This paper reviewed the important scientific progress and engineering innovations achieved in the industries of information,energy and manufacture and the exploration of macrocosm and microcosm in recent years,especially in 2008 in China, pointed out the test and inspiration of the serious natural disasters to science,technology and engineering,put forward some questions worth thinking in China's engieering academia and looked forward to future innovation mission of engineering technology in China.
This is an overview paper about mineral processing in ancient China, the main contents include the minerals and metals used by ancient Chinese people; the scale of ironmaking and copper metallurgy in ancient China; copper extraction by hydrometallurgy,the application and record of gravity separation and flotation technologies in ancient China; and the final is the establishment of recent and modern mineral processing industry in China.
To meet the requirements of saving energy and water and reducing discharge and consumption, surface active agents have developed greatly and innovatively in recent years. In this paper, the main applications and the categories of surface active agent were introduced. In addition, the applications of surface active agents in dyeing, printing, degumming and sizing were analyzed in detail.
According to the characteristics of pulp and paper making technics, the surfactants used in pulp and paper making industry were introduced in detail. The effect and mechanism of the surfactants used at pulp and paper making technology were discussed. At last, the development of the surfactants in pulp and paper making industry was put forward.
Using patented nature carboxylate and its modification as the major surfactant, we obtained compounded nonionic surfactant by the interaction parameter βm. Then we measured the pseudo ternary phase diagram of compounded surfactants/water/diesel oil, from which got three cheap and efficient diesel oil emulsifier. The emulsifier includes little flame accelerator,cetane improver and smoke suppressor. Through the bench test, we found that the average rate of economizing petrol was 20 % and the emissions of NOx dropped to 20 %. And every ton of emulsified diesel oil can save 500 yuan around.
Biosurfactants are a kind of biomolecules which have the basic structure and charactersistics of surfactarts and produced by microbial fermentation processes and enzymatic synthesis. Because of their unique properties of great bio-compatibility, low toxicity, high biodegradability and stable activity at extremes of pH, salinity and temperature, biosurfactants have been widely applied to food, pharmaceutical, cosmetic, and cleaning industries. Therefore, it is very important to raise yields and reduce production costs for the applications on large scale.
The functions of surfactants in leather-making beamhouse and dyeing processes were detailed introduced. New processes of leather dyeing in solvent medium and the advantages of high dyestuff exhaustion were discussed. The necessity of studying the functions of surfactants in bating process in leather-making industry was proposed and the future of environmental-friendly leather dyeing in solvent medium was expected.
The application of green surfactants in pesticide processing was discussed. Formulations, which utilize green surfactants such as AEO, AES, AOS and APG rather than traditional surfactants, were developed in this work. Comparing with traditional surfactants, the application of green surfactants in pesticide processing is of great interest in environmental protection.
Fengyun-3(FY-3) microwave humidity sounder antenna has the following specialties: high gain, low noise, high beam efficiency and high frequency. This Antenna has great influence on the precision of the whole system of FY-3MHS (microwave humidity sounder), offset parabolic antennae with conical corrugated horns are selected for these antennae. The frequencies of the antenna are 150 GHz and 183 GHz respectively (up to the highest frequency of the payload for the domestic satellite ), in addition, dual linear polarizations are also needed for the 150 GHz channels. Great challenges are brought about with the stringent demand for the FY-3MHS antenna. The analysis and design of this antenna need intercross knowledge of the electromagnetic theory, mechanics, manufacturing, measurements, quasi-optics, thermal and orbit etc. The successful design and assembly of FY-3MHS antennae fill up the gap of remote sensing in our country and stride a greatly leap in antenna theory.
A series of laboratory experiments have been performed to study the enhanced coupling of explosions by placing them in water-filled cavities or in air-filled cavities on a half sphere apparatus of cement mortar with 1.6 m in diameter. There is a cavity of 0.3 m in diameter at the center of the apparatus, the cavity can be filled with water or inserted a core of cement mortar, the source conditions consisted of tamped source and spherical cavities with a spherical charge of yield equivalent to 1.00 g of TNT. Measurements consisted of longitudinal strains of the aluminum bars sticking on the surface of the sphere apparatus at several points, and from which particle velocities, displacements were obtained. On the basis of the results of these small-scale experiments, conclusions are drawn concerning the coupling of the explosive energy. The effect of cavity decoupling in water is not as good as in cement mortar. When the explosive source is detonated in a water-filled cavity, the stress wave coupled into cement mortar is greatly enhanced. It follows that the damage of surrounding rock or dam by underwater explosion would be more possibly compared to the explosion detonated in themselves with same yield and same distance, and the enhanced coupling seems to be shown for air explosion nearby water.
