论魏禧“真气”说的理论内涵及其文论意义

"真气"说是清初著名古文家魏禧文论的重要组成部分。就内涵而言,"真气"说强调尊重作家的个性禀赋,也不背离"理义",同时还蕴含着对多元化文风的倡导。"真气"对魏禧文论体系的建构意义至为重要,可以避免由过度依赖"法""理""识"等所带来的种种弊端。魏禧的"真气"说中蕴含着丰富的政治意味,呼应着明遗民群体反思明朝灭亡的时代背景,也寄寓着以改造文风来挽救士风的意图。"真气"说对于桐城派文论的确立起到积极的作用,也成为评判文章优劣的重要标准。

气与道俱 斯文斐然——林雨化的古文观及其创作成就

清乾嘉之际福州名士林雨化擅长古文创作,其道德文章直接影响了梁章钜、林则徐等人。他古文观的核心是"真气"论,认为"真气"出于"中心",惟有"真"的"气脉"流贯全文,文章才能流畅顺达。与出自"中心"的"真气"相一致,文章的语言风格应该恬淡、平和、自然,这样才能文以载道、文以明道。他的古文创作融合了《左传》、《国语》、《史记》和唐宋八大家等历代名家之长,推陈出新,使文章简洁明达、平和恬淡而又不乏跌宕俊逸、醇雅隽永。

Magnesium vapor nucleation in phase transitions and condensation under vacuum conditions

Recent findings related to coagulable magnesium vapor nucleation and growth in vacuum were assessed critically, with emphasis on understanding these processes at a fundamental molecular level. The effects of magnesium vapor pressure, condensation temperature, and condensation zone temperature gradient on magnesium vapor nucleation in phase transitions and condensation from atomic collision and coacervation with collision under vacuum conditions were discussed. Magnesium powder and magnesium lump condensates were produced under different conditions and characterized by scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDS）. The right condensation zone temperature approach to the liquid transition primarily improved the magnesium vapor concentration rate. The gas-solid phase transition was primarily inhibited by setting a small condenser temperature gradient. Under the right condensation temperature and temperature gradients, increasing magnesium vapor partial pressure improved crystallization and reduced the oxidation rate.

Recycling of metals from waste Sn-based alloys by vacuum separation

In order to recycle waste Sn-based alloys, the vapor-liquid phase equilibrium composition diagrams of Sn-Pb, Sn-Sb and Sn-Zn binary systems were calculated. The calculated results indicate that Pb, Sb and Zn can be separated from Sn effectively. Based on the above calculation, the industrial experiments of vacuum distillation of Sn-Pb alloy, Sn-Pb-Sb alloy, Sn-Pb-Sb-As alloy, crude Sn and Sn-Zn alloy with different contents were carried out. The experimental results show that Pb(>99% Pb) and Sn(≤0.003% Pb) were obtained simultaneously while Sn-Pb alloy was subjected to vacuum distillation; the crude Sn(>90% Sn, ≤ 2% Pb, ≤6% Sb) and crude Pb(≤2% Sn) were obtained simultaneously while a single vacuum distillation was carried out for Sn-Pb-Sb alloy; the Pb and Bi contents in the Sn ingot(99.99% Sn) achieve the grade A of GB/T 728—2010 standard, more than 50% of As and Sb was removed after vacuum distillation of crude Sn; Zn(<0.002% Sn) and Sn(about 3% Zn) were obtained while vacuum distillation of Sn-Zn alloy was conducted at 1173 K, 20-30 Pa for 8-10 h.

Hardware-in-loop Simulation(HLS) of Homing Anti-tank Missile

The simulation techniques of hardware-in-loop simulation(HLS) of homing antitank missile based on the personal computer (PC) are discussed. The PC and MCS-96 chip controller employ A/D and D/A boards (with photoelectricity isolation) to transfer measur ment and control information about homing head, gyro and rudder and utilize the digital hand shaking board to build correct communication communication protocol. In order to satisfy the real-time requirement of HLS, this paper first simplifies the aerodynamic data file reasonably, then builds a PC software with C language. The program of the controller part is made with PL/M language. The simulation of HLS based on PC is done with the same sampling period of 10ms as that of YH-F1 and the experiment results are identical to those of digital simulation of the homing anti-tank guided missile.

