Hydroenergy is a kind of clean and renewable energy sources. As a high-quality energy source, it plays a key role in realizing the strategy of sustainable development. With consideration of the abundant hydropower resources in China, giving priority to its development becomes an important policy of China's energy resources exploitation. The development and utilization of hydropower resources may decrease the yield of coal and the environment pollution caused by thermal power generation. However, damming a river will lead to the change of water-sand regime, which will exert adverse impact on the ecosystem and environment. As a result, countermeasures should be studied and taken to well deal with the relationships between the hydropower development and the environmental & ecological protection. The development and exploitation of hydropower should be based on the comprehensive planning of a river basin and carried out in a scientific, reasonable, appropriate and orderly way. Moreover, it is necessary to reasonably combine hydropower development, environmental & ecological protection and promotion of regional economic & social development, so as to make the relevant work go smoothly, such as resettlement for reservoir areas, improvement of migrants' living and productive conditions and promotion of harmonious development between economic construction of reservoir areas and environment protection.
Ten major difficulties facing city's sustained development are summarized, including too much land occupied, traffic jam, difficulty in parking, difficulty in walking, high energy consumption, low efficiency, poor public security, unlivableness, frequent traffic accidents and high investment in traffic facilities. The basic formulas for solving these difficulties are presented. For example, traffic supply density > traffic demand density is the basic formula for addressing traffic congestion. Only when the inequality becomes realistic can the traffic problem be soloved. Based on every basic formulas, a new unimpeded city mode is sublimated from many complex city mode schemes. Once the new mode in introduced, the ten major difficulties will be solved in an all-round way, and the city's livableness index will be doubled. For the sustainable developing city pattern, the centre position should not be locked at a certain place like in the case of playing chess, instead, the positions of every centre should be formed and vary along with the development just like in the case of playing a game of go. That is the doctrine of nonspecific city centre.
It was reported that a new find on sub-layer movement in the large-scale stratum had been observed. Earthquakes with different division magnitude can represent movement of sub-layer with different thickness. Earthquakes with different division magnitude can display the different characteristic of tectonics, in a same region and same time period. A direct evidence of movement, synchronal movement in vertical direction, in the as large-scale stratum has been reported in this paper. Stratum scale can be large as up to several thousand kilometers, as in a continent dimension. Events with strong tremble of sub-layer movement have been analyzed, which were recorded by stations with seismograph of super long period (300 〜3 000 s) . A certain relationship between events with strong tremble recoded by Golmud Station in November, 2001 and earthquake occurred at west of Kunlun Mountain Pass, nearby the station, on 2001 - 11 - 14, has been found. That information is very important for earthquake prediction research and geodynamic recognition.
Based on the analysis of the aircraft structural life envelope (ASLE) under the baseline operational conditions, an approach of establishment of aircraft structural life envelope (ASLE) under nonbaseline operational conditions is presented. The method of service life supervision for individual aircraft structural system(SLSFIASS) under nonbaseline operational conditions is given. Taking the supervision of the time between the first and second overhauls for an aircraft structural system for example, the supervising methods and steps of SLSFIASS are demonstrated.
For the concreting construction and running process of north anchor foundation of Runyang suspension bridge, the three - dimension finite element simulation model considering the interaction of anchor foundation and soil is founded based on the secondary development of Marc. During the construction process, the change of groundwater level results in the change of the water pressure under foundation, and then the change of the distribution of contact stresses. By the numerical simulation from the construction to running process, the change law of the contact stresses of gravitational rock - socketed anchor foundation is opened out. By the computation for the engineering example, during different stages of concreting construction, though the contact stresses of different parts of anchor foundation take on different characters，the contact stresses of north anchor foundation from the concreting process to running process satisfy the request of design as a whole.
The bearingless permanent magnet synchronous motor (BPMSM) is an innovational type of motor, which has all excellence of magnetic bearings. In the paper, based on the basic working principle of BPMSM, the mathematical models of the radial forces and rotation part on BPMSM are deduced by adopting rotor magnetic field oriented control strategy. A digital vector control system according to the demand of decoupling is designed by using TMS320LF2407 DSP technique. The hardware and the software of the digital control system are developed in this paper. The experimental results have shown that the steady suspension of the rotor is realized and the speed of the rotor can be continuously adjusted within the range of 0〜3 000 r/min.
