synergistic effect of electric field and capture sites

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Green Energy & Environment 2024年第1期9卷 126-137页

作者： Peng Zhang Fukuan li Mingming He Silu Huo Xueli Zhang Benqiang Cen Dezhi Fang kexun li Hao Wang College of Environmental Science and Engineering Nankai UniversityTianjin300350China MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlTianjin Key Laboratory of Environmental Technology for Complex Trans-Media PollutionNankai UniversityTianjin300350China State Key Laboratory of Simulation and Regulation of Water Cycles in River Basins China Institute of Water Resources and Hydropower ResearchBeijing100038China

Phosphate removal is crucial for eutrophication control and water quality improvement.Electro-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater treatment.However,there are few works focused on phosphate electro-sorption,and reported electrodes cannot attach satisfactory removal capacities and rates.Herein,electro-assisted adsorption of phosphate via in-situ construction of La active centers on hierarchically porous carbon(LaPC)has been originally demonstrated.The resulted LaPC composite not only possessed a hierarchically porous structure with uniformly dispersed La active sites,but also provided good conductivity for interfacial electron transfer.The LaPC electrode achieved an ultrahigh phosphate electrosorption capability of 462.01 mg g^(-1) at 1 V,outperforming most existing electrodes.The superior phosphate removal performance originates from abundant active centers formed by the coupling of electricﬁeld and capture sites.Besides,the stability and selectivity toward phosphate capture were maintained well even under comprehensive conditions.Moreover,a series of kinetics and isotherms models were employed to validate the electrosorption process.This work demonstrates a deep understanding and promotes a new level of phosphate electrosorption.

关键词： Electro-assisted adsorption Electrosorption Phosphate removal Active centers MOF-derived carbon

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汽车电控发动机中的传感器检测技术分析

集成电路应用 2024年第3期41卷 176-177页

作者：李柯汛山西应用科技学院山西030062

阐述汽车电控发动机传感器的分类和特点,介绍传感器校准方法和故障检测方法,包括热线式空气流量传感器、节气门传感器、氧传感器的应用。分析汽车发动机典型传感器检测的案例。

关键词：传感器电控发动机故障检测

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构筑锆基活性位点用于电吸附磷酸盐的研究

工业水处理 2024年第3期44卷 74-80页

作者：伏培仟张鹏卜兆宇李克勋扬州市建筑设计研究院有限公司江苏扬州225012 南开大学环境科学与工程学院天津300350

水体中含有过量的磷会导致富营养化等环境污染问题,有效去除磷酸盐的方法引发了研究者们的关注。通过液相浸渍耦合焙烧法成功制备了Zr基金属掺杂的活性炭电极材料(ZrAC),并将其用于电吸附除磷。通过XRD、XPS、SEM、EDS及TEM表征了该复... 详细信息

水体中含有过量的磷会导致富营养化等环境污染问题,有效去除磷酸盐的方法引发了研究者们的关注。通过液相浸渍耦合焙烧法成功制备了Zr基金属掺杂的活性炭电极材料(ZrAC),并将其用于电吸附除磷。通过XRD、XPS、SEM、EDS及TEM表征了该复合活性炭材料,结果表明,所合成的ZrAC材料具有良好的晶体结构特征,Zr的负载为磷酸盐去除提供了充足的吸附位点。所制备的电极材料对磷酸盐的去除符合伪二级动力学模型,在1.0 V的电压下,电极对PO_(4)^(3-)的吸附量可达到29.43 mg/g,外接电压显著提升了对磷酸盐的去除性能,ZrO_(2)对PO_(4)^(3-)的捕获主要源于Zr—O—P键的形成,由此提升了电极材料对PO_(4)^(3-)的吸附能力和速度。此外,所合成的ZrAC电极材料在电吸附过程中具有较好的抗干扰能力和稳定性。

关键词：电吸附磷酸盐去除富营养化氧化锆

Adsorption of Quaternary Ammonium Compounds onto Activated Sludge

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Journal of Water Resource and Protection 2011年第2期3卷 105-113页

