磷酸盐高铝预制环在沸腾氯化炉上的应用

介绍了沸腾氯化炉用磷酸盐高铝预制环试验及使用情况。实践证明，该方法能有效地解决炉衬耐腐蚀和氯气泄露的问题。

装配式车站出入口环框预制结构沿车站纵向的受力分析

为研究装配式车站出入口环框预制结构受力,给出入口环框设计提供理论基础,首先,分析装配式车站预制环框从施工到使用各阶段不同的荷载模式。其次,采用有限元计算方法,研究环框结构从施工安装阶段、覆土回填阶段到出入口施作完成阶段的受力特点。然后,指出预制环框结构同顶板结构之间凹凸榫槽在完成接缝注浆后,沿车站纵向形成整体,对环框受力较为有利;同时,预制环框结构与顶板形成整体后共同抵抗覆土阶段及长期使用阶段的各项荷载,可以满足装配式车站拼装施工要求及后期车站结构整体受力要求。最后,提供一种设置临时钢支撑的安全储备措施,并对其结构受力进行验算,确保出入口环连续拼装的安全可靠。

Experimental study of pre-cracked concrete subjected to cryogenic freeze-thaw cycles based on an LNG concrete tank

To investigate the mechanical properties of concrete under the leakage condition for a liquefied natural gas storage tank,cryogenic freeze-thaw cycle tests were performed under liquid nitrogen refrigeration and water immersion melting.The effects of the cryogenic temperature,freeze-thaw cycle,pre-crack,and addition of steel fiber on the compressive strength,flexural strength,and splitting tensile concrete strength were analyzed.The experimental results show that the width of pre-cracks tends to expand after freeze-thaw cycles.When the freezing temperature is -80℃,the relative width of the pre-cracks expands by 1 to 2 times.However,when the freezing temperature is -120℃,the relative width of the pre-cracks expands by 2 to 5 times.Compared with the specimens without steel fibers,the specimens with steel fibers can still maintain a relatively complete appearance structure after the mechanical property tests.The compressive strength,flexural strength,and splitting tensile concrete strength decrease with the drop in the freezing temperature.After adding steel fibers,all of the three strengths increased.

Circulating DNA level is negatively associated with the long-term survival of hepatocellular carcinoma patients

AIM： To quantify the circulating DNA in plasma from patients with hepatocellular carcinoma （HCC） and to evaluate its prognostic value. METHODS： Blood samples were collected from 79 patients with HCC before operation, 20 patients with liver cirrhosis, and 20 healthy volunteers. Circulating DNA was extracted from plasma and quantified. The association between circulating DNA level and prognosis of HCC patients was evaluated. RESULTS： Compared with the healthy volunteers （17.6 ± 9.5 ng/mL）, a significant higher circulating DNA level was found in the patients with HCC （47.1 ± 43.7 ng/ mL, P = 0.000） or with liver cirrhosis （30.0 ± 13.3 ng/ mL, P = 0.002）. The circulating DNA level was closely associated with tumor size （P = 0.008） and TNM stage （P = 0.040）, negatively associated with the 3-year diseasefree survival （DFS） （P = 0.017） and overall survival （OS） （P = 0.001）. CONCLUSION： Large or invasive tumor may release more circulating DNA, and higher level of circulating DNA may be associated with poor prognosis of HCC patients.

Vector control of permanent magnet synchronous motor based on dynamic matrix control

Aiming at the control problem of strongly nonlinear and coupled permanent magnet synchronous motor(PMSM)oil rig,this paper presents a predictive control method based on dynamic matrix model.In this method,the dynamic matrix algorithm using multistep prediction technique is applied to the speed loop control of the motor vector control.And its control effect is compared with the traditional proportional integral(PI)control of the motor.By comparing the initial dynamic response and the steady-state recovery under load interference of the two methods,it is shown that the dynamic response and the robustness of the motor controlled by the new method is better than that controlled by conventional PI method.And the feasibility of new control in the application of PMSM oil rig is verified.

