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An unsupervised clustering method for nuclear magnetic resonance transverse relaxation spectrums based on the Gaussian mixture model and its application

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Petroleum Exploration and Development 2022年第2期49卷 339-348页

作者： GE Xinmin XUE Zong’an ZHOU Jun HU Falong LI jiangtao zhang Hengrong WANG Shuolong {2. Shenyuan ZHAO ji’er School of Geosciences China University of PetroleumQingdao 266580China CNPC Key Well Logging Laboratory Xi’an 710077China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Oil and Gas Survey Center of china Geological Survey Beijing 100083China china Petroleum Logging Co.Ltd. Xi’an 710077China Petrochina Research Institute of Petroleum Exploration&Development Beijing 100083China Petrochina Qinghai Oilfield Company Dunhuang 736202China Zhanjiang Branch of CNOOC Ltd. Zhanjiang 524057China Sinopec Research Institute of Petroleum Engineering Beijing 100101China

To make the quantitative results of nuclear magnetic resonance(NMR) transverse relaxation(T;) spectrums reflect the type and pore structure of reservoir more directly, an unsupervised clustering method was developed to obtain the quantitative pore structure information from the NMR T;spectrums based on the Gaussian mixture model(GMM). Firstly, We conducted the principal component analysis on T;spectrums in order to reduce the dimension data and the dependence of the original variables. Secondly, the dimension-reduced data was fitted using the GMM probability density function, and the model parameters and optimal clustering numbers were obtained according to the expectation-maximization algorithm and the change of the Akaike information criterion. Finally, the T;spectrum features and pore structure types of different clustering groups were analyzed and compared with T;geometric mean and T;arithmetic mean. The effectiveness of the algorithm has been verified by numerical simulation and field NMR logging data. The research shows that the clustering results based on GMM method have good correlations with the shape and distribution of the T;spectrum, pore structure, and petroleum productivity, providing a new means for quantitative identification of pore structure, reservoir grading, and oil and gas productivity evaluation.

关键词： NMR T2.spectrum Gaussian mixture model expectation-maximization algorithm Akaike information criterion unsupervised clustering method quantitative pore structure evaluation

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Bilateral Ureteral Fibroepithelial Polyps:a Case Report

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Chinese Medical sciences Journal 2012年第2期27卷 125-126页

作者： ji-rui niu Shi Rong Zhi-gang ji Hua Fan jing-min Zhou Zhen-yu zhang Departments of Urology Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

DRIMARY benign ureteral tumors are rare and they arise from the mesodermal tissue of the ureteral wall. Less than 2.0 cases have been docu- mented in published reports.1 Bilateral ureteralfibroepithelial polyps are extremely rare and commonly occur in the proximal ureter, causing complete ureteral obstruction. Pyeloplasty is an effective treatment for im- proving renal function. Here we report a case with se- quential bilateral ureteral fibroepithelial polyps causing obstructive hydronephrosis.

关键词： ureteral polyps fibroepithelial polyps

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2.16—2.2.年珠三角地区PM_(2.5)中多环芳烃污染特征及健康风险

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环境卫生学杂志 2024年第5期14卷 431-437,447页

作者：牛计伟李晓恒季佳佳刘宁张振裴迎新施小明中国疾病预防控制中心北京100050 广东省疾病预防控制中心广州410030 深圳市疾病预防控制中心中国疾病预防控制中心

目的评价多环芳烃暴露的人群健康风险,了解珠三角地区大气PM_(2.5)及其中16种多环芳烃的污染特征和来源。方法2.16—2.2.年在广东省珠三角地区的广州、深圳、佛山及珠海市选10个区设置10个监测点,每月10—16日采集环境空气样品,测定PM_(... 详细信息

