光纤通信SDH系统用石英晶体振荡器的研制

介绍了压控石英晶体振荡器的原理,设计特点和性能,针对光纤通信ＳＤＨ系统上的时钟频率源的基本原理和ＳＤＨ的网同步对网络单元时钟的要求,采用了适当频率温度曲线的谐振器,变容二极管移相器,高性能的放大电路,波形转换电路,振荡器具有高的稳定度,良好的调谐范围和占空比,当环境温度在０～７０℃,范围内变化时,作为网络单元时钟的压控振荡器的频率漂移优于±１０＾－６ｍ,秒稳优于２．５×１０＾－９。     

表面活性剂对镍和铁的缓蚀作用

表面活性剂十六烷基三甲基溴化铵（ＣＴＡＢ）,十二烷基硫酸钠（ＳＤＳ）,聚乙二醇辛基苯基醚（ＴｒｉｔｏｎＸ－１００）对Ｎｉ,Ｆｅ均有缓蚀作用,其缓蚀效率顺序为：ＣＴＡＢ〉ＴｒｉｔｏｎＸ－１００〉ＳＤＳ,ＨＣｌ溶液对这３种典型表面活性剂第一临界胶束浓度的均有影响,在１．０ｍｏｌ·Ｌ＾－１ＨＣｌ溶液中,ＣＴＡＢ,ＳＤＳ,ＴｒｉｔｏｎＸ－１００的第一临界胶束浓度分别为１．３×１０＾－５,１．６×１０＾－５     

甚宽带微波双极型三极管压控振荡器

着重对影响压控振荡器调谐带宽、性能的因素进行分析．提出双变容管反向串联调谐． 集总参数电路结构等方法增加调谐带宽．减少、减小谐波，改善频谱．改善调谐线性．给出一个Ｓ 波段集总参数．调谐带宽甚宽（＞２ＧＨｚ）．二次谐波小（＜－２９ｄＢ），其它杂波＜－６０ｄＢ，输出功率＞ ５ｍＷ的晶体管压控振荡器．     

半胱氨酸电氧化循环伏安研究

循环伏安法研究表明．半胱氨酸在玻璃碳电极上的氧化机理为ＲＳＨ→ＲＳ·十Ｈ＋＋ｅＲＳ·＋ＲＳ·→ＲＳＳＲＲＳ·＋２Ｈ２Ｏ→ＲＳＯ２Ｈ＋３Ｈ＋＋３ｅ测得第一步电子传递过程的βｎａ＝０．２４，ｋａ＝１．０３×１０－５ｃｍ·ｓ－１，第二步电子传递过程的βｎａ＝０．４１，ｋａ＝２．１０×１０－９ｃｍ·ｓ－１．     

藏山羊产乳性能和乳酶及乳清蛋白的测定

对分布于青藏高原地区和山谷地区藏山羊的泌乳性能和乳清蛋白组分，及山谷地区域山羊乳酶力进行了测定，结果表明：高原地区藏山羊产乳量平均为２４．０ｋｇ，乳中营养成分含量（％）：乳脂为４．８±１．２、乳糖为４．５９±０．７５、乳蛋白为４．８７±０．６１；山谷地区藏山羊产乳量平均为３６．６２ｋｇ，乳中营养成分（％），乳脂为５．３±１．５、乳糖为４．９９±０．４５、乳蛋白为３．０８±０．４８．山谷地区的藏山羊乳酶，ＬＤＨ、ＡＫＰ，Ｒ－ＧＴ和ＬＰ和活力分别为８１．９±３７．８、７．７±３．５、４３７．４±９３．０、５３２．７±２０２．６单位，ＬＰ在体外可被１０￣（－５）ｍｏｌ／Ｌ的硫氰酸根或乳酸根活化，经琼脂糖凝胶平板电脉，可将乳ＬＤＨ分离出ＬＤＨ＿１、ＬＤＨ＿２和ＬＤＨ＿３三条带，各带所占有百分比分别为５０．６±４．５、３１．６±４．２和１７．８±３；３．采用ＳＤＳ－ｐＡＧＥ，乳清蛋白显示出五条区带，即ＳＡ、Ｉｇ－Ｈ、Ｉｇ－ｌ，β－Ｌｇ和α－Ｌａ。乳清蛋组分（％）：高原地区藏山羊ＳＡ为６．６±３．０、Ｉｇ为２２．９±６．５、β－Ｌｇ为４７．５±９．１和α－Ｌａ为２３．０±１０．６；山谷地区藏山羊相应为６．６±２．６、２     

