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基于SECS/GEM协议的芯片烘箱设备智能故障诊断算法设计
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作者 梁达平 赵玉祥 张进兵 《电子与封装》 2024年第7期90-97,共8页
针对芯片烘箱设备故障排查困难,提出了一种改进型贝叶斯网络故障诊断算法。利用SECS/GEM通信协议从设备端获取故障报警数据,建立芯片烘箱设备故障树。将故障树映射为贝叶斯网络,通过对贝叶斯网络反向推理计算得到可用于指导维修工作的... 针对芯片烘箱设备故障排查困难,提出了一种改进型贝叶斯网络故障诊断算法。利用SECS/GEM通信协议从设备端获取故障报警数据,建立芯片烘箱设备故障树。将故障树映射为贝叶斯网络,通过对贝叶斯网络反向推理计算得到可用于指导维修工作的诊断决策树。将历史故障样本数据代入算法模型中进行验证分析,验证结果表明,按照诊断决策树进行故障诊断能够将诊断误差率控制在5%左右,满足企业用户要求,具有较高的应用价值。 展开更多
关键词 故障树 贝叶斯网络 机器学习 芯片烘箱 SECS/gem
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用于GEM-TPC探测器读出芯片的10 bit20 MSPS SAR ADC设计
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作者 孙志坤 千奕 +6 位作者 杨鸣宇 佘乾顺 赵红赟 蒲天磊 陆伟建 刘政强 张家瑞 《电子科技大学学报》 EI CAS CSCD 北大核心 2024年第4期481-486,共6页
随着大面积气体电子倍增器——时间投影室探测器的不断发展,其对读出电子学的密度和集成度要求越来越高。基于180 nm的CMOS工艺设计完成了一款10 bit、20 MSPS的逐次逼近寄存器型模数转换器原型芯片。利用该芯片结合模拟前端模块和数字... 随着大面积气体电子倍增器——时间投影室探测器的不断发展,其对读出电子学的密度和集成度要求越来越高。基于180 nm的CMOS工艺设计完成了一款10 bit、20 MSPS的逐次逼近寄存器型模数转换器原型芯片。利用该芯片结合模拟前端模块和数字信号处理器,可实现全数字化的前端读出专用集成电路用于GEM-TPC的读出。该ADC主要由DAC模块、动态比较器模块、异步时钟生成模块和SAR逻辑模块构成。仿真结果表明,输入信号频率为1.836 MHz时,ENOB为8.61 bit,内核功耗约为3.3 mW/Ch。 展开更多
关键词 gem-TPC ASIC SAR ADC 自举开关 动态比较器 异步SAR逻辑
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一种基于SECS/GEM协议的设备端通讯接口SDK的设计
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作者 隋明远 张春雷 +1 位作者 周维 周庆懿 《机械》 2024年第4期59-66,共8页
SECS/GEM通讯是应用于半导体制造设备和半导体工厂MES之间的通讯标准,半导体设备接入工厂的半导体MES,需要半导体设备按照SECS/GEM相关标准协议的要求实现通讯。为此,基于对SECS/GEM标准协议的研究分析,应用面向对象的设计方法,自上而... SECS/GEM通讯是应用于半导体制造设备和半导体工厂MES之间的通讯标准,半导体设备接入工厂的半导体MES,需要半导体设备按照SECS/GEM相关标准协议的要求实现通讯。为此,基于对SECS/GEM标准协议的研究分析,应用面向对象的设计方法,自上而下地进行软件设计和开发,提出一种整合了半导体设备通讯标准SECS/GEM的SDK,供设备端应用程序进行二次开发,为设备增添该通讯能力。SDK对SECS/GEM诸协议标准进行分层和实现、以动态链接库的形式进行封装、提供高级接口,并设计配置文件,将设备的本身特性进行分离,可以在不同类型的设备上进行部署。通过测试,验证了SDK可以满足SECS/GEM通讯要求,实现了标准中所述的各项能力,其可以应用于各类半导体制造设备的SECS/GEM通讯开发,实现与半导体工厂的MES互联。 展开更多
关键词 SECS/gem 半导体设备通讯标准 工厂自动化 网络通讯 智能制造
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Responses of plant diversity and soil microorganism diversity to nitrogen addition in the desert steppe,China
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作者 YE He HONG Mei +4 位作者 XU Xuehui LIANG Zhiwei JIANG Na TU Nare WU Zhendan 《Journal of Arid Land》 SCIE CSCD 2024年第3期447-459,共13页
Nitrogen(N)deposition is a significant aspect of global change and poses a threat to terrestrial biodiversity.The impact of plant-soil microbe relationships to N deposition has recently attracted considerable attentio... Nitrogen(N)deposition is a significant aspect of global change and poses a threat to terrestrial biodiversity.The impact of plant-soil microbe relationships to N deposition has recently attracted considerable attention.Soil microorganisms have been proven to provide nutrients for specific plant growth,especially in nutrient-poor desert steppe ecosystems.However,the effects of N deposition on plant-soil microbial community interactions in such ecosystems remain poorly understood.To investigate these effects,we conducted a 6-year N-addition field experiment in a Stipa breviflora Griseb.desert steppe in Inner Mongolia Autonomous Region,China.Four N