车用陶瓷催化剂能力验证标准样品的研制

根据日常质量控制及能力验证需要,制备车用陶瓷催化剂分析用标准品。并建立标准样品制备工艺流程,对制备的标准样品进行了均匀性和稳定性检验,对标准样品进行了定值分析及不确定度评估。结果显示,制备的样品均匀性符合要求,样品在一年内是稳定的。采用4种业内认可方法对样品进行协作定值,确定样品中铂、钯、铑元素的标准定值,并对其不确定度进行评估。该标准样品的研制不仅可作为车用陶瓷催化剂能力验证用,更可在日常检测中用作质量控制样品,有助于国内相关领域实验室对车用陶瓷催化器贵金属含量检测进行有效控制,提高检测精准度。     

中国散裂中子源4K低温恒温器温度校正

介绍了中国散裂中子源(CSNS)一期4 K低温恒温器的结构、性能测试及样品温度测试结果。测试结果显示样品座测点温度与实际样品温度存在温差,所以必须对样品温度进行校正。通过对样品区域进行热工分析,设计了可以密封氦气的样品盒,实现了测点温度与样品温度的一致。     

溶致液晶模板法制备形貌可控的纳米氧化锆

以ZrOCl_2·8H_2O及NH_3·H_2O为原材料,采用SDS/TritonX-100/H_2O构成的六角相为模板制备氧化锆纳米粉体,确定pH对模板稳定性的影响,讨论氯氧化锆浓度对所制备样品粒径及形貌的影响。利用偏光显微镜对模板的稳定性进行表征,利用粒度分析仪、SEM及TEM对所制备粉体粒径及形貌进行表征,利用XRD对样品的晶型及纯度进行表征,同时采用FT-IR对氧化锆纳米粒子的形成机理进行推导。结果表明:在碱性条件下,模板的稳定性不受影响,酸性条件下模板的六角相织构消失;氯氧化锆浓度对所制备样品的形貌及粒径影响很大,增大氯氧化锆的浓度,所制备的样品形貌从球形到棉絮状;通过机理分析推测样品的前驱体与模板并没有发生络合作用,样品在模板的水层中间成核及生长,模板起到限制的作用。     

老化对含铝温压炸药爆速及力学性能影响的研究

为研究高低温老化试验对含铝温压炸药性能的影响,对样品进行了质量变化和抗压强度的研究,并采用电测法测试含铝炸药在高低温试验前后的爆速。研究结果表明:样品的质量随高低温老化时间的增加而减少;老化试验前样品的爆速为6 685 m/s,老化14 d及28 d后爆速分别为6 590 m/s和6 799 m/s,爆速并未发生显著的变化;老化试验前样品的抗压强度为5.694 MPa,老化试验14 d及28 d后未经处理样品的抗压强度为9.110 MPa和9.615 MPa,处理后的样品抗压强度为6.523 MPa和6.717 MPa,处理后的样品抗压强度低于未处理样品,对样品进行处理能显著减缓抗压强度的增加。     

我国天然产物标准样品管理及技术体系发展现状

本文阐述了天然产物标准样品研制工作的背景和意义,介绍了我国天然产物标准样品研制工作的组织管理体系现状,重点对标准样品研制技术体系进行了描述,分析了构成技术体系的管理技术、信息技术和研制技术单元的特点,列举了标准样品示范性研制及技术规范工作的典型案例,探讨了如何解决标准样品分离纯化及定值等技术瓶颈问题。最后,汇总了标准样品研制工作的主要成果,并对我国天然产物研制工作的管理体系、技术体系建设,以及产业化发展前景进行了展望。     

生活饮用水3M Petrifilm^TM菌落总数测试片法的不确定度评定

对3M PetrifilmTM菌落总数测试片法检测生活饮用水中菌落总数的测量结果进行了不确定度评定,评述了引起测量结果不确定度的主要因素,对样品稀释及方法精密度因素进行了详细评价,并对单一样品重复测量10次及30个样品每个样品平行测量2次的两种情况,分别进行了重复性标准偏差评价。结果显示：单一样品重复测量时,测量结果的不确定度主要由样品稀释和重复性标准偏差引起,扩展不确定度U95为20CFU/mL,k=2;多个样品每个样品平行测量2次时,测量结果的不确定度主要由重复性标准偏差引起,在95%的置信度时,扩展不确定度U（lgxj）为0.093,k=2.75。     