目的评价多环芳烃暴露的人群健康风险,了解珠三角地区大气PM_(2.5)及其中16种多环芳烃的污染特征和来源。方法2.16—2.2.年在广东省珠三角地区的广州、深圳、佛山及珠海市选10个区设置10个监测点,每月10—16日采集环境空气样品,测定PM_(2.5)及其中16种多环芳烃含量,分析多环芳烃污染来源,使用BaP毒性当量法评价多环芳烃呼吸暴露途径的人群健康风险。结果2.16—2.2.年珠三角地区PM_(2.5)逐年平均浓度(x±s)分别为(57.45±2..66)、(51.2.±3..69)、(43.86±3..17)、(40.53.2..70)、(2..2.±3..2.)、(3..57±2..91)、(3..17±2..06)μg/m^(3.,呈下降趋势(Z=-2..83.P2.5)中多环芳烃平均浓度(x±s)分别为(6.2.±6.2.)、(5.17±6.95)、(4.00±4.46)、(3.3.±3.93.、(2.52.2.92.、(3.05±4.3.)、(2.65±2.60)ng/m^(3.,浓度虽然降低近60%,但下降趋势无统计学意义,多环芳烃16种成分除萘(NAP)外均呈下降趋势(P2.18—2.2.年PM_(2.5)中多环芳烃致癌效应健康风险CR值M(P_(2.),P_(75))为5.3.×10^(-7)(2.54×10^(-7),1.2.×10^(-6)),自第69百分位数开始大于1×10^(-6),第99百分位数为9.19×10^(-6),均小于1×10^(-4)。结论珠三角地区四城市大气PM_(2.5)污染整体呈不断改善趋势,四城市中临海的深圳和珠海市优于佛山和广州市,PM_(2.5)与多环芳烃成分含量呈显著正相关,逐月变化趋势基本一致。多环芳烃污染主要是本地源排放所致,存在石化燃料燃烧、机动车尾气排放、石油挥发和有机物质燃烧等多重来源,不同城市多环芳烃污染构成和来源并不完全一致,且高温燃煤对多环芳烃浓度变化有重要影响。珠三角地区大气PM_(2.5)中多环芳烃具有潜在致癌风险,宜引起关注。

关键词：空气污染细颗粒物多环芳烃污染特征健康风险评估

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钢轨打磨仿真试验台测试条件对试验结果的影响

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高速铁路新材料 2024年第4期3卷 1-5页

作者：吉媛贺春江张金郭鑫宇牛思仝中国铁道科学研究院集团有限公司金属及化学研究所北京100081 北京中铁科新材料技术有限公司北京100081 中航铁服人力资源(北京)有限公司北京100081

利用钢轨打磨仿真试验台,对打磨试验中砂轮转速、打磨功率、打磨时间、工件转速对试验结果的影响进行了综合研究,并对试验数据及现象进行了定性分析,得出了科学的打磨仿真试验测试条件。试验结果表明:单独提高砂轮转速时,打磨压力减小,... 详细信息

利用钢轨打磨仿真试验台,对打磨试验中砂轮转速、打磨功率、打磨时间、工件转速对试验结果的影响进行了综合研究,并对试验数据及现象进行了定性分析,得出了科学的打磨仿真试验测试条件。试验结果表明:单独提高砂轮转速时,打磨压力减小,工件磨削量减小,砂轮磨耗率减小,砂轮温升和工件温升下降;单独增大打磨功率时,打磨压力先快速增大后趋于缓慢,工件磨削量在13.50~14.2. kW时突然剧烈增加,砂轮磨耗率在10.50~11.2. kW和13.50~14.2. kW处突然剧烈增加,工件温升和砂轮温升先增大后趋于稳定;单独增加打磨时间时,打磨压力基本稳定,工件磨削量增加,砂轮磨耗率、砂轮温升和工件温升先增加后趋于平稳;单独提高工件转速时,工件磨削量减小,砂轮磨耗率减小。综合考虑现场实际工况和实验室内模拟效果,将打磨仿真试验台的测试条件定为打磨功率7.50~11.2. kW,打磨时间16 min,砂轮转速2.00 r/min,工件转速10.85 km/h。