treatment levels(N0,N30,N50,and N100,corresponding to 0,30,50,and 100 kg N/(hm2•a),respectively)were applied to simulate atmospheric N deposition.The results showed that N deposition did not significantly affect the aboveground biomass of desert steppe plants.N deposition did not significantly reduce the alfa-diversity of plant and microbial communities in the desert steppe,and low and mediate N additions(N30 and N50)had a promoting effect on them.The variation pattern of plant Shannon index was consistent with that of the soil bacterial Chao1 index.N deposition significantly affected the beta-diversity of plants and soil bacteria,but did not significantly affect fungal communities.In conclusion,N deposition led to co-evolution between desert steppe plants and soil bacterial communities,while fungal communities exhibited strong stability and did not undergo significant changes.These findings help clarify atmospheric N deposition effects on the ecological health and function of the desert steppe. 展开更多
关键词 soil microorganisms plant-microbial community interaction plant diversity nitrogen deposition desert steppe
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The Combination of Achnatherum inebrians Extracts and Soil Microorganisms Inhibited Seed Germination and Seedling Growth in Elymus nutans
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作者 Rui Zhang Taixiang Chen +4 位作者 Zhenjiang Chen Hao Chen Xuekai Wei Malik Kamran Chunjie Li 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第3期567-580,共14页
In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts f... In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans. 展开更多
关键词 Achnatherum inebrians water immersion liquid aqueous leachate precipitate ALLELOPATHY Elymus nutans soil microorganisms
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Bibliometric analysis of soil phosphate solubilizing microorganisms research using VOSviewer
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作者 Xian-yuan Du Dan-dan Li +2 位作者 Qiang-wei Wang Han-yu Zhang Yang Yang 《Life Research》 2024年第1期10-15,共6页
Phosphorus-solubilizing microbes play key roles in improving phosphorus availability and in alleviating phosphorus nutrient limitation in soils. However, we did not have a comprehensive understanding of the overall re... Phosphorus-solubilizing microbes play key roles in improving phosphorus availability and in alleviating phosphorus nutrient limitation in soils. However, we did not have a comprehensive understanding of the overall research progress and development trend of phosphorus solubilizing microorganisms. In this study, we obtain documents from the Web of Science (WOS) core collection between 2002 and 2022, and a comprehensive review of the progress of global research on soil phosphate solubilizing microorganisms was conducted by using the VOSviewer bibliometric analysis tool. The results showed an increasing trend in the number of published articles from 2002 to 2022. India, accounting for 28% of the total number of published articles, became the most productive country. However, Canada was the country with the highest average