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The determinant of performance of cross-border M&As in China: A comparative study between overseas Sino and Anglo firms 被引量:1
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作者 Ki Hyun Ryu Jae Eun Lee 《Chinese Business Review》 2009年第12期44-52,共9页
This study examines the factors that affect the performance of foreign acquiring firms in Chinese M&As (mergers and acquisitions) market. Comparing between overseas Sino-Group and Anglo-Group, this study found that... This study examines the factors that affect the performance of foreign acquiring firms in Chinese M&As (mergers and acquisitions) market. Comparing between overseas Sino-Group and Anglo-Group, this study found that familiarity and location were the most important factors influencing performance of M&A transactions in China. It also found that unrelated M&A deals should be merged with familiarity for gaining positive acquisition performance. The total sample used in this study was 3,442 cases from October 1980 to March 2005. Because this period included all deals of M&As after the opening of Chinese market in China. The authors' finding provided a more universal explanation in the cross-border M&As in China. 展开更多
关键词 cross-border m&as acquisition performance FAmILIARITY LOCATION
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Impact of BRICS Trade Facilitation on China's Exports Using Cross-Border E-Commerce
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作者 Longling LI Kaimei CHEN Zijian LONG 《Asian Agricultural Research》 2024年第5期1-7,共7页
With the rapid growth of the global digital economy, cross-border e-commerce, as an emerging form of trade, has gradually become a powerful engine to promote the development of global trade. BRICS is an important forc... With the rapid growth of the global digital economy, cross-border e-commerce, as an emerging form of trade, has gradually become a powerful engine to promote the development of global trade. BRICS is an important force in the global economy, and the progress of the BRICS countries' trade facilitation level has an important impact on the global trade environment. This paper conducts an in-depth study of the dynamic changes in BRICS trade facilitation from 2013 to 2022, and uses an extended gravity model to analyze the specific impact of this change on China's exports using cross-border e-commerce. The results show that although the BRICS countries have made some progress in trade facilitation, the overall level still needs to be improved, and there are obvious differences among member countries. However, the improvement of trade facilitation among BRICS countries has undoubtedly brought significant positive effects to China's exports using cross-border e-commerce. 展开更多
关键词 Trade facilitation BRICS cross-border e-commerce Export trade
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Micro,Small,and Medium Enterprises’Cross-Border Business Strategies
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作者 Xuan Chen Yijun Xia Tian Hou 《Proceedings of Business and Economic Studies》 2024年第2期191-197,共7页
