Preparation of fine nickel powders via reduction of nickel hydrazine complex precursors

Fine nickel(Ni) powders with controllable particle sizes were synthesized via the reduction of nickel hydrazine complex precursors of pure [Ni(N2H4)2]Cl2 and a mixture of [Ni(N2H4)2]Cl2 and [Ni(N2H4)3]Cl2 in aqueous solution. The mechanism of the formation of metallic Ni powders experiences the reduction of nickel hydroxide by hydrazine released from the ligand exchange reaction between nickel hydrazine complex and NaOH. In comparison with the method of preparing Ni powders from nickel salts,the method of making Ni powders via the reduction of nickel hydrazine complex precursors shows the advantages of using half dosage of hydrazine for complete reduction of nickel ions in solution,and the obtained Ni particles show less agglomeration and better dispersibility. Moreover,the average particle size of nickel powders can be controlled from 180 to 260 nm by adjusting the reaction molar ratio and concentration.

Debinding and sintering of warm compacted and binder-treated complex iron-base part

Regular elemental powders were used in warm flow compaction instead of the expensive micron-sized powders to fabricate cross-shaped parts. Debinding behaviors,sintering properties and shape consistency of the sintered parts were studied. Binder removal was accomplished by heating green compacts at intermediate temperatures with optimal heating rates until the debinding temperature was reached. Results show that by controlling debinding process,complex parts with good shape consistence can be obtained by warm compaction of binder-treated powder. Fine and shiny surface was obtained and no surface defect can be observed for sintered parts debinded at 2 ℃/min,while defect can be observed in sintered parts debinded at 4 ℃/min.

Production of Nanopowders of Platinum Metals Using the Chemical Reduction Method

The literary data on the application of various methods for the production of nanopowders of platinum metals and alloys have been summarized, and the selection of the method of chemical reduction from salt solutions has been substantiated as the simplest and most affordable. The optimum conditions for the production of nanoparticles of metal palladium and platinum/cobalt alloy, using the effect of boranes with various structures, have been selected.

Synthesis of Y_2O_3 Nano-Powder from Yttrium Oxalate under Ambient Temperature

High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ～1.4 mol ? L^(-1) and0.031～0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ～18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .

大麦若叶复合果蔬营养粉工艺研究

为充分提升大麦若叶粉的营养价值,本研究利用大麦若叶粉、麦芽粉、山楂粉复配制成易消化型营养果蔬粉,以感官评分为评价指标,通过单因素和正交试验优化果蔬粉的配方。结果表明,大麦若叶复合果蔬营养粉最佳配方为大麦若叶粉0.25 g、麦芽粉0.075 g、山楂粉0.06 g、白砂糖0.24 g、果胶0.12 g。经分析测定,该果蔬粉总膳食纤维含量为25.91%,黄酮含量为5.95 mg/g。

Synthesis, Spectral Characterization and Thermal Behavior of Newly Derived La(III), Co(III) and Mn(II) Complexes with Schiff Base Derived from Methionine and Salicylaldehyde

Many metal complexes of Schiff base derived from different amino acids are widely employed as biologically active materials, especially as antibacterial agents. Three new metal [Co(III), Mn(II) and La(III)] complexes with the Schiff base (L) derived from salicylaldehyde and amino acid (methionine) were synthesized and investigated by using various physico-chemical techniques such as elemental analysis, FTIR, UV-visible spectroscopy, magnetic measurement, thermo gravimetric analysis (TGA) and X-ray powder diffraction (XRD) method. From spectral studies, it has been concluded that the synthesized ligand acts as a tetra-dentate molecule, coordinates metal through azomethine nitrogen, sulfur, phenolic oxygen and carboxylate oxygen. UV-visible spectrophotometry showed the characteristic absorption bands corresponding to a square planar geometry for La(III) and Mn(II) metal complexes and tetrahedral geometry for Co(III) complex. The XRD data demonstrated that the manganese and cobalt complexes were crystalline but the lanthanum complex was amorphous in nature. The empirical formula of the synthesized complexes based on analytical data were [Co(C12H13SNO3)]·(NO3), [La(C12H13SNO3)](Cl)(H2O) and [Mn (C12H13SNO3)].