关键词：打磨仿真试验台砂轮转速打磨功率打磨时间工件转速

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SiC_(f)/SiC包壳管和Kovar合金钎焊接头的组织及力学性能研究

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兵器材料科学与工程 2024年第5期47卷 13-17页

作者：高笑语姬雄帅张华锋赵建国牛凤姣黄建源郭亚杰长安大学材料科学与工程学院陕西西安710064 国家电投集团科学技术研究院有限公司北京102209 长安大学现代工程训练中心陕西西安710064

碳化硅纤维增强碳化硅复合材料(SiC_(f)/SiC)具有较低的水蒸气化学活性、低中子吸收截面和高损伤耐受性,被视为理想的核用包壳材料。钎焊是实现SiC_(f)/SiC包壳管和Kovar合金端塞连接的重要工艺。本文用Ag-3..5Cu-3.i钎料完成了SiC_(f)/... 详细信息

碳化硅纤维增强碳化硅复合材料(SiC_(f)/SiC)具有较低的水蒸气化学活性、低中子吸收截面和高损伤耐受性,被视为理想的核用包壳材料。钎焊是实现SiC_(f)/SiC包壳管和Kovar合金端塞连接的重要工艺。本文用Ag-3..5Cu-3.i钎料完成了SiC_(f)/SiC包壳管与Kovar合金端塞的钎焊。结果表明:钎焊温度为880℃、保温时间为3. min时,钎焊焊缝组织致密,无明显缺陷。焊缝组织主要为Ag-Cu共晶,界面反应层的主要相组成为TiC和Fe2.i。钎焊接头的抗剪切强度达到了41.2.MPa。

关键词： SiC_(f)/SiC包壳管 Kovar合金 AgCuTi钎料

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北非地区Ghadames盆地早古生代岩相古地理演化特征

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古地理学报 2024年第1期26卷 45-57页

作者：张忠民李依霖郑乃熙曹喆吕雪雁李宗峰孙润明夏昌盛李磊牛博宿宇驰张浩飞冯志强季汉成鲍志东中国石油化工股份有限公司石油勘探开发研究院油气资源与工程全国重点实验室中国石油大学(北京) 中国石油大学(北京)地球科学学院东北石油大学非常规油气研究院

北非地区Ghadames盆地已成为中国海外油气勘探与项目投资的重点盆地之一,对其早古生代沉积体系及岩相古地理特征的准确认识是进一步勘探的基础,也是建立盆地早期构造与沉积演化过程的关键。以Gha dames盆地早古生界为研究目标,利用岩心... 详细信息

北非地区Ghadames盆地已成为中国海外油气勘探与项目投资的重点盆地之一,对其早古生代沉积体系及岩相古地理特征的准确认识是进一步勘探的基础,也是建立盆地早期构造与沉积演化过程的关键。以Gha dames盆地早古生界为研究目标,利用岩心、地震与测井等资料综合分析,开展古地貌恢复,对沉积体系、岩相古地理演化特征进行探讨。结果表明,Ghadames盆地早古生代共发育4种沉积体系:冲积扇、辫状河、辫状河三角洲和浅海。早中寒武世,阿瓦隆地体向波罗的板块漂移,原特提斯洋初步扩张,形成活动大陆边缘,盆地以陆相沉积为主;奥陶纪,盆地经加里东运动初步形成台内隆坳格局,Ghadames盆地西部和北部大范围剥蚀,冰川大规模出现,发育冰碛岩;早中志留世,古特提斯洋持续扩张,海平面不断上升,盆地北部发生大规模海侵,以浅海沉积环境为主,广泛发育放射性页岩与泥岩,是区域内重要的烃源岩与盖层;泥盆纪,海西运动使区域整体抬升,盆内海域范围减小,以陆相沉积为主。在此基础上,建立Ghadames盆地早古生代特提斯洋演化背景下的海陆过渡沉积模式,可为研究区下一步勘探工作提供参考依据。

关键词：沉积体系岩相古地理沉积模式早古生代 Ghadames盆地北非地区

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分布交互仿真/高层体系结构中作战想定的可视化生成系统

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系统仿真学报 2002年第3期14卷 310-312,325页

