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磷硅协同提高木质素基聚氨酯材料的阻燃性能

塑料 2022年第6期51卷 19-23,29页

作者：薛建英徐开玉孟繁敏雷昊中北大学理学院山西太原030000

为解决硬质聚氨酯(RPUF)阻燃性能较差的问题,利用改性木质素磺酸钠(SLS)部分替代聚氨酯的原料聚醚多元醇,并将纳米SiO_(2)和聚磷酸铵(APP)按不同比例加入硬质聚氨酯(RPUF)材料中,进行协同阻燃,制得复合RPUF材料。结果表明,当APP、纳米Si... 详细信息

为解决硬质聚氨酯(RPUF)阻燃性能较差的问题,利用改性木质素磺酸钠(SLS)部分替代聚氨酯的原料聚醚多元醇,并将纳米SiO_(2)和聚磷酸铵(APP)按不同比例加入硬质聚氨酯(RPUF)材料中,进行协同阻燃,制得复合RPUF材料。结果表明,当APP、纳米SiO_(2)添加量分别为25.0%、1.0%,羟甲基木质素磺酸钠(HLS)的添加量为4%时,复合材料的极限氧指数达到最大,其值为27.2%;抗压缩强度可达1.1 MPa,与纯聚氨酯(0.43 MPa)相比,提高了159.3%;最高热释放量(PHRR)和总烟释放量(TSR)分别降低了51.5%和32.5%。通过分析燃烧后残炭的微观形貌可知,与纯聚氨酯相比,添加了协同阻燃剂的聚氨酯材料的残炭更加密实,孔洞更小,这表明,添加了协同阻燃剂的聚氨酯材料的阻燃效果更好,纳米SiO_(2)和APP起到了协同阻燃作用。

关键词：硬质聚氨酯木质素磺酸钠纳米SiO_(2) 聚磷酸铵协同阻燃

Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land,China

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Research in Cold and Arid Regions 2015年第6期7卷 675-686页

作者： ChaoFeng Fu JingBo Zhao fanmin Mei TianJie Shao Jun Zuo Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of Education of China&Chang'an University College of Tourism and Environment Science Shaanxi Normal University Environmental and Chemical Engineering College Xi'an Polytechnic University

Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the south- eastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that：（1） The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest： in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope. （2） Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune. （3） The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture. （4） The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indicating that shrubs are more effective in inhibiting wind erosion in the sandy land area.

关键词： soil moisture surface sandy soil wind erosion vegetation form micro-geomorphology sand dunes deserti-fication control

Validating a dust production model by field experiment in Mu Us Desert, China

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Chinese Science Bulletin 2006年第7期51卷 878-884页

作者： MEI fanmin J. Rajot S. Alfaro L. Gomes ZHANG Xiaoye WANG Tao Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Department of Environmental Science and Technology Xi'an University of Engineering and Technology Xi'an 710048 China Center of Monitoring and Forecasting of Chemical Components of Atmosphere State Key Laboratory of Atmospheric Chemistry Institute of National Meteorology Research Beijing 100081 China Laboratoire lnteruniversitaire des Systemes Atmospheriques Universite de Paris 12 Paris 94010 France

Field experiments of dust production have been seldom performed in Chinese deserts that are identified as one of main dust sources in the world, and such an experiment to validate a dust production model (DPM) has not been made in China until now. Saltation flux, dust emission flux, surface features and meteorological parameters (U*, Z0, Ri, etc.) were investigated in Mu Us Desert of China to verify the DPM model and accumulate dust emission data during the spring of 2002. It indicates that observed saltation fluxes from 0.07 to 8.00 g·m?1·s?1 are in good agreement with the ones predicted by the DPM model when the constant of the saltation flux equation is tuned to about 2.61, which corresponds to wind fric- tion velocities from 0.26 to 0.35 m·s?1. Unfortunately, during three local dust emission events, the observed dust fluxes are from 1 to 3 μg· m?2· s?1, lower than the modeled ones, implying that the model needs to be improved further under lower wind velocity. In comparison with data from a sandy soil with physical crust and a loam soil, saltation fluxes of the loose sandy soil in Mu Us Desert are obviously higher, which suggests that deserts and sandy land with desertification are major dust sources in northern China.