树脂复合井盖施工技术研究

在文章开展的相关研究与论述过程中,基于有限元软件MARC的合理运用,对井和井周路面的情况进行检查,完成有限元模拟分析,获取自流平回填材料,以此为基础,获取最优的回填材料。结论显示,自流平回填材料会直接影响路面沉降差,但是不会受到回填深度的显著影响。在后续的实践过程中,应该对井周围出现的病害原因进行分析,提高回填质量,尽可能降低路面沉降的发生几率,为城市环境提供保护,体现一定的实践意义。文章主要探讨预制定位环辅助安装树脂复合井盖施工技术。

The main projects and development status of noise forecasting and controlling on working face in coal mine

Noise from the machine on coal working face seriously influenced the miners' physical and mental health, and also, due to the noise, there may be a major hidden danger in safety from accidents as all safety warning signals may be masked by the noise. This paper summarized the features of mine environmental noise on working face, such as the variety of noise sources, the continuity of high intensity and slow attenuation in narrow space, etc.The main projects about noise forecasting and controlling on working face was emphatically expounded;the development status about mines machinery noise mechanism and environmental noise acoustic characteristics of space-time of these main research topics were also introduced.

Closed-loop prevention and control research of coal mine safety management

According to the current problems of safety management processes in coalmine enterprises,we introduced barrel theory to coal mine safety management,constructedthe closed-loop structure of a coal mine safety management system,andpointed out that efficient safety management lies in three factors:safety quality of all ofthe staff in coal mine enterprises,weak links in security management systems,and cooperationamong departments.After conducting detailed analysis of these three factors,we proposed concrete ways of preventing and controlling potential safety hazards duringthe process of coal mine production.

Eureka Webair： Web-Based Air Quality Management, Real-Time Forecasting and Emission Control Optimization

For the assessment and management of regional to local air quality, an integrated environmental management information system was built within the multi national Eureka project 3266 Webair, http：//www.ess.co.at/WEBAIR. The system combines data bases and GIS and a range of coupled models and analytical tools that address a range of typical management problems and cover several levels of nesting from regional to city level and street canyons. The main functions are to support regulatory tasks, compliance monitoring, operational forecasting and reporting, impact assessment EIA （environmental impact assessment）, SEA （strategic environmental assessment） and public information within one consistent framework. A major objective is the improvement of air quality through emission control. The integrated model system together with its shared data bases provides a reliable, consistent basis for the non-linear techno-economic and multi-criteria optimization of emission control strategies （including greenhouse gases and energy efficiency）. A real-time expert system drives, supports and monitors the autonomous and interactive operations, and provides embedded QA/QC （quality assurance/quality control） functions for reliable operations and ease of use.

Experimental and analytical studies on the deformability of a precast RC shear wall involving bolted connections

To study the deformability and ductility of an innovative precast shear wall joined by bolted connections,experimental tests were conducted on two test walls under monotonic and cyclic loading,respectively;subsequently,theoretical analysis was performed on the deformation performance of the shear wall assembly.The test results confirmed the favorable deformability and ductility of the specimens.The top displacement of the shear wall assembly was analytically decomposed into several constituent parts,the theoretical formulae of which were subsequently deduced.The compositional analysis demonstrated that the top displacement of the test wall was primarily induced by the elastic deformation of the upper wall panel(UWP),the relative slippages within the bolted connections,and the flexural deformation within the plastic region of the UWP,while the constituent part contributed by the deformation in the connecting steel frame can be neglected.

Path Following Control of Underactuated Ships Based on Unscented Kalman Filter

A path following controller is proposed to force an underactuated surface ship which is suffering from disturbance to follow a predefined path.The controller is based on analytic model predictive control and unscented Kalman filter(UKF) techniques.The analytic model predictive control provides a systematic method to get appropriate controller parameters to guarantee the stability of the closed-loop system,and the well-defined relative degree is guaranteed by introducing output-redefinition.The UKF is used to estimate the states and uncertain parameters due to time-varying added mass matrices.With help of the proposed UKF-based controller,the underactuated ship with time-varying parameters can follow a desired straight path.Simulation results are presented to demonstrate the effectiveness of the proposed controller.