This paper explores the operational strategies of cross-border micro, small, and medium enterprises (MSMEs). Against the backdrop of globalization and digitalization, cross-border trade has become one of the important... This paper explores the operational strategies of cross-border micro, small, and medium enterprises (MSMEs). Against the backdrop of globalization and digitalization, cross-border trade has become one of the important pathways for many MSMEs to achieve growth and competitive advantage. Firstly, the paper outlines the concept and characteristics of cross-border MSMEs, as well as the analysis of their operational environment in the context of globalization, including political, economic, social, technological, environmental, and legal factors. Secondly, the paper proposes operational strategies for cross-border MSMEs, including international market selection and positioning, cross-border marketing strategies, supply chain management, cross-border financial management, and cross-border risk management. Finally, the paper summarizes the importance of effectively implementing these strategies for cross-border MSMEs to seize international market opportunities, reduce operational risks, and enhance competitiveness and profitability. 展开更多
关键词 cross-border mSmEs Operational strategies GLOBALIZATION DIGITALIZATION International market cross-border trade marketing finance and risk management Supply chain management
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Cross-border Urban Networks Based on Manufacturing Global Value Chain:A Study of Listed Companies in Western China
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作者 MAN Shan YANG Yongchun +1 位作者 ZENG Tonggang WANG Meimei 《Chinese Geographical Science》 SCIE CSCD 2023年第6期1033-1052,共20页
Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study ... Cross-border investment is essential for western China’s globalization.Global value chain(GVC)forms cross-border investment networks between industries in western China and overseas cities.Focusing on GVC,this study uses the social network analysis method,entropy method,multi-index comprehensive evaluation method,and quadratic assignment procedure analysis method to examine the characteristics and influencing factors of the urban networks of research and development(R&D),production,and sales formed as a result of the overseas investments of listed manufacturing companies in western China.Results showed that the three types of investment networks involved multiple industry types and multiple central cities with differentiated diversity and multicentrality.The R&D urban network’s leading sub-industries were the mechanical equipment and instruments,medicine and biological products,and metal and nonmetal industries.The destination cities were mostly those home to educational and scientific research centers.The production urban network’s leading sub-industries were the mechanical equipment,instrument,and food and beverage industries.The destination cities were mostly regional central cities in developing countries.The sales urban network’s leading sub-industries were the mechanical equipment and instrument,metal and