检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

中国蔡氏疣螈的成体和胚胎形态特征研究

四川动物 2024年第1期43卷 58-64页

作者：孟建平康泽沼魏平凡李先琦蓝俊麟杨云李青青袁智勇西南林业大学生命科学学院昆明650224 西南林业大学云南省高校极小种群野生动物保育重点实验室昆明650224 云南文山国家级自然保护区云南文山663099 文山市国家级自然保护区管护分局云南文山663099 昆明翔昊科技有限公司昆明650204 西南大学生命科学学院淡水鱼类资源与生殖发育教育部重点实验室重庆400715

2022年5—7月,通过野外实地观察,在云南文山国家级自然保护区对蔡氏疣螈Tylototriton ziegleri的成体形态和胚胎发育进行研究,以期了解蔡氏疣螈的成体和胚胎的形态特征。结果显示,蔡氏疣螈雌雄两性的形态特征存在明显差异,雌性整体形态... 详细信息

2022年5—7月,通过野外实地观察,在云南文山国家级自然保护区对蔡氏疣螈Tylototriton ziegleri的成体形态和胚胎发育进行研究,以期了解蔡氏疣螈的成体和胚胎的形态特征。结果显示,蔡氏疣螈雌雄两性的形态特征存在明显差异,雌性整体形态指标更大。雌性全长115.50~135.42 mm,雄性全长102.70~126.79 mm,两性异形指数为0.078。个体的全长、头体长、头长、头宽、吻长和腋至跨距在两性间的差异极显著(P<0.01),躯干长、眼间距、鼻间距、尾长和尾宽在两性间的差异显著(P≤0.05)。胚胎发育共有21个时期,历时(532.49±45.52)h。本研究通过对蔡氏疣螈形态和胚胎发育的详细观察,为有效保护该物种提供了科学依据。

关键词：蔡氏疣螈形态特征胚胎发育文山

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

富里酸污染红黏土抗剪强度试验研究

岩土工程技术 2024年第1期38卷 101-105页

作者：蒙剑坪李善梅廖勇彬张浩李骏武桂林理工大学广西桂林541004 广西壮族自治区三〇七核地质大队广西贵港537100

通过在红黏土中掺入不同含量富里酸粉末制样,并对试样采用蒸馏水饱和浸泡,对浸泡龄期为7 d、14 d和28 d的试样进行直剪试验,分析不同富里酸掺入量和浸泡时间对红黏土试样抗剪强度的影响。试验结果表明,富里酸的掺入会降低土样的抗剪强度... 详细信息

通过在红黏土中掺入不同含量富里酸粉末制样,并对试样采用蒸馏水饱和浸泡,对浸泡龄期为7 d、14 d和28 d的试样进行直剪试验,分析不同富里酸掺入量和浸泡时间对红黏土试样抗剪强度的影响。试验结果表明,富里酸的掺入会降低土样的抗剪强度,土样的黏聚力随富里酸掺入量增加而提高,内摩擦角则随富里酸含量的增加而逐渐降低,相同富里酸掺入量下,浸泡时间越长,黏聚力越大,内摩擦角则越小。富里酸分子的羧基、羟基、羰基、甲氧基等活性官能团与土体矿物表面形成吸附作用,使得富里酸包裹在土颗粒表面,对土颗粒间形成联结作用,从而影响土体的抗剪强度指标。

关键词：抗剪强度富里酸红黏土

Highly Efficient and Stable Blue OLEDs Based on B-N Bonds Embedded 6,12-Diphenyl-5,11-dihydroindolo[3,2-b]carbazole with Narrowband Emission and Extended Lifetime

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2023年第6期41卷 657-664页

作者： Hengyi Dai jianping Zhou Guoyun meng Lu Wang Lian Duan Dongdong Zhang Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education Department of ChemistryTsinghua University Beijing 100084China Center for Flexible Electronics Technology Tsinghua UniversityBejing 100084China

Emitters with narrowband spectra are of great importance nowadays because of the growing demand for ultra-high-definition displays in the fields of panel displays and solid-state *** the reported multiple resonance(MR)emitters have been widely studied with extremely sharp spectra and color-tunable emissions,the electrophilic borylation synthetic strategies and stable narrowband blue devices still face great challenges.