citation frequency of articles. Chinese Academy of Sciences (CAS) was the greatest contributor with the most publications. Among the published journals, Frontiers in Microbiology, Applied Soil Ecology and Plant and Soil were the top three core journals in this field. Based on the keyword analysis, the assessment of the mechanisms between phosphorus solubilizing microbes and the soil carbon cycles with the different management practices became the new research trend among the scientific communities. These findings would provide an important reference value for future in-depth research on soil phosphate solubilizing microorganisms. 展开更多
关键词 SOIL phosphate solubilizing microorganisms BIBLIOMETRICS VOSviewe
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Identification of Microorganisms in Poultry Farms in N’djamena and the Border Areas of Hadjer-Lamis and Chari-Baguirmi Chad
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作者 Abakar Abbo Zakaria Bebanto Antipas Ban-Bo +2 位作者 Nadine Terei Bongo Naré Richard Gandolo Abdelsalam Adoum Doutoum 《Journal of Agricultural Chemistry and Environment》 2024年第2期223-234,共12页
Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real... Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real health problems attributable to a lack of monitoring of the vaccination schedule, inadequate compliance with biosecurity measures and poor application of the Ichikawa rule based on the 5 M’s. Objective: The aim of this article is to identify the microorganisms responsible for contamination of poultry farms in the study area. Method: The study was carried out from 28/04/2022 to 31/01/2023 on the basis of 300 samples taken from feed, drinking water, droppings and scrapings from poultry housing surfaces in the 30 farms that served as a framework for our research. Sampling was of the simple random type, and farms were selected on the basis of the farmers’ consent. The data were recorded on pre-established survey forms. Our study was cross-sectional, descriptive and prospective. Bacteria were isolated using the reference method NF EN ISO 6579 for Salmonella spp. and cultured on the specific medium eosin methylene blue (EMB) for Escherichia coli, Pseudomonas and Citrobacter freundii. Results: The following results emerged from this study: Escherichia coli (5.33%), Pseudomonas (1.33%), Citrobacter freundii (12%) and Salmonella paratyphi (21.68%). Conclusion: Of the 300 samples analysed, 121 (40.33%) were contaminated with pathogens. This high level of contamination is a health problem. The study shows that biosecurity is less satisfactory on the farms visited. Nevertheless, farms with a very satisfactory level of biosafety ensure food safety and variety for the population. 展开更多
关键词 microorganisms Identification Poultry Farms N’Djamena Hadjer-Lamis Chari-Baguirmi(Chad)
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GEM框架下的广州与深圳创业环境比较研究
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作者 邓春丽 周佩钰 张巍 《企业科技与发展》 2024年第3期50-54,共5页
