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1.
单水合过硼酸钠的制备及应用   总被引:1,自引:0,他引:1  
单水合过硼酸钠是一种新型漂白剂,在反应温度60~63℃和残压2.86×104Pa下由四水合过硼酸钠经旋转蒸发脱水而制取,其活性氧含量比四水合过硼酸钠高2.43%,复配制成的彩漂洗衣粉去污力可提高3.39%。  相似文献   

2.
本文通过正交试验,得到用过硼酸钠(SP)将二丁基硫醚(DBS)氧化成(二)丁亚砜的最佳反应条件为:DBS:SP=1:1.2,时间为3小时,温度为45℃。收率达94%以上。同时还对石油亚砜、(二)丁亚砜等对钼的萃取性能进行了研究。  相似文献   

3.
2-氰基-4-硝基苯胺在一种新催化剂和实用的分散剂存在下与硫化氢或硫化铵反应,得到2-氨基-5-硝基硫代甲酰胺,硫代甲酰胺在双氧水和弱碱性介中氧化关环,形成3-氨基-5-硝基苯并异噻唑。这种合成染料中间体的方法具有实用价值。  相似文献   

4.
Tb(Ⅳ)的氧化物一般是用高温加压氧化或含氧酸盐热分解获得的,有关其性质的研究也有报导。但文献上迄今未见从水溶液中用化学氧化法制备Tb(Ⅳ)水合氧化物及其性质研究的报导。本文对化学氧化法自水溶液中制得的Tb(Ⅳ)水合氧化物的  相似文献   

5.
为寻求更高效的光催化剂,以1,3-二亚氨基异吲哚啉和2,3-二氰基-1,4-二噻英为原料,钼酸铵为催化剂,七水合硫酸亚铁为模板,用固相法合成了二(1,4-二噻英)-二苯基四氮杂卟啉铁(FePzPh(dtn)4),并对其进行了磺化改性(FePzSPh(dtn)4).2种产物的结构经过UV-Vis、IR、1H-NMR、X-射线光电子能谱(XPS)表征,并初步探讨了其溶解性能.  相似文献   

6.
以石墨粉为原料,根据改进的Hummers氧化法制得氧化石墨烯,利用氧化石墨烯表面富集的羧基与乙二醇和酰氯化的4,4′-偶氮(4-氰基戊酸)的反应,进一步得到氧化石墨烯表面负载的4,4′-偶氮(4-氰基戊酸),以此为引发剂,通过自由基聚合制备了氧化石墨烯-聚甲基丙烯酸甲酯(oxidized graphene-g-PMMA)杂化材料.采用红外(FT-IR)、透射电镜(TEM)和原子力显微镜(AFM)对产物的结构和形貌进行了表征,并研究了频率依赖下的样品的电学性能.结果表明,PMMA已在氧化石墨烯表面接枝,石墨烯-聚甲基丙烯酸甲酯杂化材料的导电率及介电常数较氧化石墨烯分别降低了0.098S.cm-1和34 000.  相似文献   

7.
烯烃的环氧化反应多用有机过氧酸作为氧化剂,但有机过氧酸易分解,操作欠安全,有爆炸的危险,为此,我们进行了用过硼酸钠取代有机过氧酸对烯烃环氧化的研究,并取得了较为满意的结果. 过硼酸钠NaBO_3·4H_2O为一稳定的无机过氧酸盐,它在有机化学中的应用甚少.为了使它有效地参与烯烃的环氧化反应,我们曾按文献中采用过的方法,在碱性水溶液中或在醋酸介质中进行反应,但均未获得成功.后经反复筛选,发现它与酷酐在二氯甲烷溶剂中可顺利地将烯烃氧化为相应的环氧化合物:  相似文献   

8.
用高效液相色谱法(HPLC)测定了α-氰基苯乙酸乙酯经 Cu~(++)-TMDA~**-O_2系统氧化偶联反应产物的组成。采用外标法和内标法测定反应产物中2,3—二氰基—2,3—二苯基丁二酸二乙酯的内消旋体(1)和外消旋体(2)的含量;用面积归一化法测定产物中四个组分的相对百分含量。实验结果表明三种不同定量方法测定内消旋体1和外消旋体2的误差分别为1.53%~0.49%、2.5%~0.70%。方法准确、快速,可满足科研和工业生产的定量分析要求。  相似文献   

9.
模拟海洋沉积物界面邻近条件下,研究了吸附硅酸盐及Cu、Pb、Co、Ni的水合氧化铁颗粒和FeS沉淀对Mn(Ⅱ)氧化反应的影响.在每升含有毫克分子数量级的FeOOH或FeS体系中,测定结果表明,氧化速度与Mn(Ⅱ)浓度为一级反应.在水合氧化铁表面的锰氧化速率常数随着氧化铁吸附硅酸盐量的增加而下降,但吸附重金属的水合氧化铁,其速率常数依然没有显著的变化.在水合氧化铁表面或新生FeS沉淀上,Mn(Ⅱ)氧化反应的速率常数具有相同的数量级.  相似文献   

10.
硝基还原酶是一种对辅酶烟酰胺腺嘌呤二核苷酸磷酸(NADPH)、烟酰胺腺嘌呤二核苷酸(NADH)以及黄素腺嘌呤二核苷酸(FAD)依赖性还原酶,本研究克隆的硝基苯硝基还原酶NN-BD-33是其中一种,它依赖于NADPH,以硝基苯维底物催化降解硝基苯成羟基苯胺,同时辅酶NADPH被氧化为NADP+。以公开报道的硝基苯硝基还原酶同源序列为参考,通过染色体步移法从Pandoraea sp.BD-33菌株中克隆得到硝基苯硝基还原酶基因。将为进一步深入研究硝基苯硝基还原酶的蛋白三维结构和作用机理奠定基础。  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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