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1.
目的建立了用HPLC在线检测对氯间二甲酚的分析方法.方法[1] 色谱柱:Zorbax RX-C18(5um,250mm×4 6mm);流动相:甲醇-0 5%醋酸(60:40);检测波长:270nm;理论塔板数不低于10000.结论本法简单、快速、准确,便于合成过程的控制,减少副产物,提高产品收率.  相似文献   

2.
黄旭  罗祎青  袁希钢 《化工学报》2018,69(5):2089-2099
提出了一种带两股循环的三塔变压精馏结构用于分离乙醇(C2H5OH)/乙酸乙酯(C4H8O2-3)/2-丁酮(C4H8O-3)三元混合物。由该三元混合物的剩余曲线图(RCM)可知,在大气压下该混合物的每一对组元均形成二元最低共沸物,且乙醇/乙酸乙酯二元共沸物组成随压力变化敏感。三个最低共沸物的同时存在形成了精馏边界线夹紧点现象,而通常压力下的精馏塔无法跨越,以至于传统变压精馏无法应用。通过对精馏塔压力的最优化克服了这一困难,提出了新的分离流程,并对过程进行严格稳态模拟。针对初分塔(T1)塔压不同的6种流程,采用序贯迭代法对各塔的塔板数、进料板位置、回流比等参数进行了优化。通过对比6种流程的经济评价和比较,得到了T1塔的最优压力,并经过能量集成使得过程的年度总费用降低了14.88%。  相似文献   

3.
应用溶剂热法合成了不同氧化石墨烯(GO)负载量的MOF-505@GO复合材料,分别采用全自动表面积吸附仪、P-XRD、SEM和Raman对材料进行了性能表征,测定了CH4、C2H6和C3H8在MOF-505@GO上的吸附等温线,并进行Langmuir-Freundlich方程拟合,依据IAST理论模型计算了C2H6/CH4和C3H8/CH4二元混合气在MOF-505@5GO上的吸附选择性。研究结果表明,随着GO负载量增大,MOF-505@GO复合材料的孔容及BET比表面积先增大后减小,当GO负载量为5%(质量)时,复合材料MOF-505@5GO的孔容及BET比表面积达到最大,当GO负载量进一步增大至8%(质量)和10%(质量)时,复合材料的孔容及BET比表面积逐渐降低。在0.1 MPa和298 K条件下,MOF-505@5GO对CH4、C2H6和C3H8的吸附容量分别为0.88、4.81和5.17 mmol·g-1,相比MOF-505分别提高了14.9%、30.7%和13.1%。MOF-505@5GO对C2H6/CH4和C3H8/CH4的吸附选择性分别为40.1和3056.1,其对C2H6/CH4和C3H8/CH4具有极高的吸附选择性。  相似文献   

4.
The postshock resistivity of polytetrafluoroethylene is determined in the pressure range of 35–63 GPa. The measurements were conducted using a cell 0.2 mm thick with uniform distribution of the resistivity over the thickness. At pressures above 35 GPa, as both the coordinate of the cell and time increase, the resistivity decreases monotonically, reaching an equilibrium value in a characteristic time of about 0.5 sec at a distance of several millimeters from the plane of discontinuity decay. The results indicate destruction of the polymer in the pressure range of 35–63 GPa. Over the entire range, the average value of the empirical dissociation energy is (3.3 ± 0.7) eV, which coincides within the error with the energy of the C–C single bond, equal to 3.6 eV. Key words: electric resistance of polytetrafluoroethylene, shock waves, polymers, electric conductivity.  相似文献   

