“置邮传命”与政治运转:清代“邮政”的传统内涵

"邮政"一词,其涵义在清末制度转型过程中有着明显的转化过程。清代的"邮政",主要以"置邮传命"为宗旨,在朝廷的政治生活中担任传书递命以及作为维系朝政运转、训谕直省督抚及肃清州县吏治的政举。其重心,不在邮递之具体运转,而在于驿传的政治含义,亦即是其与朝政国命之间的密切联系。但在传统的政治体系之中,邮驿之"政"义未能给体制本身的顺利运转提供足够的支持,在清末改革的背景中逐步被"裕国便民"的新式邮政所取代。

“德之流行,速于置邮而传命”之“置”字辩及其他

《孟子.公孙丑上》:"孔子曰:‘德之流行,速于置邮而传命。’"对于此句中的"置",历来的解释都是:"置,驿站。"虽然"置"确有"驿站"这一义项,但孟子之时还没有产生,此处释为"驿站"不合"置"词义发展的事实,考求此"置"之义,应该解释为"设置"。同时,"置"其实还存在一个义项"传车、驿车";"置邮"作为一个词,也不是"驿站"的意思,而是"形容像设置驿站来传达命令一样的迅速"的意思。

皇帝的無奈——西漢末年的傳置開支與制度變遷

本文以《漢舊儀》所錄西漢末年大司徒向計吏宣讀的"敕"所含控制厨、傳等改善條件、增加接待膳食標準為綫索,根據出土筒牘與文獻,推算出西漢末年全國傳舍與置的總數,並以尹灣漢簡《元延二年日記》的記載為標準,據各縣、置在交通绕中的位置,對不同縣、置的接待量進行了細分與統計,估算出西漢末年一年使客住宿的日子數量與消費的糧食、鷄的數量,以及其中使用的馬匹所耗糧食的總量。基於此,據懸泉漢筒,歸納出當時導致額外開銷的四點原因,並分析了開支難以控制的深層原因。指出這類機構乃是廣土衆民的帝國存在所不可或缺,使用者與管理者日久了解其運作漏洞,假公濟私,導致開支膨脹,上級的監督乃至皇帝的韶令則日漸失效,月累年積,傳置機構不堪其負,和帝國一道走向末日。如此過程反反復復,直到清末.體現了官吏群體與皇帝、帝國體制之間的長期博弈。這種"反復"構成中國歷史中延續與不變的一個側面。

評“傳置與行書無關”説

學者或據里耶簡等謂“傳置與行書無關”,本文引《孟子》及楊慎説,辨析“置”“傳”“傳車”“傳馬”“乘傳”“乘置”等簡牘文字之釋解,利用出土資料考先秦、秦漢郵置制度,認爲自春秋戰國以來已有完整的官方交通傳輸郵驛系統,秦及漢初沿用這一制度,漢代中期以後有進一步的發展,郵置網絡遍布全國,相關法律更加完備.

光纤护套材料对变压器油热老化特性影响研究

为研究内置传感光纤在热老化环境下对变压器油绝缘体系的影响,设计了130℃下普通裸纤、耐温PVC紧套光纤和ETFE紧套光纤在绝缘油中的加速热老化试验,对比分析了老化过程中绝缘油的微水含量、酸值、油色谱、体积电阻率和介质损耗因数老化特征参量的变化趋势。结果表明:普通裸纤会加速油的老化,耐温PVC紧套光纤在油中稳定性较差,ETFE紧套光纤的抗老化效果明显。增加ETFE护套可有效延缓含纤油样中微水含量和酸值达到标准规定的不合格上限的时间;老化末期,含普通裸纤油样的介质损耗因数和体积电阻率分别为含ETFE油样的2.75倍和0.305倍;含ETFE油样中的总烃含量、氢气含量和CO_2与CO比值分别为含普通裸纤油样的30.5%、70.1%和60.7%。虽然增加ETFE材料使得油的微水含量、酸值和油色谱与纯油样相比略有劣化,但对油的整体绝缘性能影响并不严重,适合作为光纤护套材料应用于变压器内部安装测试。

Mass transfer process in replacement-column purification device in zinc hydrometallurgy

It is important to remove the impurities, such as copper and cadmium, from leaching solution in zinc hydrometallurgy. To improve purification efficiency, a replacement-column purification device was proposed and its mass transfer characteristics and purification efficiency were experimentally studied. The results show that purification efficiency increases with the decrease of the zinc powder diameter and decreases with the increase of solution velocity. If appropriate structure and operation parameters are used, it is possible to make purification efficiency more than 99%, but the diameter of zinc powder should be larger than 0.45 mm. For the velocity of 0.05-0.7 cm/s, mass transfer coefficient kc is in the range of 3.94×10-7-2.76×10-6 m/s, and increases with the decrease of zinc powder diameter and the increase of solution velocity. Moreover, it can be derived by mass transfer correlations of Sherwood number:Sh=0.1069Re0.5Sc0.33, for 0.3<Re<6.

