Sulphate rock and carbonate rock both are usually distributed together, but their karst deve -lopments are most studied separately.It is mainly to research the compound karst developmental mechanism between the two soluble rocks,which are involved in the chemical karstification and the biological karst processes.The karst collapsed column is a special karst hazard of the compound karst,and the karst underground water quality is also discussed.
Karst constitutes one of the greatest landscape styles of the world and China is one of the places where its finest expressions can be seen. From the point of view of karst features and evolutional histories, and by comparative analysis on the three sites with worldwide similar karst areas under the eighth criterion of world heritage, the outstanding universal value is uncovered: Shilin stone forest in Yunnan is the most complicated in the evolution history richest in the forms,which represents a unique evolvement mechanism of stone forest development;which possesses not only the most typical karst cones, but also the most complex assemblages of the cone karst. Libo cone karst represents typical factors of cone karst landforms reflects geological evolvement models and processes in the tropical-subtropical continent; Wulong gorge karst shows integrally development and evolution system of the gorge karst, records evolutional forms of different phases of gorge karst, such as karst gorges, underground rivers, natural bridges, collapse dolines, caves and so on, and illustrats on-going evolution process on the neotectonic movement. As a result, south China karst (Phase 1) world heritage sites represent a long-term, multi-phased evolution history in south China since Paleozoic; the landform features of tropical-subtropical typical cone karst, stone forest karst and gorge karst; the development and evolution mechanism and on-going geological process of tropical-subtropical cone karst, stone forest karst and gorge karst landforms; and unique physical geography characters of the largest in the three vast karst areas in the world.
China southwest area locates at the edge of Qinghai-Tibet plateau and is close to east side of collision zone between India plate and Eurasian plate where the geologic structure is quite complicated with serious geologic hazard. Combined with the survey and design, construction and operation of such important trunk railway lines as Bao-Cheng railway, Gui-Kun railway, Cheng-Kun railway, Xiang-Yu railway, Nan-Kun railway, Nei-Kun railway and Yu-Huai railway, etc., in complicated southwest mountainous region, the general condition of geologic hazard of southwest railway is summarized and the railway geologic survey and engineering control technique experience for several kinds of main geologic hazard are systematically presented.
The fearful karst collapses have been produced in succession since 1970s by the exploitation of karst water in the area of Tai'an-Laiwu, Shandong province. The limestone buried by Quaternary System grows into karst caves, and karst collapse brings enormous harm to the local society and economy development. The spatio-temporal distributing characteristics of karst collapse are summed up in detail. The geological condition, artificial function and forming mechanism of karst collapse are discussed. The cause mode of the karst collapse aiming at the existing questions is discussed and the idea for karst collapse studying in the future is given at last.
A direct way to obtain the characteristic information about a nuclear reaction is to detect the rays released from the reaction. To explore the performances of a prompt fission or fusion reaction, sophisticated diagnostic techniques and equipments have been developed and established in China. The diagnostic equipments can measure intense and rapidly changing neutron and gamma rays fluxes in highly mixed neutron-gamma radiation fields. They operate in current mode, and meet a series of special needs in characteristic properties, such as selective radiation sensitivities, a wide dynamic range, a large linearity, a good neutron to gamma ray discrimination, a very fast time response, reliability, etc. Pulse radiation detection has found its various applications in scientific researches, including nuclear reaction mechanism, material analysis, and astronomy study. These diagnostic techniques and their relative detection systems, the design principle, the parameters which are important for current-mode applications are discussesd in th is paper.
The track irregularity which is the main vibrating resource of the vehicles and one of the main factors to limit the train highest speed, plays a very important part in the safety, stabilization and comfort of the trains. The statistic samples used by this paper are collected by track geometry inspection car from Qin-shen special line for passenger transport. Based on the stationary character test of the samples, FFT method was used to evaluate the spectrum of the statistical sample space, and MATLAB soft was used to get the PSD(power spectral sensity) of track irregularities. Based on statistical average of the samples of the track irregularities, frequency smoothing of the PSD and coupare with PSD of the main-line of Chinese railway were made. The curve to the PSD was fit. Then the track state of Qin+shen special line for passenger transport was evaluated.
Based on the principle of the integrated strengthening of steel, the strengthening and the softening of HSLC steel have been studied by controlling the precipitation of carbon in steel around A1 temperature. The results show that strength of HSLC steel produced by TSCR can be further increased. By using temper-slow cooling, σs of HSLC steel(ZJ330) produced by TSCR can be decreased from 344 MPa to 225 MPa to meet the requirement of producing basal plate for cold rolling. Problems about ferrite rolling, ultra fine grain steel and a possible new type building materials have been discussed.
The continuous rolling tension formula is the core of the theory and the application of continuous rolling system. A lot of studies have been made both in China and other countries. In 1960s, the author introduced continuous rolling differential formula, the dynamic tension formula for multi-stands and the stable state tension formula. All these formuls have been discussed in detail.The Japanese derived the tension formula in theory in 1970s and they did experimental demonstrations, among which the experimental results made by Motoho Asakawa is the most important. Herein, the tension formula is demonstrated by employing the data of the experimental results made by Motoho Asakawa and on-the-spot survey data of Baosteel 2050 heating continuous mill.
The drawback of classical matrix converter having low voltage transfer ratio is studied and a topology of a new matrix converter called as a Cuk matrix converter is proposed. The basic configuration of this new topology and its fundamental are firstly introduced, the analytic expression concerning functions relation of voltage transfer ratio to duty cycle is deduced, and the basic design method of double-loop control strategy is expounded. Finally the validity and feasibility of the new topology are tested by simulation.The results show that the output voltage and frequency can be modulated optionally by the new converter, of which the voltage transfer ratio can be greater than 1, or lower than 1, and an ideal sine wave can be directly obtained without filtering. Thus the inherent problem of classical matrix converter having low voltage transfer ratio is effectively solved by this study, which is of certain practical importance.
A new approach to solve the problem of dynamic data mining is presented. Firstly a new concept of dynamic mining process is proposed. Next the evolutionary immune mechanism in KDD is illustrated, based on a comparison between the dynamic mining process and biological immune process.Additionally how to apply the approach to temporal sequential pattern mining and evaluate the experimental results are described. Finally the work and present proposals for future work are concluded.
From the views of balanced score card,a series of indexes and a fuzzy comprehensive evaluation model for the performance evaluation of chained operation enterprise based on its finance,customer, internal management process and the ability of learning and development are introduced in this paper. This novel performance evaluation model overcomes the shortcoming of traditional method and can make benefit for comprehensive evaluation from development aspect.
This Issue
Apr 2008, Volume 10 Issue 4