道路曲折 前景光明——河北省供销合作社简史

河北省供销合作社是从早期农村的信用、生产、消费、运销等专业性或综合性的合作社,至建国前夕的供销社演变而来的。它经历了曲折的道路,至今成为按照自愿、互利、平等、民主、服务的原则,由农民群众共同集资建立起来的集体所有的合作商业。实践证明,建立供销合作社不仅有利于加强党对农民的领导,有利于从经济上巩固工农联盟,而且有利于搞活商品流通,发展商品生产,促进和引导广大农民走集体化,现代化的社会主义道路。

北约东扩之路曲折漫长

当今世界格局处于过渡时期,任何一个军事大国或军事集团都没有力量争夺全球主导权。但是对地区安全主导权,特别是欧洲安全主导权的争夺战却愈演愈烈。在这场争夺中,以美国为首的北约提出了东扩的战略计划。美国究竟能不能继续充当欧洲支柱?北约为何迟迟未东扩?北约一旦东扩将产生什么样的结果?应该说,北约东扩之路曲折漫长,存在许多制约的因素。

浅议社会主义的历史必然性和道路曲折性

由于帝国主义和国际反动势力“和平演变”策略在东欧和苏联相继得手,有人对此感到困惑,甚至怀疑社会主义代替资本主义的历史趋势。在这种情况下,进一步认识社会主义代替资本主义的必然性和曲折性,对我们坚定共产主义信念,具有重要意义。 社会主义必然代替资本主义是生产关系一定要适合生产力状况的规律在资本主义社会发生作用的最终结果,是资本主义矛盾运动的必然产物。历史上任何一种生产关系的产生和灭亡都是社会生产力发展的必然结果。资本主义之所以取代封建主义,是因为封建主义束缚了生产力的发展,而资本主义生产关系使生产力以封建社会前所未有的规模和速度向前发展。

路曲心直

在一座寺中有一个小和尚，他从小就在这里出家了。是寺中的众僧把他拉扯大的。当然，他为此也付出了很大的代价。每天清晨，他要去担水。洒扫，做过早课后要去寺后的市镇上购买寺中一天所需的日常用品。回来后，还要干一些杂活．晚上还要读经到深夜。就这样，晨钟暮鼓中，十年过去了。

路曲（外一首）

我时常路过年轻时熟悉的地方在那里我遭遇过爱情星空俯压大地，或黎明大星明亮如神。

路曲心直

在一座寺中有一个小和尚，每天清晨，他要去担水、扫地，做过早课后要去寺后的市镇上购买寺中一天所需的日常用品。回来后，还要干一些杂活，晚上还要读经到深夜。

《诗》“周行”“周道”辨

《语言教学与研究》1989年1期,发表了张清常先生的《上古汉语的SOV语序及定语后置》一文,列举了相当数量的不同类型的汉语中的SOV（主语+宾语+动词）语序（包括OV语序）和modified—modifier（中心语+修饰语）语序的例子,来进一步印证汉、藏语言间的亲缘关系。这为我们进一步认识汉藏语系,了解、研究汉语早期的语序形态提供了丰富的资料,颇具启发性。但赞赏之余,稍感遗憾的是,有些例子略欠斟酌,选释得不够妥当。本文就是想对其中“周行”、“周道”的解释谈点不同看法,并对古注做些分析。我想这绝不影响张先生整个文章的说服力和观点的。

变向思维在解题中的应用

解数学题的思路是多种多样的,有常规的思维方法,也有特殊的做题技巧,但方法却有繁有简。而我们常常遇到一些题,如果按照常规思维,则道路曲折,若转换某一角度来思考,则茅塞顿开,柳暗花明。 (一)更换命题 利用等价命题来转换解题途径。两个命题互为逆否命题,则它们就是等价命题,等价命题是同真同假命题,利用等价命题这一特征。

《利国利民,谱新篇》

人民保险五十年, 道路曲折创业艰; 国内业务一度停,

An Accurate 1.08GHz CMOS LC Voltage-Controlled Oscillator

An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.

Kinetics modeling for austenite transformation in AISI 1045 steel during rapid heating under high frequency electromagnetic field

To investigate the effect of alternating magnetic field on austenite transformation process in the case of rapid heating,the austenite kinetics model of AISI 1045 steel was built for spot continual induction hardening(SCIH)process.The results shows that the effect of alternating magnetic field on austenite transformation fraction reaches the maximum(about 3%)when heating rate is the lowest.Relatively low magnetic flux density still has a certain effect on the austenite transformation process during the SCIH process.Concave surface structure can reduce the influence scope of alternating magnetic field on surface in all cases and the minimum influence scope appears when the feed path of inductor is longitudinal.Convex surface structure can minimize the influence scope of alternating magnetic field in depth when the feed path of inductor is longitudinal.The austenite distribution of transitional region on surface for horizontal movement is more uniform than that for longitudinal movement.The austenite distribution of transitional region in depth for longitudinal movement is more uniform than that for horizontal movement.The simulated results are consistent with the experimental results and the austenite transformation kinetics model developed for SCIH process is valid.

A NURBS Fitting Optimization Method for High⁃Speed Five⁃Axis NC Machining Path Based on Curvature Smoothing Preset Point Constraint

Existing curve fitting algorithms of NC machining path mainly focus on the control of fitting error,but ignore the problem that the original discrete cutter position points are not enough in the high curvature area of the tool path.It may cause a sudden change in the drive force of the feed axis,resulting in a large fluctuation in the feed speed.This paper proposes a new non-uniform rational B-spline(NURBS)curve fitting optimization method based on curvature smoothing preset point constraints.First,the short line segments generated by the CAM software are optimally divided into different segment regions,and then the curvature of the short line segments in each region is adjusted to make it smoother.Secondly,a set of characteristic points reflecting the change of the curvature of the fitted curve is constructed as the control apex of the fitted curve,and the curve is fitted using the NURBS curve fitting optimization method based on the curvature smoothing preset point constraint.Finally,the curve fitting error and curve volatility are analyzed with an example,which verifies that the method can significantly improve the curvature smoothness of the high-curvature tool path,reduce the fitting error,and improve the feed speed.