Modeling and Simulation of the Characteristics of Pneumatic Cushion Cylinders

The analysis of the characteristics of the cushion process of the pneumatic cushion cylinder is presented, and the nonlinear model of pneumatic cushion cylinders is built in the form of nonlinear differential equations. Besides, through the simulation of the pressure in the cushion chamber, the characteristics of the pneumatic cushion cylinder are obtained, which helps to understand the performance of the pneumatic cushion cylinder and improve or design the better cushion structure.

Growth of Strained Si_(1-x)Ge_x Layer by UV/UHV/CVD

Strained Si_ 1-xGe_x and Si materials are successfully grown on Si substrate by ultraviolet light chemical vapor deposition under ultrahigh vacuum at a low substrate temperature of 450℃ and 480℃,respectively.At such low temperature,autodoping effects from the substrate and interdiffusion effects at each interface could be suppressed efficiently.The strained Si_ 1-xGe_x and multilayer Si_ 1-xGe_x/Si structures are examined by X-ray diffraction,SMIS,etc.,and it is found that the materials have good crystallinity and the rising and falling edges are steep.The technique has a capability of growing high-quality Si_ 1-xGe_x/Si strained layers.

Effect of multi-step slow shot speed on microstructure of vacuum die cast AZ91D magnesium alloy

Two multi-step （two-step and three-step） slow shot speeds were used in the vacuum die casting process of AZ91D magnesium alloy. The vacuum pressure variation in the die cavity before mold filling was monitored by using a pressure sensor. The microstructures of the produced castings were analyzed with optical microscope and image analysis software. The experimental results demonstrate that, the vacuum pressure in the die cavity at the beginning of mold filling is significantly reduced by using three-step slow shot speed, resulting in a low gas porosity level in the produced castings. At an appropriate multi-step slow shot speed, the dwell time of the liquid metal in the shot sleeve before mold filling can be reduced and the flow of the liquid metal in the shot sleeve at the later stage of the slow shot process can be restrained, which cause a low externally solidified crystal content in the produced castings.

Effect of Inertial Shock on RF MEMS Capacitive Switches Property in Low Vacuum

The influence of outside inertial shock combined with RF signal voltages on the properties of a shunt capacitive MEMS switch encapsulated in a low vacuum environment is analyzed considering the damping of the air around the MEMS switch membrane. An analytical expression that approximately computes the displacement induced by outside shock is obtained. According to the expression, the minimum required mechanical stiffness constant of an MEMS switch beam in some maximum tolerated insertion loss condition and some external inertial shock environment or the insertion loss induced by external inertial shock can also be obtained. The influence is also illustrated with an RF MEMS capacitive switch example,which shows that outside environment factors have to be taken into account when designing RF MEMS capacitive switches working in low vacuum. While encapsulating RF MEMS switches in low vacuum diminishes the air damping and improves the switch speed and operation voltage,the performances of a switch is incident to being influenced by outside environment. This study is very useful for the optimized design of RF MEMS capacitive switches working in low vacuum.

Epitaxy of SiGe HBT Structure by High Vacuum/Rapid Thermal Processing/Chemical Vapor Deposition

The strained SiGe material has been grown by using the newly developed High Vacuum/Rapid Thermal Processing/Chemical Vapor Deposition (HV/RTP/CVD) system.Device quality material is grown by handling process after careful design. The Ge fraction varies up to 0 25, and the n and p type doping is well controlled,which are both adapted to the fabrication of Heterojunction Bipolar Transistors (HBT). The SiGe HBT structure, namely n Si/i p + i SiGe/n Si structure, has been investigated, with which, the HBTs are fabricated and show good performance. The new system has been proved potential and practicable.

Nanoindentation tests on single crystal copper thin film with an AFM

Nanoindentation tests performed in a commercial atomic force microscope have been utilized to directly measure the elastic modulus and the hardness of single crystal copper thin films fabricated by the vacuum vapor deposition technique. Nanoindentation tests were conducted at various indentation depths to study the effect of indentation depths on the mechanical properties of thin films. The results were interpreted by using the Oliver-Pharr method with which direct observation and measurement of the contact area are not required. The elastic modulus of the single crystal copper film at various indentation depths was determined as (67.0±(6.9) GPa) on average which is in reasonable agreement with the results reported in literature. The indentation hardness constantly increases with decreasing indentation depth, indicating a strong size effect.