nonmetal,and petrochemical and plastics industries.The destination cities were numerous and scattered.In addition,the R&D urban network easily formed specialized clusters,core nodes easily controlled the production urban network,and individual nodes did not easily control the sales urban network.Technological and economic system advantages greatly impacted the three network types.Considering the different influencing factors,this study suggests optimizing the institutional investment environment to narrow the institutional gap,adjusting and optimizing the investment layout to expand overseas markets,and increasing R&D funds to stimulate technological progress and overseas investments in western China. 展开更多
关键词 manufacturing industry Global value chain(GVC) overseas investment cross-border networks western China
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Digital Development Rights in Developing Countries:Where the Governance Rules for Cross-Border Data Flows
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作者 李艳华 JIANG Yu(译) 《The Journal of Human Rights》 2023年第5期1040-1066,共27页
The digital development rights in developing countries are based on establishing a new international economic order and ensuring equal participation in the digital globalization process to achieve people's well-ro... The digital development rights in developing countries are based on establishing a new international economic order and ensuring equal participation in the digital globalization process to achieve people's well-rounded development in the digital society.The relationship between cross-border data flows and the realization of digital development rights in developing countries is quite complex.Currently,developing countries seek to safeguard their existing digital interests through unilateral regulation to protect data sovereignty and multilateral regulation for cross-border data cooperation.However,developing countries still have to face internal conflicts between national digital development rights and individual and corporate digital development rights during the process of realizing digital development rights.They also encounter external contradictions such as developed countries interfering with developing countries'data sovereignty,developed countries squeezing the policy space of developing countries through dominant rules,and developing countries having conflicts between domestic and international rules.This article argues that balancing openness and security on digital trade platforms is the optimal solution for developing countries to realize their digital development rights.The establishment of WTO digital trade rules should inherently reflect the fundamental demands of developing countries in cross-border data flows.At the same time,given China's dual role as a digital powerhouse and a developing country,it should actively promote the realization of digital development rights in developing countries. 展开更多
关键词 developing countries digital development rights cross-border data flows governance rules
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Analysis of the Development Environment and Trend of Cross-Border E-commerce in China
