Drawing up the overall plan for land use is the guarantee to provide land use for the construction of a well-off society, and is an important measure to strengthen the macroeconomic regulation. The paper describes the three motive forces from the theoretical point of view for promoting this plan:safety in grain production, stable development of economy, and environmental protection. In order to better serve the economic development, the author proposed to divide the overall plan into three phases based on the economic development need:The first is a strategic plan——medium and long term land use plan;the second is a campaign plan——five-year land use plan in concordance with the State's Five-year Plan;the third is a tactic plan——the detailed regional land use plan which is characterized by goal unity, total quantity invariability and dynamical demand. In order to establish a persistent effect mechanism for land use and to prohibit the unjustified appropriation of farmland, the author proposes:The National People's Congress should draw up"the law of land use planning" and"the law of basic farmland protection" ;The tracking of the basic farmland usage using the remote-sensing technology should be established;Land use should be dynamically supervised; Farmland use contract should be signed with farmars.
Foodsafetiology is the sum of human knowledge on food safety, It is a branch of food science that studies specially the risk of food hazards on human health and protects human health from risk of food hazards It is a new developing knowledge in the last30years. Discussing, exchanging and understanding theoretical and technical systems of foodsafetiology will be conducive to scientific research, scientific subject building and human resource training, and also to strengthening the national management and control capacity for food safety. On the basis of papers of international organizations, academic presentations, proceedings, as well as author's scientific research, study and understanding, the paper proposed the definition of foodsafetiology, induced its theoretical and technical systems, and discussed the scientific framework of foodsafetiology.
The deep fissure zones have been discovered during the engineering investigation at Pusiluo dam-site, Yalongjiang River. The zones, located 100-200 meters beneath the ground, are separated by thick uninterrupted rock mass between the ground gravity unloading zone and the fissure zone. The occurrence of the deep fissure zone is similar to that of a group of NE directional faults in this area. The newest fault gouge was developed 27-90 thousand years ago and had horizontal, oblique, up-down scratches on the fissure surface. All these observable facts indicate that the deep fissure zone was perhaps caused by the recent activity of the faults, which generated seismi waves and created the deep fissure zone when the stress of waves was larger than rock's tensile strength. The genesis of deep fissure zone has been observed in the ground nuclear explosion and rock dynamics experiment.
The SLIM has been widely applied in transportation for its simple-firm structure and its directly forward electromagnetic thrust. Because of its discontinuous magnetic circuit, the motor has transverse and longitudinal end effects. There are eddy currents, which become greater as motor spread increases, occurring in both entrance and exit of its secondary side for magnetic flux balance. End effects and eddy currents bring ill impact to air gap magnetic flux which reduce its available magnetic flux of air gap and pull coefficient. This paper describes particular discussions on the SLIM working characters and works out the d-q axis equivalent circuits. The changes of mutual inductance and resistance in d axis indicate both the second longitudinal end effect and the eddy current influences. Then the article establishes SLIM control equations connected with the rotor-flux oriented(RFO)vector control theory in rotary motor. The paper brings forward uds, uqs, iqs online decouple compensation based on the rotor magnetic flux, speed, current regulators, which adjust and accommodate pulsive force, d-q axis voltages, d-q magnetic fluxes, d axis mutual inductance. The result indicates that this method reduces the torque ripple and makes the stator currents flat, speed smooth during the sudden change in motor speed of no load, which provides theory guidance to the SLIM application analysis and achieves some active effects.
Yintai (p-hydroxy butrophenone) is a kind of bionic fungicides synthesized by simulating the lead compound of ginkgol isolated from the exosperm of ginkgo fruit. 8.3-time diluted solution of alcohol crude extract from the ginkgo fruit showed 100% inhibtion on the pathogen of apple canker (Valsa mali), and 50% inhibition for the 25-time solution. Both 200-time and400time solutions of ginkgol, extracted from external seed coat of ginkgo, had 100% inhibition on pathogen of apple canker(Valsa mali). EC50 of 20% Yintai ME against4kinds of pathogens, including apple canker, tomato gray mold, and so on, ranges from 17.26 mg/L to 48.43 mg/L, better than the contrast chemicals respectively. Field control effects on4kinds of diseases, e.g. , Rhizoctonia cerealis, are higher than 85%, with safety to non-target organisms, and no symptom of pesticide resistance. Both LD50of acute oral toxicity and LD50 of acute dermal toxicity to mouse are 4640 mg/kg by Yintai technical material, and 3160 mg/kg and 2150 mg/kg by 20% Yintai EC coorespondingly. Trials of subchronic toxicity (90days) revealed that oral toxicity was 19.1 mg/kg for female, and 18.3 mg/kg for male, with negative results on Ames test, micro-nucleus test, and chromosome-type aberration test.
In this paper, the predictive analysis and observational construction for the large-scale underground powerhouse cavern complex in Tianhuangping pumped storage power station are presented. The predictive analysis was carried out in three dimensions by FEM that simulated the actual staged excavation procedures. The analysis provides the sufficient information on the deformation evolution and the potential yielding zones in the cavern rocks. Based on the analysis results and the geological observation as well as the instrument measurement made during the construction, the design supporting parameters for the safety of the cavern rocks were adjusted timely. As a result, the underground powerhouse complex was successfully constructed.
The model of sound radiated from two connected rectangular enclosures consisting of one elastically supported flexible panel and five rigid panels is deduced by using Hamiltonian function and Rayleigh -Ritz method in this paper. By means of artificial springs along connected points of flexible panels, this model allows the consideration of a wide variety structure joint conditions. Numerical results on the radiation of sound are presented. These results are intended to investigate two main issues:one is that the direct force affects the radiation of sound more than the indirect force does, the other is that the translational stiffness at connected points affects the radiation of sound more than the rotational stiffness does.
