According to Qian Xuesen´s concept of the modern system of science and technology, the article focuses on his idea of the relation between science and fine arts. Science and fine arts are both different from each other and interlinked. They have origin, object, goal and soul in common. Scientific knowledge, scientific thinking (quantity intelligence) and artistic (including literary) knowledge, artistic thinking (quality intelligence) complement each other and promote each other, which is the key point of emergence of metasynthetic wisdom and creative thinking.
The paper introduces the contemporary system of science & technology and meta-synthesis established by Academician Qian Xuesen, The contemporary system of science and technology has a matrix structure which has eleven department of science and technology laterally and three hierarchies, i.e. fundamental theory, technical science and application technology longitudinally. The meta-synthetic is a methodology that consist of meta-synthetic engineering and hall for workshop of meta-synthetic engineering. The paper also discusses their applications in practice.
Based on the review of the evolution of human's exploiting and utilizing natural resources this paper declares that natural resources ecology, geography, geology and economy are four theoretical props for the exploitation and utilization research of natural resources. In the light of the problems of methods and media of exploitation and utilization research of natural resources, the paper expounds the necessity and connotation of trans-discipline synthetic research from the view of the scientific integration and complexity and the systematicness and comprehensiveness for the exploitation and utilization of natural resources. Meanwhile, the paper puts forward that research yardstick, department benefit, culture discrepancy and viewpoint difference are four mains obstructions for the trans-discipline synthetic research of exploitation and utilization of natural resources. Then the paper clarifies that defining research problem, stipulating research yardstick, selecting suitable target, organizing research group and establishing evaluation criterion are five key steps for the outstanding trans-discipline synthetic research of exploitation and utilization of natural resources. Finally, the paper points out that effective allocation for the exploitation and utilization of natural resources, reconstruction and developing renewal of ecology and environment systems, protection of geological environment, and exploitation and utilization of natural resources for the fragile regions of ecology and environment are the current hotspots of exploitation and utilization research of natural resources.
In this article, the agriculture development and achievements in China are described in detail, which includes 5 main aspects： stable growth of agricultural production, booming of township enterprises, significant improvement of farmers´ living standard, rapid development of international cooperation & exchanges and significant achievements of rural economic system reform. The particular characteristics of the new development phase of Chinese agriculture along with the opportunity and challenges it will face after China entering WTO are analyzed. The major achievements, development trend and key points for adjustment of Chinese agricultural science and technology are comprehensively studied, the related strategies and suggestions are also put forward.
Brian can protect itself from ischemia and/or hypoxia by two distinct mechanisms which probably involve two separate systems of neurons in the CNS. The first ome mediates a reflex neurogenic neuroprotection, which is associated with oxygen-sensitive sympathoexcitatory reticulospinal neurons of rostral ventrolateral medula oblongata. It can be excited within seconds by reduction in blood flow or oxygen and initiate an oxygen conserving reflex. The second is conditioned central neurogenic neuroprotection, which is represented in intrinsic neurons in cerebellar fastigial nucleus. It can be initiated by electrical excitation of intrinsic neurons of fastigial nucleus and afford a persisting for almost two weeks neuroprotection. This mode of neuroprotection is not restricted to focal ischmia,it also protects the brain against global ischemia and excitotoxic cell injury. The ne-oruprotective mechanism of the system is associated with reduced excitability of cortical neurons, inhibition of the onset of necrosis and apoptosis of ischemic neurons, reduced expression of many detrimental factors including Caspase-3 and NF-kappaB, and reduced immunoreactivity of cerebral microvessels. Fastigial neucleus stimulation can also promote the recovery of neurological deficits and can somewhat improve the cognitive function. Some prelimilary observations of clinical application of fastigial nucleus electrical stimulation on protecting neurons from ischemic injury and treating patients with stroke are presented. Recommendations of further research on fastigial nucleus stimulation before its broad clinical practice are provided.
Mathematic model of agricultural eco-engineering is to represent the knowledge of system*s present situation, function and structure. Based on study and analysis, a mathematic model of medium-sized agro-ecological engineering—Liuminying ecological agro-systemisis established. This system consists of eight branch rooms. The state variables and the control variables for each branch room are given and the mathematical models for the branch rooms are also built. The mathematical model has been applied to guiding the pratical production in Luiminying Villnge and satisfactory results are achieved.
Flue collector of master-slave mode discharging system in domicile kitchen can be taken as one dimensional vertical steady flow with friction. By calculation of the distributional condition of the physical parameter of mobile phase and particle phase of flow, it can ascertain the flow condition of particle phase and further decide the discharging condition of fume. And it is affected by some conditions, such as highness of discharging system, diameter of flue and composition of material and so on. Through presetting the highness of discharging system and ensuring a well discharging condition, the diameter of master flue can be got to fit the condition. So a better size of cross section can be found for pipe laying, which both meets the discharging condition of fume aiwl economizes the construction material.
