油炸马钱子的生物碱成分研究

从中药油炸马钱子(Strychnos nux-vomica L.)中分离得到10个生物碱类化合物.通过波谱分析,分别鉴定为士的宁(1)、士的宁氮氧化物(2)、马钱子碱(3)、马钱子碱氮氧化物(4)、诺弗新(5)、依卡精(6)、异士的宁(7)、异马钱子碱(8)、异马钱子碱氮氧化物(9)、异士的宁氮氧化物(10).为其潜在的药理活性研究提供物质基础.     

Effects of Formulation Parameters and Process Variables on the Properties of Granules Obtained by Reactive Granulation

In this work, granulation between dodecyl-benzenesulfonic acid and sodium carbonate was investigated in a laboratory-scale high shear mixer. The effects offormulation parameters and process variables, including primary carbonate size, binder content, impeller speed, and operating temperature, were correlated to the properties ofthe product granules. Design ofexperiment and analysis ofvariance were combined to analyze the experimentaldata, and results showed that larger granule sizes with fewer fine particles can be obtained by employing higher binder contents and larger sodium carbonate sizes. The shear force ofthe impeller can extensively break oversized granules. The binder content exerted a contrasting effect on the flowability ofgranules formed with two kinds ofsodium carbonate, likely because ofdifferences in the liquid saturation ofthe solids. The dissolution rate determined by in-line size analysis showed that high binder contents were beneficialto dissolution performance, and the relationships between Hunter color and tested parameters were evaluated. The results ofthis work can be used as a reliable guidance for process controland optimization in powder detergent manufacturing.     

Effect of Non-reactive Powder Particle Properties on Dry Agglomeration in a High Shear Mixer

The effect of non-reactive powder particle properties on the detergent dry agglomeration process in a high shear mixer was investigated. Three types of micron-scale silica were chosen as the non-reactive fine powders and a semi-solid alkyl ethyl ethoxy sulfate(AES) paste with ultra-high viscosity was chosen as the binder. The granules were characterized using massbased granule size distribution, scanning electron microcopy, and bulk density tests. The results revealed that powder particle size plays a leading role in agglomeration behavior. A decrease in the median particle size results in enhanced dispersion of silica particles in the AES paste binder droplets, which leads to the formation of uniform granules that are slightly affected by compacting forces. Agglomerate quality, using silica with high oil absorption as well as optimum particle size, was satisfactory, and the product exhibited a smaller median particle size, narrower size distribution, and superior anti-caking capacity under the same liquid-to-solid ratio(L/S).     

Docetaxel-loaded liposomes: preparation, pH sensitivity, Pharmacokinetics, and tissue distribution

Docetaxel (DTX), as a member of taxoid family, has been widely used in the treatment of cancers. The present study prepared pH-sensitive DTX-loaded liposomes (DTX-Lips) by thin-film dispersion method and various physico-chemical and morphological properties were examined. The pH sensitivity of in vitro DTX release and the in vivo pharmacokinetics and tissue distribution using Kunming mice were also investigated. The mean particle size and zeta potential of DTX liposomes were (277±2) nm and (−32.60±0.26) mV, respectively. Additionally, in vitro drug release study showed that the cumulative release rate was 1.3 times more at pH 5.0 than at pH 7.4, suggesting a pH-dependent release ability of DTX-Lips. Pharmacokinetic and pharmaceutical studies in comparison with Duopafei® showed that the half-time period (t _1/2) and area under the curve (AUC) of DTX-Lips in mouse plasma were 1.8 times longer and 2.6 times higher, respectively, and that DTX-Lips selectively accumulated in macrophage-rich organs such as liver and spleen. These results together suggest that the DTX-Lips could be a promising formulation for the clinical administration of DTX.     

掺铝氧化锌粉末的制备及其催化性能研究

采用溶胶凝胶法制备掺铝氧化锌粉末,通过控制铝盐的添加量来制备不同掺杂比例的掺铝氧化锌粉末,使用XRD来测试铝是否掺杂在氧化锌的晶格中,利用SEM来反映掺铝氧化锌粉末的外观以及颗粒分布聚集情况,用激光粒度分布仪来测其颗粒大小。并用所制备的氧化锌粉末样品对甲基红和溴甲酚绿进行光催化,使其降解,通过观察降解的效果,选择最佳的掺杂比例。结果表明,铝元素是掺杂在晶体中,且掺铝摩尔比为5%,煅烧温度为500℃,煅烧时间为3 h,其降解甲基红、溴甲酚绿效率最高。     

