TiO_2/ZnO粒子的制备及其抗菌性能

采用溶胶凝胶法制备了TiO2/ZnO复合粒子,通过XRD、SEM对所制备粉体颗粒的物相组成以及表面形貌进行表征,通过最小抑菌浓度法(MIC)研究了不同掺杂量的TiO2/ZnO复合粒子的抗菌性能。结果表明,掺杂TiO2的ZnO粒子显示优良的抗菌活性,对金黄色葡萄球菌(Staphylococcusaureus)的MIC≤62.5μg·mL-1。当TiO2的掺入量为20%,所得到的ZnO粒子的抗菌性能最佳,对绿脓杆菌、大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌四种菌的抑菌性能均有显著提高,并对其机理做了初步探讨。     

CdIn2S4/TiO2纳米复合材料的制备及其对Q235碳钢的光生阴极保护性能

为了提高TiO2的光电转换效率及其在可见光下的光生阴极保护性能,采用水热法在阳极氧化制备的TiO2纳米管上沉积CdIn2S4,制备了CdIn2S4/TiO2纳米复合材料.通过扫描电镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(UV-vis DRS)分析材料的表面形貌、晶相、元素组成和光响应特征;通过测试开路电位(OCP)、Tafel极化曲线以及电化学阻抗谱(EIS)等方法研究复合材料对Q235碳钢的光生阴极保护效果.结果 表明:TiO2纳米管表面成功负载了花簇状的CdIn2S4.在可见光照射下,CdIn2S4/TiO2纳米复合材料可以使Q235碳钢的开路电位明显负移,电位可以降至-1.12 V(vs SCE),表明将CdIn2S4与TiO2复合后可以明显提升TiO2对Q235碳钢的光生阴极保护性能,这是由于沉积CdIn2S4后,TiO2纳米管对可见光的响应能力显著增强,光电转换效率明显提升.     

稀土铈/纳米TiO2复合抗菌剂的研究

制备出稀土铈掺杂锐钛型纳米TiO2复合抗菌功能材料,该抗菌材料与不掺杂的纳米TiO2相比,在可见光下对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的混合菌具有较好的抑菌效果,随着Ce4+的摩尔浓度增加,制备的试样的抗菌能力越强.其原因(1)铈掺杂激活纳米TiO2在可见光下的催化活性,使其光催化杀菌能力增强,(2)Ce4+本身具有较好的杀抑菌能力.     

Ag/TiO2纳米管复合材料的合成及其光催化性能研究

采用水热法制备了TiO2纳米管,并采用光化学沉积法制得含Ag量不同的Ag/TiO2-NTs纳米管复合材料;利用XRD、TEM、XPS、UV-Vis及FL等分析手段对Ag/TiO2-NTs复合材料进行表征,并研究了Ag/TiO2-NTs对甲基橙(MO)的紫外光催化降解性能。结果表明,Ag纳米粒子均匀分散在纳米管表面,Ag/TiO2-NTs复合材料在可见光区域表现出较强的吸收性能;Ag含量为4%的Ag/TiO2-NTs复合材料光催化降解率最高,紫外光照射3h后,初始浓度为10mg/L的甲基橙溶液降解率达到99%,比未掺Ag的TiO2纳米管降解率提高了16.6%。     

ZnO复合石墨相氮化碳纳米片的制备及其光催化性能研究

为了提高石墨相氮化碳光催化性能,本文以尿素、硫脲、醋酸锌为前驱体,通过氧化热剥离与共混煅烧法分别制备g-C₃N₄纳米片和ZnO/g-C₃N₄异质结复合材料,并采用TEM、FTIR、XRD、UV-Vis DRS、BET等表征手段对制备的催化剂进行结构表征。以罗丹明、大肠杆菌为探针,考察了催化剂的光催化降解性能和抑菌活性。结果表明：以尿素和硫脲为前驱体,经过氧化热剥离处理后能得到的g-C₃N₄ 2D纳米片,其比表面积更大、光催化性能更加优异,且其对罗丹明的降解率较未剥离的g-C₃N₄提高了21.2%。在40 min氙灯照射下,纯g-C₃N₄并未表现出良好的抑菌性能,而通过ZnO复合制备的ZnO/g-C₃N₄异质结复合材料,在光催化降解率和抑菌活性方面均有很大提高,其中复合20%ZnO制得的ZnO异质结复合材料表现出最佳的光催化性能...     