作为大湾区的中心城市,广州与深圳依托其丰富的科教资源、完备的产业链及活跃的资本市场,备受创业者青睐。然而,两个城市的创业环境存在显著差异,进而对当地的创业生态和企业发展策略产生深远的影响。文章对广州和深圳的创业环境及其相... 作为大湾区的中心城市,广州与深圳依托其丰富的科教资源、完备的产业链及活跃的资本市场,备受创业者青睐。然而,两个城市的创业环境存在显著差异,进而对当地的创业生态和企业发展策略产生深远的影响。文章对广州和深圳的创业环境及其相关影响因素进行系统的文献回顾和总结,并向两地的创业者和专家学者发放调查问卷,综合运用描述性分析、主成分分析及Logit回归等方法深入剖析所得数据,借助全球创业观察(GEM)框架比较两地创业环境,分析广州与深圳的创业条件和特点,旨在为创业活动和政策的制定提供有力的数据支撑和参考。 展开更多
关键词 广州 深圳 全球创业观察(gem) 创业环境 对策建议
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GEM多频电磁在吉林市牤牛河泥砂分布测量的初步应用 被引量:1
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作者 丁志强 李飞 +2 位作者 王浩 刘裕 黄威 《工程地球物理学报》 2023年第2期143-152,共10页
通过对GEM-2多频电磁仪方法技术介绍和测试分析,首次使用多频电磁仪进行泥砂分布研究。采用425~63 025 Hz按指数增加的5个频率,以平均线距60 m完成吉林市境内牤牛河棋盘村-江密峰镇一带垂直河道测线477条测量,涉及河道长约28.11 km,覆... 通过对GEM-2多频电磁仪方法技术介绍和测试分析,首次使用多频电磁仪进行泥砂分布研究。采用425~63 025 Hz按指数增加的5个频率,以平均线距60 m完成吉林市境内牤牛河棋盘村-江密峰镇一带垂直河道测线477条测量,涉及河道长约28.11 km,覆盖面积约1.17 km2。通过不同频率同相、正交、视电导率、视电阻率等值线平面图分析,不同频率反应不同的深度,能有效识别泥砂之间的电阻率差异。根据测量的多频数据进行了深度换算,结合一维反演推断含砂层在2 m、6 m和10 m左右,分别对应高频63 025 Hz、中频5 175 Hz和低频425 Hz探测的深度;再结合收集的资料和实地勘查,进行了区域地质及电性特征分析,推测河道沉积模型或第四系覆盖层模型,从而对牤牛河流域泥砂分布的位置及深度进行了初步划分,可为流域内土壤侵蚀防治、防洪除涝、泥沙治理、生态环境保护等提供相关的基础资料和参考。 展开更多
关键词 gem-2多频电磁测量 牤牛河 泥砂分布
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GEM探测器多通道前端读出ASIC设计
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作者 马毅超 姚旭腾 +1 位作者 曾莉欣 朱林 《核电子学与探测技术》 CAS 北大核心 2023年第5期1105-1112,共8页
为满足高效率、高分辨率、高通量二维位置灵敏中子探测器的需求,设计了基于GF 0.18μm工艺的32通道GEM探测器前端读出ASIC数模混合芯片。针对GEM探测器输出的信号特点,设计了灵敏电荷放大电路、成形电路、甄别器电路等模拟电路以及刻度... 为满足高效率、高分辨率、高通量二维位置灵敏中子探测器的需求,设计了基于GF 0.18μm工艺的32通道GEM探测器前端读出ASIC数模混合芯片。针对GEM探测器输出的信号特点,设计了灵敏电荷放大电路、成形电路、甄别器电路等模拟电路以及刻度信号配置电路、译码器电路等数字电路。测试结果表明:ASIC最高计数率可达10^(7)s^(-1),前放电路具有较好的积分线性度。 展开更多
关键词 gem探测器 ASIC设计 电荷灵敏前放 准高斯成形
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GPD⁃GEM有效增益研究及其优化
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作者 蒋杰臣 姜维春 +8 位作者 董泽芳 杨生 刘晓静 刘小桦 杜园园 焦杨 戴博宇 徐玉朋 何会林 《宇航计测技术》 CSCD 2023年第1期40-44,共5页
偏振测量X射线聚焦望远镜阵列(PFA)属于增强型X射线时变与偏振空间天文台(eXTP)有效载荷之一,其位于焦平面的气体像素探测器(GPD)用于测量处于极端条件下天体辐射的软X射线偏振度等物理参数。GPD采用单层气体电子倍增器(GEM)作为气体放... 偏振测量X射线聚焦望远镜阵列(PFA)属于增强型X射线时变与偏振空间天文台(eXTP)有效载荷之一,其位于焦平面的气体像素探测器(GPD)用于测量处于极端条件下天体辐射的软X射线偏振度等物理参数。GPD采用单层气体电子倍增器(GEM)作为气体放大级,有效面积为(15.5×15.5)mm^(2),孔型为双锥形结构,相邻孔间间距为50μm,孔外直径为30μm,锥角约为10°;该GEM孔采用非聚焦激光辐照技术制作成型,生产时由于激光非均匀性以及辐照区域重叠,将引起不同孔的锥角出现差异,造成孔间增益不均匀。基于GPD基线设计参数,通过构建GPD⁃GEM模拟框架,验证了模拟的有效增益和文献测试结果的一致性;在相同工作电压下,0°~10°范围内不同锥角对应的GPD⁃GEM有效增益基本呈线性关系。该结果表明GPD⁃GEM孔型最优为圆柱形结构,为其生产工艺提供了优化方向。 展开更多
关键词 GPD⁃gem 增益 模拟
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矿用挖掘机操作界面的GEM-AHP法决策评价 被引量:2
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作者 王雅坤 任家骏 +1 位作者 李爱峰 边轩毅 《机械设计与制造》 北大核心 2023年第2期20-23,27,共5页
针对矿用挖掘机操作界面的决策评价问题,提出了采用GEM-AHP法决策理论模型对矿用挖掘机的操作界面方案决策评价。首先,在矿用挖掘机的操作界面的特点和设计标准基础上,依据层次分析法原理构建决策指标,根据矿用挖掘机的特点,改进GEM-AH... 针对矿用挖掘机操作界面的决策评价问题,提出了采用GEM-AHP法决策理论模型对矿用挖掘机的操作界面方案决策评价。首先,在矿用挖掘机的操作界面的特点和设计标准基础上,依据层次分析法原理构建决策指标,根据矿用挖掘机的特点,改进GEM-AHP算法,结合JACK人机工程软件的虚拟仿真结果,构建适用于矿用挖掘机的操作界面决策理论模型;其次,依据太原重工集团的某型号矿用挖掘机操作界面,重新设计了3个待评价方案,验证决策评价;最后,设定了6项敏感性分析试验以检验该模型决策评价结果是否可信。结果表明:该方法结合了GEM法和AHP法的优点,并参考JACK人机工程评价结果,规避了判断矩阵的不一致性问题和决策的主观性,简化了计算过程,可信度较高,节约了企业的决策成本。 展开更多
关键词 矿用挖掘机 操作界面 gem-AHP法 决策评价
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GEM相机监测EAST等离子体破裂研究
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作者 陈钰 瞿火祥 李二众 《核电子学与探测技术》 CAS 北大核心 2023年第2期434-440,共7页