一种植物蛋白复合肽盐的工艺研究

食盐与我们的日常生活密切相关,但如果摄入过多食盐,会导致体内钠离子积累过多,进而引发一系列的疾病。该研究在以谷朊粉为原料制得咸味肽的基础上,以感官评分、色差值、水分、乳化性和乳化稳定性为指标,对氯化钾、酵母提取物和柠檬粉的添加量进行单因素试验,并利用响应面试验优化肽盐的配方。结果表明,在氯化钾为0.4 g、酵母提取物为0.2 g、柠檬粉为0.3 g的条件下,复合肽盐中多肽含量为11.4 mg/g,钠离子含量为0.35 g/100 g,钾离子含量为1.181 g/100 g,且添加酵母提取物和柠檬粉掩盖了肽盐的不良气味,外观呈浅黄色;减少了生活中钠的摄入量,得到低钠、减盐不减咸的调味品。

玉米、荞麦复配粉对高脂血症大鼠的降血脂作用

为研究玉米荞麦复配粉对高脂血症大鼠脂质代谢的调节作用,将60只大鼠随机分为空白对照组、高脂模型组、阳性组、玉米组、荞麦组、玉米荞麦复配粉组,干预4周,称量大鼠体重、脏器重,测定脂质水平、肝损伤水平及抗氧化水平,并进行肝脏病理组织学检查。结果表明:与高脂模型组相比,玉米荞麦复配粉组能够显著降低血清总胆固醇(Total cholesterol,TC)(1.8 mmol/L)、甘油三酯(Triglyceride,TG)(1.38 mmol/L)、低密度脂蛋白胆固醇(Low density lipoprotein cholesterol,LDL-C)(0.62 mmol/L)的含量,回调高密度脂蛋白胆固醇(High-density lipoprotein cholesterol,HDL-C)(1.27 mmol/L)的含量(P<0.05);玉米、荞麦、玉米荞麦复配粉各组的丙氨酸转氨酶(Alanine transaminase,ALT)、天冬氨酸转氨酶(Aspartate aminotransferase,AST)活力有不同程度降低,其中玉米荞麦复配粉组活力降低效果显著。同时,玉米荞麦复配粉上调了血清中总超氧化物歧化酶(Total superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-Px)的酶活力,下调了血清中丙二醛(Malondialdehyde,MDA)、胆固醇酯(Cholesteryl ester,CHE)的含量,肝脏中亦出现此趋势。肝脏HE染色表明,玉米、荞麦、玉米荞麦复配粉组肝细胞的分布较整齐,大泡性脂滴减少,其中,玉米荞麦复配粉组的改善效果最为显著。由此可见,玉米荞麦复配粉能显著调节高血脂饮食大鼠脂代谢水平,提高肝脏抗氧化能力,修复肝损伤。

Synthesis, Rietveld Refinement and DFT Studies of Bis(4,5-dihydro-1<i>H</i>-benzo[g]indazole)silver(I) Hexafluorophosphate Complex Salt

The new salt bis(4,5-dihydro-1H-benzo[g]indazole)silver(I) hexafluorophosphate, [Ag(N2H10C11)2]PF6, has been synthesized in methanol at ambient temperature and characterized by elemental and thermal analyses, FTIR and 1HNMR spectroscopies, Rietveld refinement from powder diffraction data and DFT studies. The salt crystallizes in the triclinic space group P-1 with the parameters: a = 7.776 ?, b = 8.676 ?, c = 9.226 ?, α = 69.27° β = 89.86°, γ = 74.50°, V = 558.02 ?3, Z = 1. In the structure, the silver center is coordinated to two nitrogen atoms from two 4,5-dihydro-1H-benzo[g]indazole ligands, forming a centrosymmetric complex cation, [Ag(N2H10C11)2]+, with a linear coordination geometry around the silver center. The hexafluorophosphate ion, , acts as counter anion. The crystal packing is governed by N-H···F and C-H···F hydrogen bonds that interconnect the ionic constituents and Ag···F and Ag···π interactions help for the stabilization of the packing. The optimized structure was obtained at B3LYP/LanL2DZ level in the gas phase. The stability and reactivity of the structure were studied using respectively HOMO-LUMO gap and electronic global quantities (ionization potential (I) and electron affinity (A)) as descriptors.

