利用双向转发检测技术实现MPLS L3 VPN的快速检测

BFD(双向转发检测)技术能够极大地弥补现有的检测技术在MPLS L3 VPN(多协议标签交换类型三层虚拟专用网)中实现错误检测需时长而无法满足通信需求的缺憾.系统将利用BFD错误检测机制需时短的特性,由其实现对MPLS L3 VPN中LSP(标签交换通道)的快速检测.     

316L不锈钢non-Masing特性分析和疲劳寿命预测

对316L不锈钢在不同应变范围下分别进行了293 K和873 K试验温度下的低周疲劳试验,讨论了材料循环特性的幅值相关性和温度相关性,比较了不同条件下non-Masing特性,并利用能量方法进行了低周疲劳寿命预测。实验结果表明,在不同条件下,循环初期会出现不同程度的循环硬化现象,随后会出现循环软化、饱和直至材料失效;与873 K试验条件相比,材料在293 K温度下的non-Masing特性更为显著;在大应变范围下,两温度下材料的non-Masing特性更加明显。采用能量方法进行疲劳寿命预测时,预测结果均位于两倍分散带内,且基于non-Masing特性得到了比基于Masing特性更为精确的预测结果。在873 K温度和大应变范围下,显著的动态应变时效效应导致考虑non-Masing与Masing特性的预测结果相差不大。     

基于T213/L31并行计算和数值天气预报研究

介绍了并行计算和数值天气预报的发展概况;给出了并行算法的一般设计方法;分析了数值天气预报并行计算的可行性;最后介绍了T213/L31的基本原理,计算流程并分析其并行实现的可行性。     

API Spec 5L的发展过程及最新进展(下)

油气管道建设从最初的工业管道至今已经历了一个多世纪的发展。APISpec5L管线钢管规范自1928年发布第1版起至2007年发布第44版也经历了近80年的发展进程。该规范经分、合、再整合的不断修改与完善,已成为油气管道输送用钢管的国际通行标准。APISpec5L第44版于2007年10月1日出版．2008年10月1日生效,第一次与ISO3183：2007（第2版）等同合版发布。介绍了APISpec5L的发展历程,APISpec5L第44版的最新进展和变化。     

The composite impact of ICT industry on lowering carbon intensity: From the perspective of regional heterogeneity

The balance between low carbon development and rapid economic growth is a ‘Gordian knot’ for most countries. This study aims to explore the practicable route of lowering carbon intensity with the expansion of the Information and Communication Technologies (ICT) industry in China. Using the provincial panel data from 2000 to 2017, the paper employs five indicators to empirically investigate the determinant mechanism of carbon intensity based on the refined Stochastic Impact by Regression on Population, Affluence, and Technology (STIRPAT) and spatial econometric models. The findings demonstrate that the ICT industry is the main force in adjusting carbon intensity. Despite constraint by the rebound effect, the net effect of the ICT industry shows a significant positive impact on lowering carbon intensity under the consideration of spatial dependence. Furthermore, compared with developed regions, the contribution of ICT on regional inequality of carbon intensity shows a higher share in developing regions. By applying the Oaxaca-Ransom counterfactual decomposition, the results reveal that there are substantial regional gaps between multi-comparable groups. The composite effect of informatization, industrialization, and urbanization accounts for the major share of the regional gap. Thus, policymakers should pay more attention to enhancing the ICT infrastructure in developing regions, boosting the ICT-related technology investment in specific sectors, coordinating regional cooperation, and balancing the migration of skilled workers.     

The challenges of COVID-19 control policies for sustainable development of business: Evidence from service industries

Such large-scale disruptions as the pandemic increase the uncertainty and risk related to business. Therefore, the business continuity management (BCM) has become an essential technical solution for enterprise emergency response. Since the beginning of 2020, the COVID-19 has spread worldwide at an alarming rate causing many threats to sustainable development of the business sector. The decline in consumer demand has hugely impacted service industries, such as wholesale and retail sales, tourism. Enterprise production and operations have faced severe challenges. In this study, we develop a risk factor analysis of BCM under the presence of COVID-19 in China. Based on a statistical survey of 940 enterprises in Hangzhou City, China, this study employs ordinal logistic regression to explore the hindering effect of risk factors introduced by the epidemic on business performance. Then, the interpretive structure model (ISM) is applied to analyze the hierarchical structure of the factors under examination. The key factors influencing the enterprise production and operation during COVID-19 outbreak significantly differ across the sub-sectors of the service industry. Therefore, this paper assesses the resilience of the productive technologies and business models of different industries amid the pandemic. This paper proposes epidemic prevention and control strategy focusing on investment and government regulation to ensure sustainable business development.     

