ROBCAD仿真软件在机器人滚边压合技术中的应用

本文将机器人仿真软件ROBCAD软件强大的功能与机器人滚边压合先进的技术的工艺特点相结合，阐述了在汽车车身工艺中的具体实际应用，达到了完美的效果，指出了机器人滚边压合技术的应用前景。

光纤阵列埋入式PCB的压合技术研究

光纤阵列可实现多通道的光信号传输,在埋入PCB的制程中,难点在于压合。光纤阵列的结构决定了需要设计对应的层压结构和压合参数,以确保光线阵列埋入后的完整性和可靠性。文章以特殊的层压结构设计、开槽设计和加工流程参数设置,实现光纤阵列在PCB的完整埋入,并确保产品具有较好的热可靠性。

潘庄煤层气井分压合采技术及其应用分析

为了查明潘庄煤层气分压合采井的主控因素和适用条件,选用了潘庄区块生产达五年以上的分压合采井为研究对象,通过对储层地质特征、水力压裂施工参数和排采数据的整理分析,探讨了分压合采井成功实施的地质和工程因素。研究结果表明,煤层气合采井成功的关键是压裂裂缝在煤层中充分扩展,控制裂缝的缝高,避免煤层与顶底板含水层在近井地带发生水力联系;各煤层的原始储层压力、临界解吸压力相匹配时或相差不大时,通过坚持"连续、缓慢、稳定"的排采方针,合层排采会取得成功。

高层板关键制作技术研究

高多层板一直是行业的典型线路板之一，也是其他类型线路板的制作基础。高多层板制作技术的典型性和多样性，总能够给行业带来挑战。本次介绍一款20层板的压合、电镀、阻焊三大工序的制作方法，通过对基础问题的探讨，进一步夯实基础线路板的制作方法。

Research on the imaging of concrete defect based on the pulse compression technique

When the synthetic aperture focusing technology （SAFT） is used for the detection of the concrete, the signal-to-noise ratio （SNR） and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation （LFM） signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete.

Compression anastomosis clip for gastrointestinal anastomosis

AIM: To investigate the feasibility of compression anastomosis clip (CAC) for gastrointestinal anastomosis proximal to the ileocecal junction. METHODS: Sixty-six patients undergoing gastrointe-stinal anastomosis proximal to the ileocecal junction were randomized into two groups according to the anastomotic method, CAC or stapler. RESULTS: The postoperative recovery of patients in CAC and stapled anastomosis groups was similar. No postoperative complication related to the anastomotic method was found in either group. Both upper gastrointestinal contrast radiography at the early postoperative course and endoscopic examination after a 6-mo follow-up showed a better healing at the compression anastomosis. CONCLUSION: CAC can be used not only in colonic surgery but also in gastrointestinal anastomosis. Our result strongly suggests that CAC anastomosis is safe in various complication circumstances. However, it should be further conf irmed with a larger patient sample.

Evaluation of microstructure and mechanical properties of Mg-xCe-0.5Zn alloys by nano-indentation

The microstructure and mechanical properties of Mg-xCe-0.5Zn （x=0.5, 1.5, 2.5, molar fraction, %） alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. In addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.

Microstructure and mechanical properties of die-cast AZ91D magnesium alloy by Pr additions

Mg-9Al-xPr(x=0.4,0.8 and 1.2,mass fraction,%)magnesium alloys were prepared by high-pressure die-casting technique.The effects of Pr on the microstructures of die-cast Mg-9Al based alloy were investigated by XRD and SEM.Needle-like Al11Pr3 phase and polygon Al6Mn6Pr phase are found in the microstructure.With 0.4%Pr addition,fine needle-like Al11Pr3 phase and a small amount of polygon Al6Mn6Pr phase near the grain boundary are found in the microstructure.Increasing Pr addition to 0.8%, lots of coarse needle-like Al11Pr3 phase within grain and polygon Al6Mn6Pr phase on grain boundary are observed.Further increasing Pr addition,the size of needle-like Al11Pr3 phase decreases,while the size of polygon Al6Mn6Pr relatively increases.The mass fraction of Pr at around 0.8%is considered to be suitable to obtain the optimal mechanical properties.The optimal mechanical properties are mainly resulted from grain boundary strengthening obtained by precipitates and solid solution.