等离子体破裂是托卡马克运行中常见的一种现象,高参数等离子体运行过程中发生破裂会对实验装置安全运行产生威胁。通过对等离子体破裂的研究,可以在未来进一步做到破裂的避免和主动控制。首先介绍了EAST装置上的等离子体破裂,通过GEM相... 等离子体破裂是托卡马克运行中常见的一种现象,高参数等离子体运行过程中发生破裂会对实验装置安全运行产生威胁。通过对等离子体破裂的研究,可以在未来进一步做到破裂的避免和主动控制。首先介绍了EAST装置上的等离子体破裂,通过GEM相机对EAST放电实验中几种类型的破裂炮进行二维成像分析,对破裂的发生过程进行了具体分析。并且在分析过程中展示了GEM系统较传统多道系统的优越性,确认GEM可以为破裂机理研究提供有效的诊断数据。 展开更多
关键词 gem气体探测器 软X射线诊断 等离子体破裂
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贵州茶叶产业集群竞争力研究——基于GEM模型 被引量:1
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作者 李晓雪 《昆明学院学报》 2023年第3期42-49,共8页
以近年来茶产业发展较为迅速的贵州省为样本,利用区域产业竞争力分析模型GEM进行定量分析,围绕基础、企业、市场3个维度评价贵州茶叶产业集群竞争力水平,提出培育龙头企业、打造优质品牌,加强创新能力、提高产品质量,提升国内市场、开... 以近年来茶产业发展较为迅速的贵州省为样本,利用区域产业竞争力分析模型GEM进行定量分析,围绕基础、企业、市场3个维度评价贵州茶叶产业集群竞争力水平,提出培育龙头企业、打造优质品牌,加强创新能力、提高产品质量,提升国内市场、开拓国际市场6个方面的措施推动茶叶产业集群高质量发展. 展开更多
关键词 茶叶 产业集群 竞争力 gem模型
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Causative Microorganisms Isolated from Patients with Intra-Abdominal Infections and Their Drug Resistance Profiles:An 11-Year(2011–2021)Single-Center Retrospective Study 被引量:1
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作者 DING Rui MA Rui Rui +10 位作者 LIU Ya Li ZHAO Ying GUO Li Na DOU Hong Tao SUN Hong Li LIU Wen Jing ZHANG Li WANG Yao LI Ding Ding YI Qiao Lian XU Ying Chun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第8期732-742,共11页
Objective To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections(IAIs).Methods A total of 2,926 bacterial and fungal strain... Objective To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections(IAIs).Methods A total of 2,926 bacterial and fungal strains were identified in samples collected from 1,679 patients with IAIs at the Peking Union Medical College Hospital between 2011 and 2021.Pathogenic bacteria and fungi were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.Antimicrobial susceptibility testing(AST)was performed using the VITEK 2 compact system and the Kirby–Bauer method.AST results were interpreted based on the M100-Ed31 clinical breakpoints of the Clinical and Laboratory Standards Institute.Results Of the 2,926 strains identified,49.2%,40.8%,and 9.5%were gram-negative bacteria,gram-positive bacteria,and fungi,respectively.Escherichia coli was the most prevalent pathogen in intensive care unit(ICU)and non-ICU patients;however,a significant decrease was observed in the isolation of E.coli between 2011 and 2021.Specifically,significant decreases were observed between 2011 and 2021 in the levels of extended-spectrumβ-lactamase(ESBL)-producing E.coli(from 76.9%to 14.3%)and Klebsiella pneumoniae(from 45.8%to 4.8%).Polymicrobial infections,particularly those involving co-infection with gram-positive and gram-negative bacteria,were commonly observed in IAI patients.Moreover,Candida albicans was more commonly isolated from hospital-associated IAI samples,while Staphylococcus epidermidis had a higher ratio in community-associated IAIs.Additionally,AST results revealed that most antimicrobial agents performed better in non-ESBL-producers than in ESBL-producers,while the overall resistance rates(56.9%–76.8%)of Acinetobacter baumanmii were higher