气相色谱法测定马齿苋中的EPA和DHA

本文采用气相色谱法测定马齿苋中的ＥＰＡ和ＤＨＡ。用ＦＩＤ检测器检测定量。方法检测限：ＥＰＡ为９．６×１０＾－１０ｇ;ＤＨＡ为６．８×１０＾－９ｇ。相对标准偏差：ＥＰＡ为１．８７％;ＤＨＡ为３．６６％。平均回收率：ＥＰＡ为９８．１％,ＤＨＡ为９６．２２％。     

MET对油菜幼苗活性氧代谢的影响

试验采用质量比值分别为１００×１０－６，１５０×１０－６，２００×１０－６的ＭＥＴ喷施二叶一心期油菜幼苗，于第７，１４，２１（或２３）和４５天随机取功能叶．以比色法测定ＰＯＤ活性，滴定法测ＣＡＴ活性及ＧＳＨ含量，抗坏血酸过氧化物酶活性采用紫外吸收法测定．结果表明，喷施多效哇的油菜幼苗叶中ＰＯＤ和抗坏血酸过氧化物酶活性增高，ＣＡＴ活性降低，ＧＳＨ含量增加．从而说明了ＭＥＴ提高作物的抗逆性，可能是由于提高某些保护酶活性及增加非酶类自由基净化剂含量所致．     

催化杀虫剂西维因水解的抗体酶制备(Ⅱ)多克隆催化抗体的制备、纯化及检测

以优选的合成抗原（Ｈ(ａｐ)－ＢＳＡ）免疫动物产生了滴度为１：５５０００（１号兔,Ｒｔ－１）的兔抗多克隆催化抗体．采用盐析和ＰｒｏｔｅｉｎＡ－ＳｅｐｈａｘｏｓｅＣＬ４Ｂ亲和层析法,从兔抗血清中分离出了具有电泳纯度的多克隆催化抗体．经ＳＤＳ－ＰＡＧＥ检测,ＩｇＧｓ相对分子质量为１４８０００．纯化后的多克隆抗体,经ＥＬＩＳＡ法测定,其最低检出活性为２×１０(－６)～４×１０(－６)ｇ／Ｌ．     

基于TD-SCDMA的波形发生器中频率合成器的研究和设计

简单介绍了频率合成技术,利用Σ-Δ技术对分数频率合成器进行了研究和设计。该频率合成器主要的子单元电路包括Σ-Δ调制器、压控振荡器和环路滤波器。最后利用ADS软件对所设计的频率合成器进行了性能仿真,结果表明,本文设计的频率合成器可以满足88MHz～132MHz动态范围的高精度、高稳定度的时钟信号输出,并且通过算法能够实现88MHz～132MHz动态范围时钟信号的灵活切换。     

基于MOS电容的压控振荡器设计

传统的环形压控振荡器通常是利用控制电阻的方式来达到压控振荡的效果。文章利用容性耦合电流放大器作为压控振荡器的基本反馈单元,并在输出端增加MOS电容来控制振荡频率;分析了利用饱和区的MOS电容特性来实现压控的方法,并采用Smartspice软件和0.6μm CMOS工艺参数对该压控振荡器进行了模拟;结果表明,这种方法对电路的静态工作点影响很小,输出交流波形的频率稳定度高,有良好的线性调谐特性,达到了预期的效果。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the