可硬性盾构注浆材料试验研究

以水泥、粉煤灰、膨润土、河砂为原料制备可硬性盾构同步注浆材料,通过正交试验测试水胶比、胶砂比、水泥和膨润土掺量等因素对浆料稠度、流动度、强度及耐水性的影响,采用SEM对比分析了不同养护条件硬化浆体的微观结构及元素分布。结果表明,水胶比对浆料稠度和流动度影响显著,膨润土掺量对稠度和流动度的影响较胶砂比和水泥掺量显著。浆料的优选配合比为:水胶比0.60,胶砂比0.60,水泥占比0.25,膨润土占比0.10。标养条件下晶体颗粒之间的胶结程度较水养条件下更好,水养条件下水分子渗入注浆材料内部与SiO2反应,表现为注浆材料的强度在水养条件下会有所损失,且水胶比越小强度损失越大。

砂砾地层中盾构施工壁后同步注浆的模型实验与研究

以北京地铁十号线一期麦子西店站——亮马河站盾构隧道施工为背景,进行了模拟饱和砂砾地层中盾构施工壁后同步注浆的室内模型实验。注浆类型为盾尾同步注浆,浆液为单一的可硬性浆液。通过监测注浆过程中土体表面的位移变化;然后,系统地统计、分析实验所得数据;进而比较9组不同注浆方案的注浆效果,总结规律,最终得出优化的一组注浆方案。

Effect of pre-aging on microstructure and properties of 2000 series aluminum alloy for automotive body sheets

The effect of pre-aging treatment on the tensile properties,formability and microstructures of 2036 aluminum alloy for automobile body sheets were investigated through the tensile tests,DSC analysis and TEM observation. The results show that the alloy was softened,which was pre-aged at 180 ℃ within 20 min and then natural aging,namely T4P. However,the yield strength decreases first and then rises. The yield strength of the alloy after T4P(10 min) reach the minimal 202.3 MPa,but the elongation and strain hardening exponent arrive at the maximum,25.5% and 0.26 respectively,which can improve its formability effectively. In the early stage of T4P,GP zones dissolve,and generate some θ″ nuclei,so that the strengthening effect is restrained during the natural aging following the pre-aging. With the increment of pre-aging time,the θ″ phases are formed. The number of the θ″ phases grows,and the strength increases sharply during the paint-bake treatment. In contrast with the 6000 series aluminum alloy for automobile body sheets,the paint-bake hardenability of the 2036 alloy is lower and its yield strength before the paint bake is accordingly higher,which will add the difficulty of forming for the sheet.

盾构掘进同步注浆用抗剪切干粉砂浆施工质量控制

阐述了在盾构掘进过程中,同步注浆用抗剪切干粉砂浆(俗称厚浆)施工质量控制。这种抗剪切干粉砂浆材料与传统的抗压型可硬性浆液的力学机理截然不同。无锡地铁1号线南延线01标盾构区间掘进过程中采用了这种抗剪切干粉砂浆进行壁后注浆,施工过程中通过控制同步注浆施工质量,进一步控制地表沉降,提高了成型隧道防水功能。总结了同步注浆用抗剪切干粉砂浆施工过程质量控制指标,为今后抗剪切干粉砂浆施工质量控制提供了依据。

Catastrophe analysis on pillar instability considered mining effect

The instability of the pillar was discussed based on the potential energy principle and the cusp catastrophe theory, and a simplified mechanical model of the pillar was established considering the mining effect. The necessary-sufficient conditions, the jump value of displacement of pillar and the released energy expressions were deduced. The results show that the instability of the pillar is related to the properties of the rock, the external force and the relative stiffness of the elastic area to the plastic area. The instability of system is like to occur with the enlarging of the softening area or the decreasing of E/λ. The calculation done shows that the estimated results correspond to practical experience.

HYBRID REDUNDANCY APPROACH TO INCREASE THE RELIABILITY OF FPGA BASED SPEED CONTROLLER CORE FOR HIGH SPEED TRAIN

With the progress of the railway technology, the railway transportation is becoming more efficient, intelligent and faster. High speed trains, as a major part of the railway transportation, are engaged with passenger's safety, and therefore the reliability issue is very important in such vital systems. In this paper, a dependable speed controller core based on FPGA has been developed for high speed trains. To improve the reliability and mitigate single upset faults on basic speed controller, this paper proposes a new effective method which is based on hardware redundancy. In the proposed Hybrid Dual Duplex Redundancy(HDDR) method, the original controller is quadruplicated and correct values are voted through the comparator and error detection unit. We have analyzed the proposed system with Reliability, Availability, Mean time to failure and Security(RAMS) theory in order to evaluate the effectiveness of proposed scheme. Theoretical analysis shows that the Mean Time To Failure(MTTF) of the proposed system is 2.5 times better than the traditional Triple Modular Redundancy(TMR). Furthermore, the fault injection experimental results reveal that the capability of tolerating Single Event Upsets(SEUs) in the proposed method increases up to 7.5 times with respect to a regular speed controller.

Malicious Base Station and Detecting Malicious Base Station Signal

This paper introduces the background,illustrates the hardware structure and software features of malicious base station,explains its work principle,presents a method of detecting malicious base station,analyses the experiment and evaluates the experimental results to verify the reliability of this method.Finally proposes the future work.