The value of detained mass of material is important for researching the dead bed point of fluidized drying. In order to acquire the effect law of structure of opening hole in gas distributor on detained mass of material, the drying processes of detergent suspension liquor were investigated in the inert particle fluidized bed drier. The curves of detained mass of material for drier with vertical-hole distributor and tithed-hole distributor were measured and compared under the same experimental parameters, such as feed volume, diameter of inert particles, gas temperature of entrance, height of static bed, gas rate of entrance, and concentration of material. Based on the result, the relationship data of drier with tilted-hole distributor were determined between the production capacity and the hole ratio of distributor. The results show that the detained mass of material increase with adding the feed volume or concentration of material, and decrease with adding the diameter of inert particles, gas temperature of entrance, height of static bed, or gas rate of entrance. In addition, changing the hole shape of distributor from vertical-hole to tilted-hole and adding the hole ratio of distributor, can help drier reduce the detained mass of material and enhance the production capacity.
Based on the characteristics of the ECS, pulse width-fuzzy control concept was put forward. Four models, pulse width regulating, PID control, fuzzy control and combined control, were established with Fuzzy and Simulink tool boxes in MATLAB. The difference between the temperatures of mixed flow and the objective and its change rate were the input in the fuzzy system, and the output, the control signal, was obtained by fuzzy reasoning. Rank skipping response characteristics of the four control methods were computed and analyzed with temperature rank skipping signal. A group of dynamic parameters were selected as the input data, by which dynamic response of the combined control model was simulated. The result showed that combined control system could solve the problem of temperature fluctuation in existing pulse width regulating system efficiently.
In recent years space-time trellis codes (STTCs) have attracted a great amount of research interest in wireless communication. However, the design criterion for STTCs is still a difficult problem. In flat fast fading channels, when the number of antennas is large, the space-time trellis codes design criterion, which is based on maximizing the minimum squared Euclidean distance, is better than the traditional distance and product criteria. Nevertheless, the former criterion is still not perfect. In this paper, from the aspects of squared distance distribution and squared distance sum-square square-sum ratio distribution, an improved criterion is presented, and some new codes are also obtained, which are the best codes known. In addition, a new reason is given, which can explain the different performance of a code between in slow fading channels and in fast fading channels. Finally the improved criterion is introduced into the design of smart-greedy codes.
The real-time performance of switched Ethernet is a hot research field. However, there isn't an effective modeling to describe it until now. Through analyzing the structure of classical switch, a switch model by network calculus is proposed, in which the data flow is divided into real-time flow and non-real-time flow and the arrival curve, service curve, the max delay and max storage needed are got. The max delay provides theory direction for transmitting real-time data in switched Ethernet and the max storage provides the theory reference for constructing switch in real-time industrial Ethernet.
Based on the synthetic study of costing, quality and construction period, the multi-objective optimal model considering the maximal pure value and quality of construction project is made in order to improve economic benefit of construction enterprise. Then, a new method called differential evolution is introduced into the multi-objective optimization. The model and validity of this algorithm are tested through project case.
On account of fine appearance and lucidity of glass, fire-resistant glass has been widely used as architecture exterior materials and fire-resistant compartmentation in modem buildings. Especially, single-pane fire-resistant glass is more widely used than compounding one because of its higher light transmission and less weight in construction. However, single-pane fire-resistant glass can only prevent the spread of fire and smoke, while high temperature and thermal radiation flux on its rear surface may cause a new fire on the protected side. Furthermore, fire-resistant glass is usually quite close to evacuation passage, so it will be harmful to security evacuation. These shortcomings prevent single-pane fire-resistant glass from using in practice. This article describes the experimental study of single-pane fire-resistant glass performance with sprinkler protection. The test setup was introduced in detail, and the test results were discussed. It is showed that the temperature and thermal radiation flux on the protection side of single-pane fire-resistant glass with sprinkler protection are quite lower than those without sprinkler condition. The fast responding sprinkler can automatically spray well-proportioned water and protect certain area. The study of this article may be of benefit to the evacuation calculation in performance-based fire design and engineering application of fire-resistant glass.
