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1.
本文报道标题化合物[(bpy)_2Mn(μ-0)_2Mn(bpy)_2](ClO_1)_3·3H_2O(bpy=2,2'-bipyridine)的晶体结构重新测定的精确结果.该化合物的晶体属单斜晶系,空间群为P2_1/c(No.14),a=1.3893(5), b=1.3987(4),c=2.4317(9)nm,β=103.61(3)°,U=4.598(2)nm ̄3,Mr=9.1,Z=4,D_c=1.618g·cm ̄(-3),μ=8.1cm ̄(-1),对4032独立可观察衍射数据进行修正,最后偏离因子R_F=0.069,结果表明,该双核化合物中的两个不同价态的锰(Ⅲ,Ⅳ)离子在晶体中完全可区分.本工作的结构数据与文献值有较明显的区别.  相似文献   

2.
羟基铬交联蒙脱土的制备及物化性能的研究   总被引:4,自引:0,他引:4  
本文以钠型蒙脱土(Na-Mt)为原料,以羟基铬聚合阳离子为交联剂制备出羟基铬交联蒙脱土(Cr-Mt)并对其物化性能进行研究。结果表明Cr-Mt的物化性能优于Na-Mt,d_(001)值1.6~1.9nm,比表面积80~190m ̄2·g ̄(-1),1.8~5.0nm的孔约占半数以上,表面总酸量为6.1×10 ̄(-4)~6.5×10 ̄(-4)mol·g ̄(-1)、阳离子交换量在9.0×10 ̄(-3)~42×10 ̄(-3)mol/100g样,但其热稳定性有待进一步提问。  相似文献   

3.
拟定了测定微量锌(Ⅱ)的新方法,研究了锌(Ⅱ).水杨基荧光酮-阳离子表面活性剂体系的显色反应,实验证明,在pH(9.0~9.7)的H_3BO_3-H_3PO_4-HAc-NaOH缓冲体系中,锌(Ⅱ)与水杨基荧光酮生成1:2的配合物,在阳离子表面活性剂-溴化十六烷基三甲胺(CTMAB)存在下生成1:2:3的蓝紫色三元配合物,λ_(max)为570nm,表观摩尔吸光系数ε为7.7×10 ̄4L·mol-1·cm-1,可在水相中直接测定锌(Ⅱ);并且详细研究了最佳实验条件,锌(Ⅱ)含量在(1.0~8.0)μg/25mL,范围符合比耳定律,锌(Ⅱ)的检测限为0.04μg/mL,用于快速测定食品中的微量锌(Ⅱ),结果满意。  相似文献   

4.
标题化合物Yb(Pi)_3(Bl5C5)_2·2H_2O·CH_3CN(I)及Y(Pi)_3(Bl5C5)_2·2H_2O·CH_3CN(Ⅱ)为同晶结构,均为3斜晶系,空间群为P-对晶体(I),a=12.753(1)A,b=13.810(2)A.c=19.609(2)A,α=81.37(3)°,β=71.58(3)°,γ=70.71(2)°,Z=2.D_c=1.468g·cm ̄(-3),μ=15.928cm ̄(-1)(MoKα),M_r=1471,04,F(000)=745,R=0.031,R_w=0.039;对晶体(Ⅱ),α=12.785(1)A,b=13.850(3)A,c=19.571(2)A,α=81.05(3)°,β=70.92(2)°,γ=70.62(3)°,Z=2,Dc=l.485g·cm ̄(-3),μ=10.441cm ̄(-1)(MoKα),M_r=1386.9l,F(000)=7l4,R=0.065,R_w=0.078.测定结果表明,中心稀土离子Yb ̄(3+)(或Y ̄(3+)直接与3个苦味酸阴离子和2个水分子配位,此水化镱(或钇)苦味酸盐通过水桥氢键与冠醚Bl5C5相联而形成一个大的疏水性  相似文献   

5.
在磷酸介质中,在Mn(Ⅱ)和Twen-80存在下,DApBM与钒(Ⅴ)生成橙黄色化合物,产物至少可稳定3.5h.最大吸收波长为485nm.摩尔吸光系数ε=4.01×105L·mol-1·cm-1和ε=1.57×105L·mol-1·cm-1.钒(Ⅴ)量在0.5~3.0μg/25ml及3.0~10.0μg/25ml间符合比尔定律.该体系灵敏度高,选择性较好,用于中草药中痕量钒(Ⅴ)的测定,结果满意  相似文献   