Vectorial eigenmodes supported by the buried rectangular and rib optical waveguides are obtained using variable transformed series expansion method. The infinite x-y plane is mapped into a unit square by an elegant tangent-type variable transformation. Consequently, the boundary truncation is not necessary, and the nonphysical reflection is eliminated. As a result, the calculation accuracy is promoted. In addition, small matrix derived from this method promotes the computational efficiency. Comparatively agreeing with those previously published, the results can be used to optimize the photonic devices.
A new estimation method based on modified performance index is proposed for time-varying process to avoid the ill-condition of least squares method. Based on the new method,a series of new recursive algorithms such as the new recursive least squares algorithm,the instrumental variable algorithm are constructed. The new identification method can ease the ill-condition and improve the identification accuracy without using the additional signals. Moreover, without additional computation,it is suitable for engineering practice very much. Both simulation results and practical operation show the new identification algorithm is effective. In this paper, the justification of this modified algorithm is proved.
The usual mode sets for the dynamics modeling of flexible spacecraft are reviewed. Some mode reduction criterions for the selection of system retained modes are summarized. It is pointed out that the modal cost analysis and the internal balance theory are for the system mode selection and there is the problem how to use these criterions for the component elastic mode or the system elastic deformation mode selection. A tactic for using the order reduction criterions for the dynamics modeling is introduced. An example is given to show the comparison of modeling results with different mode sets and to illustrate how to use the mode reduction criterions for the dynamics modeling of flexible spacecraft.
In the present experiment a new simple method-Surface Tension Aided (STA)- for mouse oocyte enucleation is employed and is compared with three other ones. In method STA, the chromosome spindle was squeezed out by the surface tension of the drop edge with the help of micropipette through a slit made in advance in zona pellucida. In method A, the nucleus was aspirated out through a plat end, 25 μm micropipette via the slit. In method B, the nucleus was aspirated out through a 10μm micropipette directly. In method C, the nucleus was assumed just under the first polar body and the enucleating procedure was carried out by aspirated one third of cytoplasm beneath the polarbody. The manipulation time in method A (3 min/oocyte) was significantly longer than that in method STA (1.33min/oocyte), method B (1.30 min/oocyte) and method C (1.41 min/ oocyte) ; The cytoplasm loss in method C (28.4% ) was significantly higher than those in the other three methods. In methods STA, A and B, very small amount (approximately 5% ) of cytoplasm was lost. The accuracy rate of method C (35.3%) was significantly lower than those in the other three methods, the accuracy rate of method STA, A and B was above 95 % and there is no significant differences among these methods. Some of the cytoplasts produced by STA were used for mouse ear fibroblast cell nuclear transfer by electrofusion. Majority (76.1%) of the cell-cytoplast pairs fused to form reconstructed embryos, 85.4 % of reconstituted embryos developed to form pronuclei and 49.4% of them clove to form 2-cell embryos.
With secondary regulation, a novel hydraulic transmission technology, the secondary regulated loading system described here is oriented to rotational speed experiment of reduction gear or material. In this paper, the hardware structure of the system is introduced with specialties of the transducers, electro-hydraulic servo valves and the computer data collector used. Then, signal-adjusting circuit between computer control system and transducers or servo valves is designed. Next, a VC+ + control program under Windows operating system is worked out. Experiments on Step, Rectangle, Ramp and Sine Responses of the speed sub-system are done under alternative oil pressure and load. Finally, some meaningful results are given by contrasting the experimental curves.
Dynamic analysis for the lateral movement of a lifting pipe in deep sea mining is made by using nonlinear finite element method. The factors influencing the dynamic stress and deformation of the lifting pipe are analyzed in detail by means of AD IN A. A new concept of ‘displacement delaying time’ is put forward and related influencing factors are also discussed. The results obtained are of great importance to the design and operation of the lifting pipe.
A large amount of energy will be saved if adjustable-speed drives are adopted by high and medium power pumps and fans. The power range of most of the drives is within 0.2～2 MW. The rated voltage of most of the motors in the power range is 10 kV because the power supply is 10 kV. The adjustable-speed scheme, a 10 kV motor is fed by a 10 kV inverter, is not reasonable because this kind of inverter consists of a lot of power electronic devices in series and its cost is high and reliability is poorer than lower voltage one. Owing to the existence of input transformer of the inverter, it is not necessary to ask for that the rated voltage of the motor and inverter is the same as power supply, i. e. a lower rated voltage can be used for the motor and inverter. The reasonable rated voltages of motors and inverters with different power grades are investigated and the by-pass methods when the rated voltages of the motors are different from power supply are discussed in this paper.