Relocation method of microseismic source in deep mines

A new method, named relocation, was proposed to reduce the impact of sensor errors systematically, especially whenavailable data of sensors are abundant. The procedure includes evaluating the reliability of every sensors datum, processing the initiallocation by the credible data, and selecting a set of equations with optimal noise tolerance according to the relative relationshipbetween the initial location and sensors location, then calculating the final location by k-mean voting. The results obtained in thisresearch include comparing traditional location method with the presented method in both simulation and field experiment. In thefield experiment, the location error of relocation method reduced 41.8% compared with traditional location method. The resultssuggested that relocation method can improve the fault-tolerant performance significantly.

Genetic Diversity of Achnatherum Splendens

[Objective] Study on the genetic diversities of A.splendens from different areas of xinjiang. [Method] The genetic diversities among seven populations and within two populations were analyzed by RAPD. [Result] Genetic clustering results presented that the relationships among populations of A. splendens are directly related with geographic positions, and within population are related with habitats. [Conclusion] RAPD technique can be used to study genetic diversity of A. splendens.

Genetic Differentiation of A and B Chromosomes Between Common Wheat and Wild Emmer as Revealed by RFLP Analysis

To investigate chromosome differentiation of genome A and B between common wheat and wild emmer wheat (Triticum turgidum var. dicoccoides (Koern.) Bowden), the authors conducted a RFLP analysis of the two species using 153 genomic, cDNA and chromosome_specific probes. 75.8% of the probes had detected hybridization polymorphism in at least one of the five restriction enzymes. However, the polymorphic probes were unevenly distributed among different homoeologous groups, between different genomes and in different regions of a single chromosome. Homoeologous group 1 possessed the highest level of polymorphism (96.2%), followed by group 6 and 2 (84.6% and 82.1% respectively). In contrast, only 60%-67% of probes of the other four groups was polymorphic. In most groups the number of probes capable of detecting B chromosome polymorphism was slightly higher than that revealing A chromosome difference (totally 51.8% vs 43.1%). In a single chromosome, RFLP was predominant in the distal region (65.1%) and showed a decreasing trend from the proximal (46.2%) to the pericentric (42.4%) regions. The results suggest that there exists a substantial amount of DNA polymorphism between the A and B chromosomes of common wheat and those of wild emmer wheat, indicating that a considerable degree of genetic differentiation has taken place in the A and B genoms of two species during evolution from wild emmer to common wheat. The extent of the genetic differentiation may vary among different homoeologous groups, between A and B chromosomes and in different regions of individual chromosome.

Anti-reverse rotation startup method for sensorless brushless DC motor

In order to start up the brushless DC motor （BLDCM） without reverse rotation and smoothly switch the running state of the motor, a novel startup and smoothly switching method for a sensodess BLDCM is presented. Based on the saturation effect of the stator iron, six short voltage pulses are applied to determine the initial rotor position and the rotor can be found within 60°. After that, a series of short and long voltage pulses are used to accelerate the motor and the variation of the response current is utilized to detect the rotor position dynamically. When the motor reaches a certain speed at which the back-electromotive force （EMF） method can be applied, all the power devices are turned off and the running state of the motor is smoothly switched at the moment determined by the relationship between the terminal voltage waveform and the commutation phases. The experimental results verify the feasibility and validity of the proposed method.

THREE-PHASE BRIDGE INVERTER FOR 9kW DOUBLY SALIENT PERMANENT MAGNET MOTOR

The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet （DSPM） motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.

Distribution characteristics of respiratory aerosols in enclosed environments

This paper studies the spatial concentration distribution and temporal evolution of exhaled and sneezed/coughed droplets within the range of 1.0 to 10.0 μm in an office room with three air distribution methods,including mixing ventilation（MV）,displacement ventilation（DV）,and under-floor air distribution（UFAD）.The simulation results indicate that exhaled droplets with diameters up to 10.0 μm from normal respiration process are uniformly distributed in MV.However,they become trapped at the breathing height by thermal stratifications in DV and UFAD,resulting in a high droplet concentration and an increased exposure risk to other occupants.Sneezed/coughed droplets are more slowly diluted in DV/UFAD than in MV.Low air speed in the breathing zone in DV/UFAD can lead to prolonged human exposure to droplets in the breathing zone.

简牍所见西汉马政

马政是古代国家对于官用马匹的采办、牧养、管理、使用等方面所实施的行政管理制度。它是古代兵制、邮驿制度、财赋制度的重要组成部分。汉简中的材料显示,西汉政府对马政相当重视,汉武帝想通过天马来改良马的品种,但效果并不明显；汉廷对厩马食粟有统一的规定,厩马食粟的多少折射出西汉不同时期的经济状况；西汉官方马厩遍布全国,各有分工,相互配合,政府对马厩有较严格的管理,显现出西汉政府良好的行政秩序。

Research on new type of fast-opening mechanism in steam turbine regulating system and optimization of operation tactic

With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.