关键词： Ultrapure blue luminescence Boron-nitrogen bonds Fluorescence emitter Organic light-emitting diodes Indolocarbazole skeleton

Estimation of Gridded Atmospheric Oxygen Consumption from 1975 to 2018

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2020年第3期34卷 646-658页

作者： Xiaoyue LIU jianping HUANG Jiping HUANG Changyu LI Lei DING Wenjun meng Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center Mississauga L4X 2X7Canada Laboratory for Earth Surface Processes College of Urban and Environmental SciencesPeking UniversityBeijing 100871China

Atmospheric Oxygen(O2)is one of the dominating features that allow the earth to be a habitable planet with advanced civilization and diverse ***,since the late 1980 s,observational data have indicated a steady decline in O2 content on the scale of parts-per-million *** current scientific consensus is that the decline is caused by the fossil-fuel combustion;however,few works have been done to quantitatively evaluate the response of O2 cycle under the anthropogenic impact,at both the global and regional *** paper manages to quantify the land O2 flux and makes the initial step to quantificationally describe the anthropogenic impacts on the global O2 *** estimation reveals that the global O2 consumption has experienced an increase from 33.69±1.11 to47.63±0.80 Gt(gigaton,109 t)O2yr^-1 between 2000 and 2018,while the land production of O2(totaling 11.34±13.48 Gt O2yr^-1 averaged over the same period)increased only *** 2018,the combustion of fossil-fuel and industrial activities(38.45±0.61 Gt O2yr^-1)contributed the most to consumption,followed by wildfires(4.97±0.48 Gt O2yr^-1)as well as livestock and human respiration processes(2.48±0.16 and 1.73±0.13 Gt O2yr^-1,respectively).Burning of fossil-fuel that causes large O2 fluxes occurs in East Asia,India,North America,and Europe,while wildfires that cause large fluxes in comparable magnitude are mainly distributed in central Africa.

关键词： oxygen(O2)cycle climate change anthropogenic activities

HPMA modified aluminium nitride powder for aqueous tape casting of AlN ceramic substrates

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2023年第9期12卷 1701-1711页

作者： meng Li jianping Ai Zhengjuan Wang Zhenhai Xue Lihong Cheng Guohong Zhou Shiwei Wang School of Materials and Mechatronics Jiangxi Science&Technology Normal UniversityNanchang 330038China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

Aluminum nitride(AlN)is considered one of the most desirable materials for integrated circuits and electronic packaging ***,raw AlN powder reacts easily with water,forming Al(OH)3 or AlOOH on the surface and hindering the development of an aqueous tape-casting process for preparing AlN ceramic *** this study,hydrolyzed polymaleic anhydride(HPMA)was used to modify AlN powder,which has good water solubility and *** AlN powder was modified with 5 wt%HPMA remained stable in water for at least 90 h under magnetic stirring condition and 24 h under ball milling condition,indicating that HPMA-modified AlN powder has good resistance to *** action mechanism of HPMA is ***,–COOH of the HPMA polymer and the oxide layer on the surface of the AlN powder underwent a dehydration condensation reaction to form a ***,long chains of the polymer further coated the surface of the AlN powder,forming an anti-hydration layer with a thickness of about 7.0 nm on the surface of the AlN *** addition,AlN green sheets were successfully prepared by aqueous tape casting using the HPMA-modified AlN powder without additional ***,AlN ceramic substrates were obtained by sintering at 1750℃for 4 h under an N2 atmosphere with a pressure of 0.2 *** relative density and thermal conductivity were tested to be 97.3%and 122 W/(m·K),respectively.

关键词： aluminum nitride(AlN) surface modification hydrolyzed polymaleic anhydride(HPMA) hydrolysis resistance aqueous tape casting

High Pressure Response of Rutile Polymorphs and Its Significance for Indicating the Subduction Depth of Continental Crust

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2008年第2期82卷 371-376页

作者： meng Dawei WU Xiuling FAN Xiaoyu ZHANG Zhengjie CHEN Hong meng Xin ZHENG jianping Faculty of Materials Science and Chemical Engineering China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Imperial College London London SW 72AZ United Kingdom

α-PbO2-type TiO2 （TiO2-Ⅱ） is an important index mineral for ultrahigh-pressure metamorphism. After the discovery of a natural high-pressure phase of titanium oxide with α-PbO2- structure in omphacite from coesite-bearing eclogite at Shima in the Dabie Mountains, China, a nanoscale （〈2 nm） α-PbO2-type TiO2 has been identified through electron diffraction and high-resolution transmission electron microscopy in coesite-bearing jadeite quartzite at Shuanghe in the Dabie Mountains. The crystal structure is orthorhombic with lattice parameters a = 4.58×10-1 nm, b = 5.42×10-1 nm, c = 4.96×10-1 nm and space group Pbcn. The analysis results reveal that ruffle {011}R twin interface is a basic structural unit of α-PbO2-type TiO2. Nucleation of α-PbO2-type TiO2 lamellae is caused by the displacement of one half of the titanium cations within the {011}R twin slab. This displacement reduces the Ti-O-Ti distance and is favored by high pressure. The identification of α- PbO2-type TiO2 in coesite-bearing jadeite quartzite from Shuanghe, Dabie Mountains, provides a new and powerful evidence of ultrahigh-pressure metamorphism at 4--7 GPa, 850℃-900℃, and implies a burial of continental crustal rocks to 130-200 kilometers depth or deeper. The α-PbO2-type TiO2 may be a useful indicator of the pressure and temperature in the diamond stability field.