against all antimicrobial agents than those of other common gram-negative bacteria.Indeed,Enterococcus faecium,Enterococcus faecalis,S.epidermidis,and S.aureus were consistently found to be susceptible to vancomycin,teicoplanin,and linezolid.Similarly,C.albicans exhibited high susceptibility to all the tested antifungal drugs.Conclusion The distribution and antimicrobial susceptibility of the causative microorganisms from patients with IAls were altered between 2011 and 2021.This finding is valuable for the implementation of evidence-based antimicrobial therapy and provides guidance for the control of hospital infections. 展开更多
关键词 Intra-abdominal infection Causative microorganisms Antimicrobial susceptibility testing Gram-negative bacteria Gram-positive bacteria
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硬化水泥净浆的太赫兹介电常数和其孔结构的GEM模型分析
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作者 张文涛 王志国 +2 位作者 王志勇 杜红秀 李翔宇 《太原理工大学学报》 CAS 北大核心 2023年第6期1118-1126,共9页
【目的】深入了解水泥净浆的孔结构对于研究如何提升水泥基材料的性能是非常必要的。【方法】使用太赫兹时域光谱(THz-TDS)技术测试得到水灰比为0.3,0.4,0.5,水化龄期为7 d、28 d、56 d的干燥硬化水泥净浆在0.2~2 THz频段的时域信号。... 【目的】深入了解水泥净浆的孔结构对于研究如何提升水泥基材料的性能是非常必要的。【方法】使用太赫兹时域光谱(THz-TDS)技术测试得到水灰比为0.3,0.4,0.5,水化龄期为7 d、28 d、56 d的干燥硬化水泥净浆在0.2~2 THz频段的时域信号。利用时域信号下的延迟时间计算得到水泥净浆的折射率和介电常数。【结果】结果显示,同一龄期下水泥净浆的介电常数随水灰比增大而减小;相同水灰比水泥净浆的介电常数则随龄期变化不明显。使用General Effective Media(GEM)模型建立了水泥净浆有效介电常数和其孔结构之间的关系,通过实验数据拟合,得到水泥净浆中水化产物固体相的介电常数为8.73.【结论】通过对GEM模型进行参数分析发现,水泥净浆的孔隙率是影响其有效介电常数最主要的因素。 展开更多
关键词 太赫兹光谱技术 硬化水泥净浆 gem模型 折射率 介电常数
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湖北省区域创业环境发展的评价及其时空差异——基于GEM理论模型分析
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作者 胡瑞 赵紫睿 宾朋 《创新与创业教育》 2023年第5期44-53,共10页
创业环境是推动区域创新的重要动力与核心要素。基于GEM理论模型,建构了包含7个一级指标、28个二级指标的湖北省区域创业环境评价体系,运用熵值赋权法和空间插值法对湖北省17座城市2011—2020年的创业环境展开分析和评价。研究发现:在... 创业环境是推动区域创新的重要动力与核心要素。基于GEM理论模型,建构了包含7个一级指标、28个二级指标的湖北省区域创业环境评价体系,运用熵值赋权法和空间插值法对湖北省17座城市2011—2020年的创业环境展开分析和评价。研究发现:在时间维度上,各城市的创业环境发展呈周期性波动,且变化幅度存在差异;鄂东地区的创业环境发展长年保持优势;鄂西、鄂北地区呈波动上升;鄂中地区虽然落后,但与其他区域的差距逐渐缩小。在空间维度上,湖北省创业环境由极点式向区域式变化;省内四大区域的创业环境发展呈现空间聚集状态,且形成了“鄂东>鄂西>鄂北>鄂中”的分布格局。基于此,提出完善创业政策体系、加大创业金融支持、改善商业基础设施环境和优化创业教育与培训的建议。 展开更多
关键词 gem理论 区域 创业环境 评价
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Revisiting “Non-Thermal” Batch Microwave Oven Inactivation of Microorganisms
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作者 Victor John Law Denis Pius Dowling 《American Journal of Analytical Chemistry》 CAS 2023年第1期28-54,共27页
Over the last few decades there has been active discussion concerning the mechanisms involved in “non-thermal” microwave-assisted inactivation of microorganisms. This work presents a novel non-invasive acoustic meas... Over the last few decades there has been active discussion concerning the mechanisms involved in “non-thermal” microwave-assisted inactivation of microorganisms. This work presents a novel non-invasive acoustic measurement of a domestic microwave oven cavity-magnetron operating at f<sub>o</sub> = 2.45 ± 0.05 GHz (λ<sub>o</sub> ~ 12.2 cm) that is modulated in the time-domain (0 to 2 minutes). The measurements reveal the cavity-magnetron cathode filament cold-start warm-up