检索结果-南通市图书馆

Does China's digital economy contribute to low-carbon transition?

在线全文

学校读者我要写书评

暂无评论

Ecological Economy 2024年第2期20卷 102-122页

作者： LI Jun-jun HUANG xin-yu CHEN Mu ZhanG Meng-jiang ZhanG Zhen School of Economics Fujian Normal UniversityFuzhou 350007CHINA College of Mechanical and Electrical Engineering Wuyi UniversityNanping 354300CHINA

The digital economy,as a new emerging economic form,has become an important power for realizing Chinese-style modernization and promoting green development in *** paper measures the digital economy and low-carbon transition index based on the data of 30 provinces in China from 2013 to 2020 and analyzes the mechanism and path of the digital economy affecting low-carbon transition using the fixed effect panel data model and the threshold effect *** is found that,(1)The digital economy and low-carbon transition in China are various in different regions,with characteristics of being unbalanced and insufficient.(2)The digital economy significantly promotes low-carbon transition,with the greatest influence in the Central region,followed by the Eastern region and the Western *** different dimensions,the development of informatization and digital transactions promote low-carbon transition,but the development of the internet plays an inhibiting role.(3)The higher the degree of urbanization and environmental regulation,the greater the influence of the digital economy on low-carbon transition.

关键词： digital economy low-carbon transition threshold effect model instrumental variables quantile regression

Mass flows and river response in rapid uplifting regions——A case of lower Yarlung Tsangpo basin,southeast Tibet,China

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2020年第6期35卷 609-620页

作者： Guo-An yu Jianyin Lu Liqun Lyu Lujie han Zhaoyin Wang Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences School of Soil and Water Conservation Beijing Forestry University Tsinghua University

The fluvial geomorphology in tectonically active(particularly rapid uplift) regions often undergoes continuous *** rapid uplift is coincident with high erosion rates;consequently,incised valleys are *** flows(for example,avalanches,landslides,and debris flows) in incised valleys can markedly influence fluvial processes and even reshape valley ***,these processes and long-term evolution corresponding to mass flows require further *** campaigns were carried out in the region near the Yigong Tsangpo and Palong Tsangpo Rivers(hereafter the Yigong and Palong Rivers),the two largest tributaries of the lower Yarlung Tsangpo River Tibet,China,to examine the feedback between fluvial processes and mass *** sensing images from recent decades were used to compare the channel morphology before and after typical mass flows(particularly catastrophic ones).The morphology of the lower Yigong River has evidently been impacted by landslides,while that of the Palong River has mainly been shaped by glacial processes and debris *** present,the morphology of the latter consists of alternating sections of gorges and wide valleys,with a staircase-like longitudinal *** gorge sections exhibit single and deeply incised channels with a high-gradient channel bed and *** contrast,the wide valley sections consist of lakes,braided or anabranching channels,gentle bed gradients,and thick alluvial *** flows occur more frequently in gullies in the reaches of the gorge sections and rarely in gullies along the wide valley *** occurrence of mass flow events has resulted in an imbalance of the previous(quasi-)equilibrium in the river morphology;however,this has triggered negative feedback that is driving the transient river morphology to a new state of(quasi-)equilibrium.

关键词： Mass flow Debris flow Glacial erosion Fluvial processes Negative feedback

Engineered Fabrication of Enamel-Mimetic Materials

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Engineering 2022年第7期8卷 113-123页

作者： Lingyun Zhang yunfan Zhang Tingting yu Liying Peng Qiannan Sun Bing han Department of Orthodontics Peking University School and Hospital of Stomatology&National Engineering Laboratory for Digital and Material Technology of Stomatology&Beijing Key Laboratory of Digital StomatologyBeijing 100081China

Tooth enamel,which is a biological tissue mainly composed of well-aligned hydroxyapatite nanocrystals and an interlaced protein matrix,has remarkable mechanical and aesthetic ***,it is challenging to regenerate enamel naturally,and potential pulp involvement and tooth loss may *** the hardest biogenic composite material,enamel has long been regarded as a promising load-bearing ***,understanding the enamel formation process and enamel structural motif mechanisms is important for the design and engineering of high-performance biomimetic composites with high strength and physical *** studies have been conducted on mimicking the microstructure and mechanical properties of tooth enamel,and various enamel-like material synthesis protocols have been *** light of the engineering fabrication of enamel-like materials,this review focuses on recent progress in synthetic strategies for enamel-mimetic materials and provides a discussion of the potential applications of these materials.

