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1.
本文用T—内射模[10]、Tfg—内射模和Tfg—平坦模[5]刻划了如下一些特殊环:Tfg—正则环、Tfg—V—环和Tfg—coherent环。它们分别推广了正则环和T正则[1]、V—环、TV环[11]、p—V—环、f—V—环[6]、[1]、[4]及coherent环的相应结论。  相似文献   

2.
在介绍毛细管柱的制备基础上,对几种杯[4]芳烃固定相(PSO—C[4]A、PSO—C[4]B、PSO—CYCL—C[4]A和PSO—TBU—CYCL—C[4]A及与OV—1701混涂的柱子C[4]A—OV—1701、C[4]B—OV—1701)的柱效、麦氏常数进行了测评。结果表明,它们都具有较高的柱效;连有极性基团—CONH—呈中等极性,丁基取代的杯[4]芳烃聚硅氧烷极性偏弱。  相似文献   

3.
HeZhanbopointedout[1] thatsurfactantscanbeusedtomakenewchemicaloscillatorsinaqueoussolution ,suchasbromateoscillator[2 ] andpermanganateoscillator[3] .Untilnow ,however,thereisnotanyelectrochemicaloscillatorre latedwithsurfactant.  Anelectrochemicaloscillatorisoneofthefirstdisco veriesofchemicaloscillators .Todayhundredsofarticleshavebeenpublished[4— 6 ] aboutelectrochemicaloscillators.Theyprovidematerialstoenrichmaturetheoriesandmecha nisms[7— 8] .InourexperimentsweusedaDaniellcellasele…  相似文献   

4.
利用模的有关性质,把复数域上n维向量空间V看成是一个V上线性变换T所决定的C[x]—模,将有限加群的结构定理推广到C[x]—模V中,得到了C[x]—模V可以分解成一些循环C[x]—模的直和,进而得到任一个复矩阵都与一Jordan标准形相似。这样,在模观点下矩阵相似于若当形矩阵就与C[x]—模V分解成一些循环C[x]—子模的直和是相当的。  相似文献   

5.
Mathematicalmodelsandsimulationsofemulsionpolymerizationhavebeenstudiedforseveraldecades .Re cently ,averycomprehensivereviewofithasbeenpub lished[1] .Infact,sincethephysicalmodelofemulsionpolymerizationwasfirstproposedbyHarkins[2— 4 ] inlate194 0s ,manyscientistsandengineersdevotedtheiratten tiontothequantitativeresearchofemulsionpolymeriza tion .ThemostimportantandfamoustheorywastheclassicaltheoryestablishedbySmithandEwart[5— 7] .Onthebasisofaseriesofreasonablysimplifiedassumptions ,Smit…  相似文献   

6.
善良的心地,就是黄金。—[英]莎士比亚 我愿证明,凡是行为善良与高尚的人,定能因之而担当患难。—[德]舆多芬 阴谋陷害别人一人,自己会首先遭到不幸。—[古希腊]伊索  相似文献   

7.
以水热法合成了一个新的希夫碱大环配位聚合配合物M e6[14]N4Co[Cd(SCN)4](M e6[14]N4=5,7,7,12,14,14,1—六甲基—1,4,8,11—四氮杂环十四—4,11—二烯),并用红外光谱和元素分析的手段对其进行了表征.  相似文献   

8.
学而不思则罔,思而不学则殆。—[先泰]孔子 吾生也有涯,而知也无涯。以有涯随无涯,殆已!已而为知者,殆而已矣!—[先秦]庄子学不可以已……吾尝终日而思矣,不如须臾之所学也。—[先秦]荀子 书犹药也,善读之可以医愚。—[汉]刘向 奇文共欣赏,疑义相与析。——[晋]陶渊明  相似文献   

9.
(文中所用代号:V——动词谓语,R——补语,O——宾语,D——定语。括号中的“个”表示可以出现,也可以不出现。)在“V 他(个)R”结构中,由于其中“R”的性质不同,“他”的语义各异,又可将[3]、[4]类记为“V 他_1(个)R_1”式,[5]、[6]类记为“V 他_2(个)R_2”式.  相似文献   

10.
Self mixinginterferenceeffectshavebeenwidelystudied[1— 12 ] ,mostofwhichareconductedonsinglemodelasers.Wang[10 ] andYoshitada[11] reportedstudiesonmulti modesemiconductorlasersin 1993and 1994re spectively .Buttoourknowledge ,fewmodelsonLDpumpedmulti modesolid statelaserhavebeenreported .1 Basictheoryandgeneralmodel  Theprincipleofself mixinginterferenceeffectsisexplainedasanexternalopticalfeedbackeffect[9] .Thege neralmodelisshowninFig .1,LcandLextstandforthelengthofthecavityandtheexter…  相似文献   

11.
Liquid-liquid equilibrium data of two ternary systems methyl palmitate+ethanol+glycerol and methyl stearate+ethanol+glycerol at(318.2 and 333.2)K and atmospheric pressure were measured. The values of distribution coefficient and selectivity were calculated, which indicates that glycerol can be separated from fatty acid ester by using ethanol as an extraction solvent. The consistency of the isothermal tie-line data were checked by the Othmer-Tobias equation. The correlation coefficients R2 are higher than 0.993,9 for all the fitted curves. The NRTL activity coefficient model was applied to the correlation of the measured tie-line data. The root mean square deviation(RMSD)values are less than 0.007 for all the systems, which shows a good predictive capability of this model for such systems.  相似文献   

