三羟甲基丙烷三硝酸酯的热分解性能

利用高压DSC研究了三羟甲基丙烷三硝酸酯(TMPTN)的热分解特性.结果表明,尽管TMPTN与硝化甘油(NG)和三羟甲基乙烷三硝酸酯(TMETN)的结构相似,但TMPTN的热分解特性完全不同于NG和TMETN.常压下, TMPTN有两个峰,一个是熔化吸热峰,另一个是分解放热峰,而NG则是一个熔化吸热峰,TMETN是一个分解放热峰,没有熔化吸热峰;在高压下, TMPTN也有一个熔化吸热峰和一个分解放热峰,只是熔化吸热峰相对没有常压下的明显,随着压力的不同,峰形、峰温、放热量都明显不同.同时对TMPTN的分解机理进行了初步分析,并获得了TMPTN的热分解反应动力学参数.     

ABB色谱仪峰检测中峰宽的设定

重点介绍斜率检测方法中峰宽的设定,在峰检测时克服峰飘的影响,动态剔除未知峰的干扰,实现了色谱峰的准确测量.     

熔融条件对聚醚醚酮结晶熔融行为的影响

用ＤＳＣ法研究了熔融温度和熔融时间对聚醚醚酮地晶熔融行为的影响。实验表明，聚醚醚酮的结晶峰随熔融延长向高温移动，且峰形变窄，峰的强度增大，继续延长熔融时间，结晶峰降低，峰形变宽；熔融时间延长时，聚醚醚酮的玻璃化转变温度和冷结晶峰温度均提高，熔融峰强度减弱。熔融温度升高时，聚醚醚酮的结晶峰强度减弱，峰宽增强；而冷结晶温度提高。     

PMR内标绝对测定法检测N—羟甲基丙烯酰胺的含量

介绍了PMR内标绝对测定法测定N－羟甲基丙烯酰胺的含量的新方法，在δ4和δ9处有N－羟甲基丙烯酰胺的PMR吸收峰，而在δ7附近却没有吸收峰，所以可以用苯作为内标物（其吸收峰在δ7．3），同时丙酮作为溶剂（它的所有的吸收峰都小于δ4，不能检测出来），这样就选择－CH2OH的吸收峰进行了测定。溶剂峰，杂质峰和N－羟甲基丙烯酰胺以外的其它峰不会干扰内标物苯和－CH2OH的吸收峰。作者以作了方法的精确度测定，结果满意，同时也讨论了该方法的有关问题。     

PMR内标绝对测定法检测N-羟甲基丙烯酰胺的含量

介绍了 PMR内标绝对测定法测定 N-羟甲基丙烯酰胺的含量的新方法 ,在 δ4和 δ9处有 N-羟甲基丙烯酰胺的 PMR吸收峰 ,而在 δ7附近却没有吸收峰 ,所以可以用苯作为内标物 (其吸收峰在 δ7.3) ,同时丙酮作为溶剂 (它的所有的吸收峰都小于 δ4 ,不能检测出来 ) ,这样就选择 CH2 OH 的吸收峰进行测定。溶剂峰、杂质峰和 N-羟甲基丙烯酰胺以外的其它峰不会干扰内标物苯和 CH2 OH 的吸收峰。作者以作了方法的精确度测定 ,结果满意 ,同时也讨论了该方法的有关问题     

“十四五”东莞石油消费达峰的分析

东莞石油消费经历了从地方燃油电厂发电和企业自备发电及燃油锅炉为主,转向公路交通(燃油汽车)消费为主的历程,结构、品种和数量均发生很大变化。"十四五"是实现碳达峰的窗口期和重要期,对东莞而言,推进公路交通石油消费达峰对东莞整体碳达峰具有重要意义。本文在回顾东莞石油消费的历程中,对当前阶段石油消费达峰进行了分析,并指出了石油消费达峰的迫切性和重要性,从而提出了石油消费达峰的目标和愿景,以及达峰的路径和政策建议。     

