Ammonium illite that belongs to 2:1 layered silicate minerals is a kind of di-octahedral mica-like clay minerals, and it is the isomorphism of illite, in which the K^{+} was substituted by the NH_{4}^{+}. By means of XRD, IR and XPS, ammonium illite was discovered in some coals and coal partings of Eastern Taihang Piedmont Coalfields, and mineralogical researches were studied in detail. The result of XRD spectrogram shows that ammonium illite's X-ray diffraction peak of d_{(001)} is higher than that of ordinary illite, whereas its (002) and (003) diffraction peak intensity is similar. but the ordinary illite's(002)diffraction peak intensity is 24.4%, which is about 1/3 of the (003) diffraction peak intensity. Lattice parameters about ammonium illite in the investigative area are calculated, and the results show that its space group is C2/m, with every parameters including a (0.52133nm to 0.52774nm), b (0.89814nm to 0.91693nm), c (1.02538nm to 1.05285nm), β(101.127° to 101.699°), z (2, volume is 0.47611nm^{3} to 0.49224nm^{3}), density (2545 e^{-}/nm^{3} to 2697e^{-}/nm^{3}). The above descriptions indicate that the ammonium illite is 1M polytype. The results of IR spectrogram demonstrated that the deformation vibration peak of NH_{4}^{+} range from 1427.58cm^{-1} to 1431.95cm^{-1}, and the N 1s XPS banding energy of NH_{4}^{+} is 402.4eV. In nature the ammonium illite-illite solid solution is more general than pure ammonium illite. Thus, mostly ammonium illite contains a certain amount of K. Therefore, the K 2p peak is often observed by the XPS spectra.

In order to study the stability of complex mud roof of coal roadway under the mining pressure, example of the working surface 20307 in Gao Jialiang Coal Mine is presented. Based on the analysis of rocks microstructure characteristics and measurement of surrounding rock loose circle by hole examining method, the complex mud roof of coal roadway is the geological soft rock which is a complex type of stress dilatancy expansion. The mechanisms of roadway damage are complex deformation mechanisms includingⅠ_{AB}Ⅱ_{BD}Ⅲ_{DA}, and the bolt-mesh-cable-grout with steel band coupling support design is proposed, which adopts the finite difference program FLAC^{3D} to simulate the stability of complex mud roof of coal roadway with coupling support; Then it also adopts the in-situ investigation to perform field monitoring for the deformation of coal roadway, and the comparative analysis between numerical analysis and field monitoring is studied. The results reveal that stability of complex mud roof of coal roadway is effectively in control under the mining pressure, which consequently verifies the validity of deformation and damage mechanisms of complex type of stress dilatancy expansion and the effectiveness of coupling support proposed in this paper, meanwhile it also provides the reference to the similar engineering geologic condition of coal roadway.

In order to increase the effective payload of the prefabricated fragment projectile and enhance the comprehensive damage power, this paper studies the launching strength of the prefabricated fragment covering layer using fiber composite materials instead of metal materials both theoretically and experimentally. The results show that the covering layer using the carbon fiber T700S and the steel can satisfy the strength requirements, but not by using the E glass fiber under the high overload. By the way, the cost of fiber composite materials is lower than that of the steel. The research result can be used to evaluate the application prospect of the correlation ammunition using the fiber composite materials.

When data are scare or monitoring is difficult in the study areas which are under the risk of contamination by reproductive health estrogens, it is necessary to evaluate the leaching migration ability of the estrogens based on their structures and activities in the environment, in order to estimate the migration ability of environmental estrogens and the groundwater contamination risk. Eighty one reproductive health estrogens were selected for the evaluation of their migration abilities in the subsurface environment based on the Groundwater Ubiquity Score method (GUS). It is shown that 69.14% of these estrogens are highly leachable, and 7.40% of them are of moderate migration ability. The GUS values of the priority toxic organic pollutants on the EPA list, i.e. estradiol, estrone, estradiol three alcohol, DDT and DDE are 3.58, 7.73, 3.19, -3.34 and -2.68, respectively; among them, estradiol three alcohol has the highest GUS value. More than twenty estrogens tested have GUS values higher than the GUS value of estradiol three alcohol. The migration abilities of these reproductive health estrogens in the subsurface environment are mainly affected by the organic carbon adsorption coefficient.

