我国九种矿产资源严重短缺

从近年的情况看,由于经济的快速发展,我国已经成为世界上最主要的矿产和金属的消费国之一。有人认为,到2020年我国铁矿石的消费将占到世界的35．7l％,而消费比例超过20％的矿产由高到低有：煤、锡、锌、铅、氧化铝、铝、铅、铜等。近年来,中国矿产品产量的迅速提高并不能满足国内高涨的需求。根据中国矿业联合会的研究,到2020年中国所需的45种主要矿产可以基本划分为：可以保证、基本保证、短缺、严重短缺四类;可以保证的矿产共24种：煤、天然气、钨、钼、银、稀土、菱镁矿、萤石、耐火黏土、磷、重晶石、水泥灰岩、玻璃硅质原料、石膏、高岭土、石材、硅藻土、钠盐、芒硝、膨润土、石墨、石棉、滑石、硅灰石。基本保证的矿产两种：钛、硫。     

山西省水系沉积物含量特征及铜元素地球化学分布特征

依据山西省90年代完成的1:20万区域化探扫面成果,本文系统的统计了山西省Ag、As、Au、B、Ba、Bt、Bi、Cd、Co、Cr、Cu、F、Hg、La、Li、Mn、Mo、Nb、Ni、P、Pb、Sb、Sr、Th、Ti、U、V、W、Y、Zn、Zr、SiO_2、Al_2O_3、Fe_2O_3、MgO、CaO、Na_2O、K_2O等38元素的平均含量及其在不同地质单元中的平均含量、标准差、变异系数和浓集系数。并以Cu元素为例总结了元素的分布特征。     

1999年一季度我国基本有色金属及其制品的外贸

1999年一季度我国铜、铝、铅、锌、锡、镍六种基本有色金属及其制品的外贸结构虽无大的、根本性的变化,出口创汇的顺序是铝、铜、锌、锡、铅、镍;进口用汇顺序仍是铜、铝、锌、镍、锡、铅。     

标准样品的管理

目前,我厂使用的标准样品有:碳素钢、低合金钢、高锰钢、镍铬不锈钢、高温耐热钢、硼钢、铬钨钢、滚动轴承钢、高硅铝合金、生铁、铬钼铜合金、铸铁、稀土球墨铸铁、高铬铸铁、合金铸铁、中低碳素锰铁、中低炭素铬铁、硅铁、钛铁、烧结矿、高炉渣、锰矿、电炉渣、石灰石、萤石、硅砖、铬镁砖、镁砂、焦炭、煤等系列标准样品。在配合分析使用时,如何尽快的选择随心所需的标准样品,一度成为难题。现在能非常方便、快速、准确的找到。我们的做法如下:(1)建立台帐:新购回标准样品按不同系列分类,每瓶有新编序号,对标准样品的原编号、产地、…     

《稀有金属》(国内版)征稿及来稿注意事项

本刊是中国有色金属工业总公司主办的科技刊物,主要报道稀有金属(钛、钨、钼、稀土、锂、铍、铷、铯、锆、铪、钒、铌、钽、镓、铟、铊、锗、硒、碲、铼等)在选矿、冶炼、分析测试方面,稀有金属、有色金属材料科学与工程以及半导体材料的制备、测试等方面的科研、生产和应用成果。内容力求与国内科研、生产紧密结合,     

唐山唐钢气体有限公司

正唐山唐钢气体有限公司是由河北钢铁股份有限公司与中国气体工业投资控股有限公司共同投资创立的河北省第一家中外合资气体生产企业,注册资本7.78亿元,下设多家子分公司唐钢气体是集各类气体生产、运输、销售服务为一体的大型专业化气体公司主要生产和销售氧、氮、氦、氩、氢、二氧化碳、医用氧、车用天然气产品,并提供生产、销售、使用相关的技术咨询服务和运输,进行气体生产设备的研制。同时,从事氢、一氧化碳、硫化氢、甲烷、乙烷、丙烷、正丁烷、乙炔、丙烯、丙二烯、溶解乙炔、氯乙炔、环氧乙烷、硅烷、氯甲烷、氧、空气、氮、氦、氖、氩、氪、氙、一氧化二氮、二氧化碳、六氟化硫、氨、磷烷、一     

《太钢科技》投稿指南

《太钢科技》是太原钢铁（集团）有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。     

《太钢科技》投稿指南

《太钢科技》是太原钢铁（集团）有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。     

《太钢科技》投稿指南

《太钢科技》是太原钢铁（集团）有限公司根据党和国家的政策、法令创办的，经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。     

