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This study aims to clarify the evolution law of stress field and fracture field during the mining process of inclined coal seam, to prevent the occurrence of roof burst water and impact ground pressure accident during the advancing process of working face.

The evolution law of stress-fracture field under different mining conditions of inclined coal seam was studied by using discrete element method and similar material simulation method.

The overburden stress at the lower end of the coal seam was mainly transmitted to the deep rock mass on the left side, and the overburden stress at the upper end was mainly transmitted to the floor direction. With the increase of the inclined length of the mining coal seam, the development of the fracture zone gradually evolves from the “irregular arch” form to the “transversely developed trapezoid” form. The development range of the fracture zone was always in the internal area of the stress concentration shell.

An original element of this paper is based on the condition that the dip angle of coal seam is 35°, and the evolution law of overburden stress-fracture field during the excavation of coal seam with different lengths was analyzed by UDEC numerical simulation software. The coupling relationship between stress shell and fracture field was proposed, and the development range of fracture zone was determined by stress. The value of this paper is to provide technical support and practical basis for the safety production of a mine working face.

Based on the institutional background of mandatory requirement of performance-based executive equity incentives, this paper aims to investigate the impacts of executive equity incentives, vesting periods and vesting performance conditions on corporate innovation.

The empirical analysis is based on the detailed data of equity incentives in China’s listed companies from 2006 to 2014, the Tobit method is implemented to estimate the regression coefficients, and the instrumental variable (IV) approach, Heckman two stage regression, propensity score matching and difference-in-difference models are adopted to solve the problem of endogeneity in several robust tests.

This paper documents that equity incentives and vesting periods are significantly and positively related to corporate innovation measured by R&D investment and patent applications, yet requirements on vesting performance impede corporate innovative activities. Specifically, compared with non-equity incentive companies, the R&D investment and the number of patent applications of equity incentive companies are 40 and 46.2 per cent higher, respectively. A one year increase in equity incentive duration can correspondingly increase the R&D investment by 15 per cent and the patent applications by 18.3 per cent. However, a one standard deviation increase in industry-adjusted ROE target reduces corporate R&D investment by 5 per cent and the patent applications by 8.39 per cent. The main empirical findings still hold after several robust tests.

This paper confirms that the impact of performance-based compensation system on corporate innovation depends on its structure. Specifically, the empirical findings suggest that equity incentive plans being correctly designed can enhance corporate innovative activities, but myopic managers will damage the corporate innovation.

This paper investigates the influence of equity incentive structure on equity incentive effect based on the institutional background of mandatory requirement of performance-based executive equity incentives. It provides an opportunity to understand the mystery of equity incentives, which helps to enrich the structure of equity incentive theoretically. The empirical evidence confirms the importance of tolerating short-term failure and extending the horizon of managerial decision-making on promoting innovation. Overall, the research indicates that only well-designed equity incentive plans can promote innovation, which contributes to regulators and practitioners to form a rational understanding of the premise of equity incentives in promoting innovation and provides a reference for their decision-making.

This paper aims to study the impact of land options on the land transfer behaviour of Chinese city governments.

Based on the institutional environment of Hangzhou, China, the option pricing model is used to measure the option value of the trading plots. The effect of the option value on the land transfer price and the timing of transfers are estimated respectively, using the hedonic price model and the survival analysis models.

The results show that the option value has a significant explanation on land price and timing of land transfers. Under the effect of option value, the positive impact of fiscal pressure on the possibility of land transfer weakens. From the perspective of the annual option premium rate, the option premium is closely related to the real estate cycle. Option premiums are higher during booms but lower during recessions and in new urban areas.

By revealing the distinction of land option premiums in different places and times, this paper provides a reference for city governments seeking a balance between real estate regulation and obtaining more land revenue.

By introducing policy variables that reflect the degree of tightness of real estate regulation and indicators of local government financial pressure, the paper discusses the impact of options on the transfer behaviour of local governments in different situations.

This paper aims to study the sampling methods (or design of experiments) which have a large influence on the performance of the surrogate model. To improve the adaptability of modelling, a new sequential sampling method termed as sequential Chebyshev sampling method (SCSM) is proposed in this study.

The high-order polynomials are used to construct the global surrogated model, which retains the advantages of the traditional low-order polynomial models while overcoming their disadvantage in accuracy. First, the zeros of Chebyshev polynomials with the highest allowable order will be used as sampling candidates to improve the stability and accuracy of the high-order polynomial model. In the second step, some initial sampling points will be selected from the candidates by using a coordinate alternation algorithm, which keeps the initial sampling set uniformly distributed. Third, a fast sequential sampling scheme based on the space-filling principle is developed to collect more samples from the candidates, and the order of polynomial model is also updated in this procedure. The final surrogate model will be determined as the polynomial that has the largest adjusted R-square after the sequential sampling is terminated.

The SCSM has better performance in efficiency, accuracy and stability compared with several popular sequential sampling methods, e.g. LOLA-Voronoi algorithm and global Monte Carlo method from the SED toolbox, and the Halton sequence.

The SCSM has good performance in building the high-order surrogate model, including the high stability and accuracy, which may save a large amount of cost in solving complicated engineering design or optimisation problems.

Microribbon with meander type based on giant magnetoimpedance (GMI) effect has become a research hot spot due to their higher sensitivity and spatial resolution. The purpose of this paper is to further optimize the line spacing to improve the performance of meanders for sensor application.

The model of GMI effect of microribbon with meander type is established. The effect of line spacing (Ls) on GMI behavior in meanders is analyzed systematically.

Comparison of theory and experiment indicates that decreasing the line spacing increases the negative mutual inductance and a consequent increase in the GMI effect. The maximum value of the GMI ratio increases from 69% to 91.8% (simulation results) and 16.9% to 51.4% (experimental results) when the line spacing is reduced from 400 to 50 µm. The contribution of line spacing versus line width to the GMI ratio of microribbon with meander type was contrasted. This behavior of the GMI ratio is dominated by the overall negative contribution of the mutual inductance.

This paper explores the effect of line spacing on the GMI ratio of meander type by comparing the simulation results with the experimental results. The superior line spacing is found in the identical sensing area. The findings will contribute to the design of high-performance micropatterned ribbon with meander-type GMI sensors and the establishment of a ribbon-based magnetic-sensitive biosensing system.

The stress–strain behaviors of rockfill materials in dams are significantly affected by the anisotropy and grain crushing. However, these factors are