关键词： Regeneration Remineralization Abiotic enamel Biomimetic

Object registration using an RGB-D camera for complex product augmented assembly guidance

在线全文

学校读者我要写书评

暂无评论

Virtual Reality & Intelligent Hardware 2020年第6期2卷 501-517页

作者： Kangkang YANG yu GUO Pengzhou TANG Haopeng ZhanG han LI Department of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Background Augmented assembly guidance aims to help users complete assembly operations more efficiently and quickly through augmented reality technology,breaking the limitations of traditional assembly guidance technology which is single in content and boring in *** registration is one of the key technologies in augmented assembly guidance process,which can affect the location and direction of virtual assembly guidance information in real assembly *** This paper presents an object registration method based on RGB-D camera,which combines Lucas-Kanade(LK)optical flow algorithm and Iterative Closet Point(ICP)*** augmented assembly guidance system for complex products through this method is ***,in order to compare the effectiveness of the proposed method,we also implemented object registration based on an open source augmented reality SDK *** An engine model and a complex weapon cabin equipment are taken as an case to verify this *** result shows that the registration method proposed in this paper is more accurate and stable compared with that based on Vuforia and the augmented assembly guidance system through this method greatly improves the user's time compared with the traditional *** Therefore,we can conclude that the object registration method mentioned in this paper can be well applied in the augmented assembly guidance system,which can do enhance the efficiency of assembly considerably.

关键词： Registration Augmented assembly guidance Lucas-Kanade Iterative Closet Point Complex product

基于WRF-NAQPMS的一次沙尘天气预报评估

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国环境监测 2024年第2期40卷 212-221页

作者：韩文宇孔祥伟杨丽丽于军海张静张英俊胡爽甘肃省兰州生态环境监测中心甘肃兰州730000 中国气象局兰州干旱气象研究所甘肃兰州730020 兰州中心气象台甘肃兰州730020 甘肃省环境监测中心站甘肃兰州730000 中科三清科技有限公司北京100029

为提高沙尘天气的预报准确率,利用ECWMF再分析资料和近地面PM_(10)小时质量浓度监测数据,评估WRFNAQPMS模式对2021年3月15—21日甘肃强沙尘过程的预报能力。结果表明,WRF-NAQPMS能够在一定程度上模拟此次污染过程:WRF对“3·15”天气系... 详细信息

为提高沙尘天气的预报准确率,利用ECWMF再分析资料和近地面PM_(10)小时质量浓度监测数据,评估WRFNAQPMS模式对2021年3月15—21日甘肃强沙尘过程的预报能力。结果表明,WRF-NAQPMS能够在一定程度上模拟此次污染过程:WRF对“3·15”天气系统的模拟与实况整体趋势较为一致,随着预报时效延长,气象模拟场移动偏快,导致沙尘预报场发展偏快、沙尘二次传输影响下游时间提前;近地面风向的局地偏差是导致甘肃中东部地区沙尘浓度出现预报误差的主要气象因素。NAQPMS模式对PM_(10)小时质量浓度的模拟随着预报时效增加和离沙源地距离的增大,预报误差逐步增大:在河西地区,沙尘影响时段和起沙浓度的模拟值均接近监测值,其中嘉峪关、酒泉、张掖的PM_(10)小时质量浓度模拟值与监测值相关系数r>0.8;中部地区城市的沙尘影响时段预报略有偏差,且模拟值低于监测值;受复杂下垫面和气象场预报误差影响,省内其他地区沙尘预报结果参考性较低。

关键词：沙尘天气预报 WRF NAQPMS 预报评估 PM_(10)

全关节镜下弹性固定Latarjet手术治疗合并严重骨缺损的肩关节前向不稳临床研究

在线全文

学校读者我要写书评

暂无评论

中国修复重建外科杂志 2024年第6期38卷 666-671页

作者：韩大伟应立沙林林惠宇应鲤蔚张庆国梁军波周晓波浙江省台州医院运动医学科浙江临海317000 浙江省台州医院骨科康复科浙江临海317000 浙江省台州医院骨科浙江临海317000

目的评估全关节镜下弹性固定Latarjet手术治疗合并严重骨缺损的肩关节前向不稳的疗效。方法回顾分析2020年6月—2023年2月采用全关节镜下弹性固定Latarjet手术治疗的15例符合选择标准的合并严重骨缺损的肩关节前向不稳患者临床资料。其... 详细信息

