Hypervelocity Jet Initiation Threshold Criteria of Nitromethane and Nitromethane Mixtures

The experimental hypervelocity jet initiation threshold criteria for neat nitromethane and homogeneous- and heterogeneous-sensitized nitromethane mixtures have been determined over a range of failure diameters, jet velocities from 2–9 mm/μs, and jet diameters in two test configurations. These criteria were used to define detonation and failure conditions in nitromethane and the nitromethane mixtures as a function of contact- and bow-shock conditions. These data were compared with data reported by others in the literature on bare solid explosives. A favorable comparison of threshold values is achieved by normalization of the criteria with the failure diameters. The effect on the initiation of the confinement proximity to the jet axis was also investigated. Experimental results have shown that high impedance boundaries near the jet axis induced conditions that allowed initiation to occur at lower jet velocities than those determined by the criteria. Tests also were performed on both homogeneous and heterogeneous nitromethane mixtures, having the same failure diameters, to determine if the same or similar jet penetration distances were required for initiation. The results, within experimental error, do not show any definitive differences in initiation conditions between the two types of mixtures.     

Effect of Controlled Perturbations on Buckling of a Conical Liner during Shaped-Charge Jet Formation

Combustion, Explosion, and Shock Waves - The influence of controlled perturbations on the buckling of conical liners during their explosive compression is under study. In this case, there is...     

CL-20/TATB混合物的制备及性能表征

为了提高六硝基六氮杂异伍兹烷(CL-20)的安全性,采用机械混合法和重结晶法分别制备了CL-20/TATB混合物;通过光学显微镜、扫描电子显微镜(SEM)、X-射线衍射(XRD)、差示扫描量热仪(DSC)、感度测试仪对其形貌、晶型、热稳定性、机械感度进行测试分析。结果表明,机械混合后CL-20表面无明显包覆物,而重结晶混合粒子表面有一层致密的黄色薄膜,同时两种混合物中CL-20的晶型仍为ε型,未发生晶型转变;两种混合物的热分解表观活化能较原料CL-20分别提高了17.3、117.36kJ/mol,热爆炸临界温度分别提高了0.12、3.8℃,重结晶混合粒子的热稳定性明显提高;两种混合物的撞击感度(H50)较原料CL-20分别提高了10.4、54.5cm,摩擦感度的临界载荷分别提高了80、60N,表明重结晶混合粒子的机械感度显著降低。     

Characterization of Feed Properties for Conceptual Process Design Involving Complex Mixtures

The market for products made by biotechnology is diverse and has significantly grown in recent years. Despite this growing demand, the first proposal of product purification processes for these complex mixtures remains purely experimentally based and is not methodically targeted. The present work represents an initial study to demonstrate the benefits of a systematic approach. The study focuses on the adaptation of established methods for process development to these so‐called complex mixtures. It also assesses the suitability of these methods for complex mixtures, given the current state of research. Based on the described adaption, the most efficient method for the conceptual process development is identified and is subsequently developed. The resulting methodology consists of model‐based cost accounting with a miniaturized experimental determination of model parameters, accompanied by a comprehensive error analysis. The developed approaches are successfully validated by using a protein mixture.     

硝基甲烷与氨基及羟基化合物间的相互作用

利用密度泛函理论方法,在B3LYP/6-311++G**水平下研究了硝基甲烷与乙二胺、乙二醇、1,1-二氨基丙烷和1,1,3-丙三醇的相互作用。通过基组重叠误差和零点能校正,得到它们的相互作用能。结果表明,硝基甲烷与1,1,3-丙三醇的相互作用能为-19.90kJ/mol;含有多羟基的化合物可增加硝基化合物的热稳定性。通过热重分析方法检测添加1,1,3-丙三醇前后硝基甲烷的完全失重温度,发现添加微量1,1,3-丙三醇可明显提高硝基甲烷的完全失重温度和热稳定性。计算结果与实验数据吻合。     

Bird Aversive Properties of Methyl Anthranilate, Yucca, Xanthoxylum, and Their Mixtures

We tested the bird aversive properties of methyl anthranilate, yucca extracts, and Xanthoxylum spp. extracts in oneand two-bottle drinking assays that used European starlings (Sturnus vulgaris). In oneand two-bottle tests, methyl anthranilate proved to be the more potent stimulus in producing an avoidance response. Starlings avoided consuming Xanthoxylum and yucca only in the two-bottle tests. Previous studies showed that yucca was a good adjuvant in stabilizing lipophilic compounds in water. Starlings did not avoid binary mixtures of methyl anthranilate and yucca differently from what would be expected if they were only responding to the solution's methyl anthranilate content. However, yucca enhanced the aversive qualities of Xanthoxylum. The ability to identify mode of action for repellency and synergistic combinations of chemicals derived from natural products for use in repellent mixtures is an important aspect of the development of cost-effective, environmentally safe repellents for use in conflict resolution between humans and wildlife.     