作者： Rong Ren Dongfang liu kexun li Jie Sun Chong Zhang 不详

The performance of activated sludge in the removal of tetradecyl benzyl dimethyl ammonium chloride (C14BDMA) by adsorption from aqueous solution was investigated with different PH, contact time, ionic strength and temperature. Equilibrium was achieved within 2 h of contact time. The adsorption capacity increased largely with increasing solution pH and remained constant above pH 9. The ionic strength had a negative effect on C14BDMA removal. The adsorption isotherms were analyzed by Langmuir and Freundlich isotherm models, and equilibrium partitioning data was described well by both models. Kinetics data was best described by the pseudo second-order model. Experimental results indicated that the adsorption was favorable at lower temperatures. Thermodynamic parameters, including the Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0), were also calculated. These parameters indicated that adsorption of C14BDMA onto activated sludge was feasible, spontaneous and exothermic in the temperature range of 15-35℃. The activated sludge was shown to be an effective adsorbent for C14BDMA.

关键词： Activated Sludge Adsorption Kinetics Quaternary Ammonium Compounds Thermodynamics Analysis

食管癌静脉血栓栓塞症发生情况的真实世界研究(附8458例报告)

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中华消化外科杂志 2024年第1期23卷 109-113页

作者：杜坤义聂鑫李科汛李昌顶刘琨李智毓李昆志陆思秒倪琨涵何文武王程浩李佳龙李濠君周强王康宁刘光源肖文光方强石丘玲韩泳涛彭林冷雪峰四川省肿瘤临床医学研究中心、四川省肿瘤医院·研究所、四川省癌症防治中心、电子科技大学附属肿瘤医院胸外科成都610041 重庆医科大学公共卫生学院重庆医科大学超声医学工程国家重点实验室重庆401331

目的探讨食管癌患者静脉血栓栓塞症(VTE)的发生情况。方法采用回顾性队列研究方法。收集2017年1月至2021年12月四川省肿瘤医院收治的8458例食管癌患者的临床病理资料;男6923例,女1535例;年龄为(64±9)岁;行手术治疗3187例,非手术治疗527... 详细信息

目的探讨食管癌患者静脉血栓栓塞症(VTE)的发生情况。方法采用回顾性队列研究方法。收集2017年1月至2021年12月四川省肿瘤医院收治的8458例食管癌患者的临床病理资料;男6923例,女1535例;年龄为(64±9)岁;行手术治疗3187例,非手术治疗5271例。观察指标:(1)食管癌患者VTE的发生情况。(2)VTE患者治疗和转归情况。正态分布的计量资料以x±s表示,组间比较采用t检验。偏态分布的计量资料以M(范围)表示,组间比较采用非参数秩和检验。计数资料以绝对数或百分比表示,组间比较采用χ2检验或Fisher确切概率法。等级资料比较采用非参数秩和检验。结果(1)食管癌患者VTE的发生情况。8458例食管癌患者中,175例发生VTE,发生率为2.069%(175/8458);其中深静脉血栓形成164例,肺栓塞4例,深静脉血栓形成合并肺栓塞7例;手术患者59例,非手术患者116例。手术与非手术食管癌合并VTE患者血栓类型比较,差异无统计学意义(χ2=1.95,P>0.05)。3187例手术患者VTE发生率为1.851%(59/3187),其中肺栓塞发生率为0.157%(5/3187),占手术患者VTE的比例为8.475%(5/59)。5271例非手术治疗患者VTE发生率为2.201%(116/5271),其中肺栓塞发生率为0.114%(6/5271),占非手术患者VTE的比例为5.172%(6/116)。手术与非手术患者VTE及肺栓塞发生率比较,差异均无统计学意义(χ2=1.20、0.05,P>0.05)。(2)VTE患者治疗和转归情况。175例食管癌合并VTE患者中,163例行药物治疗,12例未治疗。163例行药物治疗患者中,158例行抗凝治疗,5例行溶栓治疗,均好转出院。结论食管癌患者VTE的发生率较低,为2.069%;手术与非手术患者VTE的发生情况、合并VTE的血栓类型比较,差异均无统计学意义。

关键词：食管肿瘤外科手术静脉血栓栓塞症深静脉血栓形成肺栓塞治疗

Study on the Formation of Cristobalite in Mesoporous Carbon from Biomass Materials via the Reaction under Autogenic Pressure at Elevated Temperature

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Study on the Formation of Cristobalite in Mesoporous Carbon ...

