糠蜡在乳化炸药中的应用*

选用糠蜡与石油副产物制备复合油相。用Span80、T152与油胺配比为4瞷1瞷1的复合乳化剂和复合油相按配方制备乳化炸药。测试结果显示,乳胶基质黏度比较高,且50℃时的黏度小于25℃时的黏度。经过13次高低温循环后,乳胶基质电导率变化较小。在转速8000r/min时离心,乳胶基质破乳程度相对弱。 SEM图显示乳胶基质粒子分布相对均匀,大部分粒子粒径在1μm左右。 DSC实验分析得分解温度在270～280℃之间,相对较高。乳化炸药爆速、猛度都比较高,距离为3 cm的殉爆测试,能保证100％爆轰。     

一级乳化工艺制备长储存期乳化炸药的试验研究

研究了一级乳化工艺条件下,乳化剂种类、油相配方及不同乳化器对乳化炸药爆炸性能和储存稳定性的影响,采用高低温循环试验考察制备乳化炸药的储存稳定性。试验研究表明:一级乳化(CYJ型乳化器)时,LZ27011乳化剂制备的乳化炸药储存稳定性、爆炸性能和微观结构均优于S/T乳化剂制备的乳化炸药;乳化剂为LZ27011时,CYJ型乳化器较JWL-YR乳化器的乳化效果更好;乳化剂(Span80和LZ27011的质量比为0.51.5)和乳化器确定时,油相配比对乳化炸药的储存稳定性有显著的影响,当油相组成复合蜡和150SN的质量比为3.21.0时,所制得的乳化炸药经34个高低温循环后,爆炸性能仍符合标准要求。     

乳化剂聚异丁烯丁二酸聚乙二醇酯的合成及其应用

以聚异丁烯丁二酸酐(PIBSA)、聚乙二醇(PEG)200为原料合成了可作为乳化炸药乳化剂的聚异丁烯丁二酸聚乙二醇酯。用红外光谱对产物进行结构表征;采用单因素变量法对影响反应的一系列条件(温度、催化剂、原料组成比例等)进行探索,确定合成聚异丁烯丁二酸聚乙二醇酯的最佳工艺条件。结果表明,采用酯化温度为190℃、酯化时间6 h、酯化催化剂2%(质量分数)NaHCO3为合成条件时,能够得到优良的聚异丁烯丁二酸聚乙二醇酯。该乳化剂的乳化力优于Span80,制备出的乳胶基质的热稳定性优于以Span80和T152作为乳化剂制备的乳胶基质。     

大孔径深孔含水爆破混装乳化炸药性能研究

大孔径深孔含水爆破中,混装乳化炸药受到来自炸药本身重压、回填渣的压力以及炮孔中水的侵蚀,炸药爆炸性能发生改变。为了分析压力及水对混装乳化炸药的影响规律,提出了一种新型乳化炸药抗压性试验方法,模拟了深孔爆破环境气泡敏化的混装乳化炸药的爆速随孔压变化规律:0.1、0.2 MPa下24 h内爆速较高,随着压力增加及加压时间的延长,爆速下降直至拒爆;同时,通过测试乳胶基质中硝酸铵的溶失值以及乳胶基质的溶胀厚度,分析了乳化剂、油相材料对其抗水稳定性的影响。结果表明:添加质量分数1%的基础油,Span80、高分子型乳化剂EPE-1添加质量比达到1:1后,溶失值及溶胀厚度较小;再增加EPE-1的含量,抗水性、稳定性基本不发生变化。提出了提高混装乳化炸药抗水稳定性的方法。     

油水相界面张力对乳化炸药性能的影响

采用白金环法测定了乳化炸药复合油相与硝酸铵水溶液的界面张力,并研究了乳化剂质量分数、温度、分子结构和热值对油水相界面张力的影响以及界面张力对乳胶基质微观结构和储存稳定性的影响。结果表明,随着乳化剂质量分数的升高,界面张力先下降后保持恒定;随着温度升高,界面张力呈线性下降趋势;复合蜡组分的异构化烷烃含量越高,环状化合物越少,热值越低,油水相界面张力越低。随着界面张力和临界质量分数的降低,乳胶基质的粒径减小。乳胶基质的储存稳定性随着油相材料界面张力的降低而增强。     