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作者 Yanxia Li Can Xu Ping Zhu 《Proceedings of Business and Economic Studies》 2023年第6期30-38,共9页
With the conclusion of the novel coronavirus pandemic and the increasingly complex market environment,China’s cross-border e-commerce has entered a new phase of development.The external landscape is evolving rapidly,... With the conclusion of the novel coronavirus pandemic and the increasingly complex market environment,China’s cross-border e-commerce has entered a new phase of development.The external landscape is evolving rapidly,and there is a gradual improvement in laws and regulations governing cross-border e-commerce,coupled with increased government support.Despite the impact of the COVID-19 pandemic on the market economy,overall development has been steadily improving.The Internet population is expanding,the online retail market is experiencing rapid growth,the consumption structure is undergoing transformation and upgrading,and the e-commerce market is demonstrating significant potential.The advancement of technologies such as big data,artificial intelligence,blockchain,and supply chain has provided more efficient operational support for the cross-border e-commerce industry.Against the backdrop of the emergence of new forms of cross-border e-commerce in China post-pandemic,this paper utilizes the PEST model to analyze the macro environment of cross-border e-commerce in China and project its future development trends. 展开更多
关键词 cross-border e-commerce Environmental analysis Development trend
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A Comprehensive Measurement Study Analyzing Cross-Border Logistics in Harbin New District
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作者 Yan Wang Xian-Ping Shi 《Proceedings of Business and Economic Studies》 2023年第6期145-152,共8页
The business environment is an important index for measuring the international competitiveness of a country or region.Improving the business environment not only helps the logistics industry reduce costs and increase ... The business environment is an important index for measuring the international competitiveness of a country or region.Improving the business environment not only helps the logistics industry reduce costs and increase efficiency but also promotes the transformation and upgrading of the logistics sector.This paper focuses on the business environment of cross-border logistics enterprises in Harbin New District as the research object.It constructs the business environment index system of logistics enterprises in Harbin New District through empirical research using the subjective weighting method.The research data are then analyzed to identify the shortcomings in optimizing the business environment of cross-border logistics in Harbin New District.The paper proposes countermeasures and suggestions,aiming to provide a decision-making reference for promoting the high-quality development and all-round revitalization of Harbin New District. 展开更多
关键词 Harbin New District cross-border logistics measurement of business environment Index system