A methodology for automatic design optimization of CMOS analog cell circuits is presented. The proposed method uses symbolic analysis technique to generate exact analytic performance equations, describing the behaviors of circuits. The symbolic model is then passed to the genetic algorithm and is used as evaluating performance criterion. For the fixed topology, the algorithm sizes all elements to satisfy the performance constraints, thereby optimizing a user-defined design objective. Practical example shows that the method quickly designs analog cell circuits, closely meeting the specifications, and that it is a flexible and reliable design and exploration methodology.
Motor needs high efficiency, high power density and low pulsating torque in hybrid electric vehicle, traditional motors have their limits; Halbach motor is a novel permanent magnet (PM) motor: One-sided and sinusoidal field is produced by special distribution of permanent magnets. The field can increase air-gap flux while decrease rotor-yoke flux and air-gap harmonic, which can improve power density and efficiency, reduce volume and pulsating torque of motor. Halbach motor design software based on MATLAB and finite element analysis software based on ANYAS reduce period of motor design greatly. Full-digital electric-driven system of hybrid electric vehicle based on DSP2407A is designed according to Halbach motor's distinguishing feature.Experiment results prove Halbach motor has much more advantages in the system than traditional permanent magnet motor.
The shock wave propagation characteristics of the polyester have been measured by recording the shock wave profile produced by the impact of projectiles accelerated in a light gas gun. The impact velocities in the experiments were from 323 m/s to 526 m/s, and the corresponding peaks of impact stresses in the targets were from 0.632 to 2.137 GPa. The Hugoniot relation, expressed as the curve of shock wave velocity versus particle velocity, obtained from the experiments shows linearity in the testing stress range. The polynomial equation of state is obtained by regression of the experimental data and the Grüneisen coefficient is calculated.
This paper mainly expatiated the essential components of aluminized thermobaric explosive powder and its energy releasing efficiency in different environments, and dealt with the information of shock wave and fireballs spread abroad within explosion. Heats of the explosive samples were determined in oxygen, air and argon confined in stainless steel container. The effect of the circumstance to the energy releasing efficiency in confined condition was analyzed. Contemporary the energy releasing rates of the different metal additives were qualitatively analyzed. The temperature of the fire balls and the fireballs' durations were measured in the field test. The relationship of shock wave with fireball expanding was researched. The results indicated that the aluminized thermobaric explosive flake had a higher energy releasing efficiency and energy releasing rates in the oxygen environment. It could have produced a high temperature fireball and strong shock wave which brought an integrative damage.
In this paper, the author summarized and proposed five important issues in the present field of knowledge discovery and data mining, which comprise two important core issues, two conjectures, challenge issues in mainstream development, important issues of relevant fields in appliance research and technique standard in knowledge discovery (data mining).Some achievements and special analysis was also presented. Those five issues correlate closely, and these researches will push the development of knowledge discovery (data mining) to a higher stage, and bring great influence to the field inside and outside.
This paper investigates process optimization for the specific rib with section s-3 during the gas-assisted injection molding firstly, which is to get relationship between process parameters and quality evaluations,based on the Taguchi experimental design. Then, in the light of the above process conditions, a comparative study of four different cross-section ribs are done, to investigate trend of the impact of the single process parameter on forming quality, by changing one of the parameters while the others remain unchanged.
In direct torque control system, the PID controller is often adopted to be the speed adjuster. When disturbances are thrown to the motor, a long time is taken to renew the motor to steady state. In this paper, new auto-disturbance-rejection controller (ADRC) is introduced into direct torque control system. Instead of PID speed adjuster, ADRC speed adjuster is designed. The speed observer is designed based on model reference adaptive system (MRAS), too. The performance difference is analyzed between PID controller and ADRC in speed sensorless direct torque control system. The simulation results show that the AC speed adjustable system has speedier response performance, stronger disturbance-rejection performance when ADRC is adopted. Moreover, according to simulation results, there is smaller warp between motor command speed and actual speed when motor parameters perturb.