文人与行——驳梁实秋之“文人有行”

梁实秋先生从普遍人性论的观点出发 ,鼓吹文学应当诉诸普遍的、共同的人性 ,提倡“文人有行” ,其最终目的在于提倡贵族文学。通过生活实例 ,批判了梁先生的这一观点 。

LEAD SCREW LINEAR ULTRASONIC MOTOR USING BENDING VIBRATION MODES

The operating principle of a lead screw linear ultrasonic motor using bending vibration modes is analyzed. The simplified beam bending vibration model is used to analyze the dynamics characteristics of the motor. Motion trajectory equations are derived for driving points of the stator. The motor operation and driving mechanisms are investigated. The vibration modes and the construction of the motor are analyzed by using the finite element method （FEM）. A prototype motor is built and its stator dimension is 13 mm × 13 mm× 30 mm. The motor is experimentally characterized and the maximum output force of 5- 2 N is obtained.

In-situ Micro-CT analysis of deformation behavior in sandwich-structured meta-stable beta Ti−35Nb alloy

Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro-computed tomography(Micro-CT)and finite element method(FEM)analyses.The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures;Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region,while the strain of the porous structure with the reinforcing layer is uniformly distributed;FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration,thereby promoting uniform deformation of the porous structure.The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124%under the condition of limited reduction of porosity,and the yield strength increases from 4.6 to 10.3 MPa.

地理新课改中的“有形无神”现象及其思考

基于地理观摩课、示范课、优质课等新课改课堂观察后发现:有些课堂虽目标齐全,像模像样,但却有意无意地落入"俗套",课堂教学"有形无神"现象甚是普遍,新课堂逐步被模式化、程式化和绑架化,这有悖新课改的初衷。

Influence of pavement frictional properties on braking distance

In order to study the relationship between pavement friction management criteria and braking distance requirements of road geometric design, an approach for determining the braking distance considering pavement frictional properties is proposed. A finite element model （FEM） of a rolling tire under steady state is established based on theoretical hydrodynamics and mechanics principles, in which factors, including tire type, water film thickness, pavement surface properties, and vehicle speed, are considered. With the FEM, braking distances under different operating conditions are calculated. Furthermore, the allowable water film thickness is determined by comparing braking distances calculated with friction management criteria and that required by road geometric design. The results show that the braking distance is affected by the above operating conditions. As a result, it is necessary to maintain consistency between geometric design braking distance requirements and pavement friction management to achieve safe road operations.

Grain statistics effect on deformation behavior in asymmetric rolling of pure copper foil by crystal plasticity finite element model

The grain statistics effect was investigated through asymmetric rolling of pure copper foil by a realistic polycrystalline aggregates model and crystal plasticity element finite model.A polycrystalline aggregate model was generated and a crystal plasticity-based finite element model was developed for each grain and the specimen as a whole.The crystal plasticity model itself is rate dependent and accounts for local dissipative hardening effects and the original orientation of each grain was generated based on the orientation distribution function（ODF）.The deformation behaviors,including inhomogeneous material flow,decrease of contact press and roll force with the increase of grain size for the constant size of specimens,were studied.It is revealed that when the specimens are composed of only a few grains across thickness,the grains with different sizes,shapes and orientations are unevenly distributed in the specimen and each grain plays a significant role in micro-scale plastic deformation and leads to inhomogeneous deformation and the scatter of experimental and simulation results.The slip system activity was examined and the predicted results are consistent with the surface layer model.The slip band is strictly influenced by the misorientation of neighbor grain with consideration of slip system activity.Furthermore,it is found that the decrease of roll force and the most active of slip system in surface grains are caused by the increase of free surface grain effect when the grain size is increased.The results of the physical experiment and simulation provide a basic understanding of micro-scaled plastic deformation behavior in asymmetric foil rolling.

略论楷书中钩画的审美价值

钩是汉字结构中的一个基本笔画,笔画与笔画之间有承接的关系。钩画具有方向暗示性。这种关系与特性,是书体演变过程中保留的笔势,即楷中有行、笔断意连。

Measuring technical efficiency of Chinese nonferrous metals enterprises on a background of industry consolidation

Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis （DEA） method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.

Modeling commuters' route choice behavior under pre-trip information system

Research about the auto commuter＇s pre-trip route choice behavior ignores the combined influence of the real-time information and all respondents＇ historical information in the existing documents.To overcome this shortcoming,an approach to describing the pre-trip route choice behavior with the incorporation of the real-time and historical information is proposed.Two types of real-time information are investigated,which are quantitative information and prescriptive information.By using the bounded rationality theory,the influence of historical information on the real-time information reference process is examined first.Estimation results show that the historical information has a significant influence on the quantitative information reference process,but not on the prescriptive information reference process.Then the route choice behavior is modeled.A comparison is also made among three route choice models,one of which does not incorporate the real-time information reference process,while the others do.Estimation results show that the route choice behavior is better described with the consideration of the reference process of both quantitative and prescriptive information.

