另一个版本的招工状况

"与沿海那些为招工问题而彻夜难眠的企业老板相比,我们巴适多了。"成都刺玫瑰鞋业有限公司的邓老板接受记窨采访的时候,他正和几个朋友在外面喝茶。在成都府南河边一边晒着暖洋洋的太阳,一边品尝着上等的好茶,有闲暇再搓几盘麻将,这是成都人最享受的一种生活方式。而这位鞋厂的老板眼下也正品味着这样的幸福生活——"你说工荒啊,我们这边可没有哦,招工情况很顺利啊,人相当地好招。"邓老板很悠闲地说,"你问我为啥这么好招人,川内人本来就多嘛,而且这几年好多人从广东,福建那边打工回来就懒得再回去了,四川的制鞋产业也发展起来了,在家门口工作多好嘛。"他用很纯正的四川话回答着记者的提问。

齿墩状内消能工的消能及压力特性

输水管道或泄洪洞常见的内消能方式为孔板和洞塞,结合明渠水流中的消能工形式提出了齿墩状内消能工,并通过物理模型试验对不同面积收缩比的齿墩状内消能工进行了研究,分析了它们的过流能力、消能率、压强沿程变化及脉动压强特性.结果表明:齿墩状内消能工的过流能力主要是由消能工的体型及尺寸决定的,其面积收缩比越大,消能率越低,过流能力就越强;齿墩状内消能工的时均压强在收缩段骤降,在其后部逐渐上升,而后恢复至稳定,其恢复长度基本相同;齿墩状内消能工的脉动压强最大点均出现在收缩段后1倍圆管直径范围内,随后迅速减小,逐渐趋于平稳;面积收缩比为0.471 2的齿墩状消能工的脉动强度最小,因而其抗空化性能优于其他情况,且脉动压强最大点的压强概率密度分布接近正态分布.

齿墩数目对齿墩状内消能工消能效果的影响

为改善传统消能方式、底流消能方式、挑流消能方式带来的不利影响,选取面积收缩比相同(ε=0.5)而齿墩数目不同的4种试验方案,通过物理模型试验,分析了各方案下齿墩状内消能工的消能率、脉动压强和空化特性。结果表明,4种试验方案的消能率大致随齿墩数目的增加而降低,方案A的消能效果最佳;脉动压强系数沿程分布规律基本相同,脉动压强在齿墩段变化剧烈,脉动压强最大点均出现在齿墩段后约1.5 D(D为圆管直径)处,随后又迅速减小,并在距齿墩段4 D后逐渐恢复平稳状态;在试验研究范围内,当n>3时脉动压强随齿墩数目的增加而增大,n=4时脉动压强最小,其抗空化性能最好;脉动压强概率密度分布基本近于正态分布。研究结果可为内消能工的工程应用提供依据。

汽车制造中防锈技术的现状与展望

论述了汽车制造中引起锈蚀的原因以及防锈技术的特点。

乙状结肠镜检查前改进灌肠方法的对照观察

目的对传统的灌肠方法进行改进,以提高灌肠效果。方法将400例拟行乙状结肠镜检查的门诊患者随机分为两组各200例。对照组采用常规大量不保留灌肠法,观察组在灌肠过程中按特定角度插入肛管,增加肛管插入深度,降低液体压力,减慢灌入速度。结果两组灌入液体量、保留时间、适舒程度、肠道清洁程度等指标比较差异均有显著性(P<0.01)。结论在灌肠术肛管插入过程中按特定角度插入、增加插入深度和降低灌入液体压力,减慢灌入速度,可以有效地减少患者不适,明显提高清洁肠道效果。

EBJ—160型掘进机截割头焊接工艺探讨

煤矿在使用掘进机时经常要进行截割头修复工作,在煤矿现有条件下,怎样既能迅速修复,不耽误生产,又能保证达到原设计的性能和质量,是一个急需解决的问题。本文阐述了EBJ—160型掘进机机割头焊接工艺流程,介绍了一种简易工装,对用户有一定的指导意义。

