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Optimal adoptions of freemium version and patching strategy:Network and security externalities

Journal of Management Science and Engineering 2022年第1期7卷 107-132页

作者： Nan Feng Hanyue Zhang changqing Dong Jie Zhang Minqiang Li jing Xie College of Management and Economics Tianjin UniversityTianjin300072China College of Business Administration University of Texas at ArlingtonArlingtonTX76019USA

The freemium pricing model has become mainstream in the software industry.A large user base can induce positive network effects while expanding security risks associated with unpatched *** study explores a two-stage decision problem faced by software vendors that involves a freemium versioning strategy and a subsequent security-patching strategy when taking both the positive network externality and negative security externality into *** is noteworthy that a joint effect of the two externalities on the vendor’s management decisions ***,we analytically derive three patching strategies for the vendor:PS_(1)(rebates all users),PS_(2)(rebates only freeware users),and PS_(3)(rebates no users).Our results indicate that,if the strength of the positive network externality is relatively low,the optimal security-patching strategy will be significantly affected by the negative security ***,when the intensity of the negative security externality is low,the vendor’s optimal patching strategy will be PS_(1).However,with the increase in the negative security externality,the optimal patching strategy changes to PS_(2) and then to PS_(3),whereas the strategy spaces of PS_(1) and PS_(2) decrease in the positive network externality to ***,if the strength of the positive network externality is relatively high,the vendor is better off selecting PS_(1) when the negative security externality is ***,when the negative security externality is high,PS_(3) is ***,based on optimal patching strategies,we reveal the optimal conditions required for the vendor to adopt the freemium model compared with commercial *** interest,we find that the vendor adopting the freemium version is also influenced by the interaction of the two ***,through numerical experiments,we find that the vendor and social planner’s interests can be aligned under certain ***,this is not always the case.

关键词： Freemium Positive network externality Negative security externality Patching strategy

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High pressure effects on the crystal structure andelectric conductivity of perovskite like (Ca/Sr)_2CuO_2Cl_2 compounds

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Chinese Science Bulletin 2008年第18期53卷 2739-2742页

作者： LIU QingQing WANG FuRen LI FengYing CHEN LiangChen YU RiCheng JIN changqing LI YanChun LIU jing College of Physics Peking University Beijing 100871 China Institute of Physics Chinese Academy of Sciences Beijing 100190 China Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The crystal structure stability as well as electric conductance of (Sr/Ca)_2CuO_2Cl_2 compound with K_2NiF_4 structure was investigated up to 31 GPa using diamond anvil technique. It seems that (Sr/Ca)_2CuO_2Cl_2 is quite stable under pressure but with obvious anisotropic compressibility. The equation of state (EOS) obtained shows relative large bulk modulus.

关键词：高压反应电导体钙钛矿型复合物循环结构同步加速器

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改良生物补片重建盆底腹膜在腹腔镜Miles手术中应用的临床研究

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腹部外科 2020年第6期33卷 434-438,444页

作者：王文琛袁浩朱学章张继准孔帅田锋苗瑞政靖昌庆李乐平徐涛山东大学附属省立医院胃肠外科山东济南250023 山东第一医科大学附属省立医院胃肠外科山东济南250023

目的探讨改良生物补片重建盆底腹膜(modified biological patch for reconstruction of pelvic floor peritoneum,MBR)用于腹腔镜Miles手术的安全性和临床效果。方法回顾性分析2015年1月至2018年12月在山东省立医院胃肠外科接受腹腔镜Mi... 详细信息

目的探讨改良生物补片重建盆底腹膜(modified biological patch for reconstruction of pelvic floor peritoneum,MBR)用于腹腔镜Miles手术的安全性和临床效果。方法回顾性分析2015年1月至2018年12月在山东省立医院胃肠外科接受腹腔镜Miles手术的343例低位直肠癌病人的临床资料。按纳入和排除标准,303例病人纳入研究,根据是否行MBR,将病人分为MBR组(47例)和未重建(Non-MBR)组(256例)。研究中使用的生物补片取材于牛心包组织,是一种交联脱细胞基质材料。比较两组的术中和术后结果,并介绍MBR方法和安全性。结果与Non-MBR组相比,MBR组术后粘连性小肠梗阻(adhesive small bowel obstruction,ASBO)的发生率降低(0比10.9%,P<0.05),术后因ASBO的再次住院率降低(0比9.8%,P<0.05)。Non-MBR组术后因ASBO平均再次住院次数为1.8次。MBR组重建盆底腹膜时间为(3.3±0.8)min,该组病人随访1年未出现生物补片排异、感染、侵蚀、磨损等不良反应。两组手术时间、术中出血量、术后首次排气时间、术后住院时间、会阴切口液化、感染、会阴疝的发生率、因会阴切口感染、会阴疝的再次住院率差异无统计学意义。结论MBR在腹腔镜Miles手术中安全易行、耗时较少,可降低术后ASBO的发生率及因ASBO再住院率。此外,交联脱细胞基质材料生物补片具有良好的组织相容性,具有临床实用价值。