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Digital Marketing and B2B Cross-Border E-Commerce: A Case Study of Alibaba International Station in China
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作者 Qianyu Li Jiaxuan Sun 《Proceedings of Business and Economic Studies》 2023年第6期76-80,共5页
The rapid development of the“Internet+”has ushered in a new era of global digital technology innovation.Concurrent with the deepening trends of economic globalization and integration,international trade is progressi... The rapid development of the“Internet+”has ushered in a new era of global digital technology innovation.Concurrent with the deepening trends of economic globalization and integration,international trade is progressively undergoing extensive digitization,with cross-border e-commerce emerging as a significant manifestation of this transformation.Within this landscape,the cross-border e-commerce B2B platform is anticipated to become a pivotal driver for China’s cross-border trade growth,representing a strategic opportunity for trade transformation.This paper provides a comprehensive examination of the concepts,characteristics,and development status of cross-border e-commerce and B2B platforms,considering both global and Chinese perspectives.Focusing on a prominent case study,Alibaba International Station,a B2B cross-border e-commerce platform,the paper delves into its business model and core competencies,offering a thorough analysis of its role in the intricacies of international e-commerce and its contribution to the field.Drawing on insights gained,the paper concludes by presenting targeted recommendations from both the platform and government perspectives.These suggestions are informed by a nuanced understanding of the development opportunities and challenges facing China’s cross-border e-commerce B2B platforms. 展开更多
关键词 Digital economy cross-border e-commerce B2B platform 2.0 Business model analysis Alibaba International Station
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高速铁路主跨320 m钢-混部分斜拉桥无砟轨道适应性研究 被引量:1
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作者 王俊冬 欧阳辉来 +2 位作者 魏周春 苏成光 高天赐 《铁道标准设计》 北大核心 2024年第5期29-35,共7页
南玉高铁六景郁江特大桥设计将钢-混部分斜拉桥结构引入时速350 km高速铁路领域,而300 m级以上大跨度桥上无砟轨道的竖向变形极易超限,影响列车通过的安全性和舒适性,因此,系统研究在此大跨桥梁结构上铺设无砟轨道的适应性十分必要。通... 南玉高铁六景郁江特大桥设计将钢-混部分斜拉桥结构引入时速350 km高速铁路领域,而300 m级以上大跨度桥上无砟轨道的竖向变形极易超限,影响列车通过的安全性和舒适性,因此,系统研究在此大跨桥梁结构上铺设无砟轨道的适应性十分必要。通过建立有限元及动力学模型,分析不同组合工况下无砟轨道结构的变形特点及动力特性,运用60 m弦测法探究各工况下无砟轨道的线形变化规律,从而确定大跨度钢-混部分斜拉桥铺设无砟轨道的适应性,并对设计和施工提出合理化建议。主要结论如下:在各种不利组合荷载作用下,桥上无砟轨道结构强度满足规范要求,列车通过大桥的各项安全性与舒适性指标均满足规范要求;混凝土收缩徐变和斜拉索升降温是影响无砟轨道线形标准的两大主因,应在无砟轨道施工前确保足够的沉降观测期和收缩徐变释放期,并充分考虑拉索的保温设计;在温度组合荷载作用下,桥上无砟轨道的60 m弦测不平顺幅值为6.79 mm,满足高速铁路静态验收标准;但在叠加列车荷载和收缩徐变后,变形弦测值均出现Ⅱ级及以上超限,通过合理设置预拱度后可有效改善轨道平顺性标准。 展开更多
关键词 高速铁路 铁路桥 钢-混部分斜拉桥 无砟轨道 车-轨-桥耦合 60 m弦测法 轨道不平顺
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M-APSK鉴相算法与并行载波同步方法 被引量:1
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作者 郇浩 任科学 《通信学报》 EI CSCD 北大核心 2024年第3期104-116,共13页
