2013年中国钨品进出口分析

2013年全球经济复苏缓慢,国际钨市场需求持续疲软,钨市场价格回落,出口钨品量明显下降,未完成年度出口配额指标,进口钨品保持小幅增长。出口初级钨品比重下降,出口硬质合金等钨深加工产品比重略有上升,进口钨品仍以钨精矿为主。2014年,中国钨市场供应量将总体保持平稳,与钨消费密切相关产业对钨的需求将有所恢复,总体将继续保持增长;国际经济形势预期向好,国际钨市场需求预期将逐渐恢复增长,出口钨品量有望恢复增长,国际钨市场形势预计保持平稳运行。     

南方某矿区钨的赋存状态分析研究

仅用钨矿石的总钨量来评价一个钨矿是很不够的,因为一个钨矿的工业价值,往往决定于该矿石中钨的赋存状态。 应用通常的钨物相分析方法,可以完成黑钨、白钨和钨华等三相的测定,但该法不适于南方几省某些风化严重的钨矿床中钨矿石赋存状态分析。因为这些钨矿中,钨不仅     

我国钨产业发展现状

近些年来,我国钨产业高速发展,钨及钨产品在国民经济各领域得到广泛应用,钨产业已成为现代社会不可或缺的支柱产业。钨是我国为数不多的的优势资源之一,然而其现状令人堪忧。介绍了我国钨资源及钨产业现状,钨及钨产品发展趋势,提出了钨产业应坚持可持续发展观点,建立科学合理的运行机制,优化产业结构,开发新产品及应用领域的发展方向。     

含钨镀层研究的某些进展

介绍了镍钨镀层、镍钨硼(磷)镀层、含钨复合镀层和含钨电刷镀镀层等的研究与开发的近期进展。已有生产实践和研究工作表明 ,用含钨镀层代替传统对环境有危害的铬镀层等方面取得了很大进展。电沉积含钨镀层所用含钨原料主要是钨酸钠、碳化钨等 ,所得含钨镀层性能特色明显 ,其钨用量很少 ,发挥钨功能很大。因此 ,在钨的深加工与综合利用方面 ,应该进一步开展含钨镀层电镀技术的研究与开发。     

2014年上半年中国钨品进出口分析

根据2014年上半年进出口钨品海关数据和中国钨精矿生产情况,对比分析了2014年和近5年上半年进出口钨品量、市场价格走势、进出口市场分布和国际钨市场供需形势,对2014年下半年进出口钨品市场形势作了预测。2014年上半年,全球经济缓慢复苏,出口钨品量小幅增长,进口钨品继续明显下降,二季度出口钨品量环比一季度增长30.28%,国际钨市场需求有所改善;随着国际钨市场需求的进一步恢复,预期下半年出口钨品量继续保持小幅增长,进口钨品继续下降,国际钨市场价格将保持平稳运行。     

2014年中国钨品进出口分析

根据海关进出口钨品数据,结合中国钨行业经济运行情况,分析2014年及近5年中国进出口钨品量、产品结构、市场分布、价格走势以及2015年进出口钨品市场形势。2014年中国出口钨品有所增长,进口钨品继续下降,市场价格呈下滑走势;2015年国际钨市场需求逐渐恢复,预期出口钨品量继续保持增长态势,进口钨品继续下降,国际钨市场价格总体趋于平稳运行。     

钨及钨合金注射成形研究进展

评述了钨及钨合金粉末注射成形的研究进展,着重介绍了钨及钨合金粉末注射成形工艺研究和理论探讨,列举了钨材料在国防军工、航空航天、能源、电子等行业领域中的应用,总结了钨材料的研究方向。通过采用高品质粉末制备与改进技术,对钨阴极进行合理的结构设计,对制备工艺进行综合优化,在新结构设计的关键钨零件方面提出了钨粉末注射成形的技术课题,展望了钨科学技术发展的美好未来。     

钨市场2001年回顾与2002年展望

回顾了2001年世界钨市场的供需状况和价格走势 ,并对2002年钨市场前景进行了展望。中国作为钨业大国 ,对国际钨市场的走向具有举足轻重的影响。中国加强钨业综合治理、控制钨的生产和出口总量初见成效 ,2001年上半年钨价持续上涨 ,但下半年由于需求下降和供应增加 ,钨价又一路下滑。进入2002年后 ,钨价仍有下滑的趋势。钨价下跌后 ,钨生产商将会减少供应量 ,随着世界经济的复苏 ,钨的需求也有望好转 ,钨价将止跌趋稳     

黑白钨强磁分选在柿竹园钨浮选回收中的应用

介绍了强磁分选黑白钨新技术在柿竹园多金属选厂钨浮选回收中的使用情况。针对该选厂原有工艺中黑白钨混浮、加温作业阶段黑钨矿物受到强烈抑制,导致黑钨矿精矿品位低、钨矿物总回收率不高的情况,经过了两个阶段的工艺改造。提出确定在钨粗选段引进强磁系统,通过强磁将黑白钨进行分离,磁性产品浓缩后再黑钨浮选,黑钨尾矿返回钨粗选的新工艺。采用黑白钨强磁分离新工艺后,黑钨精矿品位提高了8.78%,钨的总回收率提高了5.04%,创造了良好的经济效益。     