木炭颗粒对水溶液中Cd2+和Cr3+质量浓度的影响

目的及方法:采用室内模拟试验,研究木炭不同粒径和用量及不同吸附时间对水溶液中Cd2+和Cr3+质量浓度的影响。结果:木炭粒径为0.25 mm时,溶液中的Cd2+、Cr3+质量浓度最高;粒径大于0.25 mm时,Cd2+、Cr3+质量浓度随着粒径增大而减小;粒径小于0.25 mm时,Cd2+、Cr3+质量浓度随着粒径减小而减小,表明只有在粒径小于0.25 mm时,粒径越小,吸附效果越好。木炭用量达到20 g.L-1时,水溶液中Cd2+、Cr3+剩余质量浓度显著低于对照,且随着用量增加,Cd2+、Cr3+剩余质量浓度有所降低;木炭用量为40 g.L-1时,第1天至第4天,4种不同浓度Cr3+水溶液中,Cr3+质量浓度随着时间的递增而递减,随后随着时间的推移,Cr3+质量浓度呈小幅增长趋势。结论:使用木炭对水溶液中的重金属离子浓度进行吸附,需要对粒径大小、用量、吸附时间等因素进行优化,才能保证吸附效果。     

Protein and hordein fraction content in barley seeds as affected by sowing date and their relations to malting quality

INTRODUCTION Barley (Hordeum vulgare L.) is widely used as food and feed, but its most economically important use is for malting and brewing. Many barley charac- ters are involved in malt quality, of which protein content is the most important, as it has been observed to be related to malt qualities, such as extract and diastatic power (Weston et al., 1993; Eagles et al., 1995).Barley suitable for malting should have low grain protein content, as high protein content will not only reduce…     

压电超声在碳化法合成纳米碳酸钙中的应用探究

以间歇碳化法制备纳米碳酸钙的工艺为基础,以压电超声波辅助合成为方法,以实现工业化生产优质的纳米碳酸钙为目的,确定了超声辐照下纳米碳酸钙的合成反应罐结构及合成装置系统的设计,并探讨了超声波辐照下工艺过程各影响因素与纳米碳酸钙粒径的关系。图示了反应体系的传热、传质效果及与粒径的关系。结果表明,影响压电超声在碳化法合成纳米碳酸钙的粒径主要因素有料浆初始温度、C a（O H ）2乳液浓度、C O 2的流量。在自制的装置中,制备出10～30nm 优质的纳米碳酸钙产品,为纳米碳酸钙粉料的生产提供了另种方法。     

Technology-enhanced mathematics instruction: A second-order meta-analysis of 30 years of research

It is important to assess the cumulative effects of technology on student achievement captured in the last 30 years of technologyenhanced mathematics instruction. Synthesizing the thousands of articles and gray literature on this subject is necessary but would require a considerable commitment of academic resources. A second-order metaanalysis or meta-analysis of meta-analyses is an alternative that is reasonable and effective. Thus, a second-order meta-analysis of 19 prior meta-analyses with minimum overlap between primary studies was conducted. The results represent 663 primary studies (approximately 141,733 participants) and 1,263 effect sizes. The random effects' mean effect size of .38 was statistically significantly different from zero. The results provide a historical and contextualized summary of 30 years of meta-analytic research, which supports meta-analytic thinking and better interpretation of future effect sizes. Results indicate that technology function and study quality are major contributors to effect size variation. Specifically, computation enhancement technologies were most effective, while studies that examine combinations of enhancements were least effective. Implications for technology-enhanced mathematics instruction and meta-analytic research are provided.     

Effects of the amount of tetrapropyl ammonium hydroxide in synthesis on TS-1 properties and catalytic performance in epoxidation of propylene

Titanium silicalite-1(TS-1)was synthesized by a hydrothermal synthesis method with different amounts of tetrapropyl ammonium hydroxide(TPAOH)as template. The as-prepared TS-1 was characterized by scanning electron microscopy, X-ray powder diffraction, Fourier-transform infrared resonance spectroscopy, ultravioletvisible diffuse reflectance spectroscopy and nitrogen physical adsorption and desorption, and studied in the propylene epoxidation with hydrogen peroxide in a fixed bed reactor. The results showed that the amount of TPAOH had a strong influence on the grain morphology, the amount of framework Ti, and the average particle sizes of TS-1. With the increase of TPAOH amount in the synthesis(the molar ratio of TPAOH/SiO₂ increasing from 0.25 to 0.45), the morphology changed gradually from ellipsoids to cubes, the particle sizes of TS-1 decreased slightly, the amount of the framework Ti increased appreciably, and the catalytic stability in the propylene epoxidation increased markedly. Moreover, all the catalysts had the same selectivity to propylene epoxide. However, when the molar ratio of TPAOH/SiO₂ was further increased to 0.55, the particles became large hexagons with the size distribution in a wide range, and the catalytic stability decreased sharply although the amount of the framework Ti increased further, which can be attributed to the long diffusion paths of the reactants in the zeolite.     

激光快速烧结合成钨酸铪的研究

利用CO2激光快速烧结技术合成了负热膨胀材料钨酸铪,并用拉曼光谱、X射线衍射和SEM对其进行了物相和形貌观察.结果表明,合成的钨酸铪主要为立方相含有极少量的正交相,样品表面和内部的晶粒沿激光扫描的方向取向生长,形貌为柱状晶,均匀致密,尺寸在10~50 nm.     