青原禅系“曹洞”宗名发微

曹洞宗注重多方面的思想义理之间调和融会,善于兼收并蓄、长于理论整合。它对禅宗、佛教内部其他宗派,甚至于外典其他各种文化都颇有研究,自然涵养出别具一格的思辨气质,这在当时禅界是别开生面地勾连、呼应传统佛教的内在理论线索,是更宏观更宽阔的高层次上佛教与中国传统文化整体所进行的内在自觉整合,从而在文化上和理论上使佛教彻底中国化。曹洞宗名乃合其创立者洞山良价和曹山本寂之名而来,这不但符合佛教宗派命名之传统,更彰显其学理建设之特点。若将曹洞宗更名为洞云宗,由皈依曹山本寂而改宗云居道膺,这不但模糊了曹洞宗的特色,也抹杀了长久以来大批高僧大德捍卫曹洞宗名的历史。因此,曹洞宗名不仅是一个称谓,它还是一段历史,更是一种品质,不仅关乎着禅宗派别特征的确定,也与我国佛教健康发展有重大关系,其名称最好坚持沿袭传统。

那张心形的红纸片

2014年三月份的一天,我正在办公室批改《基础训练》,当我拿起一本翻开时,忽然,一个巴掌大的纸片从我的眼前划过飘落到地上。我弯腰捡起发现是一张被裁剪得很不规则的猛然看去又如心形的红纸片。我正想随手扔掉,却发现上面有行歪歪斜斜的字：田老师节日快乐。我连忙翻看练习册的封面——吴××。顿时,我激动地端详着这行字,看着看着,那熟悉的脸庞,那桩桩件件的往事又浮现在我的眼前。2013年9月,我来到距县城约四十公里的刘村学校支教,

Analysis of deformation characteristic in multi-way loading forming process of aluminum alloy cross valve based on finite element model

The deformation characteristic in the forming process of aluminum alloy 7075 cross valve under multi-way loading was investigated by numerical simulation method. The results indicate that there exist 4 deformation patterns in the multi-way loading forming process of cross valve, such as forward extrusion, backward extrusion, forward-lateral extrusion and backward-lateral extrusion; one or several patterns occur at different forming stages depending on loading path. In general, the main deformation pattern is forward extrusion or backward extrusion at the initial stage; the main deformation pattern is backward extrusion at the intermediate stage, and the backward extrusion and forward-lateral extrusion occur at the final stage. In order to improve the cavity fill and reduce the forming defects, the lateral extrusion deformation should be increased at the initial and intermediate stages, and the forward extrusion deformation at the final forging stage should be reduced or avoided.

Mechanical behavior of segment rebar of shield tunnel in construction stage

In this paper, a 3D finite element （FE） program ADINA was applied to analyzing a tunnel with 9 segment tings. The loads acting on these segment tings included the squeezing action of tail brush of shield machine under attitude deflection, the jacking forces, the grouting pressure and the soil pressure. The analyses focused on the rebar stress in two statuses： （1） normal construction status without shield machine squeezing; （2） squeezing action induced by shield machine under attitude deflection. The analyses indicated that the rebar stress was evidently affected by the construction loads. In different construction status, the rebar stress ranges from -80 MPa to 50 MPa, and the rebar is in elastic status. Even some cracks appear on segments, the stress of segment rebar is still at a low level. It is helpful to incorporate a certain quantity of steel fiber to improve the anti-crack and shock resistance performance.

The isolation of prophyra-334 from marine algae and its UV-absorption behavior

Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae （dried laver）. It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm. The absorption maximum wavelength of prophyra-334 is at 334 nm, so defined the name. The molar extinction coefficient （ε） of prophyra-334 in aqueous solution at 334 nm wavelength is 4.23×10^4. The absorption of prophyra-334 in organic solvents differs in aqueous solutions. In polar organic solvents, the absorption maximum wavelength of prophyra-334 has a slight shift toward longer wavelength compared with that in pure water. On the contrary, in inert non-polar organic solvents, the absorption maximum wavelength and the shape of absorption spectra of prophyra-334 are changed. The effects of organic solvents on prophyra-334 stability suggested that： （1） the absorbance of prophyra-334 in water is generally constant at temperature of 60℃ in 24 h, meaning that prophyra-334 is quite stable in water; （2） the absorbance of prophyra-334 in ethanol and hexane decreases at the same condition. The stability of prophyra-334 in organic solvents is less than that in aqueous solution. In benzene, the prophyra-334 is very instable.