为实现M进制幅相调制(M-APSK)体制下高阶调制信号的相位精细校正,将DVB-S2标准推荐的16APSK和32APSK的Q次方无数据辅助鉴相算法进行了扩展,以应用于64APSK、128APSK和256APSK等高阶调制。针对高阶调制的有效鉴相星座点占比较低时环路工... 为实现M进制幅相调制(M-APSK)体制下高阶调制信号的相位精细校正,将DVB-S2标准推荐的16APSK和32APSK的Q次方无数据辅助鉴相算法进行了扩展,以应用于64APSK、128APSK和256APSK等高阶调制。针对高阶调制的有效鉴相星座点占比较低时环路工作不稳定的问题提出了改进算法,通过对功率归一化后接收符号的幅值进行阈值判决,仅在高于阈值时进行鉴相,低于阈值时则不改变滤波器状态和相位补偿值,以提高星座点的鉴相有效性和可靠性,从而降低入锁门限。针对高速数传的符号速率非常高,而处理器的工作时钟频率相对较低的问题,提出了一种适用于M-APSK的并行载波同步方法,可以满足接收机工作时钟处理需要。相对于传统固定编码调制(CCM)的载波同步环路,该并行方法还可应用于可变编码调制(VCM)体制的频率跟踪。 展开更多
关键词 m进制幅相调制 鉴相 并行 载波同步
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过表达lncRNAHEM2M改善非酒精性脂肪肝病小鼠的肝脏损伤 被引量:1
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作者 孔祥 张腾 +5 位作者 张妍 高灵犀 汪文 汪梦燕 王国栋 吕坤 《南方医科大学学报》 CAS CSCD 北大核心 2024年第1期1-8,共8页
目的探讨过表达长链非编码RNA(lncRNA)HEM2M对非酒精性脂肪肝病(NAFLD)小鼠肝损伤的影响。方法野生型C57BL/6(WT)和条件性髓系细胞lncRNAHEM2M过表达(MYKI)小鼠分别喂饲普通饮食(ND)和高脂饮食(HFD),即为WT+ND、MYKI+ND、WT+HFD和MYKI+... 目的探讨过表达长链非编码RNA(lncRNA)HEM2M对非酒精性脂肪肝病(NAFLD)小鼠肝损伤的影响。方法野生型C57BL/6(WT)和条件性髓系细胞lncRNAHEM2M过表达(MYKI)小鼠分别喂饲普通饮食(ND)和高脂饮食(HFD),即为WT+ND、MYKI+ND、WT+HFD和MYKI+HFD组。12周后行腹腔糖耐量及胰岛素耐量试验后处死小鼠,检测小鼠血清和肝脏组织的肝功能指标,制备肝脏组织切片后行HE染色和F4/80免疫组化染色,ELISA法检测肝脏组织中IL-6、IL-1β和TNF-α水平,qRT-PCR检测M1型(TNF-α、iNOS和IL-6)和M2型(Arg-1、YM-1和IL-10)巨噬细胞标志物mRNA表达,免疫印迹检测肝脏组织中P-AKT、T-AKT、NLRC4、caspase-1和GSDMD蛋白表达,比色法和免疫荧光测定肝脏组织caspase-1活性。结果与HFD喂饲的WT小鼠相比,MYKI+HFD小鼠肝功能损伤减轻(P<0.01),肝脏脂肪变缓解,肝脏巨噬细胞浸润减少,糖耐量损伤及胰岛素抵抗改善(P<0.01);MYKI+HFD小鼠肝脏组织IL-6、IL-1β和TNF-α水平降低(P<0.01),M1型巨噬细胞标志物mRNA表达减少(P<0.01),M2型mRNA表达增加(P<0.01);MYKI+HFD小鼠肝脏组织NLRC4炎症小体活性降低(P<0.01),活性caspase-1减少,GSDMD-N蛋白表达降低(P<0.05)。结论过表达lncRNAHEM2M降低NAFLD小鼠肝脏炎症因子水平,进而改善胰岛素抵抗并抑制肝脏NLRC4炎症小体激活,减少肝细胞焦亡,最终改善NAFLD小鼠肝脏损伤。 展开更多
关键词 lncRNAHEm2m 巨噬细胞 非酒精性脂肪肝 细胞焦亡
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RBMX通过下调PKM2抑制膀胱癌细胞的增殖、迁移、侵袭和糖酵解 被引量:1
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作者 颜秋霞 曾鹏 +9 位作者 黄树强 谭翠钰 周秀琴 乔静 赵晓英 冯玲 朱振杰 张国志 胡鸿 陈彩蓉 《南方医科大学学报》 CAS CSCD 北大核心 2024年第1期9-16,共8页
目的探讨X连锁RNA结合基序蛋白(RBMX)对膀胱癌细胞(1376细胞和UC-3细胞)的增殖、迁移、侵袭的影响以及其在糖酵解中的作用。方法采用慢病毒表达系统和siRNA干扰技术,分别构建RBMX过表达和敲低的膀胱癌细胞模型(1376细胞和UC-3细胞)。采... 目的探讨X连锁RNA结合基序蛋白(RBMX)对膀胱癌细胞(1376细胞和UC-3细胞)的增殖、迁移、侵袭的影响以及其在糖酵解中的作用。方法采用慢病毒表达系统和siRNA干扰技术,分别构建RBMX过表达和敲低的膀胱癌细胞模型(1376细胞和UC-3细胞)。采用RT-qPCR和Westernblotting分别在mRNA水平和蛋白水平上检测细胞模型是否构建成功。通过EdU增殖实验和克隆形成实验检测过表达和敲低RBMX后细胞的生长和集落形成能力,同时通过Transwell实验分析过表达和敲低RBMX后对细胞迁移、侵袭能力的影响;随后,采用Westernblotting检测过表达和敲低RBMX后糖酵解关键蛋白PKM1(M1型丙酮酸激酶)和PKM2(M2型丙酮酸激酶)的表达变化;最后,利用葡萄糖和乳酸检测试剂盒分析过表达和敲低RBMX对膀胱癌细胞糖酵解的影响。结果RT-qPCR和Westernblotting结果显示,过表达RBMX膀胱癌细胞的mRNA和蛋白表达水平显著高于阴性对照组(P<0.05),敲低RBMX膀胱癌细胞的mRNA和蛋白表达水平显著低于阴性对照组(P<0.05)。过表达RBMX明显抑制膀胱癌细胞的增殖、克隆形成、迁移和侵袭,敲低RBMX则作用相反。Westernblotting实验结果显示,过表达RBMX使PKM1表达上升,PKM2表达下降,敲低RBMX则作用相反。葡萄糖消耗及乳酸生成实验表明,过表达RBMX均能抑制膀胱癌细胞葡萄糖消耗及乳酸生成(P<0.05),敲低RBMX均能促进膀胱癌细胞葡萄糖消耗及乳酸生成(P<0.05)。结论RBMX通过下调PKM2抑制膀胱癌的发生发展和糖酵解能力,有望成为膀胱癌诊断和治疗的潜在分子靶标。 展开更多
关键词 X连锁RNA结合基序蛋白 m2型丙酮酸激酶 膀胱癌 PKm2 糖酵解
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下调METTL5通过Wnt/β-catenin信号通路抑制三阴乳腺癌细胞增殖、迁移与侵袭 被引量:1
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作者 吴坤琳 严乾壹 +2 位作者 王德星 缪秀英 张惠灏 《中国药理学通报》 CAS CSCD 北大核心 2024年第2期285-291,共7页