Controlled synthesis and luminance properties of lanthanide-doped β-NaYF_4 microcrystals

第七届全国物理无机化学学术会议

作者： kexun li Yali Zhao Donghong Wang Electromagnetic Protection Materials and Technology Key Laboratory of Shanxi No.33 Research Institute of China Electronic Technology Group Corporation

＜正＞The Reaction under Autogenic Pressure at Elevated Temperature（RAPET）is a new kind of promising in situ preparation method of synthesizing nano-carbon composite material[1].Through this method,we have successfully prepared C/Ti O2 composite microspheres,mesoporous carbon and other nano-carbon composite structures.The specific surface area of mesoporous carbon obtained by the RAPET can achieve

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Journal of Rare Earths 2015年第4期33卷 339-345页

作者：王军梅李克训赵彦保朱珍平 Key Laboratory for Special Functional Materials Henan University State Kay Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences The Electromagnetic Protection Technology Key Laboratory of Shanxi of NO.33 Institute of China Electronic Technology Group Corporation

Hexagonal yb3＋,Er3＋-doped NaYF4 crystals with different morphologies were synthesized by a facile hydrothermal method at 140-200 ℃. Their shape and size could be controlled by varying hydrothermal temperature, time and doping effect of Ce3＋ ions. Interestingly, the products displayed hexagonal sheet, plate, crown-like prism to tube changes in the temperature range from 140 to 200 ℃. A combination of ＂diffusion-controlled growth＂ and ＂selective adsorption＂ was proposed to understand the formation of the NaYF4 crystals with well-defined shapes. NaYF4：yb3＋/Er3＋ crystals exhibited shape-dependent up-conversion （UC） luminescence under excitation of 980 nm, and their luminescence property could be tuned by doping Ce3＋ ions.

关键词： nanostructures inorganic compounds chemical synthesis optical properties rare earths

三维多孔泡沫炭电极电催化氧化高氨氮废水的试验研究

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工业用水与废水 2023年第5期54卷 33-38页

作者：伏培仟李富宽李克勋扬州市建筑设计研究院有限公司江苏扬州225000 南开大学环境科学与工程学院天津300071

采用熔化-起泡-沉降-碳化的方法制备了三维多孔泡沫炭,该材料开孔率高、水体透过性好、导电性优越,相比相同反应条件下的二维传统Ti/IrO_(2)-RuO_(2)电极,该材料对氨氮的去除率更高,能耗更低;以三维多孔泡沫炭为阳极电催化氧化去除高氨... 详细信息

采用熔化-起泡-沉降-碳化的方法制备了三维多孔泡沫炭,该材料开孔率高、水体透过性好、导电性优越,相比相同反应条件下的二维传统Ti/IrO_(2)-RuO_(2)电极,该材料对氨氮的去除率更高,能耗更低;以三维多孔泡沫炭为阳极电催化氧化去除高氨氮制碱废水,考察了电流密度、强制搅拌和极板间距对氨氮去除率的影响,结果表明提高电流密度、强制搅拌和减少极板间距均有利于提升电催化氧化氨氮的去除率。综合考虑废水处理效果和能耗确定适宜条件为:极板间距为1 cm,强制搅拌,电流密度为20 mA/cm^(2),电解时间为6 h,此时氨氮的去除率为96%,能耗为31.25 kW·h/m^(3),三维多孔泡沫炭电极能有效实现电催化氧化高氨氮制碱废水的氨氮去除。

关键词：三维多孔泡沫炭高盐废水氨氮电催化氧化