非水溶剂沥取法制取优质硫化钠

一、试剂乙醇沥取工业硫化钠法硫化钠又称硫化碱,俗名臭碱,是无色透明结晶。密度1.856克/厘米~3,熔点1180℃,在水溶液中的生成热⊿H°_(f298)=52.0千卡/克分子。其固相生成热⊿H°_(f298)=44.2千卡/克分子。在水中的溶解度如下表:     

光照后对二甲胺基肉桂醛苯腙的热效应及动力学参数的测定

对二甲胺基肉桂醛苯腙(p-Dimethylamino Cinnamaldhyde Phenylhydrozone,以下简称DMGP)是一种黄色微粒结晶,受光照射后吸收光能(hv)变成灰至深褐色,去掉光源后又回复至黄色并有放热效应,具有可逆地使光转变成热的性能.我们期望这一性质能使它用来贮蓄太阳能.探究其热效应有多大、贮能时间有多久是很有意义的.为此对它进行了有关的物理化学性质的测定,获得了该化合物的主要热学数据(熔化热和反应热),并进一步对其动力学参数(活化能、反应级数)进行了测定,以估量其作为能量贮存材料的可能性.     

低发泡聚酯聚氨酯热性能的研究(Ⅰ)

用热重分析研究了本所研制的新型低发泡聚酯聚氨酯材料,测定出六种样品的热重数求据。其热降解温度T_d为265.8℃～285,4℃。用差减微分法对TG和DTG曲线进行了处理,得其第一和第二阶段热降解动力学参数。在热降解第一阶段反应,级数n为0.9～1.4;热降解表现活化能E为16.A～22.6千卡/克分子;频率因子A为8.4×10~3～8.9×10~(10)秒~(-1)。用热重动力学数据快速评价了这类聚酯聚氨酯的热稳定性并讨论了影响TG结果的因素。     

常压空气氧化再生三氯化铁

在一个钛质搅拌器的充气装置中,进行了二氯化铁溶液常压空气氧化再生三氯化铁的研究。试验结果表明:Fe~(2 )浓度、Cu~(2 )浓度、温度、搅拌速度对氧化率有显著的影响,而酸度和氯化钠浓度的影响较小。含 Fe~(2 )54.45克/升、Cu~(2 )10克/升的溶液,在温度80℃、搅拌速度2000转/分、氧化2小时,其氧化率为70.58%,Fe~(2 )的平均氧化速度为19.06克/升·时。含Fe~(2 )146.52克/升、Cu~(2 )10克/升的溶液,在温度80℃、搅拌速度2200转/分、氧化2小时,氧化率为57.73%,Fe~(2 )的平均氧化速度为42.3克/升·时。温度80—50℃时,活化能为1.32千卡/摩尔;50—40℃时为6.06千卡/摩尔。常压空气氧化再生三氯化铁的方法比较简单,而且可使浸出过程和再生过程结合在一起,因而有可能降低浸出剂的用量。     

104种竹(木)材燃烧热的测定

<正>这篇沦文包括三个部分:样品的采集和处理,测定方法;测定结果。 1.毛竹不同器官的燃烧热量是不同的,但是,竹子的年龄对燃烧热量是没有影响的。毛竹不同器官的燃烧热量为;竹秆4532卡/克,枝条4719卡/克,叶片4203卡/克,鞭和根4286卡/克。 2.不同属种的燃烧热量是不同的:刚竹属4680卡/克,(竹剌)竹属4543卡/克,慈竹属4554卡/克,单竹属4612卡/克,大节竹属4640卡/克,唐竹属4595卡/克,青篱竹属4671卡/克,(竹思)(竹劳)竹属4478卡/克,方竹属4457卡/克,梨竹属4562卡/克。 3.竹子产地对竹材燃烧热量是有影响的,一般来说,竹子生长在高纬度比生长在低纬度含有较多的热量。 4.61种竹材的平均燃烧热量是4603卡/克,43种木材的平均燃烧热量是4776卡/克,其中针叶树种是4949卡/克,阔叶树种是4750卡/克。     

自悬浮定向流法制备纳米铝粉的DSC-TG和XPS分析

采用自悬浮定向流法制备金属纳米Al粉.用差示扫描量热-热重法(DSC-TG)和X射线光电子能谱(XPS)分析对其热性能进行研究.研究结果表明:在Ar气流中,新纳米铝粉的熔点为649.7℃,熔化焓为3.7kJ/mol,分别比粗晶铝的熔点(660℃)和熔化焓(10.79kJ/mol)低10.3℃和7.09 kJ/mol;在N2气流中,从20℃升温到800℃时,新纳米铝粉增重约为33%,熔点为648.8℃.在704℃开始有一个放热效应,终点为747.7℃,放热过程的焓为36.4 kJ/mol:在Ar气流中进行热分析前后的新纳米铝粉中未发现Ar元素存在;而在N2气流中进行热分析后的新纳米铝粉残余物中发现有N元素存在,样品表面Al,N和O原子的摩尔比为32.78:11.98:55.24.     

非晶态Ni-P合金粉体的脉冲放电制备及其催化性能

采用脉冲放电技术合成Ni-P合金粉体,研究了合金粉体的结构及其对高氯酸铵热分解的影响. 结果表明,非晶态Ni-P合金粉体是由微粒组成的团聚结构. 脉冲放电电压700、900和1100V对应的弦粒子数依次增大,粉体粒径依次减小,分别为350～500、250～400和150～300nm. Ni- -P合金粉体促进高氯酸铵的低温和高温热分解,与纯高氯酸铵相比,高氯酸铵和Ni- -P粉体混合物的第1放热峰(低温分解峰)温度降低幅度小于12℃,第2放热峰(高温分解峰)温度降低约53℃;合金粉体粒径减小,第1放热峰强度增强,第2放热峰强度减弱,低温分解失重从高氯酸铵的15.97%增加到42.78%,高温分解失重从81.62%降低到47.58%,高温分解结束时温度的降低幅度为26～43℃.     

低发泡聚酯聚氨酯动态力学性能的研究

测试了六种新型低发泡聚酯聚氨酯样品的动态力学性能.发现内耗温度曲线在—10℃和—100℃左右均有α和γ指纹吸收峰.α转变的tanδ值在0.355到0.565范围,α转变的表观活化能为38.08～55.49千卡/克分子;γ转变的表观活化能为10.18～23.83千卡/克分子.六种样品的动态模量E在—37℃～30℃的范围内均急剧下降约二个数量级至1.5×10~8达因/厘米~2左右随后进入"橡胶平台区".观察到了尚未见报导过的"多阶橡胶平台"现象.     

反应热喷涂法制备陶瓷涂层的研究

首先通过差热-失重分析和XRD测试手段对反应热喷涂Al+TiO2+H3BO3混合粉体以制备Al2O3/TiB2复合陶瓷涂层的可行性进行了分析.然后对喷涂后试样涂层的耐磨性进行了研究.结果表明:Al+TiO2+H3BO3混合粉体差热-失重分析和在1200℃烧结后XRD测试分析均表明完全可以反应生成所需的Al2O3/TiB...     

石墨纤维热电偶的性能测试与分析

目前在高温测量中常用的仪器为铂铑热电偶,但它只能测量2000℃以下温度,高温下耐腐蚀性差,资源短缺,成本高.本实验使用石墨纤维代替传统的金属材料作为热电极材料,测试其线性度和复现性等指标,以期获得新的热电偶.     

Markedness and its Interpretation in Language Use

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

Call for Papers

<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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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