2013年上半年中国钨品进出口分析

由于国际钨市场需求低迷,出口钨品量明显下降,进口钨品量小幅增长,中国国内钨市场价格上涨推动国际钨市场价格走高。预期下半年国际钨市场价格将保持平稳运行,出口量小幅增长。     

Efficacy and tolerability of Estraderm MX, a new estradiol matrix patch

Our data (Reddy et al., Radiat. Res. 141, 252-258, 1995) on the kinetics of the repair of potentially lethal damage in log-phase Chinese hamster V79 cells are used to test some predictions which arise from the different assumptions of the repair-misrepair (RMR) (C. A. Tobias, Radiat. Res. 104, S77-S95, 1985), lethal-potentially lethal (LPL) (S. B. Curtis, Radiat. Res. 106, 252-270, 1986) and double-strand break (DSB) (J. Y. Ostashevsky, Radiat. Res. 118, 437-466, 1989) models. The LPL model defines the time available for repair of PLD (t(rep)) as the time taken to reach maximal survival in a delayed-plating recovery experiment. Those data show that after this time has elapsed, contrary to the expectation of the LPL model, survival can be increased by changing the medium used for delayed plating from fresh growth medium to conditioned medium. According to the RMR model, all potentially lethal lesions should also be committed by that time and be unavailable for repair in the new medium. Only the DSB model correctly predicted that PLD (= DSBs) would still be available for repair after that time. Second, data for split-dose recovery are used to predict the first-order kinetics time constant for DSB repair (tau(DSBR)) using the DSB model (24 +/- 1.5 min). This value is nearly identical to the value of 27 +/- 1 min determined from the data obtained by Cheong et al. using pulsed-field gel electrophoresis (PFGE) (Mutat. Res. 274, 111-122, 1992). The value based on PFGE is used to calculate the value of t(rep) predicted by the DSB model (2.6 +/- 0.1 h), which agrees with the value determined experimentally as the time when changing the delayed-plating medium from growth medium to conditioned medium no longer gives the full recovery seen with delayed plating in conditioned medium (2.5 h). However, some recovery was seen for a change in the medium (growth medium to conditioned medium) up to 5-6 h postirradiation. Reanalysis of the original data on DSB repair shows that they are consistent with two first-order repair rates (18 +/- 7 min and about 52 min). These results are consistent with two pools of DSBs (or cells), each with their own t(rep). The early t(rep), associated with tau(fast), is predicted to be 1.7 +/- 0.7 h, and the late t(rep), associated with tau(slow), is predicted to be about 5 h. Both values are in excellent agreement with the times at which changing from growth medium to conditioned medium no longer gives the full recovery seen in conditioned medium only (the early t(rep)), and the time when changing from growth medium to conditioned medium produces no further increase in survival (the late t(rep)), respectively. It is noted that attempts to correlate radiosensitivity with the rates of DSB repair, rather than using an explicit model such as the DSB model, are unlikely to be productive since survival depends on both tau(DSBR) and t(rep) (as defined in the DSB model) and the latter may be the more important determinant of radiosensitivity (as it appears to be for ataxia telangiectasia cells compared to normal fibroblasts and for irs compared to V79 cells).     

The influence of medium composition on the maintenance of cytochrome P-450, glutathione content and urea synthesis: a comparison of rat and sheep primary hepatocyte cultures

Rat and sheep primary hepatocytes have been cultured in four different medium formulations: Williams' E, Chee's, Medium 199 and Modified Earle's. The total cytochrome P450 content, intracellular concentration of reduced glutathione, rate of urea synthesis and total protein content of cultures of cells from both species in each medium have been determined. Modified Earle's and Chee's medium proved to be the most favourable formulations for the culture of rat hepatocytes. After 48 h, cells cultured in Modified Earle's had significantly more cytochrome P450 and a significantly greater rate of urea synthesis than cells in any other medium. After 6 days in culture the difference in cytochrome P450 levels between rat hepatocytes in Chee's medium and those in Modified Earle's medium was abrogated. The difference in the rate of urea synthesis between rat hepatocytes cultured in each of these two media was shown to be more dependent on the medium in which the cells were maintained during the period of urea synthesis measurement than on the medium in which the cells had been previously cultured. Sheep hepatocytes cultured in Chee's medium ruptured and died within 24 h. Apart from this, sheep cells were less sensitive to changes in medium formulation than were rat hepatocytes. The initial plating efficiency was lower in sheep cells. Total cytochrome P450 content was the most discriminatory of the four parameters for evaluating the status of rat hepatocyte cultures. However, urea synthesis may be the most useful parameter for assessment of hepatocyte function in hybrid liver devices such as bioartificial liver support systems where access to the cells during operation of the device is restricted.     