关键词：盆底腹膜重建防粘连屏障粘连性小肠梗阻腹腔镜腹会阴联合切除术

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A new insight into the promoting effects of transition metal phosphides in methanol electrooxidation

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Chinese Chemical Letters 2023年第6期34卷 200-205页

作者： Junjie Ding Shaojie jing changqing Yin Chaogang Ban Kaiwen Wang Xue Liu Youyu Duan Yuxin Zhang Guang Han Liyong Gan Jinsong Rao College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331China College of Material Science and Engineering Chongqing UniversityChongqing 400044China Beijing Key Laboratory of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100024China

The construction of highly active catalysts for methanol oxidation reaction(MOR)is central to direct methanol fuel *** progress has been made in transition metal phosphides(TMPs)based ***,TMPs would be partially damaged and transformed into new substances(e.g.,Pt-M-P composite,where M represents a second transition metal)during Pt deposition *** would pose a large obstacle to the cognition of the real promoting effects of TMPs in ***,Co_(2)P co-catalysts(Pt-P/Co_(2)P@NPC,where NPC stands for N and P co-doped carbon)and Pt-Co-P composite catalysts(Pt-CoP/NPC)were controllably *** tests show that the Pt-Co-P/NPC exhibits superior MOR activity as high as 1016 m A/mg_(Pt),significantly exceeding that of Pt-P/Co_(2)P@NPC(345 m A/mg_(Pt)).This result indicates that the promoting effect is ascribed primarily to the resultant Pt-Co-P composite,in sharply contrast to previous viewpoint that Co_(2)P itself improves the *** mechanistic studies reveal that Pt-Co-P/NPC exhibits much stronger electron interaction and thus manifesting a remarkably weaker CO absorption than Pt-P/Co_(2)P@NPC and Pt/***,Pt-Co-P is also more capable of producing oxygen-containing adsorbate and thus accelerating the removal of surface-bonded CO^(*),ultimately boosting the MOR performance.

关键词： Promoting effect Transition metal phosphides Pt-Co-P composite Catalytic mechanisms Methanol oxidation reaction

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Effect of acupotomy on nitric oxide synthase and beta-endorphin in third lumbar vertebrae transverse process syndrome model rats

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Journal of Traditional Chinese Medicine 2014年第2期34卷 194-198页

作者： changqing Guo Naigang Liu Xiaohong Li Hongmei Sun Bo Hu jing Lu Yan Guo Chuxi Liang Hong Xu Haixia Wu School of Acupuncture & Moxibustion and Tuina Beijing University of Chinese Medicine Department of Acupuncture & Moxibustion China-Japan Friendship Hospital School of Basic Medical Sciences Beijing University of Chinese Medicine Department of Acupuncture & Moxibustion and Physiotherapy Beijing Shuili Hospital

OBJECTIVE： To explore the long-term effects and pain relief mechanism of acupotomy by observing changes in nitric oxide synthase （NOS） and beta-en- dorphin （~3-EP） in the hypothalamus, spinal cord, and peripheral blood of rats with third lumbar ver- tebrae （L3） transverse process syndrome. METHODS： Twenty-eight SD rats were randomly as- signed to normal, model, electroacupuncture （EA）, and acupotomy group. The last three groups were put through an operation to emulate L3 transverse process syndrome. Fourteen days after the simulation operation, EA and acupotomy treatments were applied to the respective groups. Fifty-six days afterthe simulation operation, biochemistry tests and enzyme-linked immunosorbent assay were used to measure NOS and 13-EP in the hypothalamus, spinal cord, and peripheral blood. RESULTS： Rats with the simulation operation showed significantly higher levels of NOS and II3-EP in the hypothalamus, spinal cord, and peripheral blood than those in the normal group. The EA and acupotomy groups had significantly lower levels of NOS and β-EP than those in the model group. There was no statistical difference between the EA and acupotomy groups. CONCLUSION： EA and acupotomy treatments significantly lowered NOS and β-EP levels in the hypothalamus, spinal cord, and peripheral blood and alleviated L3 transverse process syndrome.