The transport behavior of fluids in low permeability coalbed methane reservoirs is analyzed with considerations of the desorption and diffusion effects of the coalbed methane and the threshold pressure gradient. A mathematical model for gas-water two-phase nonlinear flow is established for low permeability coal reservoirs. The governing equations for the gas-water two-phase nonlinear flow are derived. The case study shows that, when the liquid phase threshold pressure gradient is increased from 0.001MPa/m to 0.007Mpa/m, the maximum gas production of coal reservoirs is reduced by nearly 15%; compared with the liquid phase threshold pressure gradient of 0.001MPa/m, the maximum gas production without the threshold pressure gradient is increased by nearly 7% and the cumulative gas production also has a certain extent of increase. Therefore the existence of the threshold pressure gradient makes the fluid in fractures more difficult to flow and leads to a low production rate. The case study shows that the mathematical model of the gas-water two-phase nonlinear flow could provide a theoretical basis for defining a reasonable gas-well deliverability of low permeability coal reservoirs.

In view of the low permeability reservoir after fracturing development that can cause the asymmetrical vertical fracture, the productivity of this oil well is little information. Thus based on the steady seepage theory, with the aid of conformal transformation method, a prediction model for the finite-conductivity asymmetrical vertical fracture wells was established, and the various factors on the productivity of oil well were analyzed, under the influence of the start-up pressure gradient in the low-permeability oil reservoirs. The result shows that the decrease of productivity decreases is caused by start-up pressure gradient. In the same start-up pressure gradient, the productivity decreases with the increase of the production pressure. When the conductivity capacity of fracture becomes small, there is obviously difference for the productivity of fracture oil well in the crack length and fracture asymmetry factor. And when the conductivity capacity of fracture becomes big, there is little difference for the productivity of fracture oil well in the crack length and fracture asymmetry factor. The longer is the crack length and the less is the fracture asymmetrical factor, the greater is the productivity of the fracture oil well.

In order to guarantee the safety and mining efficiency of the high-stage second-step stopes in the high-stress situation, finite element program ANSYS is used to analyze the stability of the stopes for section-by-section excavation. And the stress and strain distribution of roof and filling body is obtained from the simulation. The result shows that the maximum tensile stress (0.21-0.39MPa), located at the roofs, is more than tensile strength (0.17MPa) of ores. The maximum pressure (0.90-2.00MPa), located at the filling body which is one meter away from the roof, approximately reach to the limitation of its pressure strength (2.00MPa). Tensile stress at roof and pressure stress of filling body with mining upwards present a declining trend. According to the hidden danger of the second-step stopes presented by numerical simulation, it is put forward to adopt medium-length hole downward sublevel drill and fill stoping with pre-protecting roof. And the combined supporting method that combines pre-stressed resin bolt, steel ban (metal net) and gunite, is used to pre-protect the roof. Support parameters are adopted based on the radius of loosening zone, which is confirmed through the numerical simulations. Effective support measures is put forward and applied to engineering tests, and then its result confirms the high safety and mining efficiency of the stope.

In order to overcome the defects existing in the lower efficiency of structure learning caused by directly applying particle swarm algorithm to it, i.e. the search space is too large; a hybrid particle swarm algorithm for Bayesian network structure learning is presented based on unconstrained optimization problem. Firstly, for the algorithm, an unconstrained optimization problem is established and solved; the edges in the undirected graph corresponding to the optimal solution could provide a search range for structure learning and reduce the search space of particle swarm algorithm; then, Bayesian network structure learning is completed in the reduced space. Therefore, the leaning efficiency of particle swarm algorithm is raised. The simulation results indicate that the proposed method is able to quickly and accurately learn the optimum Bayesian network structure.

Information space of an urban system is a virtual space based on urban geographical space, which is filled with information elements, and interconnected by information flows both longitudinally and laterally. The development of new generation information technology is upgrading both structure and level of information space. Smart city which represents the advanced stage of urban information space has characteristics of thorough perception, interconnection, intelligent application in the process of data collection, information exchange and system application performance. Based on the information space theory, "3I" information space including instrumented, interconnected and intelligent space is proposed, and a three-dimensional model of smart city is constructed to enrich the theoretical system, so it can provide the guidance for China's smart city practice.