12.
Isobaric vapor-liquid equilibrium(VLE)data were measured for binary mixtures of toluene+N-formylmorpholine,toluene+3-methylthiophene and 3-methylthiophene+N-formylmorpholine at 101.33 kPa.The VLE data ...  相似文献   

13.
Siliconcarbide (SiC)ceramicmaterialsareusefulad vancedmaterialsinmanyfields,suchasmedicalbiomateri als ,hightemperaturesemiconductors ,synchrotronopticalel ementsandhighstrength /lightweightstructuralmaterials[1] .However,theactualapplicationisstilllimitedduetoitslowreliability ,highmachiningcosts[2 ] .Gelcastingprovidesane conomicalandfeasiblenet shape forminghomogeneousandflawlessgreenbodieswithcomplexgreenshapes.  Gelcastingconsistsofin situpolymerizationthroughwhichamacromolecularnetwor…  相似文献   

14.
According to the principles of simultaneous equilibrium and electronic charge neutrality, the thermodynamics of Zn(II)-NaOH-H2O system was studied in this paper. Varying the concentration of sodium hydroxide, in range of 0- 400 g/L, the distribution law of all zinc species and the mathematical model of equilibrium concentration of zinc in the system were obtained. The relative errors between theoretic calculation and the experimental values of total concentration of zinc were analyzed, and the absolute average error is only 0.129 8%. The mathematical model and the thermodynamic data are believable.  相似文献   

15.
INTRODUCTION Vapor-liquid equilibrium (VLE) data are veryimportant in the design and operation of separationprocesses in the chemical industry. Such informationcan be obtained experimentally or estimated by usinggeneralized methods for calculation of the propertiesof mixtures. For ideal system, it is relatively easy toestimate vapor-liquid equilibrium. However, mostsystems of industrial interest show deviations fromthe ideal behavior.The methyldichlorosilane-dimethyldichlorosi- lane-ben…  相似文献   

16.
采用石墨炉原子吸收光谱法测定了中成药中微量镉,考察了基体改进剂及其它实验参数对测定结果的影响.在优化实验条件下,采用标准加入法测定,方法的检出限为0.0614ng/ml,精密度为4.78%,回收率为99.2%~103.4%.  相似文献   

17.
建立了流动注射化学发光测定姜黄素的新方法.在优化条件下,控制姜黄素浓度为5.0×10-8~1.0×10-5 mol/L范围时,其浓度与反应体系的相对化学发光强度有良好的线性关系,方法的检出限(3σ)为6.3×10-9 mol/L,对浓度为5.0×10-6 mol/L的姜黄素平行测定9次,其相对标准偏差为2.6%.本法用于药用姜黄中姜黄素总量的测定,与紫外分光光度法测定结果基本一致,采用标准加入法,回收率为96.5%~105.2%.  相似文献   

18.
为镉的检测寻求一种快速、简便的新方法。通过玻碳悬汞电极测定淡水鱼中镉含量,考查了电沉积电位、电沉积时间、平衡电位、平衡时间对测定结果的影响。结果:当pH值为1.0~2.5、电沉积电位为-1.25V、电沉积时间为60s、平衡电位为-1.0V、平衡时间为30s时,测定结果最好。测定镉的线性范围为0~16ng,检出限为0.24ng/mL,回收率为98.6%~101.2%,相对标准偏差为2.4%。该法操作快速、简便,结果准确、可靠。  相似文献   

19.
为获得二甲基甲酰胺(DMF)与氯仿(CHCl3)精馏分离的基础热力学数据,实验采用改进型的Rose平衡釜测定了DMF-CHCl3体系在760mmHg下的汽液相平衡数据,并分别用NRTL和Margules模型对实验数据进行关联。结果表明:实验数据满足热力学一致性的检验,且NRTL和Margules模型的计算结果与实测结果偏差小,平均绝对误差分别为0.0026和0.0010,平均相对误差分别为1.81%和1.23%,可满足工业精馏工艺过程设计的需要。  相似文献   

20.
深部隧道岩爆已成为影响工程安全施工的重要危险源,室内模拟实验是研究深部岩爆问题的重要手段之一。为研究岩爆倾向性较高的模型,使用石英砂、水泥、石膏等材料进行配置,设计正交试验方案,进行力学试验,依据岩爆倾向性指数及脆性指标,利用试验试件参数进行有限元模拟,对室内试验进行验证。结果表明,配比为石英砂55%、石膏水泥比2.5:1、松香4%、水含量23.3%的2号试件具有比其他两组试件更强的脆性,配比为石英砂70%、石膏水泥比1.5:1、松香3.5%、水含量20.6%的16 号试件具有更强的岩爆倾向性。以2 号试件为例进行数值模拟,两者数据拟合较好,模拟现象与试验现象相吻合,可为岩爆室内试验及模拟提供参考。  相似文献   

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