定容燃烧器法热损失影响因素研究

推导了定容燃烧器法工作过程中热损失计算公式,通过实验对影响定容燃烧器法热损失各因素进行定性分析和定量研究.详细研究了推进剂试样的升压速率、燃烧时间、点火方式、燃速等对热损失的影响.研究表明:热损失随着燃烧器内升压速率的增大而减少;随着推进剂的试样燃烧时间减短而减少;合适的点火方式可以减少热损失;推进剂试样的燃速越快则热...     

电催化氧化法去除黄金冶炼废水中氰化物和氨氮试验研究

对黄金冶炼废水进行了电催化氧化处理研究,考察了氯离子质量浓度、极板间距、电流密度等因素对氰化物和氨氮去除效果的影响。最佳工艺参数为:废水初始pH值9.28、氯离子初始质量浓度25 g/L、极板间距20 mm、电流密度16.3 mA/cm2、废水循环流速64 mL/min。在最佳工艺条件下,电解150 min,氰化物质量浓度从28.84 mg/L降至0.20 mg/L,氨氮质量浓度从700 mg/L降至7 mg/L,去除率分别为99.3%、99.0%,处理后废水中的总氰、氨氮均可达到《GB 8978—1996污水综合排放标准》一级标准。     

刺梨产品研究现状和发展前景

为探究刺梨果醋发酵过程中成分变化,本文以刺梨为原料,采用全液态发酵技术,经酒精发酵和醋酸发酵制备果醋,动态监测发酵过程中的理化特性,并采用固相微萃取-气相色谱-质谱联用技术（Headspace solid-phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS）和气味活性值（Odor activity value,OAV）分析挥发性风味成分。结果表明,随着发酵时间的进行,可溶性固形物、pH、总糖及还原糖均呈下降趋势,而总酸和V_C含量持续增加,由原汁到醋酸发酵结束分别从1.86 g/100 mL和956.82 mg/100 mL增加至6.79 g/100 mL和1275.88 mg/100 mL。有机酸的含量不断变化,草酸、奎宁酸、丙酮酸、抗坏血酸、乳酸、乙酸及富马酸呈现不同程度的显著增加（P<0.05）,而甲酸、柠檬酸、马来酸和琥珀酸含量变化小。共检测到92种挥发性物质,结合OAV分析,10种挥发性物质被确定为刺梨果醋中OAV≥1的关键香气物质,即壬醛、乙醛、异丁酸乙酯、丁酸乙酯、2-甲基丁酸乙酯、乙醇、异戊醇、叶醇、芳樟醇及苯乙醇。其中,丁酸乙酯和叶醇对刺梨果醋香气贡献最大,是刺梨果醋具有青草香、青苹果香的特征风味物质。研究结果为有效控制发酵条件、揭示发酵刺梨果醋的理化特性和风味特征,形成刺梨果醋品质评价方法、制定质量标准提供理论基础和实践指导。

     

氨氮浓度对活性炭深度处理工艺选择的影响

以北江佛山段原水为处理对象,比较了活性炭吸附（GAC）和臭氧/生物活性炭（O3/BAC）两种深度处理工艺对氨氮的去除效果,并分析了预氯化对其处理效果的影响.结果表明,GAC和O3/BAC工艺均具有一定的耐氨氮冲击负荷能力.低氨氮浓度下,GAC和O3/BAC工艺对氨氮的去除率接近（约40%）,并随着进水氨氮浓度的增大而增加;两者出水中的CHCl3浓度均超标,但O3/BAC的较低;综合考虑处理效果及成本,建议此时优先采用GAC工艺.高氨氮浓度下,O3/BAC工艺去除氨氮的效果显著优于GAC,经消毒后其出水中的CHCl3浓度也低于GAC的,故建议在该种原水水质下优先采用O3/BAC工艺.控制沉淀池出水余氯在合适的范围内,则预氯化对O3/BAC工艺的除污效果无影响.     

