贵微重始:董仲舒“元机说”发微——从《春秋繁露·二端》及卢注说起

“端”在董仲舒思想中具有鲜明的基要性意涵,乃至成为其通识天之本体的必要关节。在由“端”及“无端”的理论进路中,本体之元机得以开显,借是进而建构起天、地、人三本的内在相通性。是故,“肃慎三本”实为崇尚精一之元机,以此诱掖人君治国理政当类天地化生而万物皆应之情,即在“本天元”之域为政,从而于无为而为以达至“君化若神”之状。

Effect of wire diameter compression ratio on drawing deformation of micro copper wire

A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire,based on rate-dependent crystal plasticity theory.The impact of wire diameter compression ratio on the micro-mechanical deformation behavior during the wire drawing process was investigated.Results indicate that the internal deformation and slip of the drawn wire are unevenly distributed,forming distinct slip and non-slip zones.Additionally,horizontal strain concentration bands develop within the drawn wire.As the wire diameter compression ratio increases,the strength of the slip systems and the extent of slip zones inside the deformation zone also increase.However,the fluctuating stress state,induced by contact pressure and frictional stress,results in a rough and uneven wire surface and diminishes the stability of the drawing process.

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.

齐口裂腹鱼幼鱼饲料中营养素适宜含量和最适能量蛋白比的研究

以增重率、饲料系数和蛋白质效率为评价指标,用正交试验法L9(34)对齐口裂腹鱼Spchizothoraxprenati摄食的9种配合饲料中蛋白质、脂肪、总能、无机盐需要量及最适能量蛋白比进行了研究。结果表明:各营养素对幼鱼的生长及蛋白质效率的影响大小依次为蛋白质>总能>脂肪>无机盐;适合幼鱼生长所需的蛋白质、脂肪、无机盐的质量分数分别为40.06%、6.02%、4%,总能为13.09 kJ/g,最适能量蛋白比(E/P)为32.68 kJ/g;各营养素中蛋白质为影响幼鱼生长和鱼体成分的主要因素,饲料蛋白质水平对鱼体水分和脂肪含量有显著影响(P<0.05),其它营养素水平变化则对鱼体成分没有显著影响(P>0.05)。

碳纳米材料红外图像遮蔽特性研究

碳纳米材料是一种新型材料，具有尺度小、重量轻、导电及吸波性能好等特点。为了探索碳纳米材料在干扰红外成像制导武器方面的应用，利用大型烟幕箱研究了碳纳米管、纳米碳纤维、纳米石墨几种碳纳米材料对8-12 μm波段红外图像的遮蔽特性。结果表明，碳纳米材料对红外辐射由于吸收和散射双重作用，具有很好的远红外消光作用，质量消光系数最小和最大值分别为0.8884 m^2·g^-1和2.6226 m^2·g^-1。

表面活性剂水热改性氢氧化镁表面性质

氢氧化镁作为无机阻燃剂具有一系列的优点,但存在与聚合物相容性不好、降低材料性能的缺点,表面改性是解决这些问题的主要方法。采用水热技术,用表面活性剂改性氢氧化镁表面性质,以氢氧化镁在液体石蜡中的沉降时间作为其表面改性的参考指标。结果发现,氢氧化镁经改性后可以均匀分散在液体石蜡中,具有良好的疏水亲油性。其中表面活性剂Tween-20和Span-80的最佳用量为5%,硬脂酸钠和油酸钠的最佳用量为8%。不同表面活性剂复配具有协同增效作用,比单一表面活性剂改性更有效地提高了氢氧化镁表面亲油性。

纳米级SiO_2填充PVC/CPE复合材料研究

In this paper the toughening mechanism of PVC/CPE filled with nanoscale SiO 2 and the effects of nanoscale SiO 2 and common SiO 2 contents on properties of PVC/CPE were studied.The experimental results showed PVC/CPE/SiO 2 had excollent notched impact strength and tensile strength when nano SiO 2 content was 6 per cent to 12 per cent.Local SiO 2 had no obvious toughening effect on PVC/CPE,but made the tensile strength and elongation at break of PVC/CPE decreased obviously.

Cellular manufacturing layout on adding/removing machines

In order to rapidly respond to the complex and mutational market, a new facility layout plan based on cellular manufacturing is proposed, which gives consideration to high efficiency and flexibility. The plan designs two phases of integrated cell layout, i.e., cell construction and cell system layout, on the condition of adding/removing machines. First, in view of the costs of logics and machine-relocation, the cell construction based on the alternative processing routes and intra-cell layout are integrated as a whole, which achieves cell formation, process planning and the intra-cell layout in a single step. Secondly, an approach of a continuous optimized multi-line layout for solving the cell system layout problem is proposed, which eliminates the coupling relationship from the machine-relocation and realizes an integrated design of the two phases of the cell layout. An application based on real factory data is optimally solved by the Matlab 7.0 software to validate and verify the models.