目的探讨甲基转移酶5(methyltransferase-like 5,METTL5)在三阴乳腺癌(triple-negative breast cancer,TNBC)中的作用和潜在机制。方法采用免疫组织化学方法和Western blot检测TNBC肿瘤组织和细胞系中METTL5的表达情况。用靶向METTL5的s... 目的探讨甲基转移酶5(methyltransferase-like 5,METTL5)在三阴乳腺癌(triple-negative breast cancer,TNBC)中的作用和潜在机制。方法采用免疫组织化学方法和Western blot检测TNBC肿瘤组织和细胞系中METTL5的表达情况。用靶向METTL5的shRNA(shRNA-METTL5)转染TNBC细胞后,用CCK-8、集落形成、伤口愈合以及Transwell实验分别检测细胞增殖活性、迁移与侵袭,Western blot检测Wnt/β-catenin信号关键蛋白的表达。构建异种移植瘤模型,验证敲降METTL5对TNBC细胞在体内生长以及Wnt/β-catenin信号活性的影响。结果METTL5在TNBC肿瘤组织和细胞系中表达上调(P<0.01)。敲降METTL5可抑制TNBC细胞的增殖、迁移和侵袭并降低了Wnt/β-catenin信号分子β-catenin、细胞周期蛋白(Cyclin)D1、基质金属蛋白酶(MMP)-2和MMP-7的表达(均P<0.01)。体内实验显示,敲降METTL5减缓了移植瘤生长和Wnt/β-catenin信号活性。结论敲降METTL5能抑制TNBC细胞的增殖、迁移与侵袭,其作用可能与抑制Wnt/β-catenin信号通路有关。 展开更多
关键词 三阴乳腺癌 甲基转移酶5 m6A甲基化 WNT/Β-CATENIN 增殖 迁移 侵袭
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关于7.63m焦炉上升管结石墨原因分析及治理对策的研究
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作者 马素娟 冯敏超 +2 位作者 万文 关晓光 马素霞 《燃料与化工》 CAS 2024年第1期32-34,共3页
德国伍德公司开发的7.63 m特大型复热式焦炉在生产过程中上升管根部结石墨严重,成为制约焦炉正常生产的突出矛盾。从焦炉加热水平、焦炉加热制度、装煤量等因素综合分析影响上升管根部结石墨的成因,研究制定降低上升管根部结石墨速率的... 德国伍德公司开发的7.63 m特大型复热式焦炉在生产过程中上升管根部结石墨严重,成为制约焦炉正常生产的突出矛盾。从焦炉加热水平、焦炉加热制度、装煤量等因素综合分析影响上升管根部结石墨的成因,研究制定降低上升管根部结石墨速率的方法及自动清除上升管根部石墨的装置,达到避免因上升管根部结石墨影响焦炉生产的目的。 展开更多
关键词 7.63 m焦炉 石墨 原因分析 上升管
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基于m×2正则化交叉验证的神经网络超参数调优方法
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作者 曹学飞 杨帆 +2 位作者 李济洪 王瑞波 牛倩 《计算机技术与发展》 2024年第4期168-173,共6页
超参数调优是神经网络建模的关键问题。针对传统的超参数调优方法存在的问题,该文提出了一种基于m×2正则化交叉验证的超参数调优方法。目的是给出一种适用于复杂模型、大数据集背景下的计算开销较小且稳健的超参数调优方法。该方... 超参数调优是神经网络建模的关键问题。针对传统的超参数调优方法存在的问题,该文提出了一种基于m×2正则化交叉验证的超参数调优方法。目的是给出一种适用于复杂模型、大数据集背景下的计算开销较小且稳健的超参数调优方法。该方法的思想是从完整的数据集上选取少部分数据进行调优,避免模型在数据集较大时非常耗时的超参数调优难题;在m×2交叉验证的基础上设置正则化条件均衡训练集与验证集之间的分布差异,从而减少分布不一致带来的性能波动;使用信噪比作为调优的优化目标,从而可以综合考虑模型性能评价指标的均值和方差;并采用正交设计选择相关性较低的超参数组合以提高调优效率。以命名实体任务为例进行实验,在CoNLL 2003数据集上的实验结果显示,提出的调优方法能够选到和网格搜索性能上没有显著差异的超参数组合,且调优时间可显著降低约66%。 展开更多
关键词 m×2交叉验证 正则化 神经网络 超参数调优 信噪比
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m1A/m5C/m6A/m7G调控基因预测胃癌预后及免疫关联性
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作者 陈小梅 王安奇 +1 位作者 杨积祯 于淼 《实用医学杂志》 CAS 北大核心 2024年第9期1230-1237,共8页
目的基于m1A/m5C/m6A/m7G甲基化调控基因建立胃癌预后风险预测模型,并分析该模型与免疫的关联性。方法通过癌症基因组图谱(TCGA)-胃癌数据集筛选表达具有显著差异的m1A/m5C/m6A/m7G调控基因,通过单基因Cox回归分析和LASSO算法构建预后... 目的基于m1A/m5C/m6A/m7G甲基化调控基因建立胃癌预后风险预测模型,并分析该模型与免疫的关联性。方法通过癌症基因组图谱(TCGA)-胃癌数据集筛选表达具有显著差异的m1A/m5C/m6A/m7G调控基因,通过单基因Cox回归分析和LASSO算法构建预后风险评分(risk score,RS)模型,使用Kaplan-Meier(K-M)统计进行RS模型验证,并应用细胞系进行RT-qPCR验证。利用单因素、多因素Cox回归分析建立nomogram模型。使用CIBERSORT算法和estimate包进行免疫关联性分析。结果建立了基于八个甲基化调控基因的预后RS模型,将胃癌患者分为高风险和低风险。这八个基因在胃癌细胞系中高表达(P<0.05)。在TCGA-胃癌训练集和GSE62254-验证集中,患者总生存率(OS)与分组状态之间存在显著相关性(P<0.001)。nomogram生存模型预测的1年(C-index=0.703)、3年(C-index=0.729)和5年(C-index=0.734)生存率与实际生存率的一致性较好。免疫关联性分析表明,与低风险患者组相比,高风险患者组免疫评分和免疫检查点相关基因的表达较高(P<0.05)。结论基于m1A/m5C/m6A/m7G调控基因的预后RS模型可预测胃癌预后并指导个体免疫治疗决策。 展开更多
关键词 m1A m5C m6A m7G 胃癌 预后 免疫浸润
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基于GNSS的2023年2月23日塔吉克斯坦M_(S)7.2地震前异常资料变化特征研究
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作者 李桂荣 李杰 +2 位作者 李瑞 苏力坦·玉散 李思妍 《内陆地震》 2024年第1期34-41,共8页
为了进一步探究中强地震发生前GNSS坐标时序中是否存在中短期异常现象,通过分析2023年2月23日塔吉克斯坦M_(S)7.2地震前后中国大陆构造环境监测网络(简称:“陆态网络”)塔什库尔干、布伦口GNSS基准站观测资料的变化特征,发现该地震震前... 为了进一步探究中强地震发生前GNSS坐标时序中是否存在中短期异常现象,通过分析2023年2月23日塔吉克斯坦M_(S)7.2地震前后中国大陆构造环境监测网络(简称:“陆态网络”)塔什库尔干、布伦口GNSS基准站观测资料的变化特征,发现该地震震前塔什库尔干、布伦口均出现较为明显的GNSS基准站时间序列异常现象,震前EW向存在趋势性W向运动,震后E向加速;震前NS向趋势性S向运动,临震前状态快速改变,布伦口在震后还显示出7.3 mm的EW向永久性形变,研究结果表明GNSS在地震发生短临阶段具有重要的预测意义。与2015年12月7日塔吉克斯坦M S7.4地震进行对比发现,两次M S≥7.0地震对塔什库尔干、布伦口基准站的影响差异较大。2015年12月7日塔吉克斯坦M S7.4地震为左旋走滑,影响方向主要为NE向,而2023年2月23日塔吉克斯坦M_(S)7.2地震为右旋走滑,影响方向主要为SE向。震前基线均有挤压缩短的前兆异常显示。梳理站点异常出现情况,发现异常持续时间越长、异常出现次数越多,发震震级可能越大。 展开更多