5.
LX-10 is a high energy density solid explosive consisting of 94.5% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 5.5% Viton A Binder pressed to 1.865 g/cm3 (98.4% of theoretical maximum density). In this paper the shock compression and initiation of chemical reaction in LX-10 by sustained shock pressures of 0.4 to 3 GPa are studied experimentally using embedded pressure and particle velocity gauges. The resulting pressure and particle velocity histories are evaluated theoretically using the ignition and growth reactive flow computer model of shock initiation and detonation. Manganin resistance and polyvinylidene fluoride (PVF2) ferroelectric pressure gauges are both employed in the low pressure (0.4 – 0.7 GPa) shock compression experiments. Multiple manganin pressure and multiple electromagnetic foil particle velocity gauges measure the growth of reaction at various positions in LX-10 shocked to 1 – 3 GPa. The reactive flow modeling results imply that less than one percent of the LX-10 shocked to 0.4 – 0.7 GPa reacts in fifteen microseconds. For the higher pressure experiments, the ignition and growth model accurately calculates the pressure and/or particle velocity buildup in LX-10 as the reaction grows toward detonation. The LX-10 calculations are compared to those for the well-calibrated explosive PBX-9404, which contains 94% HMX and a reactive binder. Since it has the inert binder Viton A and better mechanical properties than PBX-9404, LX-10 is demonstrated to be significantly less reactive than PBX-9404 at these shock pressures. Therefore LX-10 is safer than PBX-9404 in many hazard and vulnerability scenarios to which solid explosives may be subjected.  相似文献   

6.
新型的激波反应器可用于气相热解反应,具有许多优点。在反应器内,惰性载气和原料气预先分别被加热到一定程度,再超音速混合,依据激波原理使混和气体的温度瞬间上升到裂解温度,获得裂解产品。对乙烷裂解生成乙烯的模拟实验表明,乙烯收率比一般反应器得到的高20%,能耗却降低15%以上。  相似文献   

7.
经由两种途径合成了P-CH2C5H5,用IR和UV-Vis表征了其结构,结果表明第二种方法操作简单,环戊二烯基的固载量也较高。  相似文献   

8.
Combustion, Explosion, and Shock Waves - This paper touches upon a question of whether the physical state of shock-compressed copper is equilibrium. Answering this question requires that...  相似文献   

9.
The electrical conductivity of a series of metal powders under shock compression is measured by an electrocontact technique. Initially, the metal particles are covered by an oxide film, and the powder is non-conducting. Under shock compression, the powder acquires macroscopic conductivity. The electrical conductivity of the shock-compressed powder depends substantially on the metal, porosity, particle size, and shock-wave pressure. The macroscopic electrical conductivity behind the shock-wave front is uniform within the experimental error. The dependences for fine and coarse aluminum powders on the shock-wave pressure are found. It is demonstrated that these dependences are nonmonotonic. For high shock-wave pressures, the electrical conductivity of the substance decreases. This behavior is assumed to be related to strong temperature heating of the substance under shock compression. Estimates of temperature show that shock compression can induce melting and partial vaporization of the metal. The same is evidenced by the behavior of electrical conductivity whose value for fine particles is close to the electrical conductivity of the melt. The electrical conductivity of the coarse powder is heterogeneous because of the strong thermal nonequilibrium of the particle during shock compression. An analysis of results for different metals shows that the basic parameter responsible for electrical conductivity of the shock-compressed powder is the dimensionless density. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 128–139, September–October, 2005.  相似文献   

10.
The mixed matrix membranes (MMMs) consisting zeolitic-imidazolate framework-8 (ZIF-8) nanoparticles in a polymer have been of considerable interest in separation applications. The fillers used are mostly synthesized using the solvothermal method. In this study, the ZIF-8 nanoparticles were synthesized using a solvent-less and salt-free mechanochemical method and were added to 6FDA-TrMPD polyimide to prepare MMMs. The single gas permeation of C3H6 and C3H8 through the MMMs was investigated. The C3H6 permeability and C3H6/C3H8 ideal selectivity of a 20 wt% mechano-synthesized ZIF-8/6FDA-TrMPD MMM were 70% and 32% higher than those of the neat polymer membrane at 0.1 MPa and 308 K, respectively. The C3H6/C3H8 separation performance of the mechano-synthesized ZIF-8 MMM was similar to that of the conventional solvothermal-synthesized ZIF-8 MMM. This separation performance was in good agreement with the Maxwell model. Temperature and pressure dependence analyses confirmed that the mechano-synthesized ZIF-8 nanoparticles acted as molecular sieves in the MMMs for the C3H6 and C3H8 permeation.  相似文献   