工业硝酸铵添加剂对乳胶基质的影响

为了改善工业硝酸铵的吸湿结块性能,通常会加入添加剂(有机包覆剂或无机改性剂),而工业硝酸铵作为乳化炸药的主要原料,其添加剂对乳化炸药的制备和性能会产生影响。因此,分别对采用有机包覆剂蜡的泰国产工业硝酸铵和采用无机改性剂的俄罗斯产工业硝酸铵,开展了制备现场散装乳胶基质的工业试验。结果表明:两类工业硝酸铵均可作为乳化炸药原材料使用,但有机包覆剂会沉入水相罐底部或粘附在输送管道内壁,对水相和乳胶基质制备造成不利影响,因此需要在水相制备环节分离去除包覆剂蜡;硝酸镁、硝酸钙等无机改性剂对乳胶基质制备无影响,但生产的乳胶基质稳定性较差,通过调整乳化剂的种类和配比以及乳化器的转速可得到一定改进。     

工业硝酸铵添加剂对乳胶基质的影响

为了改善工业硝酸铵的吸湿结块性能,通常会加入添加剂(有机包覆剂或无机改性剂),而工业硝酸铵作为乳化炸药的主要原料,其添加剂对乳化炸药的制备和性能会产生影响。因此,分别对采用有机包覆剂蜡的泰国产工业硝酸铵和采用无机改性剂的俄罗斯产工业硝酸铵,开展了制备现场散装乳胶基质的工业试验。结果表明:两类工业硝酸铵均可作为乳化炸药原材料使用,但有机包覆剂会沉入水相罐底部或粘附在输送管道内壁,对水相和乳胶基质制备造成不利影响,因此需要在水相制备环节分离去除包覆剂蜡;硝酸镁、硝酸钙等无机改性剂对乳胶基质制备无影响,但生产的乳胶基质稳定性较差,通过调整乳化剂的种类和配比以及乳化器的转速可得到一定改进。     

改性磷脂在乳化炸药中的应用研究

为了将大豆浓缩磷脂更好的应用到乳化炸药中,研究以大豆浓缩磷脂为原料,在真空加热搅拌条件下与改性试剂A反应后加碱中和,再经真空干燥使水分含量≤1%制成改性磷脂。探讨改性磷脂替代50%的Span80制成复合乳化剂在乳化炸药中应用,通过对复合乳化剂制备的乳化炸药基质中游离铵含量、粒子形状和粒径大小、储藏时间等分析测定,评价对其稳定性及爆炸性能的影响。在小试基础上应用于中试生产中,并进行乳化炸药的爆炸和60 d储藏实验,结果表明:殉爆距离5 cm 3/3、爆速4630 m·s-1、猛度11.0 mm等性能指标均达到国家标准(GB18095—2000)中2号岩石乳化炸药的要求。     

FR型专用复合蜡在粉状乳化炸药中的应用?

以含蜡馏分油为原料,添加FR专用乳化剂和其他添加剂,利用均匀设计技术进行配方优化试验,着重考察复合蜡的滴点、黏度、含油量对粉状乳化炸药储存稳定性及抗水性的影响。试验结果表明,复合蜡适宜的滴点为70~85℃,适宜的黏度为75~85 mm2/s,适宜的含油量(质量分数)为20%~30%。通过工业应用试验结果表明,以FR型专用复合蜡为油相材料生产的粉状乳化炸药,爆炸性能满足WJ9025—2004岩石粉状乳化炸药标准的要求,可完全替代T-155、石蜡和微晶蜡等油相材料。     

Span-80和T-152对乳化炸药低温稳定性的影响

分别以Span-80、T-152为乳化剂制备乳胶基质和乳化炸药,在-30℃冷冻10天后通过水溶法测定它们的析晶率,并用显微镜观察两种乳胶基质。结果表明:用T-152制备的乳化炸药冷冻后的析晶率是用Span-80制备乳化炸药的3.57倍,前者的破乳程度高于后者。采用Chem3D软件的MM2分子动力学模块对Span-80和T-152分子进行Molecular Dynamics计算,模拟低温对乳化剂分子结构的影响,分析两种乳化剂制备的乳化炸药在低温下稳定性产生差异的原因。计算结果显示:-30℃时T-152分子失去立体结构,可能是用T-152制备的乳化炸药低温稳定性较差的主要原因。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...