生活饮用水3M Petrifilm~(TM)菌落总数测试片法的不确定度评定

对3M PetrifilmTM菌落总数测试片法检测生活饮用水中菌落总数的测量结果进行了不确定度评定,评述了引起测量结果不确定度的主要因素,对样品稀释及方法精密度因素进行了详细评价,并对单一样品重复测量10次及30个样品每个样品平行测量2次的两种情况,分别进行了重复性标准偏差评价。结果显示:单一样品重复测量时,测量结果的不确定度主要由样品稀释和重复性标准偏差引起,扩展不确定度U95为20CFU/mL,k=2;多个样品每个样品平行测量2次时,测量结果的不确定度主要由重复性标准偏差引起,在95%的置信度时,扩展不确定度U(lgxj)为0.093,k=2.75。     

实验室客服中心样品库管理的优化方案

客户所送的样品在实验室要经过接受、识别、流转、在库及保护等环节,如何在保护好样品的前提下充分利用空间、科学放置、加强识别。本文就细化样品库位,对实验室客服中心样品库进行优化管理,实现样品库的超市式管理模式进行探讨。     

阳极氧化铝的原子层淀积封孔研究

制备了多孔阳极氧化铝,利用原子层淀积技术对其封孔,借助场发射扫描电镜(SEM)分析了样品的表面及剖面形貌,对样品进行染色处理,利用酸性点滴试验测试样品抗腐蚀性能。结果表明:阳极氧化处理形成大孔径约为16 nm的多孔膜,多孔膜在循环50次的原子层淀积下能实现表面封孔而内部有空结构;经封孔后的样品抗染色及抗腐蚀能力增强。     

AZ31镁合金强流脉冲电子束表面改性研究

通过动电位极化曲线测试.光学电子显微镜及电子探针等方法研究了强流脉冲电子束表面处理对AZ31镁合金腐蚀性能的影响及样品的表面形貌与成分.结果表明,在5%NaCl溶液中,加速电压27kV、脉冲8次处理后的样品比原始样品耐蚀性提高了1.6倍;处理后样品的表面出现了典型的熔坑形貌;电子束快速凝固过程使最表层晶粒细化,进而导致表层镁、铝元素含量及分布形式发生变化.样品表层铝元素含量的提高是改善其耐腐蚀性能的主要原因.     

Effects of cooling conditions and chitosan coating on the properties of porous calcium phosphate granules produced from hard clam shells

The main inorganic components of clam shells are calcium carbonate and trace elements of magnesium, strontium, and zinc. Clam shells can be used as a calcium source to synthesize calcium phosphates, and these trace elements promote the growth of bone tissue and improve the performance of bioceramics. In this study, hydroxyapatite (HA) powders were synthesized from clam shells, and porous calcium phosphate granules were prepared through the gas foaming technique. In addition, the effects of a chitosan coating and cooling conditions on the strength of the porous granules were investigated. The results indicated that the samples produced under the furnace cooling condition were biphasic hydroxyapatite/β-tricalcium phosphate granules (HA/β-TCP), whereas the samples produced under the air-cooling condition were triphasic hydroxyapatite/β-tricalcium phosphate/α-tricalcium phosphate granules (HA/β-TCP/α-TCP). The compressive strength of the porous granules prepared through air cooling was 79% higher than that of the granules produced through furnace cooling. The compressive strength of the air-cooled sample after the subsequent application of the chitosan coating further increased by 21%. A degradability test revealed that the weight loss rate of the air-cooled samples was greater than that of the furnace-cooled samples, which was due to the presence of high-solubility α-TCP in the air-cooled samples.     