A Tangential Wind Profile for Simulating Strong Tropical Cyclones with MM5

A new tangential wind profile for simulating strong tropical cyclones is put forward and planted into the NCAR- AFWA tropical cyclone bogussing scheme in MM5. The scheme for the new profile can make full use of the information from routine typhoon reports, including not only the maximum wind, but also the additional information of the wind speeds of 25.7 and 15.4 ms-1 and their corresponding radii, which are usually provided for strong cyclones. Thus, the new profile can be used to describe the outer structure of cyclones more accurately than by using the earlier scheme of MM5 in which on- ly the maximum wind speed is considered. Numerical experimental forecasts of two strong tropical cyclones are performed to examine the new profile. Results show that by using the new profile the prediction of both cyclones’ intensity can be obvi- ously improved, but the effects on the track prediction of the two cyclones are different. It seems that the new profile might be more suitable for strong cyclones with shifted tracks. However, the conclusion is drawn from only two typhoon cases, so more cases are needed to evaluate the new profile.

Simulation and experimental study of high pressure switching expansion reduction considering real gas effect

Switching expansion reduction(SER)uses a switch valve instead of the throttle valve to realize electronically controlled pressure reduction for high pressure pneumatics.A comprehensive and interactive pneumatic simulation model according to the experimental setup of SER has been built.The mathematical model considers heat exchanges,source air pressure and temperature,environmental temperatures and heat transfer coefficients variations.In addition,the compensation for real gas effect is used in the model building.The comparison between experiments and simulations of SER indicates that,to compensate the real gas effect in high pressure discharging process,the thermal capacity of air supply container in simulation should be less than the actual value.The higher the pressure range,the greater the deviation.Simulated and experimental results are highly consistent within pressure reduction ratios ranging from 1.4 to 20 and output air mass flow rates ranging from 3.5 to 132 g/s,which verifies the high adaptability of SER and the validity of the mathematic model and the compensation method.

Numerical analysis of temperature rise within 70MPa composite hydrogen vehicle cylinder during fast refueling

The numerical simulation model for predicting fast filling process of 70 MPa type Ⅲ(with metal liner) hydrogen vehicle cylinder was presented,which has considered turbulence,real gas effect and solid heat transfer issues.Through the numerical analysis method,the temperature distributions of the gas within the solid walls were revealed; adiabatic filling was studied to evaluate the heat dissipation during the filling; the influences of various filling conditions on temperature rise were analyzed in detail.Finally,cold filling was proposed to evaluate the effect on temperature rise and SoC(state of charge) within the cylinder.The hydrogen pre-cooling was proved to be an effective solution to reduce maximum temperature and acquire higher SoC during the filling process.

Reflection of Typhoon Morakot-The Challenge of Compound Disaster Simulation

Climate change has altered locally singletype disasters to large-scale compound disasters because of increasing intensity and frequency of extreme rainfall events.The compound disasters can combine small-scale floods,debris flows,shallow landslides,deep-seated landslides,and landslide lakes into a large-scale single disaster event.Although simulation models and evaluation tools are available for single-type disasters,no single model is well developed for compound disasters due to the difficulty of handling the interrelationship between two successive single-type disasters.This study proposes a structure for linking available single-type simulation models to evaluate compound disasters and provides a useful tool of decision making for warning and planning of disaster reduction.

Vacuum chamber suppression of gas-explosion propagation in a tunnel

To control and reduce the harm of a gas explosion, a new method is proposed for suppressing gas-explosion propagation in a tunnel by using a vacuum chamber. We studied the suppression effect on gas explosions by placing a vacuum chamber at dif-ferent positions along the tunnel. The results indicate that: 1) the vacuum chamber can absorb the explosion wave and explosion energy as much as possible at the beginning of the gas explosion, and; 2) when the vacuum chamber is used the closer it is to the ignition source the more significant the suppression effect. In addition, by using the vacuum chamber: 1) the flame propagation velocity decreases from ultrasonic to subsonic; 2) the flame propagation distance is remarkably shortened; 3) the maximum peak value of overpressure (pm) decreases from 0.34 to 0.17 MPa or less, and; 4) the impulse of the blast wave (I) decreases from 20 to 8 kPa·s or less.

