The adjusting mining technology of combining fully mechanized with individual prop,rotating,hilt,irregular form,and double unit face on thin coal seam of Tianchen Mine

Analyzed the situations and characteristics of thin coal seam mining and its mining technologies,and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China.This innovation technology combined the fully mechanized mining with individual props,and the working face of mining is over length,irregular form and double units.The rotational adjusting mining technology on thin coal seam is also practiced in this new mining technology.The detail technologies,such as outlays of working face and ways,mining methods,equipments of cutting,transporting and sporting,have been introduced.So that,using the synthetic and creative mining tech- nologies,Tianchen Coal Mine solves the mining problems of thin coal seam successfully.

Back-and-forth mining for hard and thick coal seams—research about the mining technology for fully mechanized caving working face of Datong Mine

The article introduced the key technology, mining process, and back-and-forth mining method for the caving working face of hard-thick coal seams in Datong mine, and researched this innovations process, optimized the systemic design and working face out-play, tried to perfect the caving mining technology of hard-thick coal seams further.

Modeling and Free Vibration Behavior of Rotating Composite Thin-walled Closed-section Beams with SMA Fibers

Smart structure with active materials embedded in a rotating composite thin-walled beam is a class of typical structure which is using in study of vibration control of helicopter blades and wind turbine blades. The dynamic behavior investigation of these structures has significance in theory and practice. However, so far dynamic study on the above-mentioned structures is limited only the rotating composite beams with piezoelectric actuation. The free vibration of the rotating composite thin-walled beams with shape memory alloy（SMA） fiber actuation is studied. SMA fiber actuators are embedded into the walls of the composite beam. The equations of motion are derived based on Hamilton＇s principle and the asymptotically correct constitutive relation of single-cell cross-section accounting for SMA fiber actuation. The partial differential equations of motion are reduced to the ordinary differential equations of motion by using the Galerkin＇s method. The formulation for free vibration analysis includes anisotropy, pitch and precone angle, centrifugal force and SMA actuation effect. Numerical results of natural frequency are obtained for two configuration composite beams. It is shown that natural frequencies of the composite thin-walled beam decrease as SMA fiber volume and initial strain increase and the decrease in natural frequency becomes more significant as SMA fiber volume increases. The actuation performance of SMA fibers is found to be closely related to the rotational speeds and ply-angle. In addition, the effect of the pitch angle appears to be more significant for the lower-bending mode ones. Finally, in all cases, the precone angle appears to have marginal effect on free vibration frequencies. The developed model can be capable of describing natural vibration behaviors of rotating composite thin-walled beam with active SMA fiber actuation. The present work extends the previous analysis done for modeling passive rotating composite thin-walled beam.

Exploration of Market Mechanism on Controlling Air Pollution and Carbon Emissions in China

Based on increasingly grim situation of carbon emissions in China,air pollution control and carbon emission reduction are very important. Therefore,combining with China’s specific national conditions,we should explore the market mechanisms to control air pollution and reduce carbon emissions in China. The achievement of the carbon emission reduction purpose needs to establish the carbon trade market based on intensity emission reduction and suitable for China’s national conditions. By setting the cross-industry,cross-region and cross-time carbon trade scenarios in China,this paper tries to study the market mechanism of carbon intensity trade among industries and regions and based on carbon finance mechanism.

The Existence of Periodic and Almost Periodic Solutions of Logistic Type Equation

In this paper, we study the Logistic type equation x= a（t）x -b（t）x^2＋ e（t）. Under the assumptions that e（t） is small enough and a（t）, b（t） are contained in some positive intervals, we prove that this equation has a positive bounded solution which is stable. Moreover, this solution is a periodic solution if a（t）, b（t） and e（t） are periodic functions, and this solution is an almost periodic solution if a（t）, b（t） and e（t） are almost periodic functions.

Analysis and evaluation of structural complexity of circular economy system＇s industrial chain

This paper examined the method to evaluate structural complexity of circular economy system＇s industrial chain, which applied entropy information and hierarchical metrics to produce complexity degrees according to the theory of complex system. We developed an evaluation model to make a general metrics for circular economy system of industrial chains. The development of the evaluation tree drew upon five factors to identify the structural complexity. The evaluation model generated unitive entropy information from six data definition （node, level of community, metabolic span, degree of node, number of relation and connectivity of node） according to the evaluation tree. The industrial chains of Tashan circular economy park of Datong Coal Mine Group and Gujiao circular economy park of Xishan Coal-Electricity Group were evaluated by the proposed method. The key factors stunted by the decline of structural complexity were identified and the unitive metrics of entropy information of the industrial chain was shown for realigning the circular economy systems.

Query and Improvement of the Project Appraise Method Promoted by the State Planning Commission

This paper expounds the existent problems in the method and parameter of economic evaluation on construction project, which distributed by the State Planning Commission. By using technical economics principles, the author analyzes the problems and finds out the reasonable, simple, practical methods to solve the mutually exclusive schemes problems.

The Evaluating Method of Technology Innovation Risk

The thesis analyzes risk factors of enterprise＇s technology innovation, adopts the undetermined measuring model to evaluate technology innovation risk and testifies it through an example.

Notes on Noncommutative VNL-rings and GVNL-rings

In this note, a counterexample is given to show that a noncommutative VNL-ring need not be an SVNL-ring, answering an open question of Chen and Tong （Glasgow Math. J., 48（1）（2006）） negatively. Moreover, some new results about VNL-rings and GVNL-ringsare also given.

ON THE EXTINCTION OF POPULATION-SIZE-DEPENDENT BISEXUAL GALTON-WATSON PROCESSES

In this article, the population-size-dependent bisexual Galton-Watson processes are considered. Under some suitable conditions on the mating functions and the offspring distribution, existence of the limit of mean growth rate per mating unit is proved. And based on the limit, a criterion to identify whether the process admits ultimate extinct with probability one is obtained.