目的评估全关节镜下弹性固定Latarjet手术治疗合并严重骨缺损的肩关节前向不稳的疗效。方法回顾分析2020年6月—2023年2月采用全关节镜下弹性固定Latarjet手术治疗的15例符合选择标准的合并严重骨缺损的肩关节前向不稳患者临床资料。其中男11例,女4例;年龄20~54岁,平均31.1岁。三维CT示关节盂骨缺损16.3%~35.2%,平均24.4%。肩关节脱位3~8次,平均4.2次。病程6~21个月,平均10.6个月。记录手术时间、术中出血量;手术前后采用疼痛视觉模拟评分(VAS)评估疼痛缓解情况,Rowe评分、WalchDuplay评分、美国肩肘外科协会(ASES)评分评价肩关节功能恢复情况;评估肩关节各向活动度(range of motion,ROM),包括主动前屈、体侧外旋、外展90°外旋和内旋。术后6个月和末次随访时行三维CT检查,观察移植骨块吸收情况、骨块与关节盂位置以及骨块愈合情况。结果所有患者手术均顺利完成,手术时间85~195 min,平均123.0 min;术中出血量20~75 mL,平均26.5 mL。15例患者均获随访,随访时间13~32个月,平均18.7个月。随访期间患者均未出现肩关节感染、关节僵硬、血管神经损伤等严重并发症。1例术后3个月出现移植骨部分吸收、骨不连,但末次随访时肩关节疼痛较术前改善,未发生肩关节再脱位等情况;其余患者未发生明显骨块骨折、肩关节脱位等情况。术后6个月随访时骨块均已愈合。末次随访时,患者VAS评分、Rowe评分、Walch-Duplay评分和ASES评分均较术前改善,差异有统计学意义(P0.05)。结论全关节镜下弹性固定Latarjet手术治疗合并严重骨缺损的肩关节前向不稳,术后临床功能改善明显,影像学检查提示移植骨块位置满意。

关键词：肩关节前向不稳关节镜弹性固定 Latarjet手术

成都市水源地磺胺类抗生素分布特征及风险评估

在线全文

学校读者我要写书评

暂无评论

环境科学导刊 2024年第3期43卷 71-76页

作者：陈磊韩迁赖承钺张玉娇成都市环境保护科学研究院四川成都610015

为研究水源地水环境风险程度,选取成都市21个饮用水源地作为研究对象,采用固相萃取-高效液相色谱质谱联用仪法,测试16种磺胺类抗生素的含量,并利用风险熵值法评估其生态风险以及对成人、儿童的健康风险。结果表明:磺胺类抗生素的检出范... 详细信息

为研究水源地水环境风险程度,选取成都市21个饮用水源地作为研究对象,采用固相萃取-高效液相色谱质谱联用仪法,测试16种磺胺类抗生素的含量,并利用风险熵值法评估其生态风险以及对成人、儿童的健康风险。结果表明:磺胺类抗生素的检出范围为0.10~343.36 ng/L,平均浓度为34.51 ng/L。生态风险评估结果表明:有2个水源地处于高风险,5个为中风险,其余均为低风险。健康风险评估表明:水源地中磺胺类抗生素对人体及儿童健康没有潜在风险。

关键词：饮用水磺胺类抗生素分布特征生态风险评估健康风险评估

Novel Vesicular Aqueous Two-Phase Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1998年第11期9卷 0-0,0-0页

作者： Guo xi ZHAO Wang Lin yu yu Jun GONG Bu Yao ZHU (Institute of Physical Chemistry, Peking University, Beijing 100871) Institute of Physical Chemistry Peking University Beijing 100871 China

The interesting phenopmena of two aqueous phases coexisting in dilute aqueous solutions of sodium undecenoate-dodecyltrimethylammo brodride ndxture and sodium laurate-dodecyltrimethylammonium brondde mixture were investigated. Vesicles existing in both phases were shown by TEM images. The vesicles are dispersed in lower phase and flocculated in upper phase. Multilamellar structure of vesicles was found in the upper phase of sodium laurate-dodecyltrimethylammonium bromide system.

关键词： Vesicular aqueous two phase catanionic surfactants sodium carboxylates alkyltrimethylarnmonium bromide

Application of Te-Based Glass in Silicon Solar Cells

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 223-229页

作者： xin-xin Pi xiu-Hua Cao Zhen-xiao Fu Le Zhang Peng-De han Li-xi Wang Qi-Tu Zhang College of Materials Science and Engineering Nanjing University of Technology Guangdong Fenghua Advanced Technology Company Limited

（90-x）TeO2-xZnO-lOBi203 （x = 15, 17.5, 20 and 22.5, in mol%） and 70TeOz-2OZnO-（10-y）Bi2O3-y Na2O （y = 1, 3, 5, 7, and 10, in mol%） glasses, and the corresponding Ag paste were prepared in order to prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode. The relationship between structure and properties of the glasses was analyzed. The effects of glass frit on the microstructure, adhesion force, and resistivity of the Ag electrode were studied. The microstructure of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using SEM and XRD. Finally, the 70TeO2-20ZnO-5Bi2O3-5Na2O glass showed better performance in the paste. What is more, Ag crystallites could be found on the Si wafer. These results suggested that the Te-based glass frit could react with SiNx anti-reflecting coating and Si to serve as a medium for forming Ag crystallites.

关键词： Solar cells Ag electrode Silver paste Tellurite glass Ag crystallites