作者：黄四牛陈宗基张鹏北京航空航天大学自动控制系北京100083

对DIS/HLA中作战想定的可视化生成和加载进行了研究,着重分析了基本模型的管理、模型的实例化参数化、代码自动生成、文档自动生成以及模型数据的自动加载等。并研究了实体模型的可重用性和作战想定可视化生成系统的互操作性。最后针对... 详细信息

对DIS/HLA中作战想定的可视化生成和加载进行了研究,着重分析了基本模型的管理、模型的实例化参数化、代码自动生成、文档自动生成以及模型数据的自动加载等。并研究了实体模型的可重用性和作战想定可视化生成系统的互操作性。最后针对导弹攻防对抗仿真系统开发了作战想定的可视化生成系统,它基于高效的数据管理方法并提供对信息管理系统的无缝连接。论文不仅研究和实现了作战想定的可视化生成系统,同时为DIS/HLA的各种支撑系统的可视化研究提供了重要的参考依据。

关键词：分布交互仿真高层体系结构作战想定可视化生成系统 C^4I系统

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Pulse electrochemical synaptic transistor for supersensitive and ultrafast biosensors

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InfoMat 2023年第11期5卷 25-39页

作者： jianlong ji Zhenxing Wang Fan {2. Bin Wang Yan {3. Xiaoning jiang Zeng-ying Qiao Tian-ling Ren Wendong {2. Shengbo Sang Zhengdong Cheng Qijun Sun College of Electronics Information and Optical Engineering Taiyuan University of TechnologyTaiyuanthe People’s Republic of China beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijingthe People’s Republic of China Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleighNorth CarolinaUSA D Artificial Intelligence Biomedical Research Institute Taiyuanthe People’s Republic of China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijingthe People’s Republic of China Institute of Microelectronics Tsinghua UniversityBeijingthe People’s Republic of China College of Chemical and Biological Engineering Zhejiang UniversityHangzhouthe People’s Republic of China

High sensitivity and fast response are the figures of merit for benchmarking commercial *** to the advantages of intrinsic signal amplification,bionic ability,and mechanical flexibility,electrochemical transistors(ECTs)have recently gained increasing popularity in constructing various *** the current work,we have proposed a pulse-driven synaptic ECT for supersensitive and ultrafast *** pulsing the presynaptic input(drain bias,VD)and setting the modulation potential(gate bias)near transconductance intersection(VG,i),the synaptic ECT-based pH sensor can achieve a record high sensitivity up to 12. mV pH^(-1)(almost twice the Nernstian limit,59.2.mV pH^(-1))and an ultrafast response time as low as 8.75 ms(7169 times faster than the potentiostatic sensors,62.73.s).The proposed synaptic sensing strategy can effectively eliminate the transconductance fluctuation issue during the calibration process of the pH sensor and significantly reduce power ***,the most sensitive working point at VG,i has been elaborately figured out through a series of detailed mathematical derivations,which is of great significance to provide higher sensitivity with quasi-nonfluctuating amplification *** proposed electrochemical synaptic transistor paired with an optimized operating gate offers a new paradigm for standardizing and commercializing high-performance biosensors.

关键词： fast response pH sensor pulse electrochemical transistor supersensitive synaptic transistor

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Discovery and validation of prognostic markers in gastric cancer by genome-wide expression profiling

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World Journal of Gastroenterology 2011年第13期17卷 1710-1717页

作者： Yue-Zheng zhang Lian-Hai zhang Yang Gao Chao-Hua Li Shu-Qin{2.a Ni Liu Feng Cheng De-Yun {3. William CS Cho {2.a-Fu {2. Chang-Qing Zeng beijing Institute of Genomics Chinese Academy of Sciences Beijing 100029 China CAS Key Laboratory of Genome sciences andInformation Chinese Academy of Sciences Beijing Institute ofGenomics Beijing 100029 China graduate School of ChineseAcademy of sciences Beijing 100049 China Key Labora-tory of Carcinogenesis and Translational Research (Ministry ofEducation) Department of Surgery Beijing Cancer Hospitaland Institute Peking University School of Oncology Beijing100142 China Department of Clinical Oncology QueenElizabeth Hospital Hong Kong China Laboratory of Cancer Genomics and Personalized Medicine Beijing Institute of Genomics ChineseAcademy of Sciences Beijing 100029 China