关键词 GNSS 变化量 塔吉克斯坦m S7.2地震 地震异常
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泸定M S6.8地震震前变形特征及鲜水河断裂南东段地震活动性 被引量:1
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作者 申星 梁洪宝 宋成科 《大地测量与地球动力学》 CSCD 北大核心 2024年第1期69-74,共6页
针对鲜水河断裂带南东段的历史地震活动性和近10 a该断裂带上发生的中小震群展布特征,利用GNSS观测数据给出2022年泸定M S6.8地震震源区及周边区域的速度场、应变率场,识别此次地震震前的变形特征。GNSS速度场显示,鲜水河断裂带南东段... 针对鲜水河断裂带南东段的历史地震活动性和近10 a该断裂带上发生的中小震群展布特征,利用GNSS观测数据给出2022年泸定M S6.8地震震源区及周边区域的速度场、应变率场,识别此次地震震前的变形特征。GNSS速度场显示,鲜水河断裂带南东段走滑速率约为10 mm/a,区域整体运动为ES向,与断裂构造运动具有一致性;应变率场结果显示,发震断裂仍存在较强的剪切应变积累,汶川特大地震后随着应变能不断释放,龙门山断裂带的卸载作用间接影响鲜水河断裂带的南东段,该断裂长期处于应变积累高值的过渡区,现今仍具有较高的断层闭锁状态,该地区的地震活动趋势和地震危险性值得进一步关注和研究。 展开更多
关键词 泸定6.8级地震 鲜水河断裂带 地震活动性 应变率场
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地区空气污染的“压力”与企业绿色转型的“动力”——基于城市PM2.5和公司并购的实证发现 被引量:2
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作者 蔡庆丰 舒少文 黄蕾 《厦门大学学报(哲学社会科学版)》 CSSCI 北大核心 2024年第1期50-63,共14页
地区空气污染会影响域内各类市场主体行为,包括微观企业决策。碳达峰、碳中和的提出要求各地加强空气污染治理,推动企业绿色转型,而绿色并购是企业绿色转型的重要方式。利用2013—2018年我国A股上市的污染企业发起的并购为样本,并手动... 地区空气污染会影响域内各类市场主体行为,包括微观企业决策。碳达峰、碳中和的提出要求各地加强空气污染治理,推动企业绿色转型,而绿色并购是企业绿色转型的重要方式。利用2013—2018年我国A股上市的污染企业发起的并购为样本,并手动搜集整理确定绿色并购样本,实证研究地区空气污染对域内企业绿色转型的影响。研究发现,地区空气污染加剧会提升域内污染企业绿色并购的意愿。在此基础上,通过并购前后企业信息披露质量和社会责任承担变化,研究发现地区空气污染加剧下的企业绿色转型并非源于自主绿色转型发展的内生“动力”,更多是外部“压力”下的“工具主义”行为。从影响路径来看,地区空气污染引致的压力会通过行业竞争和融资约束这两个途径影响污染企业绿色转型的“动力”。最后,异质性检验发现在市场化程度高和非国有企业样本,地区空气污染加剧对企业绿色并购的促进作用更为显著。 展开更多
关键词 地区空气污染 绿色转型 公司并购 Pm2.5
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^(99m)TcO4-SPECT/CT甲状腺核素显像联合超声及TSH对甲状腺结节性质的诊断价值 被引量:1
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作者 王静 吴龙云 +5 位作者 郝宏毅 尹彩君 杨勇 倪效波 张荣 王雪霁 《宁夏医学杂志》 CAS 2024年第3期206-209,F0002,共5页
目的通过高锝酸钠-单光子发射计算机断层显像/电子计算机X射线断层扫描技术(^(99m)TcO4-SPECT/CT)核素显像提供甲状腺结节功能状态、结节解剖特点以及超声检查联合血清促甲状腺激素(TSH)水平进一步鉴别诊断甲状腺结节的良恶性,客观评价... 目的通过高锝酸钠-单光子发射计算机断层显像/电子计算机X射线断层扫描技术(^(99m)TcO4-SPECT/CT)核素显像提供甲状腺结节功能状态、结节解剖特点以及超声检查联合血清促甲状腺激素(TSH)水平进一步鉴别诊断甲状腺结节的良恶性,客观评价甲状腺结节的良恶性情况,对甲状腺结节的良恶性做出早期诊断。方法对因甲状腺结节同时行^(99m)TcO4-SPECT/CT甲状腺核素显像、甲状腺B超及TSH水平检查的患者共80例(92个结节)进行回顾性分析,对比不同方法及联合检查对甲状腺结节的诊断效能。结果92个结节中良性74个,恶性18个;^(99m)TcO4-SPECT/CT甲状腺显像与超声检查比较灵敏度(77.8%)高,特异度(70.2%)及准确度(71.7%)低,假阳性率(29.7%)高,假阴性率(22.2%)低,两者之间灵敏度、特异度、准确度、假阳性率、假阴性率差异均具有统计学意义(P<0.05);两者准确度比较差异无统计学意义(P>0.05)。^(99)mTcO4-SPECT/CT甲状腺显像与超声检查比较灵敏度高,特异性及准确度低,假阳性率高,假阴性率低,两者之间灵敏度、特异度、准确度、假阳性率、假阴性率差异均具有统计学意义(P<0.05);两者准确度比较差异无统计学意义(P>0.05);^(99m)TcO4-SPECT/CT甲状腺显像与超声检查联合较单独核素、单独超声检查灵敏度(88.9%)、特异度(87.8%)、准确度(81.5%)高,假阳性率(12.1%)、假阴性率(11.1%)低;联合检查与单独核素特异度、准确度、假阳性率比较差异有统计学意义(P<0.05),灵敏度与假阴性率比较差异无统计学意义(P>0.05);联合检查与单独超声灵敏度、准确度、假阴性率比较差异有统计学意义(P<0.05);特异度与假阳性率比较差异无统计学意义(P>0.05)。结论超声可以作为甲状腺结节的首选检查方法,其特异性高,但灵敏度低。^(99m)TcO4-SPECT/CT甲状腺显像在提供功能和代谢信息的同时,能提供解剖信息;而血清TSH水平则可为甲状腺结节的良恶性鉴别提供重要的参考依据,尤其对于核素冷结节且超声实性结节的患者,更应参考其TSH水平,将三者结合起来判断甲状腺结节的性质,为临床提供恰当的治疗方案,这具有重要意义。 展开更多
关键词 ^(99m)TcO4-SPECT/CT甲状腺核素显像 超声 血清促甲状腺激素 甲状腺结节
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