ICP-MS测定地质样品中24种痕量元素干扰校正研究

研究并优化了ICP-MS同时测定地质样品中Ag、Ba、Be、Bi、Cd、Ce、Co、Cs、Cu、Cr、Li、Mo、Mn、Ni、Pb、Sb、Sc、Sr、Th、Tl、U、V、W、Zn 24种痕量元素的方法。通过选择适合的同位素,排除了同质异位素的干扰;通过降低CeO＋/Ce＋的比率,计算干扰校正方程,对难熔氧化物的干扰进行了校正;在线加入内标Rh,有效地抑制了基体效应。将该优化的方法经过国家一级地球化学标准物质验证（GSS-1、GSS-4、GSR-1、GSD-9、GSD-10）,精密度好,准确度高,检出限大都低于0.1 ng/mL。大量实际样品的分析结果表明,该方法对于化探样品测试技术的提高有一定的实用性。     

锌精馏炉平口塔盘的研制与应用

介绍了韶冶锌精馏炉平口塔盘的研制、加工、使用过程中出现的问题及解决措施。     

Influence of various impression procedures for removable partial denture on displacement of soft mucosal tissue

In the impression-taking procedure for the distal extension removable partial denture, the pressure produced at the interface of the soft mucosal tissue and the impression material is the most important factor for the stability of the saddle under functional load. However, a review of the literature revealed little information about the displacement of the soft tissue caused by the impression pressure. In the present study, to investigate the influence of various impression procedures on the magnitude of the soft tissue displacement more precisely, a new three-dimensional deformation measurement system was devised. Compared to the previous studies, the greatest advantage of the system is that the hardened impression material can be surveyed directly without substituting a dental stone. It was found that, in the investigation using a partially edentulous simulated model, the amount of the subsidence in the soft tissue was increased as the thickness of the spacer of the impression tray was reduced or the seating speed of the tray was fast. Especially in the buccal area, a large amount of vertical displacement was present compared to the midridge and lingual area. Thus it was suggested that many factors are associated with the form of soft tissue under impression loading.     

Hybrid fixation modular tibial prosthesis. Early clinical and radiographic results and retrieval analysis

A prosthetic tibial component has been designed with features for fixation to bone using a combination of acrylic cement and ingrowth interfaces. This hybrid concept affords the component the immediate stability of cement fixation and the potential long-term stability of biologic fixation. The ingrowth interfaces (coupled with the central stem) are intended to shield the cement interface beneath the tibial tray from the tensile liftoff forces that result from eccentric loading, while avoiding the fretting and osteolysis associated with screw fixation. A disassembly capability allows the tray to be removed from the stemmed anchorage assembly, facilitating component extraction and limiting bone loss. A clinical and radiographic review of 50 consecutive primary total knee arthroplasties with a mean follow-up period of 35 months revealed stable interfaces with no progressive radiolucencies and minimal remodeling changes. The mean Knee Society knee score was 92.2. At final follow-up evaluation, 88.6% of patients noted no or mild (occasional) pain. Retrieval of three prosthetic knees with chronic sepsis showed extensive ingrowth into the porous interfaces and an osteointegrated bony sleave around the smooth central stem.     

卡罗塞尔卷取机大转盘力学性能分析

文章利用三维建模软件对结构复杂的卡罗塞尔卷取机大转盘进行了建模。在此基础上,利用有限元分析软件ANSYS对大转盘进行了最恶劣工况下的力学分析,直观展现了大转盘存在的应力、应变,为掌握卡罗塞尔卷取机的力学性能提供了可靠的理论分析依据。     

基于ZnO结瘤下SiC塔盘导热性能研究探讨

为了研究韶关冶炼厂铅塔燃烧室SiC塔盘的外壁在存在ZnO结瘤层下的导热性能 ,根据ZnO结瘤层的不同厚度 ,并结合对塔盘的热工测试 ,对铅塔燃烧室烟气向ZnO结瘤层的外表面的辐射传热以及通过ZnO结瘤层导入塔盘内的热量进行了详细的分析和推导 ,结果发现 :随着ZnO结瘤层的增加 ,ZnO结瘤层外表面的温度升高 ,而沿ZnO结瘤层传入塔盘内的热量急剧减少。当ZnO结瘤层厚度为 3 0mm时 ,传入塔盘内的热量为未结瘤时的 3 0 3 4%。这种情况将在很大程度上减少锌蒸气的产量以及降低锌蒸气的质量     

