无机盐对淀粉/聚乙烯醇共混材料结构与性能的影响

为了揭示不同结构的无机盐对淀粉/聚乙烯醇(PVA)共混材料性能的影响规律,分别以Li Cl,Mg Cl2·6H2O,Al Cl3·6H2O,Mg(NO3)2·6H2O,Ca(NO3)2·4H2O和Al(NO3)3·9H2O为改性剂,采用流延法制备了不同无机盐改性的淀粉/PVA复合膜,研究了改性前后淀粉/PVA复合膜的结构与性能。研究结果表明,无机盐可与淀粉和PVA发生相互作用,所含金属离子的价态越高,相互作用越强。无机盐会降低淀粉/PVA的结晶度,其中氯化物对淀粉/PVA结晶结构的破坏作用强于硝酸盐。淀粉/PVA在加入无机盐后热稳定性降低,硝酸盐对淀粉/PVA热稳定性的影响较氯化物小。无机盐能改善淀粉/PVA的相容性,氯化物的作用效果比硝酸盐强;与Li Cl和Al Cl3·6H2O相比,Mg Cl2·6H2O对淀粉/PVA相容性的改善最明显。无机盐可使淀粉/PVA拉伸强度下降、断裂伸长率提高,表现出增塑作用。     

助熔剂和还原气氛对掺铕硅酸锶荧光粉发光性能的影响

采用传统高温固相反应法制备了掺铕硅酸锶荧光粉。在近紫外光激发下,Sr2SiO4:Eu2+发出明亮的黄绿光。其发射光谱由峰值分别位于490nm和550nm的两个属于Eu2+的5d→4f发射带叠加组成。当Eu2+浓度为0.005mol时,发光最强。研究了不同助熔剂(NH4F、NH4Cl、NaF、Li2CO3、H3BO3)及不同还原气氛(5%H2-95%N2混合气体和C粒)对Eu2+掺杂的Sr2SiO4发光性能的影响。结果表明添加助熔剂后大大降低了烧结温度,并不同程度地提高了2个发射峰的强度。结果还表明5%H2-95%N2混合气体还原效果比C粒好。     

冷冻产品用无机盐相变蓄冷材料的制备及性能研究

研制了一种适用于冷冻产品贮藏运输的高效低温无机盐相变蓄冷材料。将NH4Br、KCl、CaCl_2等无机盐与NH_4Cl复配,利用差式扫描量热仪(DSC)筛选了NH_4Br-NH_4Cl无机盐共混物作为主储能剂,通过添加不同成核剂改善过冷性能,添加不同浓度的黄源胶改善相分离。结果表明:以30%(wt,质量分数,下同)NH_4Br-NH_4Cl无机盐共混物作为主储能剂,1%SrCl_2作为成核剂,5%黄原胶作为增稠剂可获得相变温度为-18~-22℃、相变潜热为288.7J/g、过冷度小、无相分离的相变蓄冷材料。NH_4Br-NH_4Cl无机盐共混物作为主储能剂能够达到冷冻产品温度且对相变潜热影响较小,SrCl_2作为成核剂基本无过冷,黄原胶作为增稠剂解决相分离具有显著效果。     

煤制气再燃中NH2与NO反应的物化研究

对煤制气再燃低NOx燃烧过程进行分析,采用量子化学密度泛函理论(DFT)研究NH2自由基与NO的反应机理。全参数优化了各反应物、中间体、过渡态和产物的几何构型,并计算了它们的能量,通过振动频率分析证实中间体和过渡态的真实性。同时用内禀反应坐标(IRC)计算以进一步确定过渡态。为了得到更精确的能量信息,在QCISD(T)水平上计算了单点能。对NH2自由基与NO反应机理进行分析比较,并通过模拟NH2自由基与NO的反应,得出通道NH2+NO→IM1→TS1→IM3→N2+H2O的活化能最低(206.1kJ/mol),为最佳反应通道。揭示其微观机理,对进一步认识再燃脱氮的本质和主要过程提供了重要的理论依据和实践指导。     