Posterior Selective Thoracic Fusion in Adolescent Idiopathic Scoliosis Patients:a Comparison of All Pedicle Screws versus Hybrid Instrumentation

Objective To analyze the influence of segmental pedicle screws versus hybrid instrumentation on the correction results in adolescent idiopathic scoliosis patients undergoing posterior selective thoracic fusion. Methods By reviewing the medical records and roentgenograms of adolescent idiopathic scoliosis patients who underwent selective thoracic fusion from February 2000 to January 2007 in our hospital, the patients were divided into 2 groups according to different instrumentation fashions： Group A was hook-screw-rod （hybrid） internal fixation type, Group B was screw-rod （all pedicle screws） internal fixation type, and the screws were used in every segment on the concave side of the thoracic curve. The parameters of the scoliosis were measured and the correction results were analyzed. Results Totally, 48 patients （7 males, 41 females） were included, with an average age of 14.4 years old and a mean follow-up time of 12.3 months. Thirty and 18 patients were assigned to group A and group B, respectively. The mean preoperative coronal Cobb angles of the thoracic curve were 48.8° and 47.4°, respectively. After surgery, they were corrected to 13.7° and 6.8°, respectively. At final follow-up, they were 17.0° and 9.5°, with an average correction rate of 64.6% and 79.0%, respectively, and the correction rate of group B was significantly higher than that of group A （P=0.003）. The mean preoperative coronal Cobb angles of the lumbar curve were 32.6° and 35.2°, respectively. After surgery, they were corrected to 8.6° and 8.3°, respectively. At final follow-up, they were 10.3° and 11.1°, with an average correction rate of 66.8% and 69.9%, respectively, and the correction rate of group B was significantly higher than that of group A （P=0.003）. The correction loss of the thoracic curve and lumbar curve in the 2 groups were 3.1° and 1.8°, 2.4° and 2.4°, respectively. No significant difference was noted （both P〉0.05）. The decompensation rate at final follow-up in these 2 groups were 4% （1/25） and 7.1% （1/14） respectively, with no significant difference （P〉0.05）.

MPC-based path tracking with PID speed control for high-speed autonomous vehicles considering time-optimal travel

In order to track the desired path as fast as possible,a novel autonomous vehicle path tracking based on model predictive control(MPC)and PID speed control was proposed for high-speed automated vehicles considering the constraints of vehicle physical limits,in which a forward-backward integration scheme was introduced to generate a time-optimal speed profile subject to the tire-road friction limit.Moreover,this scheme was further extended along one moving prediction window.In the MPC controller,the prediction model was an 8-degree-of-freedom(DOF)vehicle model,while the plant was a 14-DOF vehicle model.For lateral control,a sequence of optimal wheel steering angles was generated from the MPC controller;for longitudinal control,the total wheel torque was generated from the PID speed controller embedded in the MPC framework.The proposed controller was implemented in MATLAB considering arbitrary curves of continuously varying curvature as the reference trajectory.The simulation test results show that the tracking errors are small for vehicle lateral and longitudinal positions and the tracking performances for trajectory and speed are good using the proposed controller.Additionally,the case of extended implementation in one moving prediction window requires shorter travel time than the case implemented along the entire path.

Field measurement of strain response for typical asphalt pavement

In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing technology.The changing characteristics of the strain field along the horizontal and depth directions of pavements were analyzed.The results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base layer.In addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,respectively.The most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer modulus.The power function relationships between structural layer strain and vehicle speed were revealed.The semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.

Applications of Power Rail Track Program to Tracings of Brazilian Railways

In Brazil, the use of software and applications in railway geometric designs is rare. Currently, after the division and privatization of the national rail network, the concessionaires who assumed the administration, are investing in modernization, recovery and extension of this transport model to make it more efficient. The PIL （Program of Investment in Logistics） has generated growth of the sector in response to the amount of investments, greatly enhancing the load capacity and optimizing the geometric design, which would allow speed of 80 km/h. Based on this information, the objective of this research is to verify the software applications of Power Rail Track Program of Bentley Systems, Inc. for geometric designs in future deployments of railways in Brazil. This software is based on numerical calculations, including roller adjustment by the least squares method to calculate and choose the best alignments, and regression tools, to a fast and effectively optimization of various parameters of the geometry for a future or existing railway. Different variables that allow you to optimize the geometric design are analyzed, considering several optional alignments and complex restrictions present in geometric design, taking into account variables such as circular curves, transition, tangents and rays. The software regression tools include curvature diagrams identifying points and curves, tangent and spirals. The analysis results are presented quickly and points can be added or deleted from the regression analysis, providing improved tracing. The software also allows to detail the elements of the executive project of the railway line such as rails, joints, turning points, waypoints and others. The result of this study has shown that the application of the Power Rail Track Program generates significant cost savings in time and increases in productivity, providing greater opportunity to optimize the geometry and reducing geometric design costs.

Symmetric alteration of four knots of B-spline and NURBS surfaces

Modifying the knots of a B-spline curve, the shape of the curve will be changed. In this paper, we present the effect of the symmetric alteration of four knots of the B-spline and the NURBS surfaces, i.e., symmetrical alteration of the knots of surface, the extended paths of points of the surface will converge to a point which should be expressed with several control points. This theory can be used in the constrained shape modification of B-spline and NURBS surfaces.

Optimization of press bend forming path of aircraft integral panel

In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.