Physical Properties of Beeswax,Sunflower Wax,and Candelilla Wax Mixtures and Oleogels

To be able to tailor and optimize the physical properties of oleogels for various food applications, more information is needed to understand how different gelators interact. Therefore, the objectives of this study were to evaluate the interactions between binary mixtures of beeswax (BW), candelilla wax (CLW), and sunflower wax (SFW) in pure form as well as in 5% wax oleogels made with soybean oil, in terms of their crystallization and melting properties, crystal morphology, solid fat content, and gel firmness. CLW:BW mixtures had eutectic melting properties, and oleogels from these mixtures with 40:60 to 90:10 CLW:BW were firmer compared to oleogels made with one wax. The main components in SFW and BW appeared to cocrystallize or crystallize at the same temperature, but nonlinear changes in melting point and solid fat content profile of oleogels prepared with the mixed waxes indicated that SFW dominated oleogel formation. In addition, oleogels prepared with mixtures of SFW and BW had lower firmness compared to oleogels prepared with one wax, indicating an incompatibility between the two waxes. The main wax components in SFW and CLW never cocrystallized, and low levels of CLW appeared to prevent SFW from forming a crystalline platelet network. This resulted in low firmness of oleogels made from mixtures of 90:10 to 60:40 SFW:CLW compared to oleogels prepared with one wax. However, the firmest oleogels of all mixtures were made from 10:90 SFW:CLW. Changes in gel firmness and melting properties with mixed wax oleogels were likely to be due to changes observed in the crystal size and morphology. In addition, the firmest gels were shown to result from mixtures that were predicted to have >40% hydrocarbon content, and a high hydrocarbon to wax ester ratio, but minor components such as free fatty acids and fatty alcohols may have also influenced firmness.     

Synthesis,Structure, and Explosive Properties of a New Trinitrate Derivative of an Unexpected Condensation Product of Nitromethane with Glyoxal

In the condensation reaction of nitromethane with glyoxal carried out in an aqueous solution of sodium hydroxide, 3,6‐dinitro‐cyclohexane‐1,2,4,5‐tetraol was obtained (the expected product, described in the literature) and, unexpectedly, also tricyclic nitro‐triol (6b‐nitrohexahydro‐2H‐1,3,5‐trioxacyclopenta[cd]‐pentalene‐2,4,6‐triol), which has been unknown until now, was obtained as the main product. The structure of the compound was confirmed with ¹H NMR and ¹³C NMR spectroscopy, LR, and HR‐MS techniques and with single‐crystal X‐ray diffractometry. The tricyclic triol (formally a hemiacetal) was transformed into 6b‐nitrohexahydro‐2H‐1,3,5‐trioxacyclopenta[cd]‐pentalene‐2,4,6‐triyl trinitrate by reaction with 98 % HNO₃. Some explosive properties of this compound were determined including: friction and impact sensitivity, activation energy, detonation velocity, heat of combustion in an oxygen atmosphere and enthalpy of formation. The nitrate ester is a powerful explosive with performance close to that of pentaerythritol tetranitrate (PETN).     

硝基甲烷的应用及制备

介绍了硝基甲烷的性质及其在精细化工中应用，结合生产方法现状、提出未来硝基甲烷的合成朝着绿色化、增加产率的方向发展。     

The Detonation Properties of Explosive-Water Mixtures

Mixtures of crystalline explosive and water have as a rule detonation properties different from the dry material. It has been shown that the character of those changes is closely related to the structure of the particles (crystals, granules) of the explosives. The critical diameters and detonation velocities have been measured for a range of explosive-water mixtures, and the results are interpreted in terms of the hotspot theory.     

Synthesis,Characterization, and Biodistribution of a Dinuclear Gadolinium Complex with Improved Properties as a Blood Pool MRI Agent

A dinuclear gadolinium(III) chelate containing two moieties of diethylenetriaminepentaacetic acid (DTPA), covalently conjugated to an analogue of deoxycholic acid, was synthesized and thoroughly characterized. A full relaxometric analysis was carried out, consisting of 1) the acquisition of nuclear magnetic resonance dispersion (NMRD) profiles in various media; 2) the study of binding affinity to serum albumin; 3) the measurement of ¹⁷O transverse relaxation rate versus temperature, and 4) a transmetallation assay. In vivo biodistribution MRI studies at 1 T and blood pharmacokinetics assays were carried out in comparison with Gd‐DTPA (Magnevist) and gadocoletic acid trisodium salt (B22956/1), two well‐known Gd complexes that share the same chelating cage and the same deoxycholic acid residue of the Gd complex investigated herein ((GdDTPA)₂‐Chol). High affinity for plasma protein and, in particular, the availability of more than one binding site, allows the complex to reach a fairly high relaxivity value in plasma (～20 mm ^?1 s^?1, 20 MHz, 310 K) as well as to show unexpectedly enhanced properties of blood pooling, with an elimination half‐life in rats approximately seven times longer than that of B22956/1.     