随机激励下列车自动门的工作响应振型检测

采用了工作响应分析技术和PSV-400-B型激光扫描测振仪,获得列车自动门的工作响应参数,包括频率和振型。在GB/T 21563-2008模拟长寿命随机振动环境下实施工作响应参数试验,给出了实验方案和系统框图,证明了激光扫描测振仪的准确性。对于某型列车自动门,采用三种扫描测点布置方式:①包括玻璃窗的门扇,②不包括玻璃窗的门扇,③仅对玻璃窗。获得了三种扫描对象的1次工作响应参数,包括工作响应频率及其振型。

APPLICATION OF ACOUSTIC EMISSION SENSOR IN DETECTING TOOL BREAKAGE IN MICRO-MILLING

Acoustic emission （AE） sensors are used to monitor tool conditions in micro-milling operations. Together with the microphone, the AE sensor can detect the tool breakage more accurately and more effectively by applying the wavelet analysis. The processed tool breakage technique by AE sensor is used to perform the wavelet analysis on the experimental data. Results indicate the feasibility of using the AE signals for monitoring the tool condition in micro-milling.

Working Condition Real-Time Monitoring Model of Lithium Ion Batteries Based on Distributed Parameter System and Single Particle Model

Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations （ODE） during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model （SPM） is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.

Study on tracheid variation of Picea koraiensis (nakai) in natural stand and plantation

Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed that the tracheid length, diameter, and thickness of tracheid wall were significant differences between the growth rings. All those characteristics tend to increase from heart-center to bark. In natural stand, it has positive correlation between the characteristics. In plantation, the tracheid length has positive correlation with the trachied diameter, while both the trachied length and the trachied diameter has negative correlation with the thickness of trachied wall. The tracheid length and diameter have no significant difference in growth between natural stand and plantations. The thickness of tracheid wall from the plantation is a little thicker than that from the natural stand before 15 years.

Current Situation and Countermeasures of Breeding for Processing Pepper in China

Research progress on the heterosis, cytoplasmic male sterility and biotechnology breeding of processing pepper （Capsicum annuum L.） was introduced, and the problems of limited germplasm resources and varieties of processing pep- per, large gap with the foreign companies were pointed out. Some suggestions were proposed on strengthening innovation and collection of germplasm resources, breed- ing processing pepper varieties, enhancing breeding level of processing pepper and its market competitiveness.

Deformation behaviors and processing maps of CNTs/Al alloy composite fabricated by flake powder metallurgy

Deformation behaviors of CNTs/Al alloy composite fabricated by the method of flake powder metallurgy were investigated by hot compression tests, which were performed in the temperature range of 300?550 °C and strain rate range of 0.001? 10 s?1 with Gleeble?3500 thermal simulator system. Processing maps of the CNTs/Al alloy at different strains were calculated to study the optimum processing domain. Microstructures before and after hot compressions were characterized by electron backscattered diffraction (EBSD) method. Stress?strain curves indicate that the flow stress increases with the increase of strain rate and the decrease of temperature. The processing maps of the CNTs/Al alloy at different strains show that the optimum processing domain is 500?550 °C, 10 s?1 for hot working. EBSD analysis demonstrates that fully dynamic recrystallization occurs in the optimum processing domain (high strainrate 10 s?1), whereas the main soften mechanism is dynamic recovery at low strain rate (0.001 s?1).

Using particle swarm optimization algorithm in an artificial neural network to forecast the strength of paste filling material

In order to forecast the strength of filling material exactly, the main factors affecting the strength of filling material are analyzed. The model of predicting the strength of filling material was established by applying the theory of artificial neural net- works. Based on cases related to our test data of filling material, the predicted results of the model and measured values are com- pared and analyzed. The results show that the model is feasible and scientifically justified to predict the strength of filling material, which provides a new method for forecasting the strength of filling material for paste filling in coal mines.