11.
High pressure Raman, IR and X-ray diffraction (XRD) studies have been carried out on C70(Fe(C5H5)2)2 (hereafter, “C70(Fc)2”) sheets. Theoretical calculation is further used to analyze the Electron Localization Function (ELF) and charge transfer in the crystal and thus to understand the transformation of C70(Fc)2 under pressure. Our results show that even at room temperature dimeric phase and one dimensional (1D) polymer phase of C70 molecules can be formed at about 3 and 8 GPa, respectively. The polymerization is found to be reversible upon decompression and the reversibility is related to the pressure-tuned charge transfer, as well as the overridden steric repulsion of counter ions. According to the layered structure of the intercalated ferrocene molecules formed in the crystal, we suggest that ferrocene acts as not only a spacer to restrict the polymerization of C70 molecules within a layer, but also as charge reservoir to tune the polymerization process. This supplies a possible way for us to design the polymerization of fullerenes at suitable conditions.  相似文献   

12.
A general model for the shock initiation of explosive reaction in chemical explosives is proposed. The model is based on the concepts of: (1) the kinetics of decomposition in which ions and free radicals produced by the shock wave shear forces initiate chain reactions that contribute to and accelerate the decomposition produced by the thermally activated molecules; (2) the formation of statistically random reaction sites whose number in a specific explosive is a direct function of the shock pressure as the shock transits the explosive; and (3) a critical- energy-fluence requirement for initiation. This model appears to apply to explosive reaction in gases, liquids, and solids.  相似文献   

13.
赵云  刘春燕  刘家旭  贺宁  郭洪臣 《化工学报》2019,70(6):2182-2191
采用氨气程序升温脱附(NH3-TPD)、紫外-可见光谱和小型固定床反应器,重点研究了碱金属钠离子和过渡金属锌离子改性对纳米H-ZSM-5沸石表面酸性及其催化C5~C8链烷烃芳构化反应性能的影响。结果表明,用碱金属钠离子改性能够有效地消除沸石表面的强酸中心,适当降低催化剂表面酸量,从而减少甲烷、乙烷和丙烷等低值副产物的生成,优化芳构化反应产物分布。适宜的Zn2+负载量为3%(质量分数),过高的Zn2+负载量会使产物中干气生成量增大,不利于芳烃收率的提高。C5~C8链烷烃芳构化的适宜反应温度为530℃。  相似文献   

14.
罗振敏  苏彬  王涛  程方明 《化工学报》2019,70(9):3601-3615
为研究C2H6/C3H8对甲烷爆炸极限参数及动力学特性的影响,采用标准的可燃气体爆炸极限测定装置测定了不同配比的C2H6/C3H8混合气体对甲烷爆炸极限的影响规律,同时得出了氮气惰化条件下甲烷爆炸临界参数的变化规律。此外,利用Chemkin软件模拟了C2H6/C3H8混合气体对甲烷爆炸过程中中间产物浓度的影响情况,并进行了敏感性分析。结果表明,C2H6/C3H8的存在降低了甲烷的爆炸上下限,增大了甲烷的爆炸危险度;在氮气惰化过程中甲烷的爆炸上限下降,爆炸下限上升,最终爆炸上下限重合,重合点处甲烷浓度和氮气临界浓度均随C2H6/C3H8的添加而逐渐减小;此外,C2H6/C3H8混合气体使甲烷爆炸过程中CO和·H的生成量逐渐增大,而CO2、·O和·OH的生成量则有下降趋势,通过对爆炸过程中甲烷体积的敏感性分析,发现C2H6/C3H8的存在在某种程度上促进了甲烷爆炸。对比不同配比的C2H6/C3H8混合气体,发现C3H8含量越高,其对甲烷爆炸过程中相关参数的影响越大,这可为工矿企业的安全生产提供一定的理论依据。  相似文献   

