添加剂硼对纯铁粉末触媒合成金刚石的影响

本义研究了添加剂硼对纯铁粉末触媒合成金刚石的影响。实验中将不同比例的无定形硼粉直接添加到石墨-纯铁粉末体系中并均匀混合，以此方式，将硼掺杂到高温高压合成的金刚石单晶中。实验结果表明，随硼添加比例的不同，合成金刚石的最低压力点也不同；同时，通过不同添加比例的硼合成出金刚石的颜色，可得知该方法对提高金刚石内硼含醚的有效性。实验还发现，当硼添加比例一定时，合成温度对合成金刚石的特性产生了一系列的影响。     

Schiff碱N，N’-二（2，5-二羟基水杨醛基）乙二胺与Co（Ⅱ）配合物的合成及晶体的培养

水杨醛类Schiff碱N,N’-二（2,5-二羟基水杨醛基）乙二胺和六水合氯化钴在一定条件下可以形成配合物。文章重点介绍了在常温下配体与碱的摩尔比为1：2、配体与金属盐的摩尔比为1：2时,用分层法培养出N,N’-二（2,5-二羟基水杨醛基）乙二胺和六水合氯化钴所形成的黑色针状单晶。     

分子筛吸附剂的工业应用研究进展

近年来,吸附分离技术以其高效、低能耗和产品纯度高等特点在化工分离技术的发展过程中占据了重要地位.详细介绍了分子筛吸附剂在废水处理、空气净化、气体分离和油品净化等领域的工业应用.对分子筛吸附剂的研究方向提出几点建议:1)降低生产成本;2)提高吸附剂的吸附容量和选择性;3)建立和完善评价吸附剂性能的定量指标.     

多孔件TC4选区激光熔化成形及力学性能分析

采用选区激光熔化成形技术制备了两种钛合金体心立方多孔结构(BCC和BCC-Z)制件,验证了其成形复杂孔制件的可行性;进行了静态压缩试验,结果表明制件沿近45°方向断裂;压缩试验应力应变曲线表明多孔件使材料抗拉强度大大减小,且随着边径比和孔隙率的增大,峰值应力减小。同时,在边径比和孔隙率相差不大的情况下,BCC-Z结构承受载荷的能力明显高于BCC结构;通过有限元模拟分析了BCC制件在压缩过程中的应力分布情况,针对单元体节点处的应力集中现象,提出了节点加固方法。同时预测了多孔制件的弹性模量和屈服强度,模拟与试验结果基本吻合。     

Synthesis and electrochemical properties of TiO2/nanodiamond nanocomposite

Undoped nanodiamond (ND) powders were coated with TiO₂ through two steps: firstly Ti lay was deposited by cycled vacuum-feeding chemical vapour deposition from gaseous TiCl₄/H₂, and secondly an oxidation treatment was carried out in air. The structure and the morphology of the TiO₂/ND composite were characterized by Raman spectrum and transmission electron microscopy. The electrochemical properties of the TiO₂/ND powder electrode in a solution containing [Fe(CN)₆]^3?/4? or NO₂^? were investigated. The results showed that a continuous coating consisting of Ti nanoparticles covered on ND particle after the deposition. The following oxidation at 500 °C resulted in the formation of anatase phase TiO₂ nanoparticles of about 10 nm. The electrochemical results confirmed that the TiO₂/ND powder electrode exhibited higher electrochemical activity than the pristine ND electrode, especially higher catalytic ability toward the oxidation of nitrite anions. Moreover, the TiO₂/ND powder electrode presented fast response towards nitrite oxidation with a detection limit of 0.55 µM and a linear range of 0.05 to 1.0 mM.     

Preparation and characterization of PEGylated terlipressin

Terlipressin was chemically modified by reaction with succinimidyl propionate‐ monomethoxy polyethylene glycol (mPEG‐SPA). To determine the PEGylated degree, the position and the optimized condition for PEGylated terlipressin, the reactions were monitored in different pH value buffers at different molar ratios by reversed‐phase high performance liquid chromatography (RP‐HPLC). Tryptic digestion and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was used. The results showed that the amount of mono‐PEG‐terlipressin was higher at lower pH value and lower content of PEG. Meanwhile, the amount of di‐PEG‐terlipressin was higher at higher pH value and higher content of PEG under the conditions investigated. The position of PEGylated terlipressin was confirmed by tryptic digestion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effects of Different Short-Term UV-B Radiation Intensities on Metabolic Characteristics of Porphyra haitanensis

