卤化银多晶光纤传输CO2激光性能的研究

通过采用高真空熔炼、反应气氛下区域融熔和高真空石英安瓿内单晶生长等特殊工艺方法对卤化银原料进行提纯,并用热挤压成型方法制得卤化银光纤．本文研究了卤化银原料的提纯和光纤成型工艺对损耗的影响,研究结果表明,增加提纯次数可降低卤化银光纤预制棒的吸收系数．通过合理控制工艺参数,提纯后的卤化银原料制成的光纤预制棒,经ＣＯ_２激光量热计法测量在１０．６μｍ处的吸收系数＜５×１０^－4ｃｍ^－１,热挤压成型的光纤在１０．６μｍ处的损耗为０.３～０.５ｄＢ／ｍ,直径φ１０ｍｍ、长度１．６４ｍ的光纤可传输ＣＯ_２激光功率＞２０Ｗ．     

卤化银多晶光纤CO2激光手术刀的研制

卤化银多晶光纤（AgClxBr(1-x),0≤x≤1）是一种传输中红外激光性能优良的光纤，可应用于CO2激光手术治疗，光纤原料采用高真空熔炼法提纯（物理提纯）和氯气气氛下水平区域熔融超提纯（物理与化学结合）两种方法提纯，光纤用热挤压成型，制成光纤式CO2激光传感输系统（光纤式CO2激光手术刀），配有普通型和内腔专用型两种结构输出,端头。     

卤化银光纤式CO2激光手术刀

卤化银多晶光纤「ＡｇＣｌｘＢｒ（１－ｘ），０≤ｘ≤１」是一种性能优良的中红外传能光纤。光纤原料采用高真空熔炼、氯气气氛下区域融熔和高真厂长发瓿内单昌生长等特殊工艺方法提纯，光纤用热挤压法成型。已制成的直径Φ１．０（ｍｍ）光纤Ｌ＝１．６４（ｍ）输出ＣＯ２激光功率〉２０（Ｗ），损耗０．３￣０．５ｄＢ／ｍ，Ｆｏｒｕｒｉｅｒ红外光谱（ＦＴＩＲ）测量结果显示，光纤在４￣１６μｍ波段内有良好的透过率，用光纤制     

卤化银光纤原料的超提纯

高纯原料的制备是制造高品质光纤最重要的环节,本文采用氯气氛下水平区熔法生长单晶的提纯方法对卤化银原料进行超提纯．区域熔融提纯后的卤化银原料红外吸收光谱测量显示在800～4000cm^－1范围内吸收随波长的增加而降低．经CO₂激光量热计法测量提纯后的卤化银原料在10．6μm处的吸收系数为5×10^－4Cm^－1,较提纯前降低两个数量级,制成的光纤传输损耗03～0．5dB／m     

反应氯气气氛下卤化银光纤原料的超提纯

采用反应氯气气氛下水平区域熔融生长单晶的方法对卤化银原料进行超提纯,反应氯气气氛是由裂解低沸点碳氯化合物得到;化合物的通式为ＣＨ_ｎＣｌ_４－ｎ(ｎ＝０,１,２)．提纯的温度为４５０~５００℃,温区移动速度为０．２~０．８ｍｍ/ｍｉｎ;载流气体Ａｒ的流量为８０~１６０ｍＬ/ｍｉｎ．提纯后的卤化银原料红外吸收光谱显示,在４０００~８００ｃｍ^－１(２．５~１２．５μｍ)区域内的吸收随波长的增加而降低,中红外４０００~６００ｃｍ^－１(２．５~１６μｍ)区域是卤化银材料最佳的传输波段．用此原料制成的光纤可传输３．３~１６μｍ中红外光谱;传输１０．６μｍＣＯ_２激光的损耗为０．３~０．５ｄＢ/ｍ．     

卤化银多晶光纤热挤压成型的研究

采用热挤压法成型制备出卤化银多晶光纤．光纤端面扫描电镜形貌分析结果显示,挤压温度１２０～２１０℃,晶粒大小基本不变,晶粒尺寸１～２μｍ．挤压温度＞２１０℃后,随着挤压温度升高挤压压力降低,在２５０℃时晶粒尺寸５～１０μｍ,挤压温度的升高导致卤化银多晶光纤的晶粒长大,引起光纤散射损耗的增高．挤压模具中加入润滑剂可同时降低挤压压力和挤压温度,但引起光纤传输损耗的增加．     

卤化银多晶红外光纤显微结构与相关性能的研究

借助ＴＥＭ、ＸＲＤ、硬度微观测量等方法,研究了卤化银多晶红外光纤的显微结构与相关性能的关系．发现光纤是以ＡｇＣｌ_ｘＢｒ_１－ｘ。多晶体为主骨架,纳米晶粒Ａｇ镶嵌其中．由纳米晶粒带来的损耗光纤的散射损耗增加很小,即ＡＮλ^－４通过控制光纤的制备工艺条件,可以改变光纤的晶粒大小和光纤硬度．     

非常规卤化银照相感光材料

非常规卤化银照相感光材料指的是与一般卤化银——明胶照相材料所用的原料,制备方法或加工过程不同,但仍属银盐系统的感光材料。这些材料中有不少在国外已经商品化,有的还处于科研阶段,但由于其独特的性能,很值得给予一定的重视。以下分别对这些非常规卤化银照相材料加以叙述。一、卤化银蒸发材料将溴化银干粉(或片状)置于蒸发皿中,加热熔融并使之在真空下蒸发,溴化银     

卤化银光纤CO2激光手术刀头

用卤化银多晶光纤制成了一种在关节式导光臂上使用的卤化银光纤手术刀头。手术刀头由耦合器、光纤连接器、柔性金属管、聚焦透镜座组成。其中柔性金属管依据用途能在0－90℃适当弯曲，弯曲半径＞15mm，长度＜250mm，输出连续激光功率大于12W，工作焦距5mm。光纤手术刀头端面带有气体保护装置，防止端面污染。具有防污结构的手术刀头整体直径小于5．6mm，因此适合在人体天然开口部位如口腔、喉、妇科、肛门及直肠等处进行使用。     

塑料光纤的开发现状及应用趋势

塑料光纤的研究开发已有不少突破,其应用领域正在不断扩大。本文通过对塑料光纤的优越性、开发的种类和典型性质的介绍,以及对芯材高分子材料氘化、卤化、高纯化和拉丝均匀化等提高塑料光纤性能途径的论述,揭示塑料光纤的开发现状。在进一步讨论塑料光纤的应用之后,提出短距离通信是其最有前途的应用领域和我国开发塑料光纤的对策。     

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.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.……     

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.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.