防虫灵和几种惰性粉对储粮害虫作用的比较研究

本文报告了滑石粉、进口与国产硅藻土、膨润土、Ｉｎｓｅｃｔｏ、防虫灵以及不同水分、酸度的滑石粉对玉米象、谷蠹、杂拟谷盗成虫的毒力和室内药效测定结果。实验表明：国产硅藻土、Ｉｎｓｅｃｔｏ、防虫灵的作用效果显著，而滑石粉、膨润土、进口硅藻土效果较差。不同水分和酸度的滑石粉对害虫的作用差异不大。此外，还研究了防虫灵及几种惰性粉对小麦容重的影响。     

粉体的剪切试验及其装置

介绍了粉体剪切试验的方法和几种常用的剪切试验装置，对其优缺点进行了分析比较，并用实例说明了剪切试验装置的应用。     

化学沉淀法制微细SiO2粉末

采用正交分析法研究以硅酸钠和盐酸为原料,用化学沉淀法制备微细SiO2粉末过程中反应温度、乙醇/水体积比、HCl浓度等影响因素对产品质量的影响,并利用粒度分析仪和金相显微镜对产品的粒度和形貌进行测试.实验结果表明在反应温度40℃,乙醇/水体积比为0.5,盐酸浓度为1.4 mol/L条件下制得的SiO2粉末,其粒径小且颗粒分散均匀.     

粉末冶金法制备Al—12％CuO系原位铝基复合材料的组织和性能

为了制备组织均匀、压缩性能良好的原位纳米颗粒增强铝基复合材料,本文以微米级纯铝粉和氧化铜粉为原料,用改进的高能球磨＋粉末冶金技术制备了原位增强铝基复合材料,研究了所制备的铝基复合材料的显微组织和密度、压缩强度等性能与制备工艺的关系．研究发现：高能球磨480r／min,16h＋单向模压热压烧结620℃,100MPa,1h,获得纳米级CuAlO2原位增强的铝基复合材料,在铝基体中均匀分布大量尺寸约1μm的CuAl2相．热压工艺对所制备的铝基复合材料的压缩强度有显著影响,620℃,100MPa单向模压复合材料的压缩强度为843．6MPa,而双向加压材料的压缩强度提高到950MPa;当单向压力提高到150MPa时,原位铝基复合材料的压缩强度进一步提高到1090MPa．     

手性樟脑磺酸的合成及表征

以樟脑粉为原料合成了消旋樟脑磺酸;采用l-苯甘氨酸为拆分剂,经拆分、纯化分离得到了手性樟脑磺酸。合成消旋樟脑磺酸的适宜工艺条件为：反应时间25 h,浓硫酸的滴加速度0.5～1.0 mL/min,反应温度10℃,消旋樟脑磺酸的收率85.6%,熔点195～201℃。拆分的适宜工艺条件为：物料比n（dl-樟脑磺酸）∶n（l-苯甘氨酸）=1∶0.95,d-樟脑磺酸拆分收率64%,熔点194～196℃,[α]2D0=＋23°（C=5,H2O）;l-樟脑磺酸拆分收率90.8%,熔点197～198℃,[α]2D0=-22.5°（C=5,H2O）。样品经熔点、旋光率、红外光谱等检测方法,证明与目标产物一致。     

基于损伤力学的含夹杂粉末高温合金FGH96低周裂纹萌生寿命预测

研究FGH96粉末高温合金中夹杂物对低周疲劳寿命的影响,提出基于损伤力学理论的低周裂纹萌生寿命预测模型,在建立损伤演化方程后提出损伤表征参数.对含夹杂物和不含夹杂物的粉末高温合金试样在530℃和600℃下进行疲劳试验,并对具有椭圆形、半椭圆形、多边形和条形表面/亚表面夹杂物的试样进行模型验证,然后通过有限元模拟进行应力...     

Physical and surface characteristics of the mechanically alloyed SiBCN powder

A powder mixture of cubic silicon, hexagonal boron nitride and graphite, with the molar ratio of Si:BN:C=2:1:3, was high-energy ball milled for 40 h, under argon atmosphere. The physical and surface characteristics, the microstructures and the behavior on heating of the as-milled SiBCN powder were carefully studied by SEM, nitrogen adsorption–desorption isotherms, XPS, FT-IR, XRD, TEM and thermogravimetry-differential thermal analysis-mass spectrometry-infrared spectroscopy (TG–DTA-MS-IR). Results show that the as-milled powder is amorphous and mainly consists of near-spherical agglomerates, 6.6±5.3 μm in size deriving from the hard agglomeration of nano-primary particles. The specific surface area, the specific pore volume and the average pore diameter of the powder are 24.5 m²/g, 0.136207 cm³/g and 20.3 nm, respectively. The as-milled powder adsorbs water vapor, CO and CO₂, and it is easy to oxidize. When heated in helium atmosphere, the powder desorbs water vapor, CO and CO₂ at lower temperature, and rapidly degasifies CO and CO₂ at temperatures approximately between 1350 °C and 1500 °C.     

Effect of Superfine Grinding on Antidiabetic Activity of Bitter Melon Powder

The antidiabetic activities of bitter melon powders produced with lyophilization/superfine grinding and hot air drying/normal grinding were investigated in vivo for selecting a suitable bitter melon processing procedure. After a five-week treatment, bitter melon lyophilized superfine grinding powder (BLSP) had a higher antidiabetic activity with reducing fasting blood glucose levels from 21.40 to 12.54 mmol/L, the serum insulin levels from 40.93 to 30.74 mIU/L, and restoring activities of SOD compared with those in the bitter melon hot air drying powder (BAP) treated group. Furthermore, BLSP protected pancreatic tissues including islet beta cells and reduced the loss of islet cells. Combined with the difference of compositions in BLSP and BAP, it could be concluded that superfine grinding and lyophilization processes were beneficial for presenting the antidiabetic activity, which will provide a reference for direct utilization of bitter melon as a suitable functional food to relieve symptoms of diabetes.     

改性热塑性酚醛树脂的制备及残炭率的影响因素

在苯酚和甲醛原料中加入一定量的SiO2粉体改性剂,可成功制备出改性热塑性PF(酚醛树脂)。以热塑性PF的残炭率为考核指标,采用单因素试验法优选出制备硅改性PF的最优方案。结果表明,当m(苯酚)∶m(甲醛)=(1.30～1.36)∶1时,硅改性PF的残炭率较高且变化不大;当w(SiO2粉体)=0.9%、反应温度为90℃和反应时间为3 h时,改性热塑性PF的残炭率相对较高;此时,Si元素已均匀分布在PF基体树脂上,掺杂的SiO2有助于提高热塑性PF的耐热性能。     

Sorption of Brilliant Red HE-3B Reactive Dye from Aqueous Solution onto Seashells Waste: Equilibrium and Kinetic Studies

The potential of waste seashells powder, as a new adsorbent for Brilliant Red HE-3B reactive dye removal from aqueous solutions, was examined by the batch technique. The Freundlich, Langmuir, and Dubinin-Radushkevich adsorption models were applied to describe the equilibrium sorption data and to determine the corresponding isotherm constants. The values of the thermodynamic parameters, ΔG, ΔH, and ΔS, indicate that the sorption of reactive dye is a spontaneous and endothermic process. The kinetic data evaluated by pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models suggested that the sorption of reactive dye onto seashell is a complex process and both surface sorption and intraparticle diffusion contributes to the rate limiting step.