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下腔静脉滤器植入联合经皮机械性血栓清除术与球囊扩张治疗老年髋骨折合并髂股静脉血栓患者的价值

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中国临床保健杂志 2024年第1期27卷 93-96页

作者：王杰克周文华刘涛张金通张任怡郑祥坚乐清市第二人民医院骨科乐清325608 乐清市第二人民医院介入导管室乐清325608 温州市中心医院血管外科

目的探讨下腔静脉滤器植入联合经皮机械性血栓清除术(PMT)与球囊扩张治疗老年髋骨折合并髂股静脉血栓患者的价值。方法选取2021年6月至2023年1月在乐清市第二人民医院和温州市中心医院治疗的121例老年髋骨折合并髂股静脉血栓患者,按照... 详细信息

目的探讨下腔静脉滤器植入联合经皮机械性血栓清除术(PMT)与球囊扩张治疗老年髋骨折合并髂股静脉血栓患者的价值。方法选取2021年6月至2023年1月在乐清市第二人民医院和温州市中心医院治疗的121例老年髋骨折合并髂股静脉血栓患者,按照随机数字表法分为联合组61例和常规组60例,2组均接受一般抗凝治疗,常规组采用下腔静脉滤器植入联合PMT治疗,联合组在常规组的基础上联合球囊扩张。随访2个月后,对比2组静脉通畅评分、血栓清除率、Villalta评分及血栓后综合征(PTS)发生率、实验室指标[红细胞(RBC)、血红蛋白(Hb)、D-二聚体、纤维蛋白原(FIB)]、并发症发生情况。结果治疗前常规组与联合组静脉通畅评分差异无统计学意义(P>0.05);随访2个月后2组静脉通畅评分均下降,且与常规组相比,联合组评分更低(P0.05),2组治疗后血清D-二聚体及FIB水平均降低,且联合组低于常规组(P0.05)。结论下腔静脉滤器植入联合PMT联合球囊扩张可有效清除髋骨折合并髂股静脉血栓患者的静脉血栓,缓解病情,且安全性良好。

关键词：髋骨折静脉血栓栓塞腔静脉滤器血管成形术,气囊老年人

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基于机器学习的辅助逆变器进风滤网堵塞诊断

铁道车辆 2024年第3期62卷 80-83页

作者：曲涛景宁张仁义洪希仁常伟王亚茹江苏中车数字科技有限公司江苏南京210008 泰雷兹(中国)企业管理有限公司北京100125 上海觉云科技有限公司上海200030 广东毓秀科技有限公司广东广州510623

辅助逆变器是地铁牵引系统的重要组成部分,为了优化辅助逆变器的运用性能,提高地铁运行的稳定性,提出一种基于机器学习判断辅助逆变器进风滤网是否堵塞的方法。首先,在原有数据的基础上提取对辅助逆变器模块温度产生影响的特征;其次,建... 详细信息

辅助逆变器是地铁牵引系统的重要组成部分,为了优化辅助逆变器的运用性能,提高地铁运行的稳定性,提出一种基于机器学习判断辅助逆变器进风滤网是否堵塞的方法。首先,在原有数据的基础上提取对辅助逆变器模块温度产生影响的特征;其次,建立模型进行模型训练。结果表明:采用该方法进行滤网堵塞诊断时,相较于支持向量机(SVM)模型方法,基于多层感知机(MLP)模型的辅助逆变器进风滤网堵塞诊断方法在数据计算和预测中诊断精度较高、鲁棒性较强。同时,研究也为后续地铁项目中辅助逆变器滤网在开展制造、维修时的优化换型提供了重要依据。

关键词：地铁辅助逆变器进风滤网多层感知机支持向量机模型训练

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基于VR技术的野外实践平台构建

实验室科学 2024年第1期27卷 72-75页

作者：张仁懿袁建立艾得协措徐当会李文金兰州大学生态学院甘肃兰州730000

传统野外实践受地域、交通、时间、天气等多重因素的制约,难以兼顾实践内容、成本及人员的安全。采集不同时间、不同地点的影像素材制作VR实景,叠加至电子地图并通过互联网发布,可实现实践对象空天地一体化的多尺度展示。基于VR技术构... 详细信息