基于Linux3S的土地基础信息采集技术

针对现有土地基础信息获取手段存在的一些缺陷,提出基于Lin“平台的、结合3S技术的土地基础信息采集方法。采用以Linux平台为核心,设计具有自主知识产权的嵌入式GIS模块,为适应在掌上电脑中使用,提出四叉树——双缓冲存取模式,以提高电子地图显示速度,利用四叉树分割法,实现大型底图显示,集成上层土地管理软件,实现土地基础数据采集。该技术在示范应用中实现取得良好效果,证明了该技术的有效性。     

GC法研究碱式氯化铝 —有机酸溶液配合物的耐酸性

用凝胶过滤色谱法（ＧＣ）洗脱分离有机酸与６０％碱度的氯化铝形成的溶液配合物,通过比较ＧＣ图来研究它们在酸性介质中的变化。用ＳｅｐｈａｄｅｘＧ２５（Ｓｕｐｅｒｆｉｎｅ）柱（８０×２．４ｃｍ）作分离柱,铬天青Ｓ比色法测流份的铝含量。结果表明,不同浓度的碱式氯化铝与有机酸形成的溶液配合物的分子尺寸随介质ｐＨ值的降低而变小,且ｐＨ值越低,变化越大,这与有机酸种类和它们与铝盐的比例有关。试验结果说明,用较常规的ＧＣ法代替有很大局限性的水系高压洗脱的粒子排除色谱法（ＳＥＣ－ＨＰＬＣ）洗脱分离,进而研究Ａｌ（Ⅲ）－有机酸溶液配合物的耐酸性等是可行的。     

α/β-Mercaptoalkanoic acids: versatile synthons in the syntheses of fused ring 4-thiazolidinones/thiazolinones/thiazinanones ring system (s)

This review describes the reactions of β-mercaptoalkanoic acids as building blocks for the synthesis of polyfunctionalized thiazolidinones with pharmacological interest. Annelated thiazolidinones were prepared by a cyclocondensation reaction of α/β-mercaptoalkanoic acids with aldimines. This reaction takes place by a nucleophilic addition, followed by cyclization concomitant with elimination of water. The objective of this survey is to provide a comprehensive account of the synthetic utility of β-mercaptoalkanoic acids to build various heterocycles and their potential to develop better chemotherapeutic agents.     

The GENIUS-test-facility—first results on background from Rn daughters

GENIUS-TF (Nucl. Instr. and Meth. A 511 (2003) 341; Nucl. Instr. and Meth. A 481 (2002) 149.) is a test-facility for the GENIUS project (GENIUS-Proposal, 20 November 1997; Z. Phys. A 359 (1997) 351; CERN Courier, November 1997, 16; J. Phys. G 24 (1998) 483; Z. Phys. A 359 (1997) 361; in: H.V. Klapdor-Kleingrothaus, H. Pas. (Eds.), First International Conference on Particle Physics Beyond the Standard Model, Castle Ringberg, Germany, 8–14 June 1997, IOP Bristol (1998) 485 and in Int. J. Mod. Phys. A 13 (1998) 3953; in: H.V. Klapdor-Kleingrothaus, I.V. Krivosheina (Eds.), Proceedings of the Second International Conference on Particle Physics Beyond the Standard Model BEYOND’ 99, Castle Ringberg, Germany 6–12 June 1999, IOP Bristol (2000) 915), a proposed large scale underground observatory for rare events which is based on operation of naked germanium detectors in liquid nitrogen for an extreme background reduction. Operation of naked Ge crystals in liquid nitrogen has been applied routinely already for more than 20 years by the CANBERRA Company for technical functions tests (CANBERRA Company, private communication, 5 March 2004.), but it never had found entrance into basic research. Only in 1997 first tests of application of this method for nuclear spectroscopy have been performed, successfully, in Heidelberg (Klapdor-Kleingrothaus et al., 1997, 1998; J. Hellmig and H.V. Klapdor-Kleingrothaus, 1997).

On May 5, 2003 the first four naked high-purity germanium detectors (total mass 10.52 kg) were installed in liquid nitrogen in the GENIUS Test Facility at the Gran Sasso underground laboratory. Since then the experiment has been running continuously, testing for the first time the novel technique in an underground laboratory and for a long-lasting period.

In this work, we present the first analysis of the GENIUS-TF background after the completion of the external shielding, which took place in December 2003. We focus especially on the background coming from ²²²Rn daughters. This is found to be at present by a factor of 200 higher than expected from simulation. It is still compatible with the scientific goal of GENIUS-TF, namely to search for cold dark matter by the modulation signal, but on the present level would cause serious problems for a full GENIUS—like experiment using liquid nitrogen.     

基于Visual Basic 6.0的信号发生器自动测试系统

介绍了信号发生器自动测试系统的组成、功能以及实现方法,着重介绍了软件系统的结构、设计思路及设计的难点.该自动测试系统的软件基于Visual Basic 6.0编写,并通过GPIB口实现与仪器间的通信,自动完成数据处理及生成文档.该测试系统实用、高效、可靠.