阳极溶出催化伏安法理论的研究(Ⅰ)(Ⅱ)[摘]

1.可逆电极溶出本文推导得到了玻璃碳电极上可逆溶出催化过程的理论电流方程,峰电流及峰电位方程,得知溶出催化伏安法所得的峰电流比溶出伏安法的峰电流提高了数十倍,从而进     

CR硫化胶结晶度的X射线衍射分峰计算法

根据Ｘ射线衍射的基本原理,利用ＣＲ硫化胶的Ｘ射线衍射谱对结晶峰与非晶散射峰进行分离,导出各结晶峰与非晶散射峰强度的校正因子,对被忽略的结晶衍射强度进行补正,导出了分峰法ＣＲ硫化胶结晶度的计算公式,并用此公式研究了ＣＲ硫化胶结晶度与硫化时间的关系。     

城市污水处理过程中有机污染物的荧光光谱表征

采用三维荧光光谱法对城市污水二级处理工艺出水进行了光谱表征。研究结果表明,各处理单元出水的光谱图均呈现出明显的类色氨酸峰(T峰)和类富里酸峰(M峰),T峰荧光强度随处理过程逐渐减弱,M峰荧光强度变化不明显。当污水厂接纳垃圾渗滤液废水时,T峰和M峰的荧光强度异常显著。不同月份最终出水的类色氨酸(Ex/Em=280/340 nm处)荧光强度值分别下降了47.2%、56.4%和67.4%。类色氨酸荧光强度值与CODCr浓度呈线性正相关(R2=0.858)。该研究提供了一种简便、快速、有效的污水监测方法。     

高固含量改性双基推进剂的热分解

采用高压DSC方法研究了不同固含量(RDX含量)推进剂的热行为.结果表明,随着RDX含量的增加,GLX推进剂中双基组分的分解峰逐渐变小,峰温前移,而RDX的分解峰随含量的增加而变强;随着压力的增大,GLX推进剂中两个放热分解峰的DSC峰温均有不同程度的下降,GLX推进剂的放热量也明显提高,放热分解峰变得更加明显,两峰温...     

Novel Stopper Designs to Improve Argon Purging Efficiency in Slab Casting

In order to ensure consistent argon flow in the stopper gas channel and improve argon bubble performance in the slab casting mould,two patented new technologies CSC(Clean Stream Cartridge) and SHP(Slot Hole Plug) were applied in the argon purging stopper designs.The novel stopper designs can maintain a stable back pressure and argon flow in the argon line during long sequence casting,eliminate pressure increasing at the start of the casting,even distribute gas bubbles in the mould leading to improved mould flux melting and lubrication,reduce mould level fluctuation and so on.     

Pressure Effects on the Thermal Stability of Silicon Carbide Fibers

Commerically available polymer-derived SiC fibers were treated at temperatures from 1000° to 2200°C under vacuum and at argon gas pressures of 0.1 and 138 MPa. Effects of increasing inert gas pressure on the thermal stability of the fibers were determined through studies of the fiber microstructure, weight loss, grain growth, and tensile strength. The 138-MPa argon gas treatment was found to shift the onset of fiber weight loss from 1200° to above 1500°C. Grain growth and tensile strength degradation were correlated with weight loss and were thus also inhibited by high-pressure treatments. Retreatment in 0.1 MPa of argon of the fibers initially treated in 138 MPa of argon caused further weight loss and tensile strength degradation, thus indicating that high-pressure inert gas conditions were effective only in delaying fiber strength degradation and that no permanent microstructural changes were induced.     