Design and Dynamics Simulation of a Novel Double-Ring-Plate Gear Reducer

A patented double-ring-plate gear reducer was designed and its dynamic performance was simulated. One unique characteristic of this novel drive is that the phase angle difference between two parallelogram mechanisms is a little less than 180 degree and four counterweights on two crankshafts are designed to balance inertia forces and inertia moments of the mechanisms. Its operating principle, advantages, and design issues were discussed. An elasto-dynamics model was presented to acquire its dynamic response by considering the elastic deformations of ring-plates, gears, bearings, etc. The simulation results reveal that compared with housing bearings, planetary bearings work in more severe conditions. The fluctuation of loads on gears and bearings indicates that the main reason for reducer vibration is elastic deformations of the system rather than inertia forces and inertia moments of the mechanisms.

Optimization of the fully grouted rock bolts for load transfer enhancement

The purpose of this study is to investigate the role of bolt profile configuration in load transfer capacity between the bolt and grout.Therefore,five types of rock bolts are used with different profiles.The rock bolts are modeled by ANSYS software.Models show that profile rock bolt T_3 and T_ with load capacity 180 and 195 kN in the jointed rocks,are the optimum profiles.Finally,the performances of the selected profiles are examined in Tabas Coal Mine by FLAC software.There is good subscription between the results of numerical modeling and instrumentation reading such as tells tale,sonic extensometer and strain gauge rock bolt.According to the finding of this study,the proposed pattern of rock bolts,on 7 + 6 patterns per meter with 2 flexi bolt(4 m) for support gate road.

A parametric study on the contact stress of half toroidal continuously variable transmission

The most general contact in mechanical transmission is the elliptical one. In particular, a toroidal continuously variable transmission (CVT) has an elliptical shape in the contact area under the elastohydrodynamic lubrication regime, where the shearing of the fluid subjects to high contact stress and transmits the power. Many parameters affect the contact service performance of the half toroidal CVT, which include the properties of the contacting material (Young抯 modulus), operating parameters (input torque and maximum traction coefficient) and geometrical parameters (aspect cavity ratio, curvature ratio and half cone angle of the power roller). In this paper, the contacts between the input disk, the power roller and the output disk are formulated using the classical Hertzian contact theory. Based on the formulated equations, different system parameters, which affect the maximum Hertzian stresses, are compared. The comparative results will provide some observations of the relations between the maximum Hertzian stresses and transmission ratios in the form of graphs. These graphs give useful information for designer to know the maximum Hertzian stress during operation in such systems.

Theoretical calculation and experimental study on the load distribution coefficient (LDC) of three-ring gear reducer

In this paper, primary manufacturing and assembling errors of three-ring gear reducer （TRGR） are analyzed. TRGR is a new transmission type whose eccentric phase difference between middle ring plate and side ring plates is 120°, Its mass of middle ring plate is equal to that of side ring plate or 180°, and its inass of middle ring plate is twice of that of side ring plate, which affects load distribution between ring plates. The primary manufacturing and assembling errors include eccentric error of eccentric sheath E111, internal gear plate E1 and output external gear E11. A new theoretical method is presented in this paper, which converts load on ring plates into the dedendum bending stress of ring plate to calculate load distribution coefficient （ LDC ）, by means of gap element method （GEM）, one of finite element method （FEM）. The theoretical calculation and experimental study, which measures ring plate dedendum bending stress by means of sticking strain gauges on the dedendum of middle ring plate internal gear and side ring plate internal gears, are presented. The theoretical calculation and comparison with experiment result of LDC are implemented an two kinds of three-ring gear reducers whose eccentric phase difference between eccentric sheaths is 120° and 180°respectively. The research indicates that the result of theoretical calculation is consistent with that of experimental study. That is to say, the theoretical calculation method is feasible.

A Novel Bio-mimetic Wireless Micro Robot for Endoscope

A novel bio-mimetic wireless micro robot for endoscope is developed. Its autonomous manner is earthworm-like and driven by linear actuators based on DC motor. It is different from the conventional micro robot endoscope that wireless module is used for conanunicating and power transfer. The fabricated micro robot system is detailedly described, including structure, micro robot locomotion principle, communication control module and wireless power transfer module. The experimental results show that the driving force of the linear actuator can reach to 2. S5 N and supplying power is up to 480 mW DC power for receiving coil in the proposed system, which all fulfill the need of the micro robot system. The micro robot can creep reliably in the large intestine of pig and other contact environments.

Electro-Hydraulic Servo System Identification of Continuous Rotary Motor Based on the Integration Algorithm of Genetic Algorithm and Ant Colony Optimization

In order to increase the robust performance of electro-hydraulic servo system, the system transfer function was identified by the intergration algorithm of genetic algorithm and ant colony optimization(GA-ACO), which was based on standard genetic algorithm and combined with positive feedback mechanism of ant colony algorithm. This method can obtain the precise mathematic model of continuous rotary motor which determines the order of servo system. Firstly, by constructing an appropriate fitness function, the problem of system parameters identification is converted into the problem of system parameter optimization. Secondly, in the given upper and lower bounds a set of optimal parameters are selected to meet the best approximation of the actual system. And the result shows that the identification output can trace the sampling output of actual system, and the error is very small. In addition, another set of experimental data are used to test the identification result. The result shows that the identification parameters can approach the actual system. The experimental results verify the feasibility of this method. And it is fit for the parameter identification of general complex system using the integration algorithm of GA-ACO.