溶剂热法合成ZnSe纳米材料

以乙酸锌为锌源, Na₂SeO₃•5H₂O或Se粉为硒源, 采用溶剂热法在乙醇胺(EA)溶剂中一步合成晶型和形貌可控的闪锌矿和纤锌矿结构的ZnSe纳米材料。利用X射线衍射(XRD)、能量色散X射线谱 (EDS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对产物的晶型、成分和形貌进行了表征。结果表明, Se源的选取直接决定了ZnSe纳米材料的晶型和形貌: 以Na₂SeO₃•5H₂O为源, 产物为立方相闪锌矿结构的ZnSe纳米颗粒, 直径30 nm左右; 以Se粉为源, 产物为六方相纤锌矿结构的ZnSe纳米片, 厚度约50 nm。进一步的研究表明, 具有合适配位能力的乙醇胺溶剂和Se源对ZnSe纳米结构的合成起重要作用。通过紫外-可见光谱(UV-Vis)和室温光致发光光谱(PL)表征了产物的光学性质。     

乙醇对纳米CuO晶型及脱硫性能的影响

分别以硝酸铜水溶液和乙醇溶液为原料、氢氧化钠为沉淀剂,采用直接沉淀法制备了纳米CuO.通过TEM、XRD和XPS技术对比分析了乙醇对纳米CuO粒径及晶型的影响,并对比测试了制得的两种纳米CuO室温脱硫性能.实验结果表明:乙醇为分散剂制得的纳米CuO主要是球形,其平均粒径约为7nm,水为分散剂制得的样品中出现了大量棒形纳米CuO,尺寸约为8 nm×36 nm,说明溶剂极性影响纳米材料的粒径和晶型的形成;球形纳米CuO室温脱除H2S的活性时间是棒形纳米CuO的近两倍,表明纳米粒子的结构是影响脱硫性能的重要因素.     

一维纳米氧化锌的溶剂热法制备及其光致发光性能

以乙二胺为介质，利用溶剂热法合成出一维结构的纳米氧化锌，并通过透射电镜（TEM）、X射线衍射（XRD）等对产物的形貌和结构进行了表征。在反应过程中，纳米氧化锌通过“溶解-结晶”机制形成。实验制得纳米氧化锌的紫外-可见光谱体现出其纳米材料的小尺寸效应，在波长325nm处显示较强的激子吸收，与体相材料相比产生明显蓝移；荧光...     

ITO纳米棒的制备及其表征

利用化学共沉淀法,在InCl3和SnCl4混和溶液中添加PEG-1000,并滴加浓度为25%氨水,制备了ITO前驱体,在温度700℃煅烧3h后得到ITO纳米棒.利用SEM、XRD、TEM-EDS和傅立叶-红外光谱仪分别对ITO纳米棒的形貌和尺寸、结构和物相、EDS能谱和FT-IR光谱分析,并对ITO纳米棒形貌形成机理进行了探讨分析.研究结果表明,ITO纳米棒具有立方铁锰矿结构,且具有纯度高和分散性好等特点,平均直径约为φ300nm,长度可迭3000nm,长径比约达10.随着煅烧时间的延长,ITO纳米棒形貌不变,对尺寸影响不大.     

ZnSe晶体的气相法制备和性能研究

采用化学气相输运法,以单质Zn和Se为原料生长ZnSe晶体。比较了加碘(Zn-Se-I2)和未加碘(Zn-Se)两种情况下产物的特征,借助XRD和SEM检测仪器对所生长的ZnSe晶体的结构、形貌和成分进行了分析。结果表明,加入碘后生长的ZnSe晶体为橙黄色,具有较好的结晶性能,晶格常数为5.668nm,Zn与Se的化学成分比为1∶1,没有其它杂质峰;未加碘的产物为多孔状陶瓷,说明加碘可以明显提高ZnSe的结晶性能,解决了一致升华范围较窄的限制条件,避免了ZnSe生长动力学的限制,因此可以获得理想化学计量比的ZnSe晶体。     