Effects of partial and total methane flows on the yield and structural characteristics of MWCNTs produced by CVD

Multi-walled carbon nanotubes (MWCNTs) were produced in a chemical vapor deposition (CVD) process employing methane and argon as hydrocarbon and carrier gas over supported sol-gel Co-Mo/MgO catalysts. A detailed study about the influence of the gas flow of both hydrocarbon and carrier gas on carbon yield, morphology, structure and graphitization degree is presented. Methane partial pressure, methane total flow rate, as well as the flow ratios of methane to argon and methane to hydrogen (reducing gas) were the parameters systematically varied. The results reveal that high MWCNT yields in the produced materials are strongly related to the methane partial pressure and the methane total flow, while a high degree of graphitization is more closely linked to the use of argon gas as inert atmosphere.     

Comparison of a-C:H films deposited from methane–argon and acetylene–argon mixtures by electron cyclotron resonance–chemical vapor deposition discharges

Hydrogenated amorphous carbon (a-C:H) films are deposited from methane–argon and acetylene–argon gas mixtures in a microwave electron cyclotron resonance plasma reactor. The films deposited with the two different gas mixtures under similar input parameter conditions have substantially different properties, including deposition rate, mass density, optical absorption coefficient, refractive index, optical bandgap and hydrogen content. The deposition parameters varied include rf-induced dc substrate bias voltage (0 to −60 V), pressure (1–5 mTorr) and argon/hydrocarbon gas flow ratio (0–1.0). The discharge properties of the two different gas mixtures, including electron temperature, ion saturation current, and residual gas composition of the exit gas flow, are measured to help explain the different deposition results from the two different gas mixtures. The use of lower pressures is found to be critical for obtaining denser, lower hydrogen content films from acetylene. For the methane-deposited films the addition of argon to the discharge increased the film's mass density and lowered the hydrogen content. In both methane- and acetylene-based deposition processes the rf-induced bias is also a critical determining factor of film properties.     

Effect of Argon-Based Atmospheric Pressure Plasma Treatment on Hard Tissue Formation on Titanium Surface

In this paper, we suggest that the atmospheric pressure plasma treatment of pure titanium metal may be useful for improving the ability of rat bone marrow cells (RBMCs) to induce hard tissue differentiation. Previous studies have reported that the use of argon gas induces a higher degree of hard tissue formation. Therefore, this study compares the effects of plasma treatment with argon gas on the initial adhesion ability and hard tissue differentiation-inducing ability of RBMCs. A commercially available titanium metal plate was used as the experimental material. A plate polished using water-resistant abrasive paper #1500 was used as the control, and a plate irradiated with argon mixed with atmospheric pressure plasma was used as the experimental plate. No structural change was observed on the surface of the titanium metal plate in the scanning electron microscopy results, and no change in the surface roughness was observed via scanning probe microscopy. X-ray photoelectron spectroscopy showed a decrease in the carbon peak and the formation of hydroxide in the experimental group. In the distilled water drop test, a significant decrease in the contact angle was observed for the experimental group, and the results indicated superhydrophilicity. Furthermore, the bovine serum albumin adsorption, initial adhesion of RBMCs, alkaline phosphatase activity, calcium deposition, and genetic marker expression of rat bone marrow cells were higher in the experimental group than those in the control group at all time points. Rat distal femur model are used as in vivo model. Additionally, microcomputed tomography analysis showed significantly higher results for the experimental group, indicating a large amount of the formed hard tissue. Histopathological evaluation also confirmed the presence of a prominent newly formed bone seen in the images of the experimental group. These results indicate that the atmospheric pressure plasma treatment with argon gas imparts superhydrophilicity, without changing the properties of the pure titanium plate surface. It was also clarified that it affects the initial adhesion of bone marrow cells and the induction of hard tissue differentiation.     