To evaluate the cost risk and the schedule risk of the spaceflight project, the schedule-cost (S-C) correlation coefficient is directly appointed according to the experts' experience usually. This paper deduces SDMCU (the schedule distribution model considering the effect of the cost uncertainty), and then proposes the approximate formula to estimate the ln (S)-C correlation coefficient based on the models of SDMCU and CDMSU (the cost distribution model considering the effect of the schedule uncertainty). Furthermore, an approximate relationship expression of the S-C and the ln (S)-C correlation coefficients is put forward according to general facts and the Taylor expansion, and advanced by means of mass numerical validation is the general rule of obtaining the estimation value of the schedule-cost correlation coefficient based on the historical data.
Practical experience with the calibration of hydrologic models suggests that any single-objective function, no matter how carefully chosen, is often inadequate to properly measure all of the characteristic of the observed data deemed to be important. In this paper, a fuzzy multi-objective SCE-UA(FMOSCE-UA) optimization method for rainfall-runoff models which combines advantages of Pareto ranking and fuzzy multi-objective optimization is developed to solve the multi-objective optimization problem for hydrologic models. The FMOSCE-UA considers different aspects of the hydrograph, such as water balance, overall shape of the hydrograph, peak flow and its corresponding time, which makes the model's behavior match the observed hydrograph more closely. The features and capabilities of FMOSCE-UA are illustrated by means of a simple calibration study for Shuangpai Reservior with Xinanjiang model.
There are two different sides of ambiguousness and in distinguishability among systematic safety. Fuzzy synthetic assessment can only solve ambiguousness problem from front, but Vague sets have fairly strong and flexible intuition expression ability for handling indefinite data. From this, this paper suggests that Vague sets be used in the synthetic assessment, then determines the weight of each assessment index with improved AHP, and establishes the synthetic assessment model for systematic safety based on Vague sets. Through the assessment for a certain high building fire hazard in Shanxi Province, it proves that this model can make the assessment result of systematic safety more accurate and reasonable.
Aiming at the success of the franchise of Nanjing Cioss-River Tunnel, this paper analysis the structure of the risks in the infrastructure franchise and its influences. For it is impossible to get a complete contract between the private sector and the government, the goverment should take some appropriate measures and set up a good governance structure to deal with these risks, which is a key factor to affect the success of franchise.
When the output power of the CO2 laser machine reaches100W on average, the round focusing point can be formed on the surface of glass by the focusing light path. The laser energy of 10.6μm wavelength is absorbed fiercely by the15μm_thick glass layer on the surface, and the locol stress line distributing is formed. At the same time the quenching mouth is blowing the colder air onto the glass surface, quenching the thermal area quickly. The temperature of the glass surface is higher than the softening point, blowing colder air onto the surface forms the thermal stress concentrtion layer. The glass is disconnected along the cut which is made by mechanic means before cutting, and the crack is smooth. The best pace of the laser thermal stress cutting is 400 mm/s which is testified by the experiment.
To get a natural view of an object by lamp in the dark environment, the lamp should produce a uniform illuminance in a large view angle, as the sunshine does. But illuminance produced by a lamp reaches its maximum value in the right front and decreases rapidly sideways. Then a mirror is required to produce an illuminance that increases sideways, compensating the sideway illuminance. A torus illuminant is used for symmetry. To produce a peak illuminance on the edge area where illuminance drops most, the equation that expresses the wanted mirror is given. By numeric calculation and function-fit, a cap sphere is chosen as the mirror. When a cone mirror is added to the bottom of the cap sphere, the illuminance uniformity can be even improved. The warp within 90° view angle is ±15% after design compared with 65% before design.
The influence of outside air and return air on the IAQ in a typi cal air-conditioning room is analyzed. It is proved that the increasing indoor contamination makes the IAQ worse, the outside air quality has a direct effect on the IAQ, and the return air produces secondary pollutes. The theoretical formula about outside air, return air and the contaminant is induced. The simulation results show that controlling the outside air volume by contaminant mass fractin (CO2) can save energy and improve the IAQ effectively.
A real-time video processing system based on multimedia processor TMS320DM642 is designed. The function and working mode of video decoder TVP5150, encoder SAA7121and video port DM642 are presented. The working principle of software module is discussed. At last, the software design and the characteristic of the system are analyzed.
According to the definition of the damage variable basing on the stress wave attenuation, this paper makes an expansion to the original numerical manifold program which can only be used to simulate the body deformation of the linear elastic constitutive under the invariable load by adopting the stress wave attenuation damage model. The damage evolution law in the one-dimensional rock long bar under the impact load is simulated with the expanded program, and the damage evolution curves of the different points and the total material are obtained. The simulation results show that the increase of damage mainly happens in the initial time of the impact load, and with the time going on, the intensity of the stress wave attenuates and the damage do not increase evidently.
According to the definition of the damage variable basing on the stress wave attenuation, this paper makes an expansion to the original numerical manifold program which can only be used to simulate the body deformation of the linear elastic constitutive under the invariable load by adopting the stress wave attenuation damage model. The damage evolution law in the one-dimensional rock long bar under the impact load is simulated with the expanded program, and the damage evolution curves of the different points and the total material are obtained. The simulation results show that the increase of damage mainly happens in the initial time of the impact load, and with the time going on, the intensity of the stress wave attenuates and the damage do not increase evidently.
This Issue
Mar 2007, Volume 9 Issue 3