超塑性材料现状及新型超塑性低中碳合金钢研发

 在分析超塑性金属材料现状及发展趋势的基础上,对低中碳钢、高碳钢和双相不锈钢、奥氏体钢等钢铁材料的超塑性研究进行了归纳分析,提出了低成本量大面广低中碳合金钢将成为超塑性材料研发的一个重要方向。研究结果表明,通过科学合金化设计、精细组织调控和初步超塑性行为研究,可以获得在10－2/s应变速率和750～850 ℃下具有1 000%超塑性的低成本超塑性低中碳合金钢。这种优异超塑性性能主要归因于形成超细晶组织的合金化设计与组织调控。该研究成果打破传统低中碳钢不具有超塑性的局面,实现了可工业化超塑性能的低中碳合金钢创新发展,将推动超塑性钢材在航空航天和交通运输等领域的广泛应用。     

技术创新中介组织的政府行为刍议

在世界经济竞争日趋激烈和科技发展突飞猛进的今天,技术创新中介组织将拥有巨大的发展空间。必须针对我国技术创新中介组织的发展现状,规范政府和中介组织的行为。     

中厚板轧后控冷工艺的探讨

文章对三种中厚板轧后控制冷却工艺进行了分析和比较，结合安钢中板的现有工艺条件，指出了安钢中板发展控冷工艺需要解决的问题及应该采取的对策。     

含钛中碳钢中钛氧化物析出热力学分析

以含钛中碳钢为研究对象,从热力学的角度分析了含钛中碳钢中钛氧化物析出行为,结果表明:浇注温度为(1535±10)℃且钢中溶解氧含量大于0.003％(质量分数,余同)时,低钛中碳钢中的溶解Ti可与钢中的溶解氧反应生成Ti3O5、Ti2O3,生成TiO2、TiO夹杂的可能性较小;高钛中碳钢中的溶解Ti可与钢中的溶解氧反应生...     

浅谈中厚板车间的平面布置设计

本文叙述中厚板车间平面布置的重要性、应明确的条件、布置的特点与基本的要求,为中厚板设计和改造提供参考。     

Hydraulic analog for simultaneous representation of pharmacokinetics and pharmacodynamics: application to vecuronium

A variety of different media for the cultivation of mycobacteria have been described but a few of them are in use today. Those currently used can be characterized by three basic types. The first is egg-based media represented by Ogawa and L?wenstein-Jensen. The second type is agar-based media; the most common one are Middlebrook 7H10 and 7H11. The third type is liquid media such as Middlebrook 7H9. Several weeks of incubation may be required for the isolation of M. tuberculosis on solid media. Substantial improvement in the time to detection and the recovery rate was realized by using broth-based culture system such as the BACTEC 460TB, Septi-Chek AFB, MGIT and BACTEC 9000. In the BACTEC 460TB system, the mycobacteria is detected radiometrically. The processed specimen is added to a modified 7H9 medium (BACTEC 12B) containing 14C-labeled palmitic acid and an antibiotic complex, PANTA. Mycobacterial growth can be ascertained by the liberation of 14CO2 and detected by BACTEC 460TB instrument. The Septi-Chek AFB is a biphasic medium which combines broth and solid media. The liquid medium is a modified Middlebrook 7H9 in a carbon-dioxide-enriched culture bottle. After inoculation of the sample, the bottle is capped with a slide consisting of three solid media; a non-selective Middlebrook 7H11 agar, an egg-based medium, and chocolate agar. A novel system is the MGIT, which is a nonradiometric broth method for the detection of mycobacteria from clinical specimens. The MGIT consists of a modified Middlebrook 7H9 broth and a sensor embedded in silicone on the bottom of a tube. The appearance of orange-colored fluorescence in the sensor when excited indicates the growth of mycobacteria. MB Redox is a modified, serum-supplemented Kirchner medium containing p-indonitrotetrazolium violet (INT) as an indicator of microbial growth. The INT is reduced by the redox system of the mycobacteria to deep violet-colored formazan. This substance is water insoluble and is reduced to the cell surface, by which bacterial clamps can be easily detected by their violet color. At present, the egg-based media are the first choice for the culture of clinical samples. However, there are advantages to each type of medium and not all strains of mycobacteria can be recovered on a single medium. Therefore, it is recommended that one representative of each type of medium be used for primary isolation; one example in Japan may be Ogawa egg medium in combination with Middlebrook 7H11 and MGIT.     

A new experimental in vitro culture medium for cultivation of Leishmania species

A new liquid culture medium prepared with chemicals that can be obtained economically and commercially was tested in in vitro cultivation of Leishmania promastigotes to obtain a large number of organisms to use in serological studies. The number of Leishmania infantum and Leishmania tropica promastigotes taken from Novy-MacNeal-Nicolle (NNN) medium reached 1 x 10(7)/ml at the end of the 8th day in our new medium, though in NNN medium the number of organisms reached only 5 x 10(6)/ml. After 10 subsequent passages, the culture medium prepared was evaluated as being quite inexpensive, simple, and successful compared with other commercially available liquid culture media.     

Simulation of the interaction of a powder heterogeneous medium with a tool during molding

The contact interaction of a heterogeneous powder medium with the surface of a steel or hard-alloy tool is subjected to mathematical simulation. Under known compacting conditions, the developed mathematical model can be used to find the character of particle motion in the medium to be compacted and the density distribution over the volume of the semiproduct or the end product.