Effects of mask wall angle on matrix-hole shape changes during electrochemical machining by mask

The influences of the mask wall angle on the current density distribution,shape of the evolving cavity and machining accuracy were investigated in electrochemical machining(ECM) by mask.A mathematical model was developed to predict the shape evolution during the ECM by mask.The current density distribution is sensitive to mask wall angle.The evolution of cavity is determined by the current density distribution of evolving workpiece surface.The maximum depth is away from the center of holes machined,which leads to the island appearing at the center of cavity for mask wall angles greater than or equal to 90°(β≥90°).The experimental system was established and the simulation results were experimentally verified.The results indicate that the simulation results of cavity shape are consistent with the actual ones.The experiments also show that the repetition accuracy of matrix-hole for β≥90° is higher than that for β<90°.A hole taper is diminished,and the machining accuracy is improved with the mask wall angle increasing.

Filiform corrosion behaviour on machined AA7150 aluminium alloy

The microstructure and the filiform corrosion behaviour of machined AA7150 aluminium alloy were investigated using scanning and transmission electron microscopies combined with potentiodynamic polarization and filiform corrosion testing,respectively.It is found that the grain refinement,redistribution of alloying elements,and elements segregation at grain boundaries are evident within the near-surface region on the machined AA7150 aluminium alloy.The corrosion susceptibility of machining introduced near-surface deformed layer is significantly improved caused by the modified microstructure associated with severe deformation.Filiform corrosion resistance on the machined surface is obviously decreased,due to the surface roughness associated with machining tracks and the presence of the electrochemically more active near-surface deformed layer introduced by machining.

Determination of minimum cover depth for shallow tunnel subjected to water pressure

Prediction of the state of roof collapse is a big challenge in tunnel engineering, while the limit analysis theory makes it possible to derive the analytical solutions of the collapse mechanisms. In this work, an exact solution of collapsing shape in shallow underwater tunnel is obtained by using the variation principle and the upper bound theorem based on nonlinear failure criterion. Numerical results under the effect of river water and supporting pressure are derived and discussed. The maximum water depth above the river bottom surface is determined under a given buried depth of shallow cavities and the critical depth of roof collapse is obtained under a constant river depth. In comparison with the previous results, the present solution shows a good agreement with the practical results.

Anoxic Biological Phosphorus Uptake in A^2O Process

A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen (92.3%, 95.5%, 96% and 79.5%, respectively) could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.

Analysis and Comparison of the Alpha Functions of SRK Equation of State

Alpha functions of Soave-Redlich-Kwong （SRK） equation of state proposed by Soave, Twu, and Luo were different in mathematic tendency. They were compared in modeling methane-alkanes equilibria with van der Waals mixing rule and Modified Huron-Vidal （MHV1） mixing rule, respectively. Results showed that Luo＇s alpha function was a little more accurate than Soave＇s, and Twu＇s alpha function lacked accuracy in modeling methane-alkanes equilibrium. SRK equation of state was expanded as virial form, and then the equivalent terms were contrasted with terms of virial equation of state. Results showed that Soave＇s and Luo＇s alpha functions matched the tendency of virial coefficient better than Twu＇s, and Luo＇s alpha function matched better than Soave＇s in wide temperature range, which sustained the conclusions of phase equilibria calculation. Luo＇s alpha function keeps decreasing when Tr〉 1 and becomes negative at sufficient high temperature, thus the conventional cubic equation of state expressed pressure as the sum of repulsion pressure PR （〉0）, and attraction pressure PA （〈0） could be improved to be the sum of hard-sphere repulsion pressure PH （〉0） and intermolecular force pressure P1 （P1〈0 at low temperature and p1〉0 at sufficient high temperature）.

Gas-Liquid Microreaction Technology： Recent Developments and Future Challenges

Gas-liquid microreaction technology has shown great potential in a variety of industrial relevant mass transfer operations and reactions. This paper outlines the current research status of this technology with emphasis on reactor design, hydrodynamics and mass transfer phenomena as well as reaction applications. The future challenges of this important technology are also summarized.