OPTIMAL ROCK DYNAMIC FRAGMETAION BY CONTROLLED BLASTING

ＯＰＴＩＭＡＬＲＯＣＫＤＹＮＡＭＩＣＦＲＡＧＭＥＴＡＩＯＮＢＹＣＯＮＴＲＯＬＬＥＤＢＬＡＳＴＩＮＧ￥ｗｅｉＹｏｕｚｈｉ；ＬｉｕＱｉｎｇｒｏｎｇ（ＢｅｉｊｉｎｇＰｏｓｔｇｒａｄｕａｔｅＳｃｈｏｏｌ（ＲｏｃｋＢｌａｓｔｉｎｇＲｅｓｅａｒｃｈＳｅｃｔｉｏｎ...     

TECHNICAL AND ECONOMIC ASPECTS OF TUNNEL BLASTING ACCURACY CONTROL

ＴＥＣＨＮＩＣＡＬＡＮＤＥＣＯＮＯＭＩＣＡＳＰＥＣＴＳＯＦＴＵＮＮＥＬＢＬＡＳＴＩＮＧＡＣＣＵＲＡＣＹＣＯＮＴＲＯＬ￥ＲｅｎａｔｏＭＡＮＣＩＮＩ（）；ｖａｎｎｔＢＡＤＩＮ０（）；ＮｉｃｏｌａＩＮＮＡＵＲＡＴ０（＊）；ＭａｕｒｏＦＯＲＮＡＲ０（＊），Ｍ...     

热阴极电离真空计问答

热阴极电离真空计问答王逊（北京大学无线电电子学系）ＡｎｓｗｅｒｓａｎｄＱｕｅｓｔｉｏｎｓｏｎＨｏｔ－ｃａｔｈｏｄｅＶａｃｕｕｍＩｏｎｉｚａｔｉｏｎＧａｕｇｅ￥ＷａｎｇＸｕｎ（Ｄｅｐ．ｏｆＲａｄｉｏａｎｄＥｌｅｃｔｒｏｎｉｃｓ，ＢｅｉｊｉｎｇＵｎｉｖｅ...     

国际声学会议信息

１．ＡＳＡ／ＥＡＡＭｅｅｔｉｎｇ─Ｂｅｒｌｉｎ，１９９９１９９９年３月１４—１９日在德国柏林举行美国声学学会（ＡＳＡ）第１３７届学术年会和欧洲声学协会第２届会议的联合会议。会议地点：德国柏林工业大学会议秘书处地址：ＩｎｓｔｉｔｕｔｆｕｅｒＴｅｃｈｎｉｓｃｈｅＡｋｕｓｔｉｋＳｉｇｒｉｄＢａｅｒｎｄａｌＥｉｎｓｔｅｉｎｕｆｅｒ２５１０５８７Ｂｅｒｌｉｎ，ＧｅｒｍａｎｙＦａｘ：＋４９３０３１４２５１３５Ｅ－ｍａｉｌ：ｆｏｒｕｍ９９＠ｍａｃｈ．ｕｔ．ｔｕ—ｂｅｒｌｉｎ．ｄｅ２．ＷＥＳＴＰＲＡＣＶＩＩ，２…     

用于氟化镓铟高数值孔径光纤的氟磷酸盐和氟锆酸盐和氟锆酸盐包 …

为了得到用于１．３μｍ光通讯窗口掺镨化镓铟（ＰＧＩＣＥ）高数值孔光纤，本文报道以ＺｒＦ４－ＢａＦ２－ＬａＦ３－ＡｌＦ３－Ｎａ（Ｌｉ）Ｆ－ＰｂＦ２（ＺＢＬＡＮ（Ｌｉ）Ｐｂ）和ＮａＰＯ３－ＢａＦ２－ＺｎＦ２－ＰｂＦ２（ＦＰＧ）玻璃作为包层材料，研究了芯和包层玻璃在物理性质和化学组分上的匹配性，差热扫描（ＤＳＣ）和电镜（ＳＥＭ）分析表明ＰＧＩＣＺ／ＺＢＬＡＮ（Ｌｉ）Ｐｂ虽在物理性质上匹配，但在化学组分不     

FMS故障诊断的模糊行为Petri网研究

根据ＦＭＳ故障诊断推理中知识的模糊性，给出了模糊行为Ｐｅｔｒｉ网（ＦＢＰＮ）的定义，研究了用模糊行为Ｐｅｔｒｉ网表示模糊产生式规则的方法，提出了一种模糊反向推理机制，给出了算法的实现。最后以ＢＦＥＧ－ＦＭＳ的刀库换刀故障为例，证明了该方法的可行性和有效性。     

PS／粉末SBR—g—S共混体研究：Ⅱ.粉末SBR—g—S的相结构 …

测定了ＳＢＲ－ｇ－Ｓ的接枝率,用ＴＥＭ检测了粉末ＳＢＲ－ｇ－Ｓ（ＰＲ）的相结构。用ＤＳＣ测定了ＰＳ／ＰＲ共混体的Ｔｇ,研究了ＰＳ／ＰＲ共混体的相容性。结果发现,在接枝率为３２．６％的粉末非交联ＳＢＲ－ｇ－Ｓ（ＰＲ１）的相结构中ＳＢＲ为连续相,在连续相中均匀分布着直径约０．０１μ的ＰＳ微区;ＰＳ为细胞状分散相,粒径１～５μｍ,分散相含有ＳＢＲ包藏物。在接枝率为８．５％的粉末交联ＳＢＲ－ｇ－Ｓ（ＰＲ２     

梯度功能材料及其新的研究领域展望

梯度功能材料及其新的研究领域展望唐新峰，张联盟，袁润章（武汉工业大学材料复合新技术国家重点实验室武汉４３００７０）一、前言梯度功能材料（ＦｕｎｃｔｉｏｎａｌｌｙＧｒａｄｉｅｎｔＭａｔｅｒｉａｌ，ＦＧＭ）是为适应未来航天飞机、宇宙飞船等高技术领域发展的...     

双甲基丙烯酰氧基聚乙二醇与甲基丙烯酸盐共聚及导电性

在合成α，ω－双甲基丙烯酰氧基封端的聚乙二醇（ＢＭＡＰＥＧ）的基础上，通过ＢＭＡＰＥＧ与甲基丙烯酸盐（ＭＡＡＭ）共聚，制备了离子导电率（σ）在３０℃时为４．０×１０－６Ｓ／ｃｍ的单离子传导的ＡＢ交联型聚醚类固体电解质（ＡＢＣＰＥ）。研究了影响ＡＢＣＰＥ离子导电率的因素。结果表明，用甲基丙烯酰氯与聚乙二醇进行酯化反应可以合成所期望结构的ＢＭＡＰＥＧ。ＡＢＣＰＥ的σ随ＰＥＧ链段长度和共聚单体浓度的增加出现最大值；降低ＢＭＡＰＥＧ的双键官能度，或升高温度，σ升高。     

亚太地区涂料工业展望EI

亚太地区涂料工业展望北京航空材料研究所孙大海ＰｒｏｓｐｅｃｔｓｆｏｒｔｈｅＰａｉｎｔＩｎｄｕｓｔｒｙｏｆｔｈｅＡｓｉａ－ＰａｃｉｆｉｃＳｕｎＤａｈａｉ（ＩｎｓｔｉｔｕｔｅｏｆＡｅｒｏｎａｕｔｉｃａｌＭａｔｅｒｉａｌｓ，Ｂｅｉｊｉｎｇ）与世界范围内的工...     

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.     

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.……     

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...     

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 ...