关键词： Ruffle twin TiO2 UHP polymorphs Phase transformation HRTEM Dabie Mountains

Selenium Regulates Antioxidant Capacities and Diterpenoid Biosynthesis in the Medicinal Plant Isodon rubescens

在线全文

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2024年第7期93卷 1705-1716页

作者： Fenglan Zhao Shuwen Wu Xue meng jianping Xue Yongbo Duan Anhui Provincial Engineering Laboratory for Efficient Utilization of Featured Resource Plants College of Life SciencesHuaibei Normal UniversityHuaibei235000China Huaibei Key Laboratory of Efficient Cultivation and Utilization of Resource Plants College of Life SciencesHuaibei Normal UniversityHuaibei235000China

Dōng líng căo,the dried aboveground parts of Isodon rubescens(Hemls.)Hara.,is commonly consumed as a med-icinal decoction or tea *** beverages can be an important source of human dietary selenium(Se).However,how *** plants respond to exogenous Se remains *** this study,a pot cultivation experiment was employed to investigate the phenotypic and physiological responses of *** plants exposed to *** days after applying different concentrations of sodium selenate to the soil,the Se enrichment capa-city,growth indices,antioxidant capacities,and the content ofﬂavonoids and diterpenoids were measured in the ***,the oridonin content was quantiﬁed using the high-performance liquid chromatography method,and the expression levels of key diterpenoid synthesis genes were analyzed by quantitative real-time PCR(qRT-PCR).*** plants efﬁciently accumulated Se,with the Se content increasing proportionally to the applied dose,reaching levels of nearly 200 mg·kg^(-1) dry leaves as Se concentration *** of the three Se treat-ments signiﬁcantly altered the phenotypic indices,except a longer root length occurred in the 3μM·kg^(-1) Se *** three Se doses,6μM·kg^(-1) Se gave the highest accumulation ofﬂavonoids,diterpenoids,and oridonin,with the increase of 2.0-,1.8-,and 1.9-fold in aboveground parts,*** application boosted the activities of antioxidant enzymes and antioxidant capacities according to 2,2-Diphenyl-1-picrylhydrazyl(DPPH),ferric reducing/antioxidant power,and tea brewing color *** key synthase genes were upregulated signiﬁcantly by 6μM·kg^(-1) Se treatment,notably 1-deoxy-D-xylulose 5-phosphate reductoisomerase(IrDXR),with a 5-fold increase,and kaurene synthase-like 4(IrKSL4),with a 6-fold ***,Se application in *** cultivation may be a potential biofortiﬁcation method to supplement Se while increasingﬂavonoid and diterpenoid contents.

关键词： Flavonoids oridonin physiological indicators quantitative real-time PCR selenium

Templates for the synthesis of zeolites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2024年第4期43卷 48-58页

作者： Huimin Luan Qinming Wu jianping Wu Xiangju meng Feng-Shou Xiao College of Chemical and Biological Engineering Zhejiang UniversityHangzhou310027China Kente Catalysts Inc. Fengxi West RoadModern Industrial ClusterXianju CountyZhejiang317300China Key Laboratory of Applied Chemistry of Zhejiang Province Department of ChemistryZhejiang UniversityHangzhou310007China

Though zeolites have been successfully synthesized for several decades,the roles of templates for zeolite synthesis are still not fully understood ***,many types of templates have been employed such as inorganic alkali metal ions,organic quaternary ammonium cations,organic amines,organic quaternary phosphonium cations,metal complexes and zeolite seeds,and the roles are mainly summarized into three aspects:structure-directing,space-filling and *** order to synthesize zeolites efficiently,the proposed principles to guide zeolite synthesis are the stabilization of energy between templates and zeolite framework,charge density mis-matching(CDM)and structure matching between zeolite frameworks and *** purpose of this review is to briefly summarize the progresses in recent years,clearly showing the roles of the templates for zeolite synthesis.

关键词： Zeolites Templates Zeolite synthesis Zeolite structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

浙江省公立医院改革实践及其策略选择

中华医院管理杂志 2017年第2期33卷 92-95页

作者：王晓迪郭清马伟杭杨华吴夏秋任建萍胡小璞孟凡莉杭州师范大学医学院 310036 浙江中医药大学浙江省卫生和计划生育委员会

介绍了浙江省公立医院改革实践，并分析其中存在的问题及其原因，提出要“以健康为中心”推进公立医院综合改革，鼓励公立医院承担政府健康责任；以全科医师服务能力提升为重点，坚持推行分级诊疗制度及契约式服务；鼓励社会资本参与健... 详细信息

介绍了浙江省公立医院改革实践，并分析其中存在的问题及其原因，提出要“以健康为中心”推进公立医院综合改革，鼓励公立医院承担政府健康责任；以全科医师服务能力提升为重点，坚持推行分级诊疗制度及契约式服务；鼓励社会资本参与健康服务体系建设；重视利用非政府组织，满足群众Et益多样化的健康服务需求。

关键词：浙江省公立医院改革以健康为中心