传统野外实践受地域、交通、时间、天气等多重因素的制约,难以兼顾实践内容、成本及人员的安全。采集不同时间、不同地点的影像素材制作VR实景,叠加至电子地图并通过互联网发布,可实现实践对象空天地一体化的多尺度展示。基于VR技术构建与应用野外实践平台,拓展了野外实践的地域范围,同时降低教学成本和风险。VR实景的制作及发布所涉及的技术门槛低,节点的拓展性强,有利于提高野外实践教学资源共享效益,为全国性的仿真平台建设提供参考。

关键词：虚拟现实野外实践全景照片电子地图

Particle number concentration, size distribution and chemical composition during haze and photochemical smog episodes in Shanghai

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Journal of Environmental Sciences 2014年第9期26卷 1894-1902页

作者： Xuemei Wang Jianmin Chen Tiantao Cheng renyi zhang Xinming Wang Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Fudan Tyndall CentreDepartment of Environmental Science & EngineeringFudan University Center for Atmospheric Chemistry and Environment Department of Atmospheric ScienceTexas A&M UniversityTX 77843USA State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of Sciences

The aerosol number concentration and size distribution as well as size-resolved particle chemical composition were measured during haze and photochemical smog episodes in Shanghai in 2009. The number of haze days accounted for 43%, of which 30% was severe （visibility 〈 2 km） and moderate （2 km 〈 visibility 〈 3 km） haze, mainly distributed in winter and spring. The mean particle number concentration was about 17,000/cm3 in haze, more than 2 times that in clean days. The greatest increase of particle number concentration was in 0.5-1μm and 1-10 μm size fractions during haze events, about 17.78 times and 8.78 times those of clean days. The largest increase of particle number concentration was within 50-100 nm and 100-200 nm fractions during photochemical smog episodes, about 5.89 times and 4.29 times those of clean days. The particle volume concentration and surface concentration in haze, photochemical smog and clean days were 102, 49, 15 μm3/cm3 and 949, 649, 206 μm2/cm3, respectively. As haze events got more severe, the number concentration of particles smaller than 50 nm decreased, but the particles of 50-200 nm and 0.5-1μm increased. The diurnal variation of particle number concentration showed a bimodal pattern in haze days. All soluble ions were increased during haze events, of which NH4, SO24- and NO3 increased great/y, followed by Na＋, IC, Ca2＋ and CI-. These ions were very different in size-resolved particles during haze and photochemical smog episodes.

关键词： HazePhotochemical smogParticle number concentrationSize distributionChemical compositionShanghai

Numerical Simulation of the Scavenging Rates of Ice Crystals of Various Microphysical Characteristics

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Advances in Atmospheric Sciences 1991年第2期8卷 175-200页

作者： Richard L. Pitter renyi zhang Atmospheric Sciences Center Desert Research Institute University of Nevada System Reno Nevada 89506 U. S. A.Atmospheric Sciences Center Desert Research Institute University of Nevada System Reno Nevada 89506 U. S. A.

Numerical models of trajectories of small aerosol spheres relative to oblate spheroids were used to determine ice crystal scavenging efficiencies. The models included the effects of aerodynamic flow about the ice particle, gravity, aerosol particle inertia and drag and electrostatic effects. Two electric configurations of the ice particle were investigated in detail. The first applied a net charge to the ice particle, of magnitude equal to the mean thunderstorm charge distribution, while the second applied a charge distribution, with no net charge, to the ice particle to model the electric multipole charge distribution. The results show that growing ice crystals with electric multipoles are better scavengers than single ice crystals with net thunderstorm charges, especially in the Greenfield gap (0.1 to 1.0 um), and that larger single crystals are better scavengers than smaller single crystals. The results also show that the low density ice crystals are more effective scavengers with net charges than they are with charge distribution.