QFD-Taguchi based hybrid approach in die casting process optimization

The present research work emphasized on identifying and optimizing various significant process parameters of high pressure die casting by using QFD-Taguchi based hybrid approach in order to yield the optimum casting density of the A380alloy.Identification of critical process parameters,selection of appropriate orthogonal array,analysis of means and analysis of variance are employed to study the performance characteristic of the die casting process.The most critical process parameters identified and optimized by QFD-Taguchi based hybrid approach,such as the injection pressure,the molten metal temperature,the plunger velocity(first and second stage)and the die temperature were explored in the experimental work.The results show that injection pressure is the most significant factor among the selected parameters.The contribution of the injection pressure to the variation of mean casting density is around61.483%.Confidence interval(CI)has also been estimated as0.000718for95%consistency level to validate the predicted range of optimum casting density of aforesaid alloy.

Enhancing mechanical properties and corrosion performance of AA6063 aluminum alloys through constrained groove pressing technique

The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.

Effect of thermal-cooling cycle treatment on thermal expansion behavior of particulate reinforced aluminum matrix composites

Two micron SiC particles with angular and spherical shape and the sub-micron Al2O3 particles with spherical shape were introduced to reinforce 6061 aluminium by squeeze casting technology. Microstructures and effect of thermal-cooling cycle treatment （TCCT） on the thermal expansion behaviors of three composites were investigated. The results show that the composites are free of porosity and SiC/Al2O3 particles are distributed uniformly. Inflections at about 300℃ are observed in coefficient of thermal expansion （CTE） versus temperature curves of two SiCp/Al composites, and this characteristic is not affected by TCCT. The TCCT has significant effect on thermal expansion behavior of SiCp/Al composites and CTE of them after 3 cycles is lower than that of 1 or 5 cycles. However, no inflection is observed in Al2O3p/Al composite, while TCCT has effect on CTE of Al2O3p/Al composite. These results should be due to different relaxation behavior of internal stress in three composites.

Casting-cold extrusion of Al/Cu clad composite by copper tubes with different sketch sections

Casting-cold extrusion technology was presented to fabricate alttminum/copper clad composite, and copper tubes with different sketch sections were designed. The technology of aluminum/copper clad composite fabricated by casting-cold extrusion was simulated by DEFORM software using tubes with four arc grooves. The stress and strain in different deformation zones were analyzed. The groove size reduces gradually and the groove shape drives to triangle during the extrusion procedure. The maximum values of equivalent effective stress and radial stress appear in groove zones, and the maximum equivalent effective strain firstly is obtained also in groove zones. The grain size in groove zones is less than that in other zones. The experimental results are consistent with simulation results, which prove that the copper tubes with sketch section are favorable to the metallurgy bond of boundary interface between aluminum and copper.

Pressure-relief and permeability-increase technology of high liquid–solid coupling blast and its application

As for the coal seam with high stress,high gas and low permeability,a single technology cannot prevent the complex dynamic disasters.Because of this,the study proposes a new method of pressure-relief and permeability-increase technology of the high liquid–solid coupling blast.Through coal seam injection and charging structure change,the paper fully works out the dual functions of the water and explosion.Using the theoretical calculation,numerical simulation and physical experiments,we obtained that the initial blasting stress,displacement and overpressure of the liquid–solid coupling blast are much better than that of ordinary blasting.The technology has been used in the relative coal mine,and the application results show that the technique has effectively prevented the coal and gas outburst,which has a wide range of application.

The Hydraulic Control Using LabVIEW for a Synthetic Rubber Spring Testing Machine

The application is a control movement of two hydraulic cylinder for a synchronize movement. The main purpose of this paper is to show a short programming code in LabVIEW to control the movement of two cylinders with an automatic control program using only analog inputs from the sensor of pressure and linear displacement sensor and the digital output from the hydraulic valves. This is designed for one of the test of this synthetic rubber spring testing machine.

