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Optimization of investment casting process parameters to reduce warpage of turbine blade platform in DD6 alloy

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China Foundry 2017年第6期14卷 469-477页

作者： jia-wei tian Kun Bu Jin-hui Song Guo-liang tian Fei Qiu Dan-qing Zhao Zong-li Jin Yang Li Key Laboratory of Contemporary Design and Integrated Manufacturing Technology Northwestern Polytechnical University Xi 'an 710072 Shannxi China

The large warping deformation at platform of turbine blade directly affects the forming precision. In the present research, equivalent warping deformation was firstly presented to describe the extent of deformation at platform. To optimize the process parameters during investment casting to minimize the warping deformation of the platform, based on simulation with Pro CAST, the single factor method, orthogonal test, neural network and genetic algorithm were subsequently used to analyze the influence of pouring temperature, shell mold preheating temperature, furnace temperature and withdrawal velocity on dimensional accuracy of the platform of superalloyDD6 turbine blade. The accuracy of investment casting simulation was verified by measurement of platform at blade casting. The simulation results with the optimal process parameters illustrate that the equivalent warping deformation was dramatically reduced by 21.8% from 0.232295 mm to 0.181698 mm.

关键词： ProCAST optimization of process parameters warping deformation of platform orthogonal test genetic algorithm BP-neural network

Restoration of thumb opposition by transposing the flexsor pollicis brevis muscle:thirteen-year clinical application

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Chinese Medical Journal 2006年第3期119卷 207-210页

作者： ZHU wei WANG Shu-huan ZHANG You-le wei jia-ning tian Guang-lei Department of Hand Surgery Jishuitan Hospital Beijing 100035China

Background To repair late median nerve injury, many methods have been used in the past years. The aim of this study was to review a thirteen-year experience in restoration of thumb opposition by transposing flexor pollicis brevis muscle. Methods From July 1992 to August 2005, 63 patients without thumb opposition because of late median never injury were treated by transposing the flexor pollicis brevis muscle. All the patients had received primary nerve repair after the jnjury. The interval between the injury and the second operation was （1.87±9.31） years （6 months to 4.2 years）. The patients were followed up for 3 to 48 [months mean （22.93±9.31） months]. A functional evaluation system designed in 1992 were used to estimate the outcomes of the patients. Results All the patients gained excellent functional results without complications and disabilities during follow-up. Conclusions Restoration of thumb opposition by transposing flexsor pollicis brevis muscle has the following advantages： 1. Operative trauma is minimal; 2. It is not necessary to transpose other tendons; 3. Except for the thumb in opposition, movements of other fingers and the wrist are not restricted postoperatively.

关键词： thumb median nerve wounds and injuries

Stress Echocardiography for Chronic Coronary Syndrome:Clinical Practice Guidelines(2023)

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Journal of Geriatric Cardiology 2024年第5期21卷 475-505页

作者： Peng-Fei ZHANG jia-wei tian tian-Gang ZHU Jue-Fei WU Xiao-Ping LENG Yi WANG Meng-Meng LI Xin-Hao LI Qian-Qian WANG Xiao-Peng FENG jia-Yan LV Li-Xue YIN Yun ZHANG Mei ZHANG Chinese Society of Echocardiography,Superficial Tissue and Vascular Group of Chinese Society of Ultrasound in Medicine,Ultrasound Professional Committee of Chinese Medicine Education Association State Key Laboratory for Innovation and Transformation of Luobing Theory Key Laboratory of Cardiovascular Remodeling and Function ResearchChinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesDepartment of CardiologyQilu Hospital of Shandong UniversityJinanChina The Second Affiliated Hospital of Harbin Medical University HaerbinChina Peking University People's Hospital BeijingChina Sichuan Province People's Hospital ChengduChina Nanfang Hospital Southern Medical UniversityGuangzhouChina Peking Union Medical College Hospital Chinese Academy of Medical SciencesBeijingChina 不详

In the context of the People's Republic of China,coronary artery disease(CAD)presents a sig-nificant clinical challenge,with over 11.3 mil-lion patients ***,the diagnos-is of CAD has predominantly relied on invasive coronary angiography.[1]However,recent advances in clinical research have revealed a notable trend:a substantial 82% of patients subjected to such invas-ive diagnostics do not necessitate interventional therapy.

关键词： coronary clinical patients

Epididymis cell atlas in a patient with a sex development disorder and a novel NR5A1 gene mutation

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Asian Journal of Andrology 2023年第1期25卷 103-112页

作者： jian-Wu Shi Yi-Wen Zhou Yu-Fei Chen Mei Ye Feng Qiao jia-wei tian Meng-Ya Zhang Hao-Cheng Lin Gang-Cai Xie Kin Lam Fok Hui jiang Yang Liu Hao Chen Institute of Reproductive Medicine Medical School of Nantong UniversityNantong 226000China Department of Plastic and Reconstructive Surgery Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China Department of Urology Peking University Third HospitalBeijing 100191China School of Biomedical Sciences Faculty of MedicineThe Chinese University of Hong KongHong Kong SARChina

This study aims to characterize the cell atlas of the epididymis derived from a 46,XY disorders of sex development(DSD)patient with a novel heterozygous mutation of the nuclear receptor subfamily 5 group A member 1(NR5A1)***-generation sequencing found a heterozygous c.124C>G mutation in NR5A1 that resulted in a p.Q42E missense mutation in the conserved DNA-binding domain of *** patient demonstrated feminization of external genitalia and Tanner stage 1 breast *** surgical procedure revealed a morphologically normal epididymis and vas deferens but a dysplastic ***-based single-cell RNA sequencing(scRNA-seq)analysis found that the fibroblast cells were significantly increased(approximately 46.5%),whereas the number of main epididymal epithelial cells(approximately 9.2%),such as principal cells and basal cells,was dramatically *** analysis of cell–cell communications and gene regulatory networks at the single-cell level inferred that epididymal epithelial cell loss and fibroblast occupation are associated with the epithelial-to-mesenchymal transition(EMT)*** present study provides a cell atlas of the epididymis of a patient with 46,XY DSD and serves as an important resource for understanding the pathophysiology of DSD.

