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41.
在中国加入WTO多年以后,中国市场开放进程进入“后过渡期”。后过渡期将向我们提出更高的市场开放要求。针时后过渡期的应对问题,探计了如何把握和应用好中央提出的“四个结合”原则的问题。 相似文献
42.
近年来 ,随着我国加入世界贸易组织 (以下简称ＷＴＯ)的谈判逐步进入实质性阶段 ,以及我国的造纸工业逐步与国际接轨 ,国家行业管理与环保政策的实行 ,我国的造纸工业在产品结构和生产规模等方面都在进行自我调整 ,再加上一些国外大的造纸集团在我国建厂 ,这些都使得国内造纸工业的市场竞争变得日益激烈。我国加入ＷＴＯ以后 ,进口纸的关税将调低 ,届时将会有大量的纸和纸板拥入中国市场 ,由于其性能价格比大 ,竞争力强 ,无疑会对我国的造纸工业产生很大的冲击。如何面对现实 ,迎接新的挑战 ,是我国造纸企业面临的一个重大课题。这里本人谈… 相似文献
43.
本文分析了电力系统工程勘察设计院的现状以及国际市场的发展方向 ,提出了在加入WTO后面临的机遇以及应采取的应对策略 相似文献
44.
我国入世和融入经济全球化,将给中国经济运行的大环境带来深刻变化,科技事业也面临着全新挑战。电力科研所实行企业化转制,与国际接轨,按照国际规则办事势在必行。作者作为电力科研单位的一把手就电力科研院所的企业化转制阐述了个人的观点。转制必须有利于回忆科技创新和高新技术产品的开发;必须有利于抓紧培养和造就复合型人才队伍;必须有利于更好地为电网、为发供电企业提供规范化、制度化、长期化和现代化的全方位服务。 相似文献
45.
《Journal of the European Ceramic Society》2022,42(13):5195-5207
Molybdenum and a molybdenum alloy were fusion welded to ZrB2-based ceramics to determine if the electrical and thermal properties of the metals and ceramics affected their weldability. Commercial ceramic powders were hot pressed, machined into coupons, and preheated to 1600 °C before joining the ceramics to commercial metals using plasma arc welding. Weldability varied as indicated by the range of porosity observed within the fusion zones. Measured thermal and electrical properties appeared to have little to no effect on the weldability of metal-ceramic welds despite the large range of values measured across each property. Differences in melting temperatures between metal and ceramic coupons did affect weldability by changing the weld penetration depth into ceramic coupons. Future studies on metal-ceramic welds are suggested to investigate the effect that work function, melt viscosity, wetting, or other properties have on weldability. 相似文献
46.
《Ceramics International》2022,48(6):8025-8030
In order to meet the high demand for joining ceramic/superalloy composite structure in extreme environments, a novel high-temperature resistant adhesion technique was developed for joining ZrO2 and Inconel 625 by applying an aluminum phosphate emulsion/zirconium sol based adhesive. With increasing temperature, a series of reactions occurred in adhesive, and its high-temperature bonding was attributed to the formation of a composite structure containing various ceramics and intermetallics. The adhesive after RT curing could find direct applications in extreme environments, and provide bonding strength no less than 2.5 MPa in the temperature range of RT-1100 °C. The bonding strength was higher than 4 MPa in the temperature range of 800–1000 °C, which was further attributed to the formation of an effective CTE-gradient relationship among ZrO2, adhesive and Inconel 625, as well as the interfacial reactions between the two substrates. The work broadened the application of adhesion technique and brought new ideas for joining dissimilar engineering materials. 相似文献
47.
Hajnalka Laura Plinks L&#x;rinc Pongor Mt Balajti dm Nagy Kinga Nagy Angla Bksi Giampaolo Bianchini Beta G. Vrtessy Balzs Gy&#x;rffy 《International journal of molecular sciences》2022,23(2)
The clonal composition of a malignant tumor strongly depends on cellular dynamics influenced by the asynchronized loss of DNA repair mechanisms. Here, our aim was to identify founder mutations leading to subsequent boosts in mutation load. The overall mutation burden in 591 colorectal cancer tumors was analyzed, including the mutation status of DNA-repair genes. The number of mutations was first determined across all patients and the proportion of genes having mutation in each percentile was ranked. Early mutations in DNA repair genes preceding a mutational expansion were designated as founder mutations. Survival analysis for gene expression was performed using microarray data with available relapse-free survival. Of the 180 genes involved in DNA repair, the top five founder mutations were in PRKDC (n = 31), ATM (n = 26), POLE (n = 18), SRCAP (n = 18), and BRCA2 (n = 15). PRKDC expression was 6.4-fold higher in tumors compared to normal samples, and higher expression led to longer relapse-free survival in 1211 patients (HR = 0.72, p = 4.4 × 10−3). In an experimental setting, the mutational load resulting from UV radiation combined with inhibition of PRKDC was analyzed. Upon treatments, the mutational load exposed a significant two-fold increase. Our results suggest PRKDC as a new key gene driving tumor heterogeneity. 相似文献
48.
Rajiv Asthana Natalia Sobczak Mrityunjay Singh 《International Journal of Applied Ceramic Technology》2022,19(2):1029-1049
Joining and integration technologies are integral to manufacturing of components based on ultrahigh-temperature ceramics (UHTCs) such as transition metal diborides. Brazing is a particularly attractive joining technique because of its simplicity and versatility, but its use to join the UHTCs demands knowledge of the complex interplay among high-temperature wettability, interfacial reactions, and chemical and thermoelastic compatibilities. This paper summarizes the research and development activities carried out over the last two decades to characterize the wettability and interfacial phenomena in brazing of refractory diboride ceramics. The contact angle data of various metal alloys on diboride-based ceramics have been collected and critically evaluated in conjunction with an analysis of the chemistry and structure of the interface to understand the underlying mechanisms and phenomena that govern interface formation. It explores how solid–liquid interactions impact and are impacted by physical, chemical, and mechanical properties of joined materials. It also describes how this knowledge has been successfully utilized to create liquid-phase bonded diboride-based joints. The paper concludes with a summary of the current state of the art and highlights integration challenges and future research and technology development needs in the area. 相似文献
49.
采用激光诱导燃烧合成连接方法实现Cf/Al复合材料和TC4钛合金的可靠连接.放热中间层的燃烧合成反应为连接过程提供所需能量.结合理论计算和实验,对Ni?Al?Zr中间层的化学成分进行优化设计,并对连接接头的显微组织和力学性能进行研究.结果表明,Zr的加入轻微降低中间层的放热性,但显著提高连接质量,是实现可靠连接的关键.... 相似文献
50.
分析了国内聚苯乙烯行业现状,包括国内PS生产、需求、市场占有率及价格预测以及影响PS的价格因素等,指出了我国加入WTO后PS行业受到的影响和相应对策。 相似文献