AIM: To develop a prognostic gene set that can predict patient overall survival status based on the whole genome expression analysis. METHODS: Using Illumina HumanWG-6 BeadChip followed by semi-supervised analysis, we analyzed the expression of 47 2.6 transcripts in two batches of gastric cancer patients who underwent surgical resection. Thirty-nine samples in the first batch were used as the training set to discover candidate markers correlated to overall survival, and thirty-three samples in the second batch were used for validation. RESULTS: A panel of ten genes were identified as prognostic marker in the first batch samples and classified patients into a lowand a high-risk group with significantly different survival times (P = 0.000047). This prognostic marker was then verified in an independent validation sample batch (P = 0.0009). By comparing with the traditional Tumor-node-metastasis (TNM) staging system, this ten-gene prognostic marker showed consistent prognosis results. It was the only independent prognostic value by multivariate Cox regression analysis (P = 0.007). Interestingly, six of these ten genes are ribosomal proteins, suggesting a possible association between the deregulation of ribosome related gene expression and the poor prognosis. CONCLUSION: A ten-gene marker correlated with overall prognosis, including 6 ribosomal proteins, was identified and verified, which may complement the predictive value of TNM staging system.

关键词： Gastric cancer Gene expression profiling Survival markers Prognosis Ribosomal proteins

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Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region,china:A petrological record

Contribution of subducted Pacific slab to Late Cretaceous ma...

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中国科学院地质与地球物理研究所2.08学术年会

作者： jin zhang,Hong-fu zhang,~* ji-feng Ying,Yan-jie Tang and Li-feng niu State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of sciences,PO Box 982.,beijing 10002.,china

The occurrence of the Pishikou mafic dike in the Qingdao region,china provides important constraints on the origin of Late Cretaceous(86-78 Ma) mafic magmatism on the eastern North china *** Pishikou mafic dike is distributed in the Cretaceous Laoshan granitoid body,Qingdao region and contains peridotitic and granulitic xenoliths, xenocrysts,and *** from the Pishikou mafic dike are basanites and have low SiO(2.wt%) and AlO(12.5 wt%) contents,and high MgO(>8 wt%),total alkalis (NaO + KO>4.8 wt%,NaO/KO>1),TiO(>2.5 wt%),CaO(>9 wt,%) and PO (>1 wt%).In trace element abundances,they are highly enriched in large ion lithophile elements(LILEs) and light rare-earth elements(LREEs)(ΣREE = 3.9-403.ppm,(La/ Yb) = 3.-42. without high field strength element(HFSE) *** rocks have radiogenic Sr and Pb,and less radiogenic Nd isotopic compositions[(Sr/Sr);>0.7059,εNd≈2.7-3.8(Pb/Pb)≈18.0±0.1].The diagnostic elemental ratios,such as Nb/La, Nb/U,and Nb/Th,are compatible with those of mid-oceanic ridge basalts(MORBs) and oceanic island basalts(OIBs).Therefore,the Pishikou mafic dike has a geochemical feature completely different from those of the Early Cretaceous mafic dikes from the Qingdao region,but similar to those of back-arc basalts from the Japan *** geochemical feature suggests that the Pishikou mafic dike was derived from an asthenosphere source, but contaminated by materials from the subducted Pacific *** discovery of this mafic dike thus provides a petrological evidence for the contribution of subducted Pacific slab to the Late Cretaceous magmatism in the Qingdao region of the eastern North china craton.

关键词： asthenospheric source contribution of subducted Pacific slab Late Cretaceous mafic dike Qingdao

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