氯化铵对Al粉材料直接氮化的影响

分析了NH4Cl对Al粉直接氮化程度的促进作用,并采用实验的方法进行验证.实验中对NH4 Cl的含量比例进行优化,并通过XRD、SEM、XRF和EDS进行测试、分析和表征.结果表明,当铝粉与NH4Cl的质量比不同时,NH4Cl对Al粉直接氮化起到不同程度的促进作用,产物表现为不同的外观形貌、不同的含量及不尽相同的结晶情况.当Al粉与NH4Cl的质量比为9∶4时,反应产物氮化铝纳米线的含量比较多,且外观形貌最好,结晶情况最佳.最后,结合V-S机制对NH4Cl促进AlN纳米线的生长机理进行了解释.     

用量子理论对煤粉再燃中NH自由基与NO反应的物化研究

对气体再燃低NOx燃烧过程进行分析,采用量子化学密度泛函理论研究了NH自由基与NO反应的机理,优化了反应过程中反应物、中间体、过渡态和产物的几何构型,并计算了它们的能量,同时对它们进行振动分析,以确定中间体和过渡态的真实性。对NH自由基与NO反应机理进行了比较,并通过模拟NH自由基与NO的反应,得出通道NO+NH→IM3→TS1→IM4→N2+OH的活化能(100.03kJ/mol)最低,为主要反应通道。揭示其微观机理,对认识再燃脱硝的本质和主要过程具有重要的理论参考价值和实践指导意义。     

BaF2纳米粉体的沉淀制备和成核机制

采用NH4F和Ba（NO3）2水溶液沉淀反应制备BaF2纳米粉体，在临界过饱和和快速混合过饱和反应条件下分别获得了10nm和80nm的BaF2沉淀粉体，对不同沉淀反应条件下的成核机制进行了分析。对于低浓度Ba（NO3）2溶液和NH4F固体快速混合反应情形，讨论了过饱和度的合理计算和扩散对形核的作用。     

CO2-NH3低温复叠式制冷循环的热力学分析与比较

本文介绍了一种用于低温环境的采用自然工质CO2-NH3的复叠式制冷循环，介绍和分析了CO2和NH3的物性特征，并且进行了该复叠式制冷循环的热力学理论分析，通过计算得出了不同蒸发温度下的最佳低温循环的冷凝温度和最佳流量比。通过与R13-R22和NH3-NH3复叠式循环的比较，可以看出CO2-NH3的复叠式制冷循环在低温制冷条件下有明显优势。     

静电纺丝工艺对PVP/TEOS/硝酸盐复合纳米纤维成纤性状的影响

采用静电纺丝技术制备了PVP/[Sr(NO3)2+Mg(NO3)2+TEOS+Eu(NO3)2+Dy(NO3)2]复合纳米纤维,研究了不同静电纺丝工艺参数对其成纤性状的影响。结果表明:纤维的直径均随着电压、无机盐和PVP含量的增加呈现先减小后增大的趋势;随着纺丝液中无机盐含量的增加,纺丝液的黏度、表面张力和电导率均逐渐增大;随着PVP含量的增加,纺丝液的黏度、表面张力逐渐增大、电导率先减小后增大。SEM分析表明,当纺丝电压在13~15kV,纺丝液中无机盐含量为5%~6%,PVP含量为15%时,易获得形貌较好的复合纳米纤维。     

纳米ZnO/CeO2抗紫外剂制备工艺研究

以Zn(NO3)2·6H2O、Ce(NO3)3·6H3O、(NH4)2CO3·H2O和PEG400为原料,采用直接沉淀法制备ZnO/CeO2抗紫外剂复合粉体,用XRD测试了纳米颗粒的粒径,研究了n(Zn2+)/n(Ce4+)、PEG400的用量、煅烧温度的最佳工艺,结果表明n(Zn2+)/n(Ce4+)为1∶3、PEG400用量为3mL、煅烧温度为500℃时效果最佳.     

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.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

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.