Numerical modeling of time-dependent closure of coal seam artificial fractures

In order to improve efficiency of coal seam gas drainage, many fracturing techniques, such as waterjet fracturing, hydraulic fracturing and explosive fracturing, etc, have been developed and widely used in China coal mining industry. How- ever, during the engineering applications, it is observed that the efficiency of gas drainage initially improves, but reduces there- after. Thus, it is speculated that the contrasts in coalbed methane drainage efficiency may reflect variation of the closure be- havior of the artificial fracture created. Based on comprehensive gas drainage monitoring data in underground coal mines, the work presented herein uses numerical simulation to show the behavior of the time-dependent closure of coal seam fractures as- sociated with various levels of waterjet fracturing parameters and geomechanical conditions.

Hybrid H_2/H_∞ force/position control based on neural networks

A neural network control scheme with mixed H2/H∞performance was proposed for robot force/position control under parameter uncertainties and external disturbances. The mixed H2/H∞tracking performance ensures both robust stability under a prescribed attenuation level for external disturbance and H2optimal tracking. The neural network was introduced to adaptively estimate nonlinear uncertainties, improving the system’s performance under parameter uncertainties as well as obtaining the H2/H∞tracking performance. The simulation shows that the control method performs better even when the system is under large modeling uncertainties and external disturbances.

Components Qualification for the Safe Operation of Nuclear Power Plants

AREVA operates a world-wide unique thermal hydraulic platform to ensure high safety standards in the nuclear industries. This platform is operated as an accredited test and inspection body according to ISO 17025 and 17020 to grant a high and independently confmned quality standard. The accreditation also ensures the independency of the organization and confidentiality to the individual stakeholders, for example research centers, utilities, components suppliers, engineering companies and vendors. Especially for nuclear power plants, it is very relevant to consider that reliability depends on the integrity of its components during its life time-from design through construction, operation and maintenance. For example, a typical NPP （nuclear power plant） has 1,000 to 2,000 large valves and 7,500 to 12,500 small valves, of which about 200 to 400 are designated Safety Class 1. The qualification of these Safety Class 1 components is relevant for reactor new builds but also for installed plants. This paper explains newly established qualification tasks, the corresponding testing infrastructure, and the state of the art of testing technology. By way of example, the paper describes the program and possible sequence of qualifying NPP safety-related components.

Hybrid decompression technique and two-level corpectomy are effective treatments for three-level cervical spondylotic myelopathy

The optimal surgical strategy for multilevel cervical spondylotic myelopathy （CSM） has not been defined, and few comparative researches between hybrid decompression and multilevel corpectorny have been conducted. Here, we reported 28 patients of three-level CSM, of whom 12 underwent hybrid decompression and 16 two-level corpectomy, with each type of procedure chosen according to radiologic characteristics of those patients. Clinical and radiologic parameters of both groups showed various degrees of improvement. However, no statistically significant differences in Japanese Orthopedic Association （JOA） score improvement rate, graft fusion rate, post-operative neck disability index （NDI） or segmental lordosis between the two groups were found. We conclude that both hybrid decompression and two-level corpectomy could obtain satisfying clinical efficacy in the management of three-level CSM for appropriate patients.

Liquid metal-integrated ultra-elastic conductive microfibers from microfluidics for wearable electronics

Liquid metal(LM) has shown potential values in different areas. Attempts to implement LM are tending to develop new functions and make it versatile to improve its performance for practical applications.Here, we present an unprecedented LM-integrated ultra-elastic microfiber with distinctive features for wearable electronics. The microfiber with a polyurethane shell and an LM core was continuously generated by using a sequenced microfluidic spinning and injection method. Due to the precise fluid manipulation of microfluidics, the resultant microfiber could be tailored with tunable morphologies and responsive conductivities. We have demonstrated that the microfiber could act as dynamic force sensor and motion indicator when it was embedded into elastic films. In addition, the values of the LMintegrated ultra-elastic microfiber on energy conversions such as electro-magnetic or electro-thermal conversions have also been realized. These features indicate that LM-integrated microfiber will open up new frontiers in LM-integrated materials and the wearable electronics field.