Single step preparation of nanosilver loaded calcium phosphate by low temperature co-conversion process

The preparation and characterization of nanosilver loaded calcium phosphate aiming to enhance the bactericidal performance by a single step co-conversion technique using low temperature ion exchange phosphorization in combination with Tollen's reaction were performed. Silver nitrate was used as a silver ion supply source (0.001-0.1?M) and glucose was employed as a reducing agent. After conversion, surface and shell zones of all samples comprised hydroxyapatite and metallic silver as the main phases regardless of silver nitrate concentration. However, hydroxyapatite, residual calcium sulfate and monetite were found in the core zone when using silver nitrate concentration lower than 0.1?M. The microstructure of all samples comprised the distribution of spherical-shaped silver nanoparticles within the cluster of calcium phosphate nanocrystals. Total silver content (range, 0.09-6.5?%) in the converted samples was found to linearly increase with increasing silver nitrate content. Flexural modulus and strength of converted samples generally decreased with increasing silver content. Effective antibacterial activity of two selected samples (0.001 and 0.005?M AgNO(3)) against two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus) was observed. Cytotoxic potentials by MTT assay of both samples were observed at 24 and 48?h extraction respectively.     

Mg<Superscript>2+</Superscript> substituted calcium phosphate nano particles synthesis for non viral gene delivery application

Gene therapy provides a unique approach to medicine as it can be adapted towards the treatment of both inherited and acquired diseases. Recently, calcium phosphate vectors as a new generation of the non viral gene delivery nano carriers have been studied because of their biocompatibility and DNA condensation and gene transfer ability. Substituting cations, like magnesium, affects physical and chemical properties of calcium phosphate nano particles. In this study, Mg²⁺ substituted calcium phosphate nano particles have been prepared using the simple sol gel method. X-ray diffraction analysis, Fourier transform infra red spectroscopy, transmission electron microscopy, specific surface area analysis, zeta potential measurement and ion release evaluation were used for characterization of the samples. It was concluded that presence of Mg ions decrease particle size and crystallinity of the samples and increase positive surface charge as well as beta tricalcium phosphate fraction in chemical composition of calcium phosphate. These properties result in increasing the DNA condensation ability, specific surface area and dissolution rate of the samples which make them suitable particles for gene delivery application.     

Calcium hydroxyapatite,Ca10(PO4)6(OH)2 ceramics prepared by aqueous sol–gel processing

Aqueous sol–gel chemistry routes based on ammonium–hydrogen phosphate as the phosphorus precursor and calcium acetate monohydrate as source of calcium ions have been developed to prepare calcium hydroxyapatite samples with different morphological properties. In the sol–gel processes, an aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) or tartaric acid (TA) as complexing agents were added to the reaction mixture. The monophasic Ca₁₀(PO₄)₆(OH)₂ samples were obtained by calcination of precursor gels for 5 h at 1000 °C. The phase transformations, composition and micro-structural features in the polycrystalline samples were studied by thermoanalytical methods (TGA/DTA), infrared spectroscopy (IR), X-ray powder diffraction analysis (XRD) and scanning electron microscopy (SEM). It was shown that adjusting the nature of complexing agent in the aqueous sol–gel processing can be used to control the morphology of the ceramic samples.     

Improving the biocompatibility of NiTi alloy by chemical treatments: An in vitro evaluation in 3T3 human fibroblast cell

The nearly equi-atomic nickel titanium alloy was coated with calcium phosphates by socking the chemically treated alloy in simulated body fluid in order to prepare bioactive NiTi implants. The biocompatibility of the calcium phosphates coated NiTi alloy was investigated by in vitro 3T3 human embryonic fibroblast cell culture tests. The cells attachment and morphologies were studied using phase contrast light microscope and environmental scanning electron microscope. The mechanically polished and the calcium phosphates coated NiTi samples were well tolerated by the cells, whereas, the controlled pure Ni samples exhibited strong toxicity to the cells. Furthermore, the calcium phosphates coated NiTi samples showed good osteoconductivity.     

