NHC硅化法及其应用

NHC硅化加固方法 ,已在数十项工程中推广应用 ,均取得满意效果 ,介绍了这一方法的作用原理及其特性 ,并列举了在几项工程中的应用实例。     

A Reflection on Mg, Cd, Ca, Li and Si Isotopic Measurements and Related Reference Materials

This contribution aims to report the reflections we had with the scientific community during two international workshops on reference materials for stable isotopes in Davos (2002) and Nice (2003). After evaluating the isotopic homogeneity of some existing reference materials, based on either certificates, literature data or specific inter-laboratory rounds, we confirm these as primary reference materials or propose new ones relative to which stable isotope compositions should be reported. We propose DSM-3 for Mg, NIST SRM 915a for Ca, L-SVEC for Li and NBS28 for Si. Cadmium does not yet have a well identified delta zero material, although three commercial mono-elemental Cd solutions have yielded the same isotopic composition relative to one another. In order to scale the linearity of any mass spectrometer, some secondary reference materials are also proposed: Cambridge-1 solution for Mg, the "Münster-Cd" and JEPPIM Cd solutions for Cd and the "Big Batch" silicate for Si. The team from Nancy propose to prepare a mixed spike solution for Li isotopes. Well-characterised natural samples such as ocean or continental waters, diatoms, sponges, rocks and minerals are needed to validate the entire analytical procedure, particularly to take into account the effect of sample mineralisation and of chemical manipulations for elemental separation prior to analysis.     

由膨润土提铝残渣直接合成五配位体有机硅化合物

研究了以膨润土提铝残渣为原料，采用低温加热法直接合成有机硅化合物新方法。由实验确定了最佳的合成条件。用红外光谱法和X射线衍射法分析了合成产物的结构。结果表明，当以碱金属氢氧化物为介质时，合成的产物为五配位体有机硅化合物；在最佳合成条件下，钠盐和锂盐的收率分别为63．0％和44．9％。     

粉状煤系土的物理力学特性

采用不同天气下的原位及室内试验方法,对广东云浮地区粉状煤系土的工程地质性质进行了测试,系统研究了煤系土的物理力学特性,重点论述了粉状煤系土不同干密度、不同含水率下抗剪强度和现场静力触探比贯入阻力的变化规律,提出了粉状煤系土的多项强度指标,建立了具有实用参考价值的经验性公式。研究结果为合理评价粉状煤系土的特性、路基处理和边坡处治提供理论依据,具有一定的实际意义。     

荣成大疃刘家铍矿矿物赋存状态

大疃刘家铍矿铍元素主要以羟硅铍石单矿物赋存在矿石中。以羟硅铍石单矿物存在的BeO占79．45％;少部分分散在其他矿物中,以赤铁矿、褐铁矿中 BeO 含量较高,其次是绢云母、重晶石等。BeO 呈分散状态占20．55％,主要集中在绢云母中,这是由于矿石中绢云母含量高所致,分散状态的BeO无法回收。根据矿石中有用矿物和脉石矿物组合,矿石类型为羟硅铍石绢云母碳酸盐岩长石石英型铍矿石。     

机载粉剂催化剂播撒设备的研制及其在奥运和残奥消云中的应用

人为引发的下沉气流可以抑制对流云的发展,这一现象已在试验中得到验证。用“人工下沉气流法”实施人工消云试验时,需在云顶大剂量的播撒粉剂催化剂。北京市人工影响天气办公室研制了能完成此类大剂量播撤任务的设备,并通过外场飞行试验对设备进行检验和改进。这是国内人工影响天气领域首个采用空投播撒法的粉剂催化剂播撤设备;可减少催化剂对飞机和播撤设备的污染。分析发现,新设备能够满足人工消云作业中播撒大剂量粉剂催化剂的需要。该设备在北京奥运会、残奥会开闭幕式当日的消云试验作业中投入使用,共实施消云飞行作业9架次,累计利用新设备播撒吸湿性粉剂催化剂34吨。     

ICP-AES法测定金属硅中硼磷铝锰钙镁铁等28种微量和痕量元素

采用ICP-AES法对金属硅中的B、P、Al、Mn、Ca、Mg、Fe等28种微量和痕量元素进行分析。根据元素的化学性质制定预处理方法,优化ICP-AES光谱仪测试样品的最佳工作条件。在缺少金属硅标准物质的情况下,选择硅含量较高的国家一级岩石标准物质（GBW07106）进行试验,该标准物质的回收率在95.0%～104.4%之间,相对标准偏差RSD在0.21%～4.01%之间。实际分析工作表明,该方法准确、快速,符合DZ/T 0130—2006的要求。     

Parameter analysis for gate metal—oxide—semiconductor structures of ion-implanted 4H silicon carbide metal—semiconductor field-effect transistors

From the theoretical analysis of the thermionic emission model of current--voltage characteristics, this paper extracts the parameters for the gate Schottky contact of two ion-implanted 4H-SiC metal--semiconductor field-effect transistors (sample A and sample B for three and four times multiple ion-implantation channel region respectively) fabricated in the experiment, including the ideality factor, the series resistance, the zero-field barrier height, the interface oxide capacitance, the interface state density distribution, the neutral level of interface states and the fixed space charge density. The methods to improve the interface of the ion-implanted Schottky contact are given at last.     

微波消解-等离子体发射光谱法同时测定水中硅铁钠

讨论使用电感耦合等离子体发射光谱法测定水样中si、Fe、Na时，四种水样前处理方法对测试结果的影响。提出采用HNO3^-HF体系微波消解、H3BO3掩蔽HF的方法前处理水样，用等离子体发射光谱法可同时准确快速地测定水中Si、Fe、Na三种元素的含量。5次测定的相对标准偏差小于4％，加标回收率为89．2％-106％。     

Silicon Isotope Geochemistry of Micro—Fine Disseminated Gold Deposits in SW Guizhou and NW Guangxi,China

Quartz was studied with respect to its silicon isotopic composition and cathodoluminescence in micro-fine disseminated gold deposits in SW Guizhou and NW Guangxi.The results showed that quartz in wall rocks.ores and that in association with hydrothermal silicification are distinctive in silicon isotopes and cathodoluminescence characters.Quartz in association with primary silicification is non-luminescent while that in wall rocks and associated with secondary silicification exhibits striking luminescence.Based on the dynamic fractionation of silicon isotopes,it is suggested that the mineralization was accompanied by rapid transport of aprimary siliceous fluid along the major deep fault system into subordinate faults before ore components deposited in favorable strata via penetration and metasomatism.Therefore,a deep origin is implicit for gold deposits of this type.