关键词：沙漠尘埃模拟野外试验

Simulation of Silty Clay Compressibility Parameters Based on Improved BP Neural Network Using Bayesian Regularization

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Earthquake Research in China 2020年第3期34卷 378-393页

作者： CAI Run PENG Tao WANG Qian HE fanmin ZHAO Duoying Chengdu Surveying Geotechnical Research Institute Co Ltd.of MCCChengdu 610023China Key Laboratory of Loess Earthquake Engineering Gansu Earthquake AgencyLanzhou 730000China Lanzhou Institute of Seismology China Earthquake AdministrationLanzhou 730000China

Soil compressibility parameters are important indicators in the geotechnical field and are affected by various factors such as natural conditions and human interference.When the sample size is too large,conventional methods require massive human and financial resources.In order to reasonably simulate the compressibility parameters of the sample,this paper firstly adopts the correlation analysis to select seven influencing factors.Each of the factors has a high correlation with compressibility parameters.Meanwhile,the proportion of the weights of the seven factors in the Bayesian neural network is analyzed based on Garson theory.Secondly,an output model of the compressibility parameters of BR-BP silty clay is established based on Bayesian regularized BP neural network.Finally,the model is used to simulate the measured compressibility parameters.The output results are compared with the measured values and the output results of the traditional LM-BP neural network.The results show that the model is more stable and has stronger nonlinear fitting ability.The output of the model is basically consistent with the actual value.Compared with the traditional LMBP neural network model,its data sensitivity is enhanced,and the accuracy of the output result is significantly improved,the average value of the relative error of the compression coefficient is reduced from 15.54%to 6.15%,and the average value of the relative error of the compression modulus is reduced from 6.07%to 4.62%.The results provide a new technical method for obtaining the compressibility parameters of silty clay in this area,showing good theoretical significance and practical value.

关键词： Silty clay Compressibility Correlation analysis Bayesian regularization Neural networks

艾司氯胺酮用于不同年龄段患儿术前镇静的半数有效剂量

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中华麻醉学杂志 2022年第3期42卷 320-322页

作者：张贝贝杨倚天贾佳孟凡民张加强河南省人民医院(郑州大学人民医院)麻醉与围术期医学科郑州450003

目的确定艾司氯胺酮用于不同年龄段患儿术前镇静的半数有效剂量(ED_(50))。方法选择全身麻醉下择期手术患儿,年龄1~6岁,ASA分级Ⅰ级,术前父母分离焦虑量表(PSAS)评分≥3分。根据年龄将患儿分为1岁≤年龄<4岁低龄组(L组)和4岁≤年龄<6岁... 详细信息

目的确定艾司氯胺酮用于不同年龄段患儿术前镇静的半数有效剂量(ED_(50))。方法选择全身麻醉下择期手术患儿,年龄1~6岁,ASA分级Ⅰ级,术前父母分离焦虑量表(PSAS)评分≥3分。根据年龄将患儿分为1岁≤年龄<4岁低龄组(L组)和4岁≤年龄<6岁高龄组(H组)。每组首例患儿静脉注射艾司氯胺酮剂量为0.5 mg/kg,根据PSAS评分确定下一例给药剂量,若上一例患儿PSAS评分≥3分则下一例调高剂量;若上一例患儿PSAS评分<3分则下一例调低剂量,相邻剂量梯度为0.1 mg/kg,直到出现7个转折点结束试验。采用Probit法计算艾司氯胺酮术前镇静的ED_(50)及其95%置信区间。结果本研究共纳入患儿54例,L组26例,H组28例。L组和H组艾司氯胺酮用于患儿术前镇静的ED_(50)及其95%置信区间分别为0.413(0.314~0.530)mg/kg和0.282(0.252~0.318)mg/kg。与L组比较,H组ED_(50)降低(P<0.05)。结论艾司氯胺酮用于1岁≤年龄<4岁患儿术前镇静的ED_(50)为0.413 mg/kg,用于4岁≤年龄<6岁患儿ED_(50)为0.282 mg/kg,随年龄增大艾司氯胺酮术前镇静效力增强。

关键词：氯胺酮儿童剂量效应关系,药物清醒镇静手术前护理

激光重熔对浇铸及CMT堆焊巴氏合金组织的影响

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激光与光电子学进展 2023年第15期60卷 261-270页

作者：邓德伟汪峻宇孟凡民万泓明孙奇张勇大连理工大学材料科学与工程学院辽宁省凝固控制与数字化制备技术重点实验室辽宁大连116024 沈阳鼓风机集团股份有限公司辽宁沈阳110869