6.
AgNO_3和a-ph_2ppy,(a-(C_6H_5)_2P(NC_5H_5))在加有少量H_2O_2和NaOH的C_2H_5OH水溶液中反应生成标题化合物的灰黑色晶体。属四方晶系,空间群P4_1,a=1.300nm,C=4.076nm,v=6.884nm ̄3,Z=8,D_c=1.67gcm ̄(-3),R=0.059,r_ω=0.072.每一不对称单元中存在二套独立而结构基本相同的[Ag_2(a-ph_2PPy)_2] ̄2+,它的二个Ag原子和二个a-ph_2PPy中-N-C-P-桥的N,P原子联接成为一个稳定非共面八员环,而环内Ag,Ag间距分别是0.314,0.3l0(nm),均未成键。不对称单元中的二个八员环通过的O原子与环上Ag原子的弱成键而具有结构联系。环内还出现了罕见的三配位Ag原子。  相似文献   

7.
研究了2种类型的乙烯气相聚合高活性催花剂.用SiO2,MgCl2作复合载体,负载TiCl4制得的SM型催化剂,载体中含w(Ti)为2%~3%,w(Ti3+)为35%~59%,比表面积105~120m2/g,催化活性每小时每克催化剂Ti催化得5.0~5.7kg产物PE(kg·g-1·h-1),聚合动力学曲线为衰减型.用镁粉、卤代烷、四氯化钛为主要组分制备的MG-2型催化剂,载体中w(Ti)为6%~7%,w(Ti3+)为55%~69%,比表面积70~85m2/g,催化活性1.8~2.0kg·g-1·h-1,聚合动力学曲线为平稳型.对SM型催化剂扫描电镜及图象分析得到颗粒平均粒径(d),颗粒长短轴比(dl/ds)及颗粒大小粒径比(dmax/dmin)分别为31μm,1.402,4.1,MG-2型催化剂为33μm,1.524,7.0,相应聚合产物颗粒的d,dl/ds,dmax/dmin,SM型催化剂为247μm,1.295,4.6,MG-2型催化剂为263μm,1.540,9.0.显示出SM催化剂更优良的聚合性能.  相似文献   

8.
复合型纳滤膜的制备及表征   总被引:12,自引:0,他引:12  
在聚砜基膜上用界面聚合法制备了两种复合型纳滤膜PA01和PA02。在0.3MPa下,PA01膜对MgSO4溶液和FeCl3溶液的脱直 96.0%和78.0%,水通量分别为8.5(L.m^-2.h^-1)和7.9(L.m^-2.h^-1);PA02膜对MgSO4ipwkiyw (2.0g.L^-1)和CaCl溶液(0.5g.L^-1)的脱盐率分别为98.0%和88.8%,水通量分别为1.0(L。m^  相似文献   

9.
本文对新型超分子配合物[Na(NPh)15C5(Et2O)]2Na2Mo8O26进行了X射线四园衍射测定,该晶体属单斜晶系,空间群为P21/c,a=17803(4),b=13674(3),c=14610(3),β=11233(2)°,V=3290(1)nm3,Mr=20213,Dc=214g/cm3,μ=171mm-1,F(000)=207963,R=00256和Rw=00295,并联系差热热重分析和1HNMR实验,讨论了配合物的热分解过程.  相似文献   

10.
使用化学纯的糠醛和氨基硫脲,在少量冰醋酸的催化下,缩合反应生成呋喃醛缩氨基硫脲腙C_6H_7N3OS,M_r=169.21,单斜晶系,空间群P2_1/n,a=1.350 6(3),b=0.5656(5),C=2.1023(2)nm,β=97.43°(3),V=1.5926nm ̄3,Z=8,D_x=1.411g/cm ̄3λ(M_Oka=0.071073nm),μ=3.348cm ̄(-1),F(000)=704.850可观察独立反射(I>3σ(I)使结构解出并精修到R=0.053,Rw=0.050,Δ/σ=0.14,单位权重观察值的最大误差为1.169.不对称单位含有二个非结晶学对称相关的独立分子,分子构型存在较大差异.缩合反应发生在杂环羰基和氨基硫脲分子中的肼基-NHNH_2上,酸催化可以加速缩合反应,获得较高的产率.  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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