A mosquito uses a natural "microneedle" system called fascicle, with a large ratio of the length to the diameter and high flexibility and strength, to painlessly penetrate into human skin and suck blood. The strength of natural "microneedle" system has never problem in the penetrating process. A set of force measurement device with high precision of micro-Newton is designed to measure the insertion force to understand the penetrating process of mosquito fascicle into human skin. The measured results show that the penetrating force of mosquito fascicle into skin is approximately 16μN. In addition, it has also been found that after the mosquito fascicle tip penetrates into the surface of skin, the force of the mosquito's fascicle penetrating deeper into the skin will decrease as the insertion depth increase, and then levels out at a surprisingly low mean force (even almost be zero). While the insertion force of an artificial needle is 165mN, the force of the artificial needle penetrating deeper into the skin will continue to increase. The study on the insertion mechanism of the mosquito fascicle shows that the mosquito's micronano-structure fascicle and its amazing oscillation inserting skill make it easily penetrate into human skin with a surprising low force. The results are helpful for the optimum design of the microneedles and transdermal drug delivery system.

The suitable guidance law of air-to-air in Endgame must ensure that the missile with the minimum miss-distance hits the target implementing best escape strategy. Because the characteristic of maneuverable target is hard to be mastered, and in order to improve the hit accuracy of missile, it required the higher motor overload and the smaller time constant of missile flight control system in practical design of engineering. Thus introduce of reaction-jet control can obviously improve the missile maximum available overload, and reduce the time constant of missile flight control system. In this paper a variable structure guidance law is designed based on the proportional guidance law. Variable structure control system can provide the same features to overcome the influence of target maneuver, and achieve the goal of zero under the bounded maneuvering condition of LOS angular velocity, which made the ballistic flight to show the characteristics of parallel approaching method in the missile-after guidance process, and then it can improve the missile guidance performance. Analysis of the guidance loop on the stability and simulation analysis of the guidance system with or without the reaction-jet controller demonstrated that the miss-distance of the variable structure guidance law is smaller than PNG and the effect is better with reaction-jet controller.

Path routing for Unmanned Combat Aerial Vehicle (UCAV) can be defined as the task of Unmanned Combat Aerial Vehicle automatically executing, which is a complex optimization problem. It is very hard to get the optimal solution in polynomial time. Therefore, in this paper a path planning method was proposed based on Voronoi diagram and Quantum-behaved Particle Swarm Optimization (QPSO) algorism. Firstly, the cost model for path planning of UCAV was defined by totally consideration for the radar threat and fuel consumption, and the Voronoi diagram was generated according to the given threat source. And then the initial path planning set was constructed by initial sites, the vertex of Voronoi diagram and the final sites. Finally, in order to conquer the problem of PSO algorism that has the defects of falling to optimal location, the Cauchy mutation random number was introduced to improve the global search ability of QPSO algorism, and using the improved QPSO algorism to plan path the specific algorism was defined. The result of simulation experiment shows the method proposed in this paper can obtain the optimal solution for UCAV, and it has the optimal cost 280 in comparison with PSO 600 and QPSO 350, respectively. Meanwhile, at the mean time, when the iteration time is 250, the improved QPSO in our paper is in convergence, so it can provide not only the optimal solution but also the rapid convergence speed. Thus it has big superiority over the other methods.

The adjuvant therapy of video games is developed to be a new type of treatment in recent years. Video Games and psychology principle play the important roles in the therapy, and a combination of these two methods is the key pathway in order to obtain the better effect of the adjuvant therapy. In this paper, firstly, the possible mechanism of adjuvant therapy using video games in the medical field is described. Then, the situations of virtual reality game applying in treatment of various diseases are reviewed. From the present situation, the difficulties are respectively pointed out in the views of effect, operability and position. Because of its unique interactivity and privacy advantages, the adjuvant therapy of video games is generally accepted and is regarded as a promising treatment in the medical field, however further improvement is required. To further expand the indications, professionals and systems supported in the combination of medicine and video games are the focus of further development in the future.

书评

Select

Science & Technology Review. 2013, 31 (22): 80-80. ; doi:
Full text:
HTML
(0 KB)
PDF
(466 KB)
(
61
)