新型配合物点火药设计与表征

为探索新型点火药,以满足武器装备更高的需求,以3,5-二硝基苯甲酸根(DNBA)为阴离子,1-烯丙基咪唑(AIM)为配体,过渡金属Mn、Co、Cu为中心离子,合成了3种新型含能配合物燃料,对其晶体结构、热分解特性、燃烧热和机械感度进行了测试;基于此,设计并制备了3种点火药,对其燃烧热、线燃烧速率、输出压力、点火能力和感度进行了测试。结果表明:3种新型含能配合物燃料的热分解温度处于272.93~427.85℃范围,燃烧热处于16.69~18.91 kJ·g^(-1)范围,对机械刺激不敏感;3种点火药的燃烧热处于3.88~4.71 kJ·g^(-1)范围,线燃烧速率处于153.28~187.33 mm·s^(-1)范围,输出压力处于4.36~4.62 MPa范围,撞击感度处于28~32 J,摩擦感度处于216~252 N。

菌酶复合添加剂对花生秸混合青贮饲料品质的影响

为评估菌酶复合添加剂对花生秸及花生秸混合青贮饲料发酵效果的影响,以花生秸为原料分别制作花生秸单独青贮饲料(PA),花生秸和玉米芯混合青贮饲料(PC),花生秸和稻壳粉混合青贮饲料(PR),添加菌酶复合添加剂(包含植物乳杆菌、副干酪乳杆菌、纤维素酶、木聚糖酶、葡聚糖酶、果胶酶),以等量蒸馏水为对照组(CK)。对不同处理青贮饲料的发酵品质、微生物数量和营养品质进行检测。结果表明,PC具有最低的pH、氨态氮和ADL含量,最高的体外干物质消化率,但是也有一定负面效果,如增加了霉菌和酵母菌数量,降低了粗蛋白含量。菌酶复合添加剂的使用显著提升了乳酸产量,降低了青贮饲料中的pH和氨态氮含量,同时降低了aNDF含量,提升了体外干物质消化率。且PC在菌酶复合添加剂处理下pH降低到4.16。因此,菌酶复合添加剂的使用对于提升花生秸青贮饲料以及花生秸混合青贮饲料发酵品质和营养品质效果显著,具有显著的应用价值。

桑蚕蛋白复合粉抗运动疲劳功效研究

为了研究桑蚕蛋白复合粉的抗运动疲劳功效与作用机制,C57BL/6雄性小鼠分为对照组、低剂量组(50 mg/kg·d)、中剂量组(100 mg/kg·d)和高剂量组(200 mg/kg·d),灌胃30天后检测力竭游泳时间和运动疲劳标志性生化指标(血尿素氮、血乳酸、肌乳酸、肝糖原、肌糖原和骨骼肌中抗氧化相关酶活性)。与对照组相比,各剂量蚕蛋白复合粉组小鼠力竭游泳时间显著延长,血尿素氮、血乳酸、肌乳酸水平显著降低,肝糖原、肌糖原含量显著升高,骨骼肌中总抗氧化能力、谷胱甘肽过氧化物酶、超氧化物歧化酶和过氧化氢酶的活性显著升高,脂质过氧化产物丙二醛水平显著降低。桑蚕蛋白复合粉可以通过减少代谢废物乳酸与尿素氮的积累、增加肝糖原和肌糖原的储量、降低骨骼肌的氧化应激水平来发挥抗运动疲劳的功效。

复合蛋白粉安全性和免疫功能评价

本研究旨在评估复合蛋白粉(Complex Protein Powder,CPP)的安全性和免疫功能。急性经口毒性实验、遗传毒性实验和亚急性口服毒性实验(28 d)结果显示,CPP安全性较高,不会对小鼠的生长发育产生负面影响。CPP对小鼠免疫功能的影响试验显示,中剂量组(1667 mg·kg^(-1)bw·d^(-1))CPP可以显著提升小鼠的NK细胞活性、巨噬细胞吞噬率等指标,有效增强小鼠的免疫功能。

点火药的研究进展与展望

作为武器系统的重要组成部分,点火系统的性能直接影响到武器的发射效率和作战效果,因而点火药的性能尤为重要。以硼/硝酸钾为代表的非金属类点火药的研究已经较为深入,但该点火药面临着点火温度过高、硼粉老化及吸湿等问题。以金属粉作为可燃剂的金属类点火药具有高能量密度、良好的机械性能和独特的能量释放特性,但燃烧速率较慢。因此,研究人员进行了大量实验研究,制备出具有层状或核壳结构的反应材料,可以大大增加氧化剂和金属燃料之间的接触面积,并缩短传质距离,从而提高反应效率。近年来,含能配合物类点火药的研究成为本领域的研究热点,研究表明以含能配合物作为燃料,设计点火药配方,能够显著实现点火药的性能调控性能。

复合活化对废弃混凝土再生微粉活性的影响及机理研究

再生微粉具有潜在活性,可作为辅助性胶凝材料取代水泥,但活性低限制了其应用。采用物理-化学复合活化方法激发再生微粉的活性,研究了活化再生微粉的活性指数、力学性能和微观形貌。结果表明:随着研磨时间的延长,胶砂的抗压、抗折强度先提高后降低;当研磨时间为4 h时胶砂试块的28 d抗压强度为28.6 MPa,28 d活性指数为64.3%。采用物理-化学复合活化时,当研磨4 h且掺加1%Na2SO4+1%Ca(OH)2激发剂时,胶砂28 d抗压强度为35.2 MPa,28 d活性指数达到79.1%,再生微粉的活性显著提高。

化学镀法制备银包铜粉研究进展

银包铜粉具有优异的导电、抗氧化、抗菌和催化活性,并且具备成本经济性,被视为银粉的理想替代品,目前已在光伏、电子、医药和催化等多个领域得到应用。化学镀法是目前制备银包铜粉的最主要方法,该方法中需要使用多种化学试剂,然而现有综述文献鲜有对该方法中常用试剂的种类及作用进行阐释。本文详细阐述了不同种类试剂在化学镀法制备银包铜粉过程中的作用及机理,分析对比了不同试剂种类、工艺路线的优缺点,并展望了银包铜粉的研究趋势与技术发展方向。

化学镀铜影响镀层光亮性的因素研究

本文研究了化学镀铜工艺中影响光亮性的关键因素。通过实验分析和理论探讨,确定了络合剂种类以及浓度,添加剂的种类浓度、操作条件、表面活性剂的种类和浓度,化学镀铜反应副产物的累积,污染物的累积等因素对镀层光亮性有较大的影响。

激光-感应复合加热蒸发-冷凝法制备超微锌粉

提出了一种制备超微粉的新方法 ,并制作了原型装置。该方法利用激光 高频感应复合热源加热金属 ,以蒸发 冷凝的方式获取超微粉。用该方法制取了超微锌粉 ,产率为 12g/min ,粉末平均粒径为 33.2 0nm。

WC颗粒表面超声波化学镀镍工艺

研究了利用超声波化学镀技术制备等离子熔覆用Ni包WC复合粉末的工艺方法 ,确定了一种优化的超声波化学镀镍工艺 ,并对复合粉末的形貌、性能及其等离子熔覆层的组织进行了分析与讨论。试验结果表明 ,经化学镀镍处理后的WC颗粒形状圆整 ,流动性得到改善 ;经等离子熔覆后 ,熔覆层组织均匀致密 。

络合沉淀法合成纳米氧化铜粉体及其性能表征

以Ｃu（ＮＯ３）２为原料，采用络合沉淀法合成了纳米级CuＯ粉体，并对产品结构性能进行了表征．探讨了氨水，柠檬酸，乙二胺三种不同络合剂对粉体粒径的影响，三种络合剂得到粉体平均粒径在４０～６０nm之间，粉体的粒径随着络和物稳定性的增加而增大．获得了以氨水为络合剂制备纳米氧化铜粉体的最佳工艺条件，以氨水为络合剂所得ＣuＯ粉体平均粒径４０nm，分散性好、收率高．