负载有ZnSe的TiO2纳米带复合材料的制备及其可见光催化性能

采用水热法制备了立方相ZnSe负载的锐钛矿型TiO3纳米带复合材料.在140℃下反应6h制得的产物是六方相ZnO负载的TiO2纳米带,但此样品再在160℃下反应6h,则获得的产物是ZnSe负载的TiO2纳米带;若在140℃下将反应时间延长至24h,只有少量ZnO转变为ZnSe.紫外-可见吸收测试结果表明,负载的ZnSe对TiO2起到了可见光光敏化作用;可见光催化测试结果表明,ZnSe在TiO2纳米带的负载对罗丹明B的光催化降解活性起到一定程度的增强作用,但随着ZnSe负载量的增大,光催化降解活性显著降低.     

抗菌天然橡胶纳米复合材料的研制

研究了自制ZnO/Ag纳米复合抗菌剂的亲油改性,利用改性后的ZnO/Ag纳米复合抗菌剂制备天然橡胶(NR)纳米复合材料,探讨了抗菌NR纳米复合材料的抗菌、抗藻性能.结果表明:ZnO/Ag纳米复合抗菌剂经磷酸三丁酯(TBP)改性后,沉降率从接近1减小到0.2以下,亲油性和稳定性大大提高,将TBP改性后的抗菌剂加入到油性介质正己烷中,抗菌剂分散均匀,粒径在100nm以内;在NR纳米复合材料的制备中,随着ZnO/Ag纳米复合抗菌剂添加量的增加,正硫化时间减小;经检测,抗菌NR纳米复合材料对大肠埃希氏菌的抗菌率达98%以上,且抗菌率随抗菌剂添加量的增加而增大,抗藻性能达到最优零级标准.     

介孔TiO2载银纳米复合材料的制备及性能研究

运用醇热法制备介孔二氧化钛(m-TiO_2),并借助光还原法制备m-TiO_2载银(m-TiO_2/Ag)复合材料,通过透射电镜和X射线衍射等手段对复合材料的形貌和组成进行表征,并以亚甲基蓝(MB)的脱色降解来表征不同Ag含量样品的光催化性能,通过生长曲线、最小抑菌浓度和抑菌环对其抗菌性能进行表征。结果表明:用醇热法制备的m-TiO_2是以锐钛矿为主含有少量板钛矿的混晶,金属Ag颗粒沉积在m-TiO_2表面;纳米银负载可显著提高mTiO_2的可见光光催化性能;亚甲基蓝的光催化降解反应遵循一级反应动力学模型;m-TiO_2/Ag复合材料的抗菌性能随着载银量的增加而逐渐提高。     

羧甲基壳聚糖/Ce^3＋掺杂TiO2复合抗菌材料的研究

采用溶胶-凝胶法制备稀土（Ce^3＋）掺杂纳米TiO2（纳米Ce/TiO2）,借助XRD、BET、SEM对Ce/TiO2进行表征。结果表明纳米Ce/TiO2晶型为锐钛矿,平均晶粒大小为19.95nm,比表面积为43.302m^2/g。采用超声波催化法合成了羧甲基壳聚糖（CMC）,并与Ce/TiO2复配制得羧甲基壳聚糖/Ce3＋掺杂纳米TiO2复合材料（CMC/Ce/TiO2）,借助FT-IR对CMC及CMC/Ce/TiO2复合材料进行了结构表征。初步研究了纳米Ce/TiO2、普通纳米TiO2、CMC/Ce/TiO2、CMC的抗菌性能,结果显示纳米Ce/TiO2对大肠杆菌和金黄色葡萄球菌的抗菌率分别为55%和53%,普通纳米TiO2对两种菌的抗菌率分别为50%和45%,Ce^3＋的掺杂可提高纳米TiO2的抗菌性能;CMC/Ce/TiO2对大肠杆菌和金黄色葡萄球菌的抗菌率分别达到99%和95%,CMC对两种菌的抗菌率分别为90%和80%,Ce/TiO2的复合可显著提高CMC的抗菌性能。     

合成条件对Bi_2MoO_6/ZnO纳米复合材料光催化性能的影响

采用水热法在不同的反应温度、反应时间和不同pH值条件下原位合成纳米Bi_2MoO_6/ZnO复合材料,使用XRD,SEM分析了产物的相结构与微观相貌,通过Bi_2MoO_6/ZnO光催化降解亚甲基蓝溶液,分析复合物的光催化性能。研究结果表明,在pH=6、反应温度为160℃、反应时间为12 h的条件下,可以得到结晶度较高的Bi_2MoO_6/ZnO纳米复合材料,且在可见光照射条件下90 min,对亚甲基蓝的降解率最大达到97.6%。Bi_2MoO_6/ZnO纳米复合材料在光降解领域具有潜在应用价值。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

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.