关键词： Numerical Simulation of the Scavenging Rates of Ice Crystals of Various Microphysical Characteristics

Species abundance distributions as a proxy for the niche-neutrality continuum

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Journal of Plant Ecology 2018年第3期11卷 445-452页

作者： Xianzhi Wang M.D.Farnon Ellwood Dexiecuo Ai renyi zhang Gang Wang State Key Laboratory of Grassland Agro-Ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou University768 Jiayuguan RoadChengguan DistrictLanzhou730020China Centre for Research in Biosciences University of the West of EnglandColdharbour LaneBristol BS161QYUK State Key Laboratory of Grassland Agro-Ecosystems School of Life SciencesLanzhou University222 Tianshui RoadChengguan DistrictLanzhou730000China

Aims Species abundance distributions(SADs)are often used to verify mechanistic theories underlying community ***,it is now accepted that SADs alone are not sufficient to reveal biological *** attention focuses on the relative importance of stochastic dispersal processes versus deterministic processes such as interspecific competition and environmental ***,we combine a study of the commonness and rarity of species(*** SAD)with mechanistic processes underlying community *** comparing the occurrence frequen-cies of each and every species with its abundance,we quantify the relative contributions of common and rare species to the maintenance of community ***,we relate the continuum between commonness and rarity with that of niches and *** An individual-based,spatially explicit model was used to simu-late local communities in niche spaces with the same *** generated sets of assemblages from which species were elim-inated in opposing sequences:from common to rare and from rare to common,and investigated the relationship between the abundance and frequency of *** tested the predictions of our model with empirical data from a field experiment in the environmentally homogeneous alpine meadows of the Qinghai-Tibetan *** Findings Our simulations support the widespread notion that common species maintain community structure,while rare species maintain species diversity,in both local and regional *** results,both from theoretical simulations and from empirical observations,revealed positive correlations between the abundance of a particular species and its occurrence *** curves describe a continuum between commonness and *** species from the‘rare’end of this continuum has little effect on the similarity of communities,but remov-ing species from the‘common’end of the continuum causes significant increases in beta diversity,or specie

关键词： rarity commonness continuum occurrence frequency community similarities

Advances in studying interactions between aerosols and monsoon in China

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Science China Earth Sciences 2016年第11期59卷 1-16页

作者： WU GuoXiong LI ZhanQing FU CongBin zhang XiaoYe zhang renyi zhang RenHe ZHOU TianJun LI JianPing LI JianDong ZHOU DeGang WU Liang ZHOU LianTong HE Bian HUANG RongHui LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China School of Atmospheric Sciences Nanjing UniversityNanjing 210093China Chinese Academy of Meteorological Sciences Chinese Meteorological AdministrationBeijing 100081China Department of Atmospheric Sciences Texas A&M UniversityTexas 77843USA CMSR Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Joint Center for Global Change Studies Beijing Normal UniversityBeijing 100875China

Scientific issues relevant to interactions between aerosols and the Asian monsoon climate were discussed and evaluated at the 33 rd "Forum of Science and Technology Frontiers" sponsored by the Department of Earth Sciences at the Chinese Academy of Sciences. Major results are summarized in this paper. The East Asian monsoon directly affects aerosol transport and provides a favorable background circulation for the occurrence and development of persistent fog-haze weather. Spatial features of aerosol transport and distribution are also influenced by the East Asian monsoon on seasonal, inter-annual, and decadal scales. High moisture levels in monsoon regions also affect aerosol optical and radiative properties. Observation analyses indicate that cloud physical properties and precipitation are significantly affected by aerosols in China with aerosols likely suppressing local light and moderate rainfall, and intensifying heavy rainfall in southeast coastal regions. However, the detailed mechanisms behind this pattern still need further exploration. The decadal variation in the East Asian monsoon strongly affects aerosol concentrations and their spatial patterns. The weakening monsoon circulation in recent decades has likely helped to increase regional aerosol concentrations. The substantial increase in Chinese air pollutants has likely decreased the temperature difference between land and sea, which favors intensification of the weakening monsoon circulation. Constructive suggestions regarding future studies on aerosols and monsoons were proposed in this forum and key uncertain issues were also discussed.

关键词：大气气溶胶中国科学院季风气候相互作用气溶胶浓度年代际变化东亚季风东南沿海地区

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Aerosol Microphysical and Radiative Effects on Continental Cloud Ensembles

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Advances in Atmospheric Sciences 2018年第2期35卷 234-247页

作者： Yuan WANG Jonathan M. VOGEL Yun LIN Bowen PAN Jiaxi HU Yangang LIU Xiquan DONG Jonathan H. JIANG Yuk L. YUNG renyi zhang Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA 91106 USA Department of Atmospheric Sciences Texas A&M University College Station TX 77840 USA Environmental & Climate Sciences Department Brookhaven National Laboratory Upton NY 11973 USA Department of Hydrology and Atmospheric Sciences University of Arizona Tucson AZ 85721 USA Jet Propulsion Laboratory California Institute of Technology Pasadena CA 91109 USA Department of Atmo wheric and Oceanic Sciences McGill University Montreal Quebec QC H3A OG4 Canada

Aerosol-cloud-radiation interactions represent one of the largest uncertainties in the current climate assessment. Much of the complexity arises from the non-monotonic responses of clouds, precipitation and radiative fluxes to aerosol perturbations under various meteorological conditions. In this study, an aerosol-aware WRF model is used to investigate the microphysical and radiative effects of aerosols in three weather systems during the March 2000 Cloud Intensive Observational Period campaign at the US Southern Great Plains. Three simulated cloud ensembles include a low-pressure deep convective cloud system, a collection of less-precipitating stratus and shallow cumulus, and a cold frontal passage. The WRF simulations are evaluated by several ground-based measurements. The microphysical properties of cloud hydrometeors, such as their mass and number concentrations, generally show monotonic trends as a function of cloud condensation nuclei concentrations. Aerosol radiative effects do not influence the trends of cloud microphysics, except for the stratus and shallow cumulus cases where aerosol semi-direct effects are identified. The precipitation changes by aerosols vary with the cloud types and their evolving stages, with a prominent aerosol invigoration effect and associated enhanced precipitation from the convective sources. The simulated aerosol direct effect suppresses precipitation in all three cases but does not overturn the aerosol indirect effect. Cloud fraction exhibits much smaller sensitivity （typically less than 2%） to aerosol perturbations, and the responses vary with aerosol concentrations and cloud regimes. The surface shortwave radiation shows a monotonic decrease by increasing aerosols, while the magnitude of the decrease depends on the cloud type.

关键词： aerosol-cloud-radiation interactions cloud-resolving model cloud microphysics and macrophysics precipita-tion

分光光度法测定涡轮机油中的N-苯基-α-萘胺

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合成润滑材料 2022年第4期49卷 10-14页

作者：章仁毅中国石化润滑油有限公司上海研究院上海200080

对涡轮机油中N-苯基-α-萘胺(T531)抗氧剂的含量进行监控可以有效地评估涡轮机油在使用过程中的氧化程度,进而预测涡轮机油的剩余使用寿命,为此建立了一种用分光光度法测定涡轮机油中T531含量的方法。用重氮盐与T531进行重氮偶合反应生... 详细信息

对涡轮机油中N-苯基-α-萘胺(T531)抗氧剂的含量进行监控可以有效地评估涡轮机油在使用过程中的氧化程度,进而预测涡轮机油的剩余使用寿命,为此建立了一种用分光光度法测定涡轮机油中T531含量的方法。用重氮盐与T531进行重氮偶合反应生成蓝紫色的偶氮化合物,并测定偶氮化合物在570 nm波长(最大吸收波长)处的吸光度来测定T531的含量。通过对T531正庚烷标准溶液进行测定,得到了定量分析T531的标准回归方程(相关系数为0.9993)。T531的检测范围在133μg/g~1332μg/g之间,共存的烷基二苯胺对T531的测定基本没有影响。建立的测定方法区分性明显,可操作性强,分析速度快,弥补了现有检测体系的空白。

关键词：偶氮化合物回归方程定量分析