Applicability and variability of liver stiffness measurements according to probe position

AIM: To investigate the liver stiffness measurement (LSM) applicability and variability with reference to three probe positions according to the region of liver biopsy. METHODS: The applicability for LSM was defined as at least 10 valid measurements with a success rate greater than 60% and an interquartile range/median LSM < 30%. The LSM variability compared the inter-position concordance and the concordance with FibroTest. RESULTS: Four hundred and forty two consecutive patients were included. The applicability of the anterior position (81%) was significantly higher than that of the reference (69%) and lower positions (68%), (both P = 0.0001). There was a signif icant difference (0.5 kPa, 95% CI 0.13-0.89; P < 0.0001) between mean LSM estimated at the reference position (9.3 kPa) vs the anterior position (8.8 kPa). Discordance between positions was associated with thoracic fold (P = 0.008). The discordance rate between the reference position result and FibroTest was higher when the 7.1 kPa cutoff was used to define advanced fibrosis instead of 8.8 kPa (33.6% vs 23.5%, P = 0.03).CONCLUSION: The anterior position of the probe should be the fi rst choice for LSM using Fibroscan, as it has a higher applicability without higher variability compared to the usual liver biopsy position.

Breeding of New Processing Apricot Cultivar ‘Jinxiu'

‘Jinxiu' is a processing apricot(Armeniaca vulgaris L.) cultivar derived from the cross of ‘Chuanzhihong'בJintaiyang'.The fruit is oval-shaped with the ground color of orange and 1/4-1/2 sheet red in the surface. The average fruit weight is65.5 g, and the maximum value is 106 g. The flesh is orange, fine with very less fiber, toughness, less juice and freestone, and tastes sour and sweet. The soluble solid content is 12.5%. The edible rate is 95.8%. The fruit skin hardness is 12.9 kg/cm2 and storable. The preserved apricots have orange color and are tasty. The preserved yield is 40%. The fruit development period is 72 d. The fruit has high yield, and the fruit yield in full fruit period can reach 37 000 kg/hm2. ‘Jinxiu' was examined and approved by Hebei Examination and Approval Committee of Forest Tree Variety in 2013.

Software architecture based software deployment reliability estimation considering architectural style

Software today often consists of a large number of components offering and requiring services. Such components should be deployed into embedded, pervasive environments, and several deployment architectures are typically possible. These deployment architectures can have significant impacts on system reliability. However, existing reliability estimation approaches are typically limited to certain classes or exclusively concentrate on software reliability, neglecting the influence of hardware resources, software deployment and architectural styles. The selection of an appropriate architectural style has a significant impact on system reliability of the target system. Therefore, we propose a novel software architecture （SA） based reliability estimation model incorporating software deployment and architectural style. On the basis of two architectural styles, we design influence factors and present a new approach to calculate system reliability. Experimental results show that influence factors provide an accurate and simple method of reflecting architectural styles and software deployment on system reliability. It is important for considering the influence of other architectural styles on system reliability in large scale deployment environment.

Fruit development rule of two Chinensis Actinidia cultivars ‘Fengyue’and ‘Cuiyu’

The fruit development rules of two Chinensis Actinidia cultivars were studied in this paper. ‘Fengyue’has the same fruit development cycle as‘Cuiyu’. According to soluble solids content, there are four stages during fruit development phase named comparatively stable period, slow increase period, rapid increase period and stagnating increase period. Fruit firmness change exhibits two periods, i.e. slowly declining period and rapidly declining period. There is an obvious corresponding relation between the changes of fruit firmness and the soluble solids content, i.e. the rapidly declining time of fruit firmness corresponds with the rapidly increasing time of soluble solids content. According to the experiment, the best picking periods of ‘Fengyue’and ‘Cuiyu’are mid September to mid October and early October to early November, respectively.

盾构隧道施工中同步注浆新材料的实验研究

位移的大小是综合控制盾构工法的主要参数之一。盾尾间隙引起的地层损失在总的地层损失中所占比例较大,而减小盾尾间隙及其引起的地层损失较为成熟的方法,是在盾尾后部注浆以填充盾尾的间隙,本文就是从注浆材料出发,将不同注浆材料对地面沉降的影响加以对比研究。

Accelerator Control System and Its Progress

Currently accelerator control systems adopt distribution architecture and are developed with integration tools,such as EPICS,TANGO and SCADA.The digital controller based on FPGA,DSP is widely used in accelerator controls and embedded EPICS IOC is a hot point.On the software side,laboratories have built their software develop- ment environments and the open sources Eclips,Abeans serve software development too.The high availability research is a challenge in the control world.The paper describes accelerator controls and progress of correlative technologies.

Soft error reliability in advanced CMOS technologies—trends and challenges

With the decrease of the device size,soft error induced by various particles becomes a serious problem for advanced CMOS technologies.In this paper,we review the evolution of two main aspects of soft error-SEU and SET,including the new mechanisms to induced SEUs,the advances of the MCUs and some newly observed phenomena of the SETs.The mechanisms and the trends with downscaling of these issues are briefly discussed.We also review the hardening strategies for different types of soft errors from different perspective and present the challenges in testing,modeling and hardening assurance of soft error issues we have to address in the future.