关键词： Acupotomy Small needle knife Electroacupuncture L3 transverse process syndrome Nitric oxide synthase Beta-endorphin

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Permeability Estimation of Shale Oil Reservoir with Laboratory-derived Data: A Case Study of the Chang 7 Member in Ordos Basin

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Applied Geophysics 2024年第3期21卷 440-455,616页

作者： Zhang Lin Gao Li Ba jing Zhang Meng-Bo JoséM.Carcione Liu Wei-Hua School of Earth Sciences and Engineering Hohai UniversityNanjingJiangsu211000 Exploration and Development Research Institute of PetroChina Changqing Oilfield CompanyXi'an Shanxi710018 National Institute of Oceanography and Applied Geophysics(OGS) SgonicoTrieste 34010 Sinopec Geophysical Research Institute NanjingJiangsu211103

The shale oil reservoir within the Yanchang Formations of Ordos Basin harbors substantial oil and gas resources and has recently emerged as the primary focus of unconventional oil and gas exploration and *** to its complex pore and throat structure,pronounced heterogeneity,and tight reservoir characteristics,the techniques for conventional oil and gas exploration and production face challenges in comprehensive implementation,also indicating that as a vital parameter for evaluating the physical properties of a reservoir,permeability cannot be effectively *** study selects 21 tight sandstone samples from the Q area within the shale oil formations of Ordos *** systematically conduct the experiments to measure porosity,permeability,ultrasonic wave velocities,and resistivity at varying confining *** reveal that these measurements exhibit nonlinear changes in response to effective *** using these experimental data and effective medium model,empirical relationships between P-and S-wave velocities,permeability and resistivity and effective pressure are established at logging and seismic ***,relationships between P-wave impedance and permeability,and resistivity and permeability are determined.A comparison between the predicted permeability and logging data demonstrates that the impedance–permeability relationship yields better results in contrast to those of resistivity–permeability *** relationships are further applied to the seismic interpretation of shale oil reservoir in the target layer,enabling the permeability profile predictions based on inverse P-wave *** predicted results are evaluated with actual production data,revealing a better agreement between predicted results and logging data and productivity.

关键词： shale oil reservoir P-wave impedance resistivity permeability rock physics experiment

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田菁不同部位营养价值、分子结构特性和体外瘤胃降解率研究

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动物营养学报 2024年第5期36卷 3386-3400页

作者：王路遥江应松曹晓风韩波卜登攀邓娴赵庆华于静尤常清张晓冬马露贾亚军田雨佳天津农学院动物科学与动物医学学院天津市农业动物繁育与健康养殖重点实验室天津300392 天津市农业农村委天津300454 中国科学院遗传与发育生物学研究所基因组生物学研究中心北京100101 天津梦得集团有限公司天津300188 中国农业科学院北京畜牧兽医研究所反刍动物营养创新部北京100193 山东省农业科学院农作物种质资源研究所济南250100 海南省崖州湾种子实验室创新研究部三亚572024

本试验旨在研究田菁不同部位(包括叶、茎、根及全株)的营养价值、分子结构特征及体外瘤胃降解率,为反刍动物优质粗饲料资源的开发提供基础数据。试验按照概略养分分析法和康奈尔净碳水化合物和蛋白质体系(CNCPS)分析田菁叶、茎、根及全... 详细信息