316L不锈钢薄板焊缝成形及力学性能研究

目的 减少1 mm厚度316L不锈钢薄板在焊接生产过程中出现的缺陷等问题,并提高不锈钢薄板焊缝成形质量和焊接接头力学性能。方法 采用脉冲激光焊接技术实现对厚度1 mm的316L不锈钢薄板的精确焊接,并利用金相显微镜、维氏硬度计、万能拉伸试验机和扫描电镜对焊缝的表面形貌、微观结构、力学性能、断口形貌进行表征分析。结果 当激光功率为403 W、输出电流为150 A、焊接速度为150 mm/min、离焦量为−5.525 mm时,焊缝正反面的形貌规则无缺陷。焊缝区内的微观结构主要由δ-铁素体和奥氏体2种晶粒构成,相较于母材及热影响区,焊缝区晶粒尺寸更细小均匀,平均硬度为156HV,表现出更高的硬度特性。焊接接头的抗拉强度和屈服强度均值分别达到643.28 MPa和305.95 MPa,相对于母材的强度分别提高了7%和49%;平均断后伸长率为37.2%,达到原始母材伸长率的55%;断裂呈现韧性断裂的塑性变形和延展性特征。结论 优化调整焊接工艺参数后,1 mm厚度316L不锈钢薄板的焊缝成形质量提高,无缺陷且微观组织分布均匀,焊接接头强度显著提高。     

316L不锈钢激光快速成形过程中熔覆层的热裂机理

采用微观测试分析方法，针对316L不锈钢粉末，深入研究了激光快速成形过程中熔覆层的开裂行为及其形成机理，研究结果表明，316L不锈钢激光熔覆层裂纹多发生在树枝晶的晶界，呈现出典型的沿晶开裂特征，裂纹断面上有明显的氧化彩色，扫描电镜照片显示裂纹断面上树枝晶的方向与轮廓清晰可见，树枝晶晶界相当圆滑，表明裂纹是在高温下产生的，熔覆层中的裂纹是凝固裂纹，属于热裂纹范畴，裂纹产生的主要原因是熔覆层组织在凝固温度区间晶界处的残余液相受到熔覆层中的拉伸应力作用所导致的液膜分离的结果。     

灰毡毛忍冬花蕾抑菌及抗炎作用研究

为了研究灰毡毛忍冬花蕾抑菌及抗炎的药理作用,通过采用纸片琼脂扩散法分别测试药材对6种常见致病菌的敏感性及微量稀释法测定其最小抑菌浓度(MIC)和最小杀菌浓度(MBC);采用二甲苯致小鼠耳廓肿胀、角叉菜胶致大鼠足肿胀及大鼠棉球植入致肉芽肿等模型评价药材体内抗炎作用。结果显示:灰毡毛忍冬花蕾提取物对6种常见致病菌均有显著的体外抑制作用,其MIC和MBC分别为10~80mg/mL和≥320mg/mL;灰毡毛忍冬花蕾提取物1.6、3.2、6.4g/kg均能显著降低小鼠耳廓肿胀率(p<0.01),1.125、2.25、4.5g/kg均能显著降低大鼠足肿胀度(p<0.01),2.2、4.5g/kg均能显著降低大鼠肉芽组织增生(p<0.01)。提示灰毡毛忍冬花蕾具有良好的体外抗菌效果和在体抗炎作用。      

Long-term contract auctions and market power in regulated power industries

A number of countries with oligopolistic power industries have used marginal cost pricing to set the price of energy for small customers. This course of action, however, does not necessarily ensure an efficient outcome when competition is imperfect. The purpose of this paper is to study how the auction of long-term contracts could reduce market power. We do so in a two-firm, two-technology, linear-cost, static model where demand is summarized by a price inelastic load curve. In this context we show that the larger the proportion of total demand auctioned in advance, the lower are both the contract and the average spot price of energy.