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1.
不对称变色酸双偶氮试剂是分光光度法测定稀土元素的灵敏显色剂,三氯偶氮氯膦[2-(4-氯-2-膦酸基苯偶氮)-7-(2,4,6-三氯苯基偶氮)-1,8-二羟基-3,6-二磺酸萘]应用于催化光度法测定微量钌、铑已有报道,但用于铂的测定未见报道.  相似文献   

2.
本文研究了α-胺基芳基膦酸对萤石、重晶石、白钨矿的捕收性能。浮选结果表明,α-胺基芳基膦酸对三种矿物的捕收能力顺序为萤石大于重晶石大于白钨矿。在弱碱性pH范围,α-胺基芳基膦酸作捕收剂,抑制剂对重晶石及白钨矿有选择性仰制作用。混合矿分离结果表明在该条件下,能实现萤石与重晶石及白钨矿的分离。根据解离组分分布图及红外光谱,α-胺基芳基膦酸起捕收作用的有效组分为((R_1)(R_2)NCH(R_3)PO_3H)~-,在萤石表面存在静电力和化学力吸附,在重晶石和白钨矿表面以化学吸附为主。  相似文献   

3.
本文对合成产物———新型水处理剂乙二胺 -N,N'-二乙酸 -二甲叉膦酸 (EDDAP)阻磷酸钙垢的性能进行了研究。结果表明 ,EDDAP具有优异的阻磷酸钙垢性能 ,且明显优于羟基乙叉二膦酸(HEDP)。  相似文献   

4.
光度法测定镁的显色剂已有不少报导.但由于各显色剂结构不同,在测定中就各有优缺点.通过实践,一致认为含有膦酸基团的变色酸单偶氮衍生物——偶氮氯膦-Ⅰ是一个较好的测镁显色剂,它具有操作简便,发色迅速,灵敏、稳定且选择性较好等优点.因此,在实际工作中已得到广泛的应用.但是,偶氮氯膦-Ⅰ在灵敏度和比耳定律范围等方面还不能满足生产和科研的需要.为此,我们设计并合成了新试剂——兴多偶氮氯膦-Ⅰ(KCPA-I)[2-(4-氯-2-膦酸苯偶氮)-7-(N,N-二羧甲基氨基甲基)-1,3-二羟基-3,6-萘二磺酸],其结构式如下: ?? 兴多偶氮氯膦-Ⅰ在碱性介质中能与镁发色,灵敏度及选择性均优于偶氮氯膦-Ⅰ,是一个性能良好的光度法测镁显色剂,我们应用于铝合金中微量镁的测定,已取得良好的结果.  相似文献   

5.
膦酸单酯是酸性磷(膦)酸(酯)中现尚未见有文献记载的一类新型非硫化矿捕收剂,本文报道了6个苯基膦酸单酯化合物的合成,即:PhP(O)(OR)OH,a:R=C_2H_5-,b:R=C_4H_9-,c:R=s-C_4H_9-,d:R=t-C_4H_9-,e:R=C_6H_(13)-,f:R=C_8H_(17)-。测试了它们在不同浓度时水溶液的表面张力和对锡石、黑钨矿、赤铁矿、方解石和石英的浮选行为。实验结果表明苯基膦酸单酯是一类良好的非硫化矿捕收剂;烃基长度对药剂捕收活性影响极大,实验获得的最适烃链长度与按王淀佐提出的公式nφ=Δx_R~2 Δx_M~2计算预测值吻合;对药剂非极性基支链化引起的浮选性能差异进行了探讨,认为这些差异主要由空间位阻效应所决定。  相似文献   

6.
高温水中阻垢剂阻垢性能及影响因素   总被引:6,自引:0,他引:6  
采用静态法评价了高温(100℃)水中几种阻垢剂的阻垢性能及其影响因素。结果表明,阻垢剂2-膦酸丁烷-1,2,4-三羧酸(PBTCA)明显优于多元醇膦酸酯(PC-604)和羟基乙叉二膦酸(HEDP),HEDP与PBTCA复配明显优于与PC-604复配。HEDP与PBTCA复合配方对体系pH值、Ca2+和HCO-3浓度变化有一定适应性,且比PBTCA经济。  相似文献   

7.
多功能的彩显防灰雾剂“EBP”是由烃基膦酸和含氮烃基膦酸所组成。其中烃基膦酸是按1:3:1.5(摩尔比)PCl_3、RCOOH 和水混合加热,回流付产物得到94.5%的烃基膦酸;含氮烃基膦酸是按2:1:2摩尔比的PCl_3、RNH_2、RCHO 的水溶液,在适当的温度下反应得到。将烃基膦酸和含氮烃基膦酸分别在低温条件下结晶,各自得到纯度在98%以上的固体结晶产物。  相似文献   

8.
将次膦酸铝(Al(HP))、甲基次膦酸铝(Al(MP))以及甲基环己基次膦酸铝(Al(MHP))及其环氧树脂(EP)阻燃聚合物性能进行对比研究。结果表明:含两个烷基基团的Al(MHP)阻燃剂的热稳定性最高,含一个烷基基团的Al(MP)具有最好的热膨胀性,而不含烷基基团的Al(HP)阻燃剂与环氧树脂(EP)的相容性最差。  相似文献   

9.
以对甲基苯甲腈和亚磷酸三乙酯为原料合成了(对氰基苄基)膦酸二甲酯,研究了反应温度对氰基氯苄及(对氰基苄基)膦酸二甲酯的收率的影响。实验结果表明对氰基氯苄的反应温度在145℃;(对氰基苄基)膦酸二甲酯的反应温度150℃收率较高。  相似文献   

10.
用新方法合成了膦胺基苯膦酸及由膦,对,间胺基苯膦酸与β-萘酚,薛弗酸,R盐, J-酸,H-酸,及α-萘胺合成了一系列单偶氮染料。 由隣胺基苯膦酸合成的偶氮染料都能与铬,钴生成络合物。而膦酸染料上的膦酸基则能 和钼酸铵生成络合物。 膦酸染料在染色时很易被羊毛所吸收。但膦酸染料或经过铬盐或钼酸铵处理后的染料耐 洗坚牢度却非常不好。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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