水溶液法制备CdSe和ZnSe纳米棒

用水溶液法直接合成了水溶性、发荧光的ZnSe和CdSe纳米棒。ZnSe纳米棒的直径约20～30nm,长度可达60～70nm;CdSe纳米棒的直径约30～60nm,长度可达150～450nm。用X射线衍射仪(XRD)、透射电镜(TEM)、高分辨透射电镜(HR-TEM)、荧光仪等仪器对纳米棒进行了表征。XRD和HRTEM的结果显示纳米棒具有立方结构,结晶度较高。讨论了纳米棒的形成机理以及pH对纳米棒发光强度的影响。合成的纳米棒在水溶液中至少稳定半年,表面被氨基和羧基化,在生物分析中具有广泛的应用前景。     

ZnS：Mn^2＋,Eu^3＋发光纳米材料的油-水界面法合成

以硬脂酸锌为Zn源、硫化钠为S源,首次采用油水界面法制备出单分散于环己烷和甲苯的ZnS纳米材料,探索有机溶剂、锌源和油酸浓度等对紫外吸收影响的同时,以ZnS为基质,掺杂Mn^2＋和Eu^3＋制得ZnS：Mn^2＋,Eu^3＋发光纳米材料,采用高分辨率透射电子显微镜（HRTEM）、X射线粉末衍射仪（XRD）、紫外可见（UV-VIS）和荧光分光光度计（PL）对产物进行了表征,紫外和HRTEM测试结果均表明,产物为单分散性,平均粒径为4.3 nn;荧光测试表明,产物所发荧光较强,肉眼可观测到明显的橙黄色（585 nm）和橙红色（616 nm）发光;XRD结果显示,产物结构为立方闪锌矿结构     

ns脉冲激光诱导制备铬掺杂ZnSe纳米粒子独特的生长以及光学特性

在液相环境中,利用纳秒（ns）脉冲激光器轰击消融铬掺杂ZnSe（Cr^2＋：ZnSe）微米颗粒,制备出Cr^2＋：ZnSe纳米粒子,扫描电镜以及X射线衍射检测,结果显示,制备所得的粒子为平均尺寸为50nm的ZnSe闪锌矿结构纳米粒子。基于Cr^2＋：ZnSe纳米粒子,观察到中心波长为2180nm、阈值为0．4mJ／pulse的随机激光效应。相比于Cr^2＋：ZnSe晶体激光器,纳米粒子随机激光的中心波长发生了约170nm的蓝移,Cr^2＋：ZnSe纳米粒子的光致发光寿命也比Cr^2＋：ZnSe晶体要短。     

以Zn(NH4)3Cl5为输运剂气相生长ZnSe单晶

以化合物Zn(NH4)3Cl5为气相输运剂,ZnSe多晶为原料,用化学气相输运技术(CVT)在封闭石英管中生长出直径9 m m、长度25 mm的Zn1+0 031Se单晶晶体生长区的温度为898～915℃,温度梯度为1.5℃@cm-1,生长周期为21 d.晶体生长端由{111}和{100}单形包围.用RO-XRD技术研究了晶体的结晶质量,ZnSe(111)的RO-XRD谱的FWHM为24 s.光致发光特性研究表明,Zn1+0.031Se单晶体的PL谱由Fx(439 nm)和BBT(418 nm)等发光峰组成,晶体的短波吸收限位于465 nm处,腐蚀点密度为(5～7)×104cm-2.化合物Zn(NH4)3Cl5具有较高的热稳定性,是一种适合气相生长ZnSe单晶的新型输运剂.     

一维纳米氧化锌的溶剂热法制备及其光致发光性能

以乙二胺为介质,利用溶剂热法合成出一维结构的纳米氧化锌,并通过透射电镜(TEM)、X射线衍射(XRD)等对产物的形貌和结构进行了表征。在反应过程中,纳米氧化锌通过"溶解-结晶"机制形成。实验制得纳米氧化锌的紫外-可见光谱体现出其纳米材料的小尺寸效应,在波长325nm处显示较强的激子吸收,与体相材料相比产生明显蓝移;荧光光谱分析表明其在410nm和475nm处出现明显的PL峰,分别为自由激子发光和束缚激子发光,小尺寸效应及氧空位数量会使激子发光信号增强。     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to     

Win-Win Cooperation

正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in     

Systematic Approach for Emerging Industry

正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.     

Strictest Pollutants Emission Standards

正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.     

Instructions to Authors

New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope     

Progress on Standards Copyright Protection

正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.