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31.
近年来,为了更好地应对新的市场挑战,钢铁企业都在积极推进信息化建设,以实现管理提升、效益提升的目标。本文结合安钢集团的实际情况,对信息化实施策略进行初步的探讨,希望能对企业信息化建设有所借鉴。 相似文献
32.
溶胶-凝胶生物玻璃多孔材料显微结构和生物活性的扫描电镜及红外光谱分析 总被引:13,自引:0,他引:13
本文利用溶胶.凝胶法制备了CaO-P2O5-SiO,系统生物活性玻璃,并以其为原料制备了用于骨修复及骨组织工程支架的块状生物活性材料。利用体外实验方法(invitro)结合x射线衍射(XRD)、扫描电子显微镜(SEM)和傅立叶变换红外光谱分析(FTIR)技术对不同烧结工艺制备的材料结构、晶相和生物活性的影响进行了分析研究。研究表明,经800℃和1100℃烧结5min的两种材料均有硅磷酸钙Ca5(PO4)2SjO4微晶相析出。烧结温度越高,析出微晶相的体积比例越大,材料的生物活性则越低。在模拟生理溶液中碳酸羟基磷灰石(HCA)只在烧结体中的玻璃颗粒表面形成,而在其硅磷酸钙Ca5(PO4)2SiO4微晶相表面未发现HCA形成。 相似文献
33.
34.
Novel algorithms for shared segment protection 总被引:8,自引:0,他引:8
Dahai Xu Yizhi Xiong Chunming Qiao 《Selected Areas in Communications, IEEE Journal on》2003,21(8):1320-1331
The major challenges in designing survivable schemes are how to allocate a minimal amount of spare resources (e.g., bandwidth) using fast (e.g., polynomial-time) algorithms, and, in case a failure occurs, to be able to recover quickly from it. All existing approaches invariably make tradeoffs. We propose novel shared segment protection algorithms which make little or no compromise . We develop an elegant integer linear programming (ILP) model to determine an optimal set of segments to protect a given active path. Although the ILP approach is useful for a medium-size network, it is too time consuming for large networks. Accordingly, we also design a fast heuristic algorithm based on dynamic programming to obtain a near-optimal set of segments. Although the heuristic algorithm has a polynomial time complexity, it can achieve a bandwidth efficiency as high as some best-performing shared path protection schemes and, at the same time, much faster recovery than these shared path protection schemes. The proposed scheme is also applicable to a wide range of networking technologies, including Internet Protocol and wavelength-division multiplexing networks under the generalized multiprotocol label switched framework. 相似文献
35.
Achieving fast and bandwidth-efficient shared-path protection 总被引:4,自引:0,他引:4
Yizhi Xiong Dahai Xu Chunming Qiao 《Lightwave Technology, Journal of》2003,21(2):365-371
Dynamic provisioning of restorable bandwidth guaranteed paths is a challenge in the design of broad-band transport networks, especially next-generation optical networks. A common approach is called (failure-independent) path protection, whereby for every mission-critical active path to be established, a link (or node) disjoint backup path (BP) is also established. To optimize network resource utilization, shared path protection should be adopted, which often allows a new BP to share the bandwidth allocated to some existing BPs. However, it usually leads the backup paths to use too many links, with zero cost in term of additional backup bandwidth, along its route. It will violate the restoration time guarantee. In this paper, we propose novel integer linear programming (ILP) formulations by introducing two parameters (/spl epsi/ and /spl mu/) in both the sharing with complete information (SCI) scheme and the distributed partial information management (DPIM) scheme. Our results show that the proposed ILP formulations can not only improve the network resource utilization effectively, but also keep the BPs as short as possible. 相似文献
36.
37.
一种可切削玻璃陶瓷的压痕断裂特性 总被引:4,自引:2,他引:2
将断裂韧性测试的压痕方法与压痕弯曲方法相结合,独立地分离出了压痕残余应力因子x,使其成为可测参量,并建立了压痕一压痕弯曲的断裂韧性测试方法.将这种方法应用于一种可切削玻璃陶瓷的测试,获得的K1c值为K1c=2.03MPa·m1/2,与单边切口法(SENB)获得的K1c值有较好的一致性.测得的残余应力因子X=0.093,符合Anstis经验公式的预测. 相似文献
38.
J Braunstein L Qiao F Autschbach G Schürmann S Meuer 《Canadian Metallurgical Quarterly》1997,41(2):215-220
BACKGROUND: The transmission of hepatitis A virus (HAV) has been associated with the use of a number of solvent/detergent-treated factor VIII concentrates and possibly a factor IX concentrate. These reports have emphasized the necessity of using virus-inactivation methods for plasma products that are capable of inactivating nonenveloped viruses such as HAV. STUDY DESIGN AND METHODS: A simple, highly accurate titration procedure for HAV, which allows extensive kinetic investigations of virus-inactivation procedures, has been developed. This system has now been used to evaluate the efficacy of vapor heating in inactivating HAV after the addition of the virus to a range of human plasma products. RESULTS: It was demonstrated that HAV was significantly more thermostable than other picornaviruses, which reinforced the fact that such viruses cannot be used as model viruses for HAV-inactivation studies. A one-step vapor-heating procedure was demonstrated to inactivate between 5.9 and > 6.3 log10 of HAV in different products. A two-step vapor-heating procedure had the capacity to inactivate between > 8.7 and > 10.4 log10 of HAV. Both procedures were more effective in inactivating HAV than was the pasteurization procedure used for virus inactivation in human albumin solutions. CONCLUSION: These data demonstrate the efficacy of vapor heating in inactivating high-titer HAV after the spiking of plasma products with virus. This study confirms and explains the results of controlled clinical trials and long-term clinical usage with respect to the lack of HAV transmission by such vapor-heated products. 相似文献
39.
���þ��ܰ�ȫ�Բ������������� 总被引:1,自引:1,他引:0
本文通过对在用钻机井架的现场实际测试,建立数据库、测评模型,对实测的数据用计算机技术进行分析,提出了初始弯曲应力;数据正态分布检验——x~2检验;建立回归方程;在给定置信度下测评当前承载能力的技术概念。解决了在用钻机A型井架的安全性评估问题,是一种较为合理、可靠、科学的测评技术和方法。 相似文献
40.
富集孢粉化石的一种方法 总被引:2,自引:0,他引:2
本论述了孢粉,沟鞭藻化石与矿物颗粒相互分离的方法,并与传统的氢氟酸冷处理方法进行实验对比。结果表明,该方法摒弃有毒重液,提高了化石收获率。 相似文献