Global Climate Internal Variability in a 2000-year Control Simulation with Community Earth System Model(CESM)

Using the low-resolution （T31, equivalent to 3.75°× 3.75°） version of the Community Earth System Model （CESM） from the National Center for Atmospheric Research （NCAR）, a global climate simulation was carried out with fixed external forcing factors （1850 Common Era. （C.E.） conditions） for the past 2000 years. Based on the simulated results, spatio-temporal structures of surface air temperature, precipitation and internal variability, such as the E1 Nifio-Southem Oscillation （ENSO）, the Atlantic Multi-decadal Oscilla- tion （AMO）, the Pacific Decadal Oscillation （PDO）, and the North Atlantic Oscillation （NAO）, were compared with reanalysis datasets to evaluate the model performance. The results are as follows： 1） CESM showed a good performance in the long-term simulation and no significant climate drift over the past 2000 years; 2） climatological patterns of global and regional climate changes simulated by the CESM were reasonable compared with the reanalysis datasets; and 3） the CESM simulated internal natural variability of the climate system performs very well. The model not only reproduced the periodicity of ENSO, AMO and PDO events but also the 3-8 years vari- ability of the ENSO. The spatial distribution of the CESM-simulated NAO was also similar to the observed. However, because of weaker total irradiation and greenhouse gas concentration forcing in the simulation than the present, the model performances had some differences from the observations. Generally, the CESM showed a good performance in simulating the global climate and internal natu- ral variability of the climate system. This paves the way for other forced climate simulations for the past 2000 years by using the CESM.

Impacts of salinity parameterizations on temperature simulation over and in a hypersaline lake

In this paper,we introduced parameterizations of the salinity effects(on heat capacity,thermal conductivity,freezing point and saturated vapor pressure) in a lake scheme integrated in the Weather Research and Forecasting model coupled with the Community Land Model(WRF-CLM). This was done to improve temperature simulation over and in a saline lake and to test the contributions of salinity effects on various water properties via sensitivity experiments. The modified lake scheme consists of the lake module in the CLM model,which is the land component of the WRF-CLM model. The Great Salt Lake(GSL) in the USA was selected as the study area. The simulation was performed from September 3,2001 to September 30,2002. Our results show that the modif ied WRF-CLM model that includes the lake scheme considering salinity effects can reasonably simulate temperature over and in the GSL. This model had much greater accuracy than neglecting salinity effects,particularly in a very cold event when that effect alters the freezing point. The salinity effect on saturated vapor pressure can reduce latent heat flux over the lake and make it slightly warmer. The salinity effect on heat capacity can also make lake temperature prone to changes. However,the salinity effect on thermal conductivity was found insignificant in our simulations.

Dynamic action simulation system and preliminary experiments of coal seams and gas

In order to study the dynamic action and physical effects of coal seams and gas, a simulation system for this dynamic action was developed and a physical model built in our laboratory. Using this newly built model, the volume of coal outbursts and the temperature during the outburst process were studied. The results show that： l） for coal seams with similar structure and com- ponents, two factors, i.e., gas pressure and ground stress affect the volume of coal outbursts, with gas pressure being the more im- portant of the two and 2） the changes in coal temperature, both its increase and decrease, are affected by ground stress and gas pressure, it is a process of change. Preliminary tests show that the system can simulate the dynamic interaction of coal and gas, which is helpful for studying the dynamic mechanism of solid-gas coupling of gas and coal.

Numerical simulation of subsonic and transonic flow flieds and aerodynamic characteristics of anti-tank intelligent mine

Anti-tank intelligent mine is a kind of new intelligent anti-tank bomb relying on high precision detector.It can effectively capture and damage targets with wind resistance coefficient and other factors affecting its flight characteristics under consideration.This article is based on the three-dimensional model of intelligent mine.To analyze its subsonic and transonic flow fields and the change law of aerodynamic force factor with the growth of the angle of attack,computational fluid dynamics software is used for intelligent mine flow field numerical calculation and the change law of pressure center.The results show that the large drag coefficient is conducive to the stability of scanning.Drastic changes of the flow field near the intelligent mine will disable its scanning movement.The simulation results can provide a reference for scanning stability analysis,overall performance optimization and appearance improvement.