15.
Etherification of two alkenes, 2-methyl-1-butene and 2,4,4-trimethyl-1-pentene, was studied with seven different C1- to C4-alcohols. Although etherification was of primary interest, the isomerisation of the alkenes was the main reaction to occur. For the primary alcohols the etherification and isomerisation rates correlated well with the properties of the alcohols. Both rates increased with decreasing polarity and with increasing carbon number, acidity and Mulliken charge of the oxygen atom of the alcohol. It is difficult to distinguish the effect of each property separately, and probably the differences in the reactivities are not due to any one property alone but rather the synergy of the properties affects the reactivities. The secondary alcohols behaved in a different way than the primary ones: the etherification was almost negligible. The effect of alcohol on the isomerisation of alkenes was notable even though alcohol does not directly react in the reaction, which was concluded to be due to the stronger adsorption of the more polar alcohols which hinders the reactions of other components.  相似文献   

16.
The structure of the electromagnetic field in a conducting magnetic compressed in a shock wave is analyzed. It is shown that compression of a magnetic material in an external magnetic field leads to origination of a system of two currents identical in magnitude but opposite in direction. One of them passes ahead of the shock front in the undisturbed substance, and the oppositely directed current passes over the shockcompressed substance. As the shock wave moves further, the absolute value of current monotonically increases. The parameters determining the global electromagnetic pattern in the shockcompressed magnetic are found. These parameters can be considered as the generalization of the governing parameters found previously by the authors for a nonmagnetic conductor. The formulated model offers a qualitative explanation for the results of dynamic experiments with an 80NKhS magnetic soft alloy. The voltage record on the specimen surface indicates effective shockinduced demagnetization of the material.  相似文献   

17.
Two synthetic routes have been developed to produce high-molecular-weight organic precursors containing a high weight fraction of nitrogen. One of the precursors is a pyrolysis residue of melamine-formaldehyde resin. The second precursor is the byproduct of an unusual low-temperature combustion reaction of tetrazole and its sodium salt. These precursors have been shock compressed under typical conditions for diamond and wurtzite boron nitride synthesis in an attempt to recover a new ultrahard carbon nitride. The recovered material has been analyzed by X-ray diffraction, FTIR, and Raman microprobe analysis. Diamond is present in the recovered material. This diamond is extraordinarily well ordered relative to diamond shock synthesized from carbonaceous starting materials.  相似文献   

18.
The shock Hugoniot of boron carbide, from 0 to 80 GPa, has been obtained using first principles quantum mechanics (density functional theory) and molecular dynamics simulation. The Hugoniot for six different structures which vary by structure or stoichiometry were computed and compared to experimental data. The effect of stoichiometry, and structural variation within a given stoichiometry, are shown to have marked effects on the shock properties with some compositions displaying bilinear behavior in the computed shock velocity‐particle velocity profiles while others show a continuous Hugoniot curve with no evidence of a phase transition over the pressure range considered in this work. Two structures, B12(CBC) and B11Cp(CCB), have predicted phase transition pressures lying within the 40–50 GPa range suggested experimentally. It is shown that the phase transition is driven by deformation of the 3‐atom chain within the boron carbide crystal structure which induces a discontinuous volume change at the critical shock pressure. The effect of defects, in the form of chain vacancies, on the shock response is presented and the ability of shear to significantly lower the phase transition pressure, in accord with experimental observation, is demonstrated.  相似文献   

19.
Triorganoantimony(V) complex (C5H5FeC5H4C(CH3)NO)2SbPh3 (1) has been prepared by the reaction of Ph3SbCl2 with acetylferroceneoxime C5H5FeC5H4C(CH3)NOH (2) in 1:2 molar ratio in anhydrous toluene. The complexes have been characterized by elemental analyses, IR and NMR (1H and 13C) spectroscopic studies, and biologic activity was measured. And crystal structures of 1, 2 were reported. The coordination geometry around the antimony atom in 1 was slightly distorted trigonal bipyramidal with the carbon atoms of the SbPh3 unit in equatorial positions and the two oxygen atoms of the oxime group occupying axial positions. The free oxime was clearly hydrogen bonded (H–N 2.10 Å/2.04 Å in 2) to essentially form a dimer.  相似文献   

20.
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