In- and Anti-transition of Firing Patterns Induced by Random Long-range Connections in Coupled Hindmarsh-Rose Neurons System

The effects of random long-range connections （shortcuts） on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is found that, on one hand, the system can achieve the transition of neural firing patterns from the fewer-period state to the multi-period one, when the number of the added shortcuts in the neural network is greater than a threshold value, indicating the occurrence of in-transition of neural firing patterns. On the other hand, for a stronger coupling strength, we can also find the similar but reverse results by adding some proper random connections. In addition, the influences of system size and coupling strength on such transition behavior, as well as the internality between the transition degree of firing patterns and its critical characteristics for different external stimulation current, are also discussed.

Investigation of Mechanical Stresses for Cylinder Head of High Power Diesel Engine

Aim To ivestigate the influence on the cylinder head's stress distribution and value caused by its structure's changes.Methods Three types of cylinder heads of high power diesel engines were analysed with finite element method using I-DEAS Master series software.The actual condition of the cylinder head was simulated with different kinds of elements.Tempera- ture method was used to exert the predeformation of the bolts to the finite element model,so the pretightening force was discribed accurately Results Stress distribution regularities of the cylinder head under different working conditions were taken On the basis,the analysing results ofthreeof design schemes were compared and the optimum structure was taken Conclusion Transition condition between the head plate and the standing board ,shape of the head plate and the jobbing sheet,etc will affect the cylinder head's bearing condition

Wavy Distribution of Trace Elements in Phytolacca Samples from Different Areas

To study the distribution of 25 elements, i.e. Be, Cd, Ce, Cr, Cu, Dy, Er,Eu, Gd, Ge, Ho, La, Lu, Mo, Nd, Pb, Pr, Sm, Sr, Tb, Tl, Tm, Y, Yb and Zn in Phytolacca, atraditional Chinese medicinal herb, collected from nine areas of P. R. China. Methods Twenty-fiveelements in Phytolacca including essential elements, toxic elements and rare earth elements intraditional Chinese medicinal herbs from different areas were analyzed by ICP-MS. Results The 25elements in Phytolacca were determined by ICP-MS under optimized conditions. The detection limitswere 0.003 -0.71 ng·mL^(-1). The recoveries were 88% - 118% . The relative standard deviations ofthe measurements were 1.7% - 13.3%. Conclusion The determined concentrations of elements inPhytolacca acinosa Roxb vary from one area to another; however, the distribution tendency ofelements in all the samples is similar. The distribution tendency of rare earth elements inPhytolacca acinosa Roxb is consistent with that in nature.

Inorganic Elements in Kernel of Amygdalus communis L. Measured Using ICP-OES Method

[Objective] The aim was to study on distribution of inorganic elements in kernel of Amygdalus communis L., providing reference for quality evaluation of A. communis L. species. [Method] Totally 26 species of inorganic elements in kernel, including Al, B, Be, Ca, Co, Cu, Fe, Mg, Mn, Mo, Na, Ni, P, Pb, Si, Sn, Sr, Ti, Zn, Cd, As, Se, V, Hg, Cr and K were measured with inductively coupled plasma emission spectrum （ICP-OES） and principal components analysis （PCA）. [Result] A. communis L. of different species and in different factories showed a similar curve in content of inorganic elements; absolute contents of the elements differed significantly. In addition, the accumulated variance contribution of five principle factors achieved as high as 84.371% and the variance contribution made by the first three factors accounted for 67.546%, proving that Fe, Ti, Pb, Na, Se, Cu, Mo, K, Zn, Ni, Ca and Sr were characteristic elements. [Conclusion] The method, which is brief, rapid and accurate, can be used for determination of inorganic elements in kernel of A. communis L., providing theoretical references for further development and utilization of A. communis L.

Modeling of rock failure based on physical cellular automata

To analyze the effects of heterogeneous material characteristics on rock failure,a micro-heterogeneous physical cellular automata （Mh-PCA） model is introduced according to the cellular automata theory from a general power view.In this model,the neighbor is the Moore pattern and the Weibull distribution is adopted to simulate the rock heterogeneousness.Using this model,the evolvements and acoustic emission of rock failure are simulated for four materials of different degree of homogeneousness （m＝1,5,10,15）.The results show that the heterogeneous characteristic has a great effect on the rock failure,the more the homogeneousness,the fewer the crack branches and the more concentrated acoustic emissions.The physical cellular automata theory gives a new idea for studying rock failure.