Sorption of Argon by Glass in a Gas-Discharge Lamp

The kinetics of the absorption of argon from a mixture of argon and neon by glass in a gas-discharge lamp were investigated with a mass spectrometer and by measurement of the intensity of certain lines in the mission spectrum of the gas mixture. The magnitude of the cleanup (sorption) after a certain time is a function not only of the dimensions of the gas-discharge tube, the filling pressure, the composition of the filling gas, and the discharge current but also of the temperature, type, and surface state of the glass. The results can be explained by assuming that three processes participate simultaneously in the disappearance of the argon: (1) absorption of argon ions as a result of electric discharge, (2) thermal desorption from a very thin layer at the surface of the glass, and (3) diffusion of argon ions from this thin layer into the body of the glass. Under the conditions of the investigation, neon is not absorbed appreciably. The cleanup of argon can be reduced by surface treatment of the glass.     

惯性约束聚变靶用空心玻璃微球纵横比的调控

为实现对惯性约束聚变(ICF)靶用空心玻璃微球(HGM)纵横比的调控,基于对干凝胶法制备HGM炉内成球过程的分析,建立了HGM纵横比的定量控制模型,实验研究了载气组分和压力对HGM直径和纵横比的影响。结果表明:通过调节载气中氩气分压可以控制熔融玻璃液泡的膨胀程度,从而定量控制最终HGM的直径和纵横比。但是,通过大幅度降低载气中的氩气分压来提高HGM半径和纵横比是不可行的。为提高载气的传热能力,确保HGM球形度、表面粗糙度和合格率满足ICF制靶的要求,必须在载气中添加一定分压的氦气。除部分极端工艺条件外,提出的HGM纵横比控制模型预测值与实验结果吻合良好。     

吹氩宽厚板坯连铸结晶器内液面波动行为的水模型研究

基于相似理论,利用物理模拟研究了吹氩条件下宽厚板坯结晶器内的液面波动行为,考察了吹气量、水口侧孔倾角及水口浸入深度对结晶器内液面波动行为的影响.结果表明,结晶器吹氩后,各气量下液面平均波高均增加了1.2倍以上;结晶器内液面平均波高随吹气量的增加先增大后减小;随水口侧孔倾角及浸入深度的增大,液面平均波高均先减小后增大.从实验条件下得到的控制液面波动的最佳工艺参数为4 L/min的吹气量,-15°的水口侧孔倾角,140 mm的水口浸入深度.     

Enhanced adhesion of steel filaments to rubber via plasma etching and plasma-polymerized coatings

Zinc-plated steel filaments were coated with RF plasma polymers of acetylene or butadiene in order to enhance adhesion to rubber compounds. Plasma polymerization was carried out as a function of the plasma power, deposition time, and gas pressure. In order to maximize adhesion, argon plasma etching was performed and carrier gases such as argon, nitrogen, and oxygen were used. Plasma polymer coatings were characterized by FT-IR, Alpha-Step, and a dynamic contact angle analyzer. The adhesion of steel filaments was evaluated via a tire cord adhesion test (TCAT). The best results were obtained from a combined process involving argon etching (90 W, 10 min, 30 mTorr) and acetylene plasma polymer coating (10 W, 30 s, 30 mTorr) with argon carrier gas (25/5, acetylene/argon). These samples exhibited a pull-out force of 285 N, which is comparable to that from the brass-plated steel filament (290 N).     

Fast pyrolysis of cellulose with reactive methane gas in a single-pulse shock tube

A shock tube technique was employed to study the fast pyrolysis of cellulose with methane under conditions of high temperature, high heating rate, short reaction time, and rapid quenching. The effects of temperature, methane atmosphere, and reaction time are investigated. Experiments were carried out at temperatures between 700 and 2200°C in 1% methane (diluted in argon), and comparisons in the yields of major gas products are made with the results obtained in pure argon atmosphere. The total gas yield decreased about 25–30% in methane. The principal gas products—carbon monoxide, carbon dioxide, and acetylene, except ethylene—were significantly decreased in methane as compared to the yields in pure argon. An increase of about 25% in ethylene yield in methane over argon was observed. The onset of the decomposition of cellulose and the evolution of major pyrolysis products were changed with the reaction times, which also affected the amplitude and the distribution of the pyrolysis products. © 1994 John Wiley & Sons, Inc.