The effects of ultraviolet (UV) radiation, particularly UV-B on algae, have become an important issue as human-caused depletion of the protecting ozone layer has been reported. In this study, the effects of different short-term UV-B radiation on the growth, physiology, and metabolism of Porphyra haitanensis were examined. The growth of P. haitanensis decreased, and the bleaching phenomenon occurred in the thalli. The contents of total amino acids, soluble sugar, total protein, and mycosporine-like amino acids (MAAs) increased under different UV-B radiation intensities. The metabolic profiles of P. haitanensis differed between the control and UV-B radiation-treated groups. Most of the differential metabolites in P. haitanensis were significantly upregulated under UV-B exposure. Short-term enhanced UV-B irradiation significantly affected amino acid metabolism, carbohydrate metabolism, glutathione metabolism, and phenylpropane biosynthesis. The contents of phenylalanine, tyrosine, threonine, and serine were increased, suggesting that amino acid metabolism can promote the synthesis of UV-absorbing substances (such as phenols and MAAs) by providing precursor substances. The contents of sucrose, D-glucose-6-phosphate, and beta-D-fructose-6-phosphate were increased, suggesting that carbohydrate metabolism contributes to maintain energy supply for metabolic activity in response to UV-B exposure. Meanwhile, dehydroascorbic acid (DHA) was also significantly upregulated, denoting effective activation of the antioxidant system. To some extent, these results provide metabolic insights into the adaptive response mechanism of P. haitanensis to short-term enhanced UV-B radiation.     

柠檬酸复合改性对多环芳烃选择性开环铂/Beta催化剂性能的影响

通过水热处理、柠檬酸处理及其复合处理对Beta分子筛进行后改性,并以改性后的载体制得铂/Beta催化剂。采用X射线衍射（XRD）、X射线荧光光谱仪（XRF）、程序升温脱附（NH₃-TPD）、红外吡啶吸附（Py-IR）、骨架铝核磁共振技术（²⁷Al MAS NMR）及骨架硅核磁共振技术（²⁹Si MAS NMR）等表征了改性前后Beta分子筛的物化性质,并考察了改性前后铂/Beta的多环芳烃选择性开环性能。结果表明,Beta分子筛在柠檬酸处理过程中可同时发生络合脱铝与骨架补铝,实现骨架铝的再分布;Beta分子筛在水热处理过程中优先脱除稳定性相对较低的Si（2 Al）处骨架铝,产生骨架缺陷的同时生成一定比例的二次介孔结构;水热-柠檬酸复合处理影响Beta分子筛骨架补铝及骨架铝再分布的效果,水热处理后Beta分子筛中存在更多的骨架缺陷,促进活性Al（OH）₂⁺物种的骨架补铝作用。当Beta分子筛采用水热-柠檬酸复合处理顺序时,骨架补铝及骨架铝再分布效果显著,样品以中强酸为主,且具有较高的B酸量与L酸量的比值,所制备催化剂的多环芳烃选择性开环活性及稳定性最优。     

Enhanced photocatalytic degradation of dye pollutants under visible irradiation on Al(III)-modified TiO2: structure, interaction, and interfacial electron transfer

Aluminum(III)-modified TiO2 was prepared by sol-gel process via a sudden gelating method. The structure of the modified material and the local environment of aluminum were investigated using X-ray diffraction, HRTEM, XPS, 27Al MAS NMR, and xi-potential measurements. The effect of the aluminum modification on interaction between the dye and photocatalyst, the interfacial electron transfer process, and thereby the degradation of dye pollutants under visible irradiation were also examined by FTIR spectra and UV-vis diffuse reflectance spectra. It was found that, rather than incorporating into the crystal lattice of TiO2, the aluminum forms an overlayer of Al2O3 on the surface of TiO2, interfaced with Ti-O-Al bonds. It is interesting that the carboxylate-containing dyes such as Rhodamine B (RhB) adsorb preferentially on the Al2O3, rather than the Ti(IV) sites on the surface of TiO2. The photodegradation rate observed for RhB is nearly 5-fold faster than that obtained in the pristine TiO2 system. The photodegradation of dyes on the aluminum(III)-modified photocatalyst is of great dependence on the structure and anchoring group of the dyes. Structure with carboxylate as anchoring group and amino group as electron donor is favorable for degradation. The mechanistic details are discussed on the basis of experimental results.     

吉林台混凝土面板砂砾-堆石坝砂砾排水料特性试验

吉林台一级水电站大坝为混凝土面板砂砾-堆石坝,大坝运用中能及时地排除坝体内的水是大坝安全运行的关键之一。该坝体内设置的排水通道是由料场开采的砂砾料经筛分填筑而成。为掌握该排水料的特性,对其进行了颗粒大小分析,密度、含水率、渗透系数等试验;同时也进行了不同含水情况下的碾压施工参数试验。为该砂砾料在坝工中的应用提供了重要资料,满足了工程要求。