关键词： disorders of sex development human epididymis NR5A1 scRNA-seq

Photosynthetic reaction pathways of natural and artificial systems

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Science China Chemistry 2025年

作者： Shixing Lei Liting Bi Lingxuan Chen Zhanting Li jia tian State Key Laboratory of Organometallic Chemistry and Shanghai Hong Kong Joint Laboratory in Chemical Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences

Photosynthesis converts solar energy into chemical energy through highly coordinated photosynthetic *** by natural systems,artificial photosynthesis aims to develop an efficient,sustainable,and cost-effective pathway for solar-tochemical *** review examines natural photosynthetic pathways,including retinal/rhodopsin-,bacteriochlorophyll-,and chlorophyll-based systems,highlighting their key components and ***,we outline reaction pathways in artificial photosynthetic systems constructed via heterogeneous,homogeneous,self-assembly,and semi-artificial strategies,focusing on water splitting,carbon fixation,and nitrogen ***,we offer insights into future directions for artificial photosynthesis,emphasizing the importance of using self-assembly strategies and the potential of using primitive phototrophic microorganisms as models.

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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

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Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-Bo Li Qi Zhang Jun-Zhao Xiao Yi-Fan Wang tian-Yu wei jia-wei jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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光纤放大器中受激布里渊散射的抑制

激光与红外 2017年第1期47卷 38-41页

作者：韦佳天吕宏伟杨小亮中国电子科技集团公司第三十四研究所

建立了一种考虑受激布里渊散射(SBS)效应和输出光纤影响的光纤放大器模型,该模型能有效描述低频脉冲的放大过程。数值仿真表明,通过优化设计掺杂光纤长度,缩短输出光纤长度,增大输入脉冲峰值功率等操作可以有效抑制光纤放大器中的受激... 详细信息

建立了一种考虑受激布里渊散射(SBS)效应和输出光纤影响的光纤放大器模型,该模型能有效描述低频脉冲的放大过程。数值仿真表明,通过优化设计掺杂光纤长度,缩短输出光纤长度,增大输入脉冲峰值功率等操作可以有效抑制光纤放大器中的受激布里渊散射。本文的结果可为单频放大系统的设计提供理论依据。

关键词：受激布里渊散射光纤放大器短脉冲

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北京市区域教育资源分配研究

数学的实践与认识 2016年第22期46卷 65-73页

作者：王佳熊巍田茂再中国人民大学应用统计科学研究中心中国人民大学统计学院北京100872 对外经济贸易大学统计学院大数据与风险管理研究中心北京100029 兰州财经大学统计学院甘肃兰州730020 新疆财经大学统计与信息学院新疆乌鲁木齐830012

北京市作为中国的政治文化中心,其教育发展问题更是各界关注的焦点.而区域教育的发展状况及区域教育的协调发展程度.不仅体现着一个地区的教育发展水平,也体现着一个社会全面、协调和可持续发展的程度.北京市教育科学十二五规划中也将... 详细信息

北京市作为中国的政治文化中心,其教育发展问题更是各界关注的焦点.而区域教育的发展状况及区域教育的协调发展程度.不仅体现着一个地区的教育发展水平,也体现着一个社会全面、协调和可持续发展的程度.北京市教育科学十二五规划中也将北京市区域教育均衡发展和教育现代化建设列为重要内容.为考察北京市区域教育发展状况并对今后教育发展趋势给出合理化建议,采用多元统计分析方法对北京市16个区县基础教育资源分配进行研究.首先使用脸谱图直观展示多维数据指标,其次利用因子分析综合评价各地区基础教育资源分配,最后通过聚类分析将北京市区县按基础教育资源状况分成三大类,并绘制教育发展状况地图,直观展示地理分布特点.总体来看北京市教育资源在人均数量上并没有偏重教育发展程度高的市区,反映了北京市区域教育均衡发展的方针.并针对北京市区县教育发展状况因地制宜提出合理化建议.

关键词：区域教育脸谱图因子分析聚类分析

Multivariate synergy for heightening ionic HOF robustness and proton conductivity

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Science China Chemistry 2025年

作者： Xiang-tian Bai Li-Hui Cao Xu-Yong Chen jia-Yu Wang Zi-Ye Zhou Shaanxi Key Laboratory of Chemical Additives for Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and Technology

Multicomponent crystalline materials construct more complex and diversified structures with different combinations and modes,which expands the material structure space and application *** this work,we have successfully synthesized two twocomponent ionic hydrogen-bonded organic frameworks （iHOF-32 and iHOF-33） and a three-component iHOF （iHOF-34）.Guanidine hydrochloride which is rich in N and H and has a short chain length strengthens the hydrogen bonding network of iHOF,thereby aiding in the efficient migration of *** rigid architecture of 1,1'-diamino-4,4'-bipyridine diiodide furnishes additional scaffolding for the iHOFs and enhances its robustness under harsh ***-34 accomplishes the combination of the ultra-high proton conductivity of iHOF-32 and the robustness of iHOF-33 by the synergistic interaction among the three components of *** addition,iHOF-34 was fabricated as a composite membrane with a peak proton conductivity of 1.55×10-1S cm-1,which is 3.8 times higher than that of recast Nafion,and has extensive potential in fuel *** self-assembly strategy of multicomponent HOFs opens up new avenues for constructing diverse structures while promising new opportunities for applications in the fields of proton conduction and energy storage.

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