High-Temperature Reactions of Clay Mineral Mixtures and Their Ceramic Properties: I, Kaolinite-Mica-Quartz Mixtures with 25 Weight % Quartz

The mineralogy and ceramic properties (linear shrinkage and porosity) of fired compacts of quartz, kaolinite, and mica containing 25% of quartz and variable proportions of kaolinite and mica were studied systematically in relation to composition and firing temperature. A procedure for the quantitative determination of components by X-ray diffraction measurements is outlined and applied to the determination of quartz and mullite in the fired samples. For a mixture containing 25%, quartz, 75% kaolinite, the amount of mullite developed at 1300°C. is 41% and this contains 85% of the total Alsoa available. In micarich mixtures, mullite develops at lower temperatures and in smaller proportions. The shrinkage and porosity vary systematically with the percentage of mica in the samples and with firing temperature. The formation of cristobalite depends on the kaolinite content and is not related to the quartz content. Mullite and cristobalite develop at about 1100°C. from the transitory Si-Al spinel-type phase derived from kaolinite.     

N-辛基-2- 吡咯烷酮表面活性剂复配体系的研究

研究了３０℃下Ｎ 辛基吡咯烷酮（Ｃ８Ｐ） 分别与十二烷基硫酸钠（ＳＤＳ） 、十六烷基三甲基溴化铵（Ｃ１６ ＴＡＢ）的水溶液表面张力随浓度的变化。计算这２ 种复配体系中的分子相互作用参数βσ、βＭ 值分别为－２ ．７０ ,－２ ．７８ ,－ １．２７,－ ０．８７,并比较了这２ 种复配体系的协同效应     

铌酸钾的合成、表征及性能研究

相比于PZT等铅基压电陶瓷,碱金属铌酸盐陶瓷具有下列特点:介电常数小,压电性高,频率常数大,密度小,因此多年来常被作为电光材料。铌酸钾作为一种典型的铌酸盐化合物,具有良好的催化活性、选择性及稳定性,本文系统介绍了铌酸钾粉体的性质,制备方法、表征以及性能研究的现状。     

无机-无机纳米复合材料的构筑与性能

无机-无机纳米复合材料以其独特的光学、电学、催化性能和广泛的应用受到人们的关注，成为纳米材料领域的研究热点，本论文主要研究了核壳结构的二氧化硅／银复合材料的制备和性能。     

活性黑KN-B的复配与深色性能

活性黑KN-B(C.I.R.B15)是活性染料重要的品种,但是活性黑KN-B在390～ 520nm范围内的吸收偏低,染得的织物在520nm以下的反射率偏高,乌黑度不够,染色平衡时间长,实际上得到的是藏青色.此文结合近期的研究进展,对活性黑KN-B的性能进行了讨论,对染料结构改进、染料的复配性能的近期发展进行了评述,对进一步提高该染料的染色性能,以及进行复配拼黑,提高染料的乌黑度的研究具有一定的指导意义.     

Preparation,Characterization, and Anticorrosive Properties of Polyaniline Nanotubes

Self-assembled polyaniline nanotubes were synthesized using sodium dodecylbenzene sulfonate both as dopant and soft template by the oxidative polymerization of aniline. Electrical conductivity, electrochemical behavior, and solubility of polyaniline nanotubes were investigated and compared with that of conventional polyaniline synthesized similarly. Polyaniline nanotubes showed enhanced electrical, electrochemical, and solubility properties. Emeraldine base nanotube coating exhibited superior anticorrosion effect, especially in NaCl (3.5%w/w) solution. According to the results of Tafel slope analysis, the corrosion current of iron coupons coated with polyaniline nanotubes was much lower than that of coupons coated with conventional polyaniline in all studied corrosive environments.     

液固下喷自吸环流反应器流体力学特性

采用改进皮托管测定了液固下喷自吸环流反应器中的液体平均速度及液相湍流强度分布,采用PV4A颗粒浓度速度测量仪测定了固含率分布。试验结果表明:随着液体喷射流量的增大,液体平均速度、液相湍流强度及固含率均增大;在导流筒内液相平均速度近似管流分布,在环隙中的速度分布基本均匀;在导流筒和环隙内固含率沿径向分布均匀。该研究对于下喷环流反应器的放大与优化有重要指导意义。     

醛,2-异丁腈与硝基甲烷的多组分passerini反应

Passerini反应是一类重要的多组分反应,它可以快速的合成许多结构复杂的药物中间体,文章以苯甲醛,2-异丁腈和硝基甲烷为原料,氯化锌为催化剂,在微波作用下,发展新的多组分Passerini反应。     

有机-金属超分子化合物的合成、结构及性质研究

本论文设计合成了一系列含功能团的有机配体，并研究了它们与金属离子的自组装、组装体结构以及物理化学性质．取得了一系列创新性成果，主要包括以下几个方面：