本试验旨在研究田菁不同部位(包括叶、茎、根及全株)的营养价值、分子结构特征及体外瘤胃降解率,为反刍动物优质粗饲料资源的开发提供基础数据。试验按照概略养分分析法和康奈尔净碳水化合物和蛋白质体系(CNCPS)分析田菁叶、茎、根及全株的营养成分含量,同时利用傅立叶变换红外光谱(FTIR)技术对田菁不同部位的分子结构进行分析,最后进行体外瘤胃模拟发酵,分析田菁不同部位在瘤胃内的降解率以及产气量。结果表明:1)田菁不同部位间的蛋白质组成和二级结构光谱参数存在显著差异(P<0.05)。其中,叶的蛋白质成分含量较高,根的较低;叶的酰胺Ⅰ区和酰胺Ⅱ区的峰高和峰面积以及β-折叠峰面积较高,茎的酰胺Ⅰ区峰高和峰面积较低。2)田菁不同部位间的碳水化合物组成和分子结构光谱参数存在显著差异(P<0.05)。其中,根的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和酸性洗涤木质素(ADL)含量较高,叶的较低;根的总碳水化合物峰高和峰面积较高。此外,田菁的蛋白质和碳水化合物组成与分子结构之间存在一定的相关性。3)田菁叶的体外发酵粗蛋白质和干物质降解率最高,显著高于全株、茎和根(P<0.05);叶的48 h总产气量显著高于茎和根(P<0.05)。由此可见,田菁不同部位的营养价值与分子结构之间具有一定的相关性;其中,叶和茎的营养价值及利用率相对较高,而根的营养价值及利用率较低。

关键词：田菁傅立叶变换红外光谱分子结构营养价值瘤胃降解

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罗莫佐单抗治疗骨质疏松症的研究进展

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广西医学 2024年第3期46卷 434-437页

作者：蒋明晖胡璟肖常青文玉梅高永鸿王志威广西国际壮医医院内分泌代谢病科广西南宁市530201

罗莫佐单抗是近年来在多个国家相继获得批准用于治疗骨质疏松症的新药物,是首个同时具有抑制骨吸收和促进骨形成双重作用的骨硬化蛋白抑制剂。本文就罗莫佐单抗治疗骨质疏松症的作用机制及临床应用进行综述,以期为该药的临床应用提供参考。

关键词：骨质疏松症罗莫佐单抗骨硬化蛋白作用机制临床应用综述

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A Long Type of TBCK Is a Novel Cytoplasmic and Mitotic Apparatus-Associated Protein Likely Suppressing Cell Proliferation

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Journal of Genetics and Genomics 2014年第2期41卷 69-72页

作者： Jin Wu Qianyi Li Yan Li jing Lin Dong Yang Guixin Zhu Limin Wang Dacheng He Guanting Lu changqing Zeng Laboratory of Disease Genomics and Individualized Medicine Beijing Institute of GenomicsChinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for Cell Proliferation and Regulation of the Ministry of Education Beijing Normal University

Autoantibodies from patients with various connective tissue diseases have been shown to be specific probes that can detect cellular structures, including centrosome, centromere/kineto- chore, spliceosome, Golgi comple... 详细信息

关键词： Cell TBC A Long Type of TBCK Is a Novel Cytoplasmic and Mitotic Apparatus-Associated Protein Likely Suppressing Cell Proliferation

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鄂尔多斯盆地东南部黄龙背斜的构造几何学与运动学

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地质科学 2024年第3期59卷 612-624页

作者：何登发邹松于波包洪平毛丹凤魏柳彬井向辉石婧中国地质大学(北京) 北京100083 中国石油长庆油田分公司西安710018

研究克拉通内构造变形对于揭示克拉通的构造属性具有重要意义,对于油气勘探也具有重要的参考价值。本文应用钻井与高精度反射地震资料,剖析了鄂尔多斯盆地东南部黄龙背斜的构造几何学与运动学特征。研究表明,黄龙背斜发育在渭北隆起东端... 详细信息

研究克拉通内构造变形对于揭示克拉通的构造属性具有重要意义,对于油气勘探也具有重要的参考价值。本文应用钻井与高精度反射地震资料,剖析了鄂尔多斯盆地东南部黄龙背斜的构造几何学与运动学特征。研究表明,黄龙背斜发育在渭北隆起东端,是一长18 km、宽15 km的短轴状背斜,地层起伏幅度达200 ms;黄龙背斜自长城系往上至三叠系均具有相似的背斜形态;它是在燕山期基底断层复活而形成的断层传播褶皱背斜;黄龙背斜区内东西向与南北向剖面控制的缩短分别为70 m和90 m,缩短量较小,指示该部位处于燕山期冲断变形的前锋部位,变形即将终止。黄龙背斜响应于周缘构造边界挤压作用,是克拉通内部的基底正断层反转而在沉积盖层形成的褶皱背斜,因地层能干性差异发生了分层剪切。黄龙背斜是一个有利的天然气勘探目标。

关键词：黄龙背斜构造几何学构造运动学克拉通盆地鄂尔多斯盆地东南

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