With experimental measurement and analytical technology, the research of fire propagation over the surface of some combustible solid is conducted. Within mini-typed wind tunnel, the fire propagation over some typical solid surface under different air stream is studied. Four types of materials were studied： thin paper, typical upholstery wood (three-ply, five-ply)and the commonly used thick paper for packing. The effect with the conditions of water mist loading is analyzed and some results are gained, which may give some instruction for the project work.
To solve the problem of slope caused by blasting vibration damage at a certain iron mine, YBJ-1 blasting vibration seismometer and CD-1 velocity-meter were used to observe the velocity of particle caused by blasting according to the rock properties and the scale of blasting. The spreading law of blasting wave in the iron mine were acquired to propose an effective method of controlling the maximum blasting vibration velocity, which will keep slope close to blasting area safe from blasting vibration damage. The vibration velocity was proved to be relevant to explosive quantity and the location of testing spot. The magnifying effect of velocity along the height of slope was proved to decline with the relative height increasing. In terms of control of the maximum explosive quantity at the same time and the millisecond delay interval, blasting vibration has been reduced at the ratio of 23.6% . 15 ms delay interval was proved to be rational through the experiments in an open pit.
In order to solve the problems of stone exploitation, the mechanism of crack initiation and its expansion of directional fracture controlled blasting with linear cavity effect cutter in rock were roughly studied based on the theories of cumulative energy effect, mechanics of explosive and rock fracture mechanics, then the blasting parameters were designed and tested by model test in laboratory and field. The experimental results show that the energy from blasting can be directionally concentrated by the cumulative energy jet. The directional expansion of crack is satisfactory. Model test and field test suggest that the directional fracture controlled blasting with linear cavity effect cutter is a good means in excavating tunnels or cutting rock. It points out that the prospect of this method is promising. All these will give beneficial references to related theoretical study and field application.
The friction factor for the turbulent flow in pipes is the binary nonlinear function of Reynolds number and relative roughness. Calculating friction factor by implicit Colebrook equation have to use iterative algorithm, which is discommodious.The intelligent fitting method for binary nonlinear polynomials was presented in order to obtain a high precise and simple form explicit equation for calculating the friction factor. The binary nonlinear polynomial was firstly transformed into multivariate linear polynomials, and the least squares standard matrix was established. Then the number, the form, the index and the coefficient of polynomials term were searched to obtain the optimum function by genetic algorithms combined with matrix method. Fitting the data calculated by Colebrook equation with the above method, a new explicit equation for calculating the friction factor for the turbulent flow in pipes was obtained. The new equation can reproduce the Colebrook equation with average deviation of 0.5% and the maximum deviation of 1.8% in the range of Reynolds number being 3 000≤Re≤108 and relative roughness being 0≤e/d≤0.05，and it has an average deviation of 2.3 % to the experimental data. The new equation has the advantages such as simple form, high precise, wide range of application, and can be simplified to the equation for calculating the friction factor in the range of smooth pipe and the rough region easily.
Circulation economy is a new mode of economic development, and is an effective approach for new industrialization and sustainable development. Corporations must reconsider and adjust its development strategy and make innovation in aspects of concept, organization, management, institution, technology and product.
The double-membrane(ultrafiltration and reverse osmosis) water treatment process features high quality of treated water, easy for realizing autocontrol, less land occupied, low water consumption, environmentally friendly, etc. The paper introduced the application of the double-membrane process in the reuse system of the waste water in Handan iron and Steel (Group) Co. Ltd.
Risk evaluation is the basis of acquisition management for weapon and equipment. Based on the totally analyzing and summarizing risk matrix widely used abroad, the paper firsdy discusses the application of risk matrix in acquisition risk evaluation for weapon and equipment in China. Then, the paper, beginning with the two rules of risk impact and risk probability, demonstrates risk evaluation of a type of weapon and equipment as a case study, thus lays a basis for the scientific and rational risk management decision making.
The extensive marketing power is the ability of obtaining the consumers' approval during the course of market competition. This kind of approval may directly bring the sales volume, the profit, or just cause the consumer's interest to the enterprise or the product, the brand, but certainly will be able to build the good foundation for the enterprise's future. This paper puts forward a new method to evaluate this important power, so as to make a relatively scientific way to help raising enterprise's influencing power in market.