氧化铝厂石灰炉炉底转盘跑偏分析与改造

对石灰炉炉底转盘经常跑偏问题进行受力分析和在线测试，并对炉底转盘机构进行了改造。     

Placement of multiple and different stent types for very long dissections during coronary angioplasty

A coordinate measurement machine with laser probe was used to measure the vertical distortion of the casts produced by use of three types of impression materials (irreversible hydrocolloid, condensation silicone, and addition silicone) and two types of trays (stock and custom trays). Results indicated that all impression groups showed positive vertical distortion (ranging from 0.00566 to 0.30299 mm) at the edentulous ridges and palatal area. The amount of the vertical distortion was greatest at the palatal area and was followed by the high edentulous ridge and the low edentulous ridge. Addition silicone, with either custom tray or stock tray, was the most accurate impression material. Condensation silicone was more accurate than irreversible hydrocolloid in custom tray impression. However, in stock tray impression the irreversible hydrocolloid was more accurate than the condensation silicone. The results suggest that, with careful manipulation, irreversible hydrocolloid with stock tray impression may provide a satisfactory cast for fabricating the framework of a distal extension removable partial denture.     

Renal expression of parathyroid hormone-related protein (PTHrP) and PTH/PTHrP receptor in a rat model of tubulointerstitial damage

The effect of a meniscal bearing on knee laxity in anterior cruciate ligament-sacrificing total knee arthroplasty was evaluated in 7 cadaver knees using a knee testing device that measured knee flexion angle as well as laxity to medial-lateral, anterior-posterior [AP], and rotational loads. A standard fixed tibial component and mobile tibial components (AP sliding, rotationally sliding, and AP and rotationally sliding) were used to evaluate AP, rotational, and varus-valgus stability and maximal flexion and extension with the neutrally positioned and malrotated tibial tray. The AP movable components increased AP laxity, and the fixed component decreased rotational laxity significantly when compared with the normal knees. The rotationally movable components did not change knee laxities significantly even when the tibial tray was malrotated. No significant difference among the components was detected when the maximal flexion and extension angles were compared in the neutrally positioned tibial tray. Malrotation of the tibial tray decreased the maximal extension angle in the fixed component. This study showed that the rotationally movable component can achieve near-normal laxity regardless of tibial tray rotation, but AP mobility of the bearing produces AP laxity that could lead to implant failure.     

Patellar tracking after total knee arthroplasty. The effect of tibial tray malrotation and articular surface configuration

The effect of total knee arthroplasty (TKA) with neutrally aligned and malrotated tibial trays was studied in five fresh anatomic specimen knees. Patellar shift, tilt, and rotation, and the rotational position of the tibia were measured in normal knees and after TKA with the Ortholoc Modular knee system. Both semiconstrained and unconstrained articular surfaces were assessed in the neutral position and at anatomic, 15 degrees internal, and 15 degrees external rotation of the tibial tray. After TKA, the patellae shifted slightly medially in the early phase of knee flexion because the anterior lateral flange of the femoral component was longer than the lateral trochlea of the femur and because the tibia rotated internally. The raised lateral flange on the femoral component tilted the patella medially at full extension after TKA. The semiconstrained tray allowed minimal tibial rotation because of its articular configuration. As much as 15 degrees malrotation of the unconstrained tibial tray did not affect patellar tracking. The semiconstrained tibial tray in the neutral position had almost the same patellar tracking as the unconstrained tray, but at 15 degrees external rotation, the semiconstrained tray internally rotated the tibia, leading to medial shift of the patella. Although 15 degrees internal rotation caused external rotation of the tibia, the patella did not shift as much laterally, despite the increase in the Q angle.     

Summation in the chimpanzee (Pan troglodytes).

In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it was necessary to sum the contents of the food wells on each tray. In experiments where food wells contained from zero to four chocolates, the chimpanzees chose the greater value of the summed wells on more than 90% of the trials. In the final experiment, the maximum number of chocolates assigned to a food well was increased to five. Choice of the tray containing the greater sum still remained above 90%. In all experiments, subjects reliably chose the greater sum, even though on many trials a food well on the "incorrect" tray held more chocolates than either single well on the "correct" tray. It was concluded that without any known ability to count, these chimpanzees used some process of summation to combine spatially separated quantities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)