原子吸收法测定钠钙玻璃中常量元素的方法改进

传统原子吸收法测定钠钙玻璃中各元素的标准溶液的配制方法既繁琐且不容易消除干扰。通过实验,我们根据标准钠钙玻璃和样品基体元素相近来消除干扰,改进了配制标准溶液的方法,使标准溶液配制简单易行。     

Hydrothermal-electrochemical CaTiO3 coatings as precursor of a biomimetic calcium phosphate layer

The hydrothermal-electrochemical method was used to coat Ti and Ti6Al4V with calcium titanate CaTiO₃. The film exhibited a plate-like structure with several isolated pinholes around 100 nm in diameter. These coated samples were treated by a biomimetic procedure, immersing them in a simulated body fluid (SBF) solution for 5, 10 and 28 days. Characterization was performed by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. The CaTiO₃-coated samples after the SBF treatment showed a significant increment in their calcium and phosphorous amounts as compared with SBF-treated samples with no previous CaTiO₃ coating; the latter exhibited only surface phosphate incorporation.     

不同品种重质碳酸钙粉在外墙涂料中的应用

为考察不同矿种相同细度和相同矿种不同细度的重质碳酸钙粉体在涂料中的应用差异,设计3种外墙涂料基础配方,研究以不同重质碳酸钙粉为主要体质颜料的外墙涂料的白度、黏度、遮盖性、韧性、耐擦洗性。结果表明:在一定实验条件下,以高白度重质碳酸钙粉为体质颜料的涂料其白度越高,白度提高2%～11%;不同品种重质碳酸钙粉为体质颜料的涂料的韧性相差不大;以品质好、细度小的重质碳酸钙粉为体质颜料的涂料其耐洗刷性好;以粗细搭配配制成的重质碳酸钙粉为体质颜料的涂料,除涂料白度变化较小外,其黏度值降低,耐洗刷性、遮盖性分别为以单一重质碳酸钙粉为体质颜料的涂料的11.01%～27.50%,遮盖性能提高1.6%～19.0%,耐洗刷性提高0.5～3倍。     

Investigations of the initial stage of recombinant human-like collagen mineralization

To found the theoretical foundation for applying recombinant human-like collagen (RHLC) to bone tissue engineering, the initial stage of RHLC mineralization was studied for the first time by using Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). SEM images showed that samples of RHLC/calcium phosphate were spongy. TEM images and Selected Area Electron Diffraction (SAED) exhibited that the RHLC fibers in the mineralized samples were surrounded by HA nanocrystals. By comparing the FTIR spectra of RHLC, RHLC/Ca²⁺ and RHLC/calcium phosphate, it was observed that the peak for amide I shifted to a lower wavenumber indicating that there is chemical interaction between carbonyl groups of RHLC and calcium ions. These results are consistent with previous studies of natural collagen mineralization. It is reasonable to conclude that RHLC can regulate the deposition of HA nanocrystals and may be used in bone tissue engineering.     

Preparation and characterization of novel diatomite/ground calcium carbonate composite humidity control material

Three kinds of novel diatomite/ground calcium carbonate composite humidity control materials were prepared with different calcination temperatures using diatomite and ground calcium carbonate (GCC) as raw materials. The microstructure and morphology properties of samples were studied by nitrogen gas adsorption, mercury intrusion porosimetry (MIP) and fractal dimensions on the basis of gas adsorption isotherms with FHH methods. Fourier transform infrared spectroscope (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the mineral composition and surface properties. Furthermore, X-ray diffraction (XRD), thermo-gravimetry and differential scanning calorimetry (TG-DSC) were used to analyze the formation mechanism of composite material. It was indicated that DG750 showed the better moisture adsorption performance. The 72 h moisture adsorbed amount of DG750 reached 11.66%, 8.81% and 8.00% at 98%RH, 85%RH and 75%RH, respectively, which improved about 0.46, 0.54 and 0.53-fold as those of diatomite. The hydrophilic calcium silicate, calcium oxide and calcium hydroxide were formed in the DG750 during the calcinations process. As compared with the raw materials, the content of mesoporous component increases in the DG750, which is in favor of capillary condensation and improving moisture adsorption ability.