METHOD FOR ESTIMATING GEOMETIC CHARACTERISTICS OF NUMERICAL CONCEPTUAL AIRCRAFT MODELS BASED ON SURFACE ELEMENTS

To estimate the geometric characteristics, especially wet areas and section areas, of three dimensional numerical conceptual aircraft models, a method based on surface elements is proposed. On the premise that numerous surface elements are generated to represent each component surface, a component wet area of the surface is estimated by adding up the areas of such elements that are not covered by any other component surfaces. The elements are also used to get the section polygons of such composite surfaces as the whole aircraft at a given body station, then a section area is approximated with the sum of trapezoidal areas between such sides of polygons that are not covered by any other component and a reference axis. Practical application to a computer aided aircraft conceptual design system shows that the methed is applicable to different kinds of conceptual aircraft models and its precision is satisfying to the conceptual design.

无机陶瓷膜在水处理中的初步应用

简要介绍了无机陶瓷膜在给水和废水处理中的应用,讨论了无机陶瓷膜在给水和废水处理以及环境保护方面的发展方向.

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.

Electrochemical properties of nanocrystalline and amorphous Mg-Y-Ni alloys applied to Ni-MH battery

The as-cast Mg2Ni-type Mg20–xYxNi10 (x=0, 1, 2, 3 and 4) electrode alloys were prepared by vacuum induction melting. Subsequently, the as-cast alloys were mechanically milled in a planetary-type ball mill. The analyses of scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) reveal that nanocrystalline and amorphous structure can be obtained by mechanical milling, and the amount of amorphous phase increases with milling time prolonging. The electrochemical measurements show that the discharge capacity of Y0 alloy increases with milling time prolonging, while that of the Y-substituted alloys has a maximum value in the same condition. The cycle stabilities of the alloys decrease with milling time prolonging. The effect of milling time on the electrochemical kinetics of the alloys is related to Y content. Whenx=0, the high rate discharge ability, diffusion coefficient of hydrogen atom, limiting current density and charge transfer rate all increase with milling time prolonging, but the results are exactly opposite whenx=3.

Simulated and experimental investigation on discontinuous dynamic recrystallization of a near-α TA15 titanium alloy during isothermal hot compression in βsingle-phase field

A cellular automaton（CA） modeling of discontinuous dynamic recrystallization（DDRX） of a near-α Ti-6Al-2Zr-1Mo-1V（TA15） isothermally compressed in the β single phase field was presented.In the CA model,nucleation of the β-DDRX and the growth of recrystallized grains（re-grains） were considered and visibly simulated by the CA model.The driving force of re-grain growth was provided by dislocation density accumulating around the grain boundaries.To verify the CA model,the predicted flow stress by the CA model was compared with the experimental data.The comparison showed that the average relative errors were10.2%,10.1%and 6%,respectively,at 1.0,0.1 and 0.01 s^-1 of 1020 ℃,and were 10.2%,11.35%and 7.5%,respectively,at 1.0,0.1and 0.01 s^-1 of 1050 ℃.The CA model was further applied to predicting the average growth rate,average re-grain size and recrystallization kinetics.The simulated results showed that the average growth rate increases with the increasing strain rate or temperature,while the re-grain size increases with the decreasing strain rate;the volume fraction of recrystallization decreases with the increasing strain rate or decreasing temperature.

Photolithography Process Simulation for Integrated Circuits and Microelectromechanical System Fabrication

Simulations of photoresist etching,aerial image,exposure,and post-bake processes are integrated to obtain a photolithography process simulation for microelectromechanical system（MEMS） and integrated circuit（IC） fabrication based on three-dimensional （3D） cellular automata（CA）. The simulation results agree well with available experimental results. This indicates that the 3D dynamic CA model for the photoresist etching simulation and the 3D CA model for the post-bake simulation could be useful for the monolithic simulation of various lithography processes. This is determined to be useful for the device-sized fabrication process simulation of IC and MEMS.

STOCHASTIC BOUNDARY ELEMENT METHODS FOR 3D PROBLEMS WITH BODY FORCES AND ITS APPLICATION IN RELIABILITY OF TURBINE DISKS

The stochastic boundary element method(SBEM)is developed in this paper for 3D problems with body forces and reliability analysis of engineering structures.The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables,considering the yield limit,rotation speeds and material density to be the fundamental stochastic variables.Through analyzing a numerical example and a turbo-disk of an aeroengine,the results show that the method developed is successful.