period and the pulse width modulation periods (time-on time-off and base-time period, where time-on minus base-time = duty cycle). The waveform information is used to reconstruct historical microwave “non-thermal” homogeneous microorganism inactivation experiments: where tap-water is used to mimic the microorganism suspension;and ice, crushed ice, and ice slurry mixture are used as the cooling media. The experiments are described using text, diagrams, and photographs. Four key experimental parameters are indentified that influence the suspension time-dependent temperature profile. First, where the selected process time > the time-base, the cavity-magnetron continuous wave rated power should be used for each second of microwave illumination. Second, external crushed ice and ice slurry baths induce different cooling profiles due to difference in their heat absorption rates. In addition external baths may shield the suspension resulting in a retarding of the time-dependent heating profile. Third, internal cooling systems dictate that the suspension is directly exposed to microwave illumination due to the absence of surrounding ice volume. Fourth, four separated water dummy-loads isolate and control thermal heat transfer (conduction) to and from the suspension, thereby diverting a portion of the microwave power away from the suspension. Energy phase-space projections were used to compare the “non-thermal” energy densities of 0.03 to 0.1 kJ·m<sup>-1</sup> at 800 W with reported thermal microwave-assisted microorganism inactivation energy densities of 0.5 to 5 kJ·m<sup>-1</sup> at 1050 ± 50 W. Estimations of the “non-thermal” microwave-assisted root mean square of the electric field strength are found to be in the range of 22 to 41.2 V·m<sup>-1</sup> for 800 W. 展开更多
关键词 Thermal NON-THERMAL MICROWAVE-ASSISTED Microwave Oven Acoustic FOOD microorganismS
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Shape Effect of Nanoparticles on Nanofluid Flow Containing Gyrotactic Microorganisms
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作者 Umair Rashid Azhar Iqbal Abdullah M.Alsharif 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第1期483-494,共12页
In this paper,we discussed the effect of nanoparticles shape on bioconvection nanofluid flow over the vertical cone in a permeable medium.The nanofluid contains water,Al2O3 nanoparticles with sphere(spherical)and lami... In this paper,we discussed the effect of nanoparticles shape on bioconvection nanofluid flow over the vertical cone in a permeable medium.The nanofluid contains water,Al2O3 nanoparticles with sphere(spherical)and lamina(non-spherical)shapes and motile microorganisms.The phenomena of heat absorption/generation,Joule heating and thermal radiation with chemical reactions have been incorporated.The similarity transformations technique is used to transform a governing system of partial differential equations into ordinary differential equations.The numerical bvp4c MATLAB program is used to find the solution of ordinary differential equations.The interesting aspects of pertinent parameters on mass transfer,energy,concentration,and density of themotilemicroorganisms’profiles are computed and discussed.Our analysis depicts that the performance of sphere shape nanoparticles in the form of velocity distribution,temperature distribution,skin friction,Sherwood number and Motile density number is better than lamina(non-spherical)shapes nanoparticles. 展开更多