Time-dependent behavior comparison of long-span concrete arch bridge between prototype and model

Beipanjiang Bridge is a long-span concrete arch bridges with stiffened skeleton(CABSS)in China.It has a fixed end arch with the span of 445 m and the rise of 100 m.To evaluate the rationality of the construction sequence and the time-dependent behavior of CABSS,an experimental study of a model bridge was explored.But the measured displacement and stress ratios of arch rib between prototype and model bridge did not subject to linear similarity relation when the time-dependent behavior was considered.So,the three-dimensional finite element models were established,and verified by the measured data.Then,the displacements and stresses of the prototype and model were compared with each other,when the elastic analysis or coupling of temperature and shrinkage,creep effect was considered.Furthermore,a parametric study was studied.The results showed that when the temperature,shrinkage and creep effect of concrete are considered,the finite element analysis results of prototype and model agree well with the measured results.The displacement and stress ratios of prototype and model bridge in construction and bridge completed stage do not present the geometric similarity ratio 7.5 and 1.0,respectively.They are also much influenced by concrete predicting model and variation of temperature.

Reactive Crystallization of Calcium Sulfate Dihydrate from Acidic Wastewater and Lime

The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from plateletlike and nee dlelike shape to rodlike shape when the temperature was increased from 25 to 70 ℃. An increase in the agglom.

Parallel computation of unified finite-difference time-domain for underwater sound scattering

In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain （FDTD） scheme, which is suitable for distributed parallel computing in a message passing interface （MPI） programming environment. The algorithm is implemented on a cluster-based high performance computer system. Parallel computation is performed with different division methods in 2D and 3D situations. Based on analysis of main factors affecting the speedup rate and parallel efficiency, data communication is reduced by selecting a suitable scheme of task division. A desirable scheme is recommended, giving a higher speedup rate and better efficiency. The results indicate that the unified parallel FDTD algorithm provides a solution to the numerical computation of acoustic scattering.

On the Asymptotic Behavior of Certain Second Order Differential Equations

Two criteria for asymptotic behavior of certain second order differential equations are obtained. The results extend and improve Feng's theorem.

Time-Ordered Collaborative Filtering for News Recommendation

Faced with hundreds of thousands of news articles in the news websites,it is difficult for users to find the news articles they are interested in.Therefore,various news recommender systems were built.In the news recommendation,these news articles read by a user is typically in the form of a time sequence.However,traditional news recommendation algorithms rarely consider the time sequence characteristic of user browsing behaviors.Therefore,the performance of traditional news recommendation algorithms is not good enough in predicting the next news article which a user will read.To solve this problem,this paper proposes a time-ordered collaborative filtering recommendation algorithm(TOCF),which takes the time sequence characteristic of user behaviors into account.Besides,a new method to compute the similarity among different users,named time-dependent similarity,is proposed.To demonstrate the efficiency of our solution,extensive experiments are conducted along with detailed performance analysis.

Tasks and Priorities for Comprehensively Deepening Reform of China’s State Sector of Economy

The Third Plenary Session of the 18th CPC Central Committee ushered in a new chapter of China＇s comprehensive deepening of reform. The basic objective of comprehensively deepening reform of the state sector of economy in the new chapter is to fully integrate this sector with a sophisticated market economic system with the market playing the decisive role in resource allocation. In order to achieve this objective, China is confronted with the four major priorities of adjusting the functions and layout of the state sector of economy according to national mandates, expediting the mixed ownership reform, creating a classified and multi- tiered new system for the administration of the sector, and developing a modern corporate system for SOEs to ensure an efficient micro-level governance mechanism for the sector. （1） The functions of the different types of SOEs should be accurately defined and SOEs should be divided into the three types of public policy SOEs, functional SOEs, and commercial SOEs. This classification forms the premises for reforming the state sector of economy. Based on the functions of the three types of SOEs, the directions and emphases for strategic adjustment should differ as well. （2） The mixed ownership reform should adhere to the methodological principles of combining top-down and bottom-up approaches, implementing pilot programs, and promoting coordinated progress. Practical implementation should ensure fair and standard reform procedures, reform programs consistent with laws and regulations, open and fair equity transfers, as well as fair and transparent internal distributions. The mixed ownership reform of SOEs should introduce the employee stock ownership system and adhere to the principles of compatible incentives, shared growth, and long-term development. Monopolistic sectors should be transformed into competitive market structures to create conditions for the implementation of mixed ownership for SOEs. （3） The new system for the administration of the state sector of economy should comprise three hierarchies： the Commission for the Administration of State Economy at the top level, state capital operation companies or state capital investment companies at the intermediate level and general for-profit enterprises at the bottom level, which administer public policy, functional SOEs, and commercial SOEs respectively. （4） Under the new system for the administration of the state sector of economy characterized by the three hierarchies and categories, the key for perfecting the modern corporate system of SOEs is to establish a differentiated, classified governance mechanism, i.e., different corporate governance mechanisms should be created for SOEs of different functions and roles.