在工业领域中,通过铸造所制备的巴氏合金往往存在缺陷。为了探究如何减少巴氏合金在组织和性能上的缺陷,对比了通过传统浇铸和冷金属过渡焊接(CMT)两种方法在20钢基体上所制备巴氏合金层的组织和性能,并在其表面进行了激光重熔试验。利... 详细信息

在工业领域中,通过铸造所制备的巴氏合金往往存在缺陷。为了探究如何减少巴氏合金在组织和性能上的缺陷,对比了通过传统浇铸和冷金属过渡焊接(CMT)两种方法在20钢基体上所制备巴氏合金层的组织和性能,并在其表面进行了激光重熔试验。利用金相显微镜、扫描电镜、能谱仪以及维氏硬度计等仪器检测了浇铸、堆焊巴氏合金和重熔巴氏合金层的组织和硬度,通过对比分析可知,CMT堆焊层组织较浇铸层更细,与钢基体的冶金结合更强。激光重熔在细化晶粒、消除粗大组织的同时,未产生偏析、气孔等缺陷。不同激光功率对于巴氏合金层的组织和性能影响各不相同,激光功率分别为300 W和500 W时,堆焊、浇铸试样的重熔层硬度达到最大值35.16 HV_(0.025)和36.92 HV_(0.025)。激光重熔对巴氏合金组织和性能的强化效果显著,对于滑动轴承的研究有着巨大的工程应用价值和发展前景。

关键词：激光技术巴氏合金激光重熔表面与界面硬度

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空间视域下义务教育质量对房价的影响

华东师范大学学报（自然科学版） 2022年第1期 97-108页

作者：杨慧曾进杨乃孔凡敏中国地质大学地理与信息工程学院武汉430078 湖北第二师范学院马克思主义学院武汉430205

以湖北省武汉市为例,通过收集搜房网、家长帮、武汉市教育局等网站的学校和房价数据,借用地理加权回归(Geographic Weighted Regression,GWR)方法探究义务教育质量对房价的影响,运用反距离权重插值法进行可视化分析.结果表明:①义务教... 详细信息

以湖北省武汉市为例,通过收集搜房网、家长帮、武汉市教育局等网站的学校和房价数据,借用地理加权回归(Geographic Weighted Regression,GWR)方法探究义务教育质量对房价的影响,运用反距离权重插值法进行可视化分析.结果表明:①义务教育质量对房价具有正相关影响,省级示范学校对房价的溢价程度相对较高;②初中质量的资本化效应高于小学;③新城区的中小学教育质量对房价的影响较大,江岸区中部及北部地区的对口中小学组合质量对房价的影响最大,武昌区、硚口区和江汉区学校质量整体上对房价影响较小.

关键词：学区房教育资源特征价格模型 GWR模型教育资本化

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中国共产党群众观的百年发展历程与现实思考

福建工程学院学报 2022年第5期20卷 416-421页

作者：范凡敏福建师范大学马克思主义学院福建福州350117

回顾中国共产党成立百年以来的发展历程,党运用群众观点在指导我国革命、建设和改革开放新时期的伟大社会实践过程中,逐渐形成了中国共产党群众观。坚持人民群众的主体地位是习近平群众观的核心内容,新的历史时期习近平群众观推动群众... 详细信息

回顾中国共产党成立百年以来的发展历程,党运用群众观点在指导我国革命、建设和改革开放新时期的伟大社会实践过程中,逐渐形成了中国共产党群众观。坚持人民群众的主体地位是习近平群众观的核心内容,新的历史时期习近平群众观推动群众工作进一步走深走实。今后要进一步厚植群众观点,全面践行群众路线,健全评价检验群众工作机制,注重人民群众对政府的监督。

关键词：中国共产党群众观发展历程现实思考

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泡囊短波单胞菌致血流感染1例

中国感染与化疗杂志 2017年第2期17卷 204-205页

作者：孟凡民时东彦乐亭县医院检验科河北乐亭063600 河北医科大学第二医院检验科

泡囊短波单胞菌属需氧、不发酵糖革兰阴性菌，偶可自临床标本中分离获得，该菌可引起中枢神经系统感染、血流感染、肺炎等。本文报道1例自成神经细胞瘤化疗期发热的患者血培养中分离出泡囊短波单胞菌。

关键词：泡囊短波单胞菌血流感染儿童患者