Establishment of Comprehensive Evaluation Model of the New Generation Migrant Workers' Employability

Through literature research and expert interviews,we extract 10 variables influencing the new generation migrant workers' employability,and establish the comprehensive evaluation model of the new generation migrant workers' employability. Using factor analysis,we derive that the model includes three factors: skill literacy,relationship literacy and basic literacy. The weights of each factor are 0. 580,0. 244 and 0. 174 8,respectively. Skill literacy is affected by skill level,learning ability,career aspiration,ability to analyze problems,physical health status and other factors. Relationship literacy is affected by the sense of teamwork,interpersonal skills,social support and other factors. Basic literacy is affected by educational level,hardworking spirit and other factors. According to the results,we put forth the following recommendations to improve the new generation migrant workers' employability: strengthening the vocational skill training; coordinating the vocational education resources.

Degree of Compactness in I-fuzzy Topological Spaces

In this paper, the concept of degree of compactness is introduced in the general framework of I-fuzzy topological spaces, and its property is discussed. All good compactness are generalized to I-fuzzy topological spaces accordingly.

Strong Convergence of an Implicit Iteration Process for a Finite Family of Asymptotically Ф-pseudocontractive Mappings

Strong convergence theorems for approximation of common fixed points of asymptotically Ф-quasi-pseudocontractive mappings and asymptotically C-strictly- pseudocontractive mappings are proved in real Banach spaces by using a new composite implicit iteration scheme with errors. The results presented in this paper extend and improve the main results of Sun, Gu and Osilike published on J. Math. Anal. Appl.

The Study on the Evolutional Mechanics of Technological Innovation Network

Based on the statistical mechanics and technology innovation network, this paper analyzed network evolutional mechanics, and constituted its evolutional model.

Long Term Assessment of a Grid Connected Solar PV System in Sydney

This paper assesses 4 years of operation of a 1.75 kW roof top solar PV system installed in a Sydney suburban house. The system consists of 10 PV panels, a DC/AC inverter, and a grid connected gross meter. Solar electricity delivered to grid is verified with the results from a computer simulation package （PVSYST） by adopting the installed component specifications, operation conditions, and weather data of the site. The results show high consistency between the values of energy delivered to the grid measured by the energy company and the energy estimated by system simulation. New system performance indicator is developed and called the optimum performance compliance ratio （PCR）. It is a measure of the compliance of the output of the designed PV system with the output which would be produced by the same system with a solar tracker. This indicator provides system designers, contractors and energy providers with the actual capacity of the system that they can offer the end-users.

Optimal parameterization of conic curves

Optimal parameterization of specified segment on the algebraic curves is a hot issue in CAGD and CG. Take the optimal approximation of arc-length parameterization as the criterion of optimal parameterization, and the optimal or close to optimal rational parameterization formula of any specified segment on the conic curves is obtained. The new method proposed in this paper has ad- vantage in quantity of calculation and has strong self-adaptability. Finally, a experimental comparison of the results obtained by this method and by the traditional parametric algorithm is conducted.

A multi-scale scheme for image segmentation using neuro-fuzzy classification and curve evolution

In this paper, we present a new scheme to segment a given image. This scheme utilizes neuro-fuzzy system to derive a proper set of contour pixels based on multi-scale images. We use these fuzzy derivatives to develop a new curve evolution model. The model automatically detect smooth boundaries, scaling the energy term, and change of topology according to the extracted con- tour pixels set. We present the numerical implementation and the experimental results based on the semi-implicit method. Experi- mental results show that one can obtains a high clualitv edge contour.

High Speed Versatile Reed-Solomon Decoder for Correcting Errors and Erasures

A new Chien search method for shortened Reed-Solomon （RS） code is proposed, based on this, a versatile RS decoder for correcting both errors and erasures is designed. Compared with the traditional RS decoder, the weighted coefficient of the Chien search method is calculated sequentially through the three pipelined stages of the decoder. And therefore, the computation of the errata locator polynomial and errata evaluator polynomial needs to be modified. The versatile RS decoder with minimum distance 21 has been synthesized in the Xilinx Virtex-Ⅱ series field programmable gate array （FPGA） xe2v1000-5 and is used by coneatenated coding system for satellite communication. Results show that the maximum data processing rate can be up to 1.3 Gbit/s.

Biphasic behavior of energy in a stepped chain

The impact energy decay in a step-up chain containing two sections is numerically studied.There is a marked biphasic behavior of energy decay in the first section.Two sections close to the interface are in compression state.The degree of compression of the first section first decreases and becomes weakest at ＂crossing＂ time of biphasic behavior of energy,then increases.The further calculations provide the dependence of the character time on mass ratio（m1/m2）,where m1 and m2are the particle mass in the first and second section respectively.The bigger the α（α = [（？ m1-m2）/（？ m1＋ m2）]2 with？ = 1.345）,the bigger the energy ratio is.The multipulse structure restricts the transport of energy.

On π-regularity of General Rings

A general ring means an associative ring with or without identity.An idempotent e in a general ring I is called left (right) semicentral if for every x ∈ I,xe=exe (ex=exe).And I is called semiabelian if every idempotent in I is left or right semicentral.It is proved that a semiabelian general ring I is π-regular if and only if the set N (I) of nilpotent elements in I is an ideal of I and I /N (I) is regular.It follows that if I is a semiabelian general ring and K is an ideal of I,then I is π-regular if and only if both K and I /K are π-regular.Based on this we prove that every semiabelian GVNL-ring is an SGVNL-ring.These generalize several known results on the relevant subject.Furthermore we give a characterization of a semiabelian GVNL-ring.