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1.
邻香兰素与乙二胺双希夫碱的晶体属单斜晶系,空间群Pc,a=9.418(2)×10~(-1)nm,b=6.278(1)×10~(-1)nm,c=14.495(4)×10~(-1)nm,β=93.35(2)°,V=856(0)×(10~(-1)nm)~2,Z=2。最后的一致性因子R=0.063,R_w=0.061。  相似文献   

2.
三聚磷酸二氢铝二水物的合成和表征   总被引:9,自引:0,他引:9       下载免费PDF全文
袁爱群 《广西科学》2000,7(4):266-269
用磷酸和氢氧化铝为原料制备三聚磷酸二氢铝二水物。用X-衍射、红外光谱、化学分析、DTA-TG结合X-ray分析,证明产品的化学结构式为AlH2P3O10*2H2O。其晶体结构属正交晶系,空间群为PZ1/bZ1/aZ/m,D92h,晶胞参数a=15.919×10-8 cm,b=8.884×10-8cm,c=9.936×10-8 cm,单位晶胞体积V=1 405×10-8 cm3,Z=6。防绣性能测试表明其防锈能力与红丹颜料相当。毒理学试验表明该颜料半致死量LD50=18.0 g/kg(小白鼠),属实际无毒级,符合食品容器及儿童玩具涂装的要求。  相似文献   

3.
本文从统计的角度指出在理论上Wein位移定律λ_mΥ=0.29×10~(-2)(m·k)和λ_mT=0.51×10~(-2)(m·k)的形式和内容必须保持一致;从实验的角度确认了Wein位移定律的本来形式应该是λ_mΥ=0.29×10~(-2)(m·k),而不是λ_mT=0.51×10~(-2)(m·k)。  相似文献   

4.
本文合成并测定了{MoOS_3Cu_3(PPh_3)C1}的晶体结构,簇合物属正交晶系,空间群为P_(212121)晶胞参数:a=12.833(5)×10~(-10)m,b=17.552(5)×10~(-10)m,c=22.778(7)×10~(-10)m;Z=4。结构用直接法解出,经最小二乘法修正,偏离因子R=0.069.  相似文献   

5.
在pH=11.7的B—R缓冲溶液和甲醇:水=1:1底液中,1—(4—硝基萘)—3—(4—偶氮苯基苯)—三氮烯(Cadion2B)可产生良好的还原波。其浓度在2×10~(-5)~1×10~(-8)mol/L范围内与一阶导数峰电流成良好的线性关系,检测下限可达8×10~(-9)mol/L。方法用于实验废液中题示试剂的测定,结果良好。  相似文献   

6.
Tm3+在氟氧化物玻璃中的光谱性质   总被引:1,自引:1,他引:0  
通过测量Tm掺杂氟氧化物玻璃的光吸收谱,根据Judd-Ofelt理论,拟合得到了Tm3+离子的J-O强度参量Ω2=1.955×10-20 cm2,Ω4=2.629×10-20 cm2,Ω6=1.279×10-20 cm2.利用强度参量,给出氟氧化物玻璃中Tm3+离子各激发能级的自发辐射跃迁速率、辐射寿命、荧光分支比和积分发射截面等光谱参量的预计值,发现许多跃迁振子强度大于10-6且积分发射截面大于10-18cm,如(3F,3H)4→3H6(1707nm)跃迁的振子强度、积分发射截面分别为3.593×10-6,3.180×10-18cm,若上能级有足够高的量子效率,可能实现激光发射.而蓝光波段1G4→3H6(466nm)跃迁也有较大的振子强度(1.112×10-6)和积分发射截面值(0.984×10-18cm).  相似文献   

7.
釆用3种辐射分量来拟合典型的γ爆GB780325的观测能谱.这3种辐射分量分别是:起源于同一辐射区的同步辐射谱和正负电子对湮灭谱,以及从源区逃逸出来的正电子所形成的成束粒子系的同步辐射谱.由拟合参数,获得以下源区物理特性:磁场B=4.3×10~8T,电子密度n_(?)≈6.12×10~(28)cm~(-3),源区厚度τ≈2.45×10~(-5)cm,源距离d≈0.975Mpc.  相似文献   

8.
本文提出一个热分析反应动力学的验证方程式。用热重法(TG)结合微商热重法(DTG)与等温实验,从判断固相反应机理入手,研究了常压下碳酸氢钠热分解反应的动力学与机理。实验表明,其反应属于Avrami-Erofeev的核生成与核成长为控制步骤的A_(1.5)机理。动力学方程式为:da/dt=7.57×10~8×e~(-86.6×10~3)J/(RT){3/2(1-a)[-ln(1-a)]~(1/3)}。表观活化能E为86.6kJ·mol~(-1),频率因子A为7.57×10~8s~(-1),两者补偿关系为:lnA=0.287E-4.44。  相似文献   

9.
用高温投下法,通过控制炉内气氛,在铜卡量热计中测定了硼泥及其分解产物的比热容,其值为硼泥 Cp=-1.608+3.279×10~(-3)T+2.847×10~5T~(-2),/(g·x) 硼泥分解产物 CP=0.461+0.633×10~(-3)T+0.510×10~5T~(-2),J/(g·K)其复相关系数分别为0.9920和0.9996.  相似文献   

10.
本文研究尼可刹米的单扫描示波极谱行为,在pH2.6的B.R.缓冲液中,于-1.28V(vs.CE)呈现一还原电流峰,与其含量有线性关系,线性范围是4.5×10~(-8)~4.0×10~(-8)mol/L,4.0×10~(-8)~8.0×10~(-8)mol/L。还用多种手段详细研究了极谱波的性质,确定其波是不可逆吸附还原波。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

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