关键词 Nanoparticle shape NANOFLUID numerical technique gyrotactic microorganisms MAGNETOHYDRODYNAMICS
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Impact of microorganism degradation on hydrocarbon generation of source rocks:A case study of the Bozhong Sag,Bohai Bay Basin
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作者 Wei Li Yufei Gao Youchuan Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第3期243-253,共11页
The discovery of the Bozhong 19-6 gas field,the largest integrated condensate gas field in the eastern China in 2018,opened up a new field for the natural gas exploration deep strata in the Bohai Bay Basin,demonstrati... The discovery of the Bozhong 19-6 gas field,the largest integrated condensate gas field in the eastern China in 2018,opened up a new field for the natural gas exploration deep strata in the Bohai Bay Basin,demonstrating there is a great potential for natural gas exploration in oil-type basins.The ethane isotope of the Bozhong 19-6 condensate gas is heavy,showing the characteristics of partial humic gas.In this paper,aimed at the source rocks of the Bozhong 19-6 gas field in the Bohai Bay Basin,the characteristics of the source rocks in the Bozhong 19-6 structural belt were clarified and the reason are explained from impact of microorganism degradation on hydrocarbon generation of source rocks why the condensate oil and gas had heavy carbon isotope and why it showed partial humic characteristics was explored based on the research of parent materials.The following conclusions were obtained:The paleontology of the Bozhong 19-6 structural belt and its surrounding sub-sags is dominated by higher plants,such as angiosperm and gymnosperm.During the formation of source rocks,under the intensive transformation of microorganism,the original sedimentary organic matter such as higher plants was degraded and transformed by defunctionalization.Especially,the transformation of anaerobic microorganisms on source rocks causes the degradation and defunctionalization of a large number of humic products such as higher plants and the increase of hydrogen content.The degradation and transformation of microorganism don't transform the terrestrial humic organic matter into newly formed“sapropel”hydrocarbons,the source rocks are mixed partial humic source rocks.As a result,hydrogen content incrased and the quality of source rocks was improved,forming the partial humic source rocks dominated by humic amorphous bodies.The partial humic source rocks are the main source rocks in the Bozhong 19-6 gas field,and it is also the internal reason why the isotope of natural gas is heavy. 展开更多
关键词 Bozhong Sag natural gas types of source rocks microorganism degradation hydrocarbon generation of source rocks
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