磁性纳米粒子尺寸可控合成的研究

采用柠檬酸盐溶胶-凝胶法制备Ba2Co2Fe12O22铁氧体,在热处理阶段,分别通过控制热处理的温度和时间来制备不同粒径大小的磁性纳米粒子,利用高分辨率激光粒度仪分析测试在不同条件下获得的铁氧体,同时探讨了反应溶液不同的PH值对合成的影响。实验结果表明,延长加热时间和提高热处理温度都会使纳米粒子的粒径增大,在PH值略高...     

再生铝铝渣粒度及成分研究

采用激光衍射式粒度仪、扫描电镜能谱分析和X射线衍射方法,对比分析了不同粒径的再生铝铝渣,比较了其物相与粒度分布之间的差异,就如何提高铝渣聚集效果进行了探讨,结果表明：Na3AlF6在一定程度上有助于聚集提高铝渣颗粒,MgO不利于铝渣颗粒的聚集,应当避免或减少使用.     

沥青路面微波加热器电磁仿真与实验分析

为了研究微波加热再生沥青路面时的热电效率和再生温度分布的均匀性,设计了一种波导激励腔,并应用于微波加热器的结构设计.运用波导传输线理论,确定了激励腔的结构尺寸.采用IE3D分别对磁控管探头(天线)与短路板间距、不同喇叭长度和口面尺寸、不同沥青混合料介电性能和加热腔口面与沥青路面不同距离4种情况进行了电磁仿真.结果表明:...     

球形果蔬差压预冷过程实验研究

通过搭建的果蔬差压预冷实验台分别研究了不同的送风速度、开孔大小、开孔形状及排列方式,对球形果蔬在差压预冷过程中所产生的影响,实验结果发现：风速越大球形果蔬降温速率越快,冷风送风速度1.5～2m/s为最经济送风风速;椭圆形的送风口球形果蔬降温速度最快;交叉排列摆放方式降温速度快,但降温的均匀性较差;     

反应型纳米级磁核聚烯烃类磁性材料的研究——(Ⅳ)纳米级NdxFe_(3-x)O_4磁性载体的制备和性能研究

用化学共沉淀法合成出平均粒径在40-50nm的NdxFc_(3-x)O_4纳米晶,用TEM和PSD及XRD分析其结构、粒径和形貌.用磁天平和交流性自动测量仪研究其磁性能.结果表明,NdxFc_(3-x)O_4纳米晶是尖晶石结构,晶粒为立方形.比饱和磁化强度虽比相同制备条件下的Fe_3O_4略小,但矫顽力比Fe_3O_4高50%左右.     

The class size question in primary schools: policy issues, theory, and empirical findings from the Netherlands

Primary schools in the Netherlands are autonomous in their decisions on grouping of pupils, and therefore on class size matters, because the state may not interfere in pedagogical-didactical issues according to the constitution. Surveys indicate that both across as well as within schools (across grades) class sizes consequently vary quite a lot. Capitalizing on this situation, a randomly drawn sample of 416 schools was used to collect data on class sizes and pupil achievement in grades 2, 4, 6 and 8. Social-ethnic status, IQ and gender also were examined. Using multi-level statistical models the strongest size effects were obtained in grade 2 in classes below 25 and above 35. Interaction effects between socio-ethnic status, sex and IQ with class size on achievement showed inconsistent trends. In three out of ten cases the achievement gap widened with decreasing class size.     

The impact of NiO on microstructure and electrical property of solid oxide fuel cell anode

INTRODUCTION The solid oxide fuel cell (SOFC) has attracted much attention as a promising source of electrical power generation because of its high efficiency in converting chemical energy to electrical power. De- velopment of SOFC with operating temperature of less than 800 °C has been extensively studied. SOFC has the potential to have the cost of its materials, cell fabrication, and corrosion of its stack components dramatically reduced. Gadolinia-doped ceria with the chemical fo…     

汕头龙湖片陆生植物现状调查与评价

对龙湖片陆生植物的种类组成、植被类型、优势种污染物含量和污染现状等进行了分析和评价。结果表明,本片区植物种类较丰富,无原生植被,植物中重金属的超标率较高。植物所受污染与水、土壤的污染情况相似。     

纳米TiC粉末的分散与表征综合实验设计

纳米TiC粉末具有高强度、高硬度、高耐磨、高耐腐蚀、低热膨胀率、优良的导热导电能力和抗热震性,被广泛用作复合材料的增强体。纳米粉末粒度小、表面能和表面活性大,在储存和使用过程中极易产生团聚。采用胶体分散技术分散纳米TiC粉末;利用TEM、激光粒度分析和Zeta电位测试等手段对纳米TiC的分散效果进行表征。实验研究了分散介质、超声时间、分散剂种类和加量、溶液pH值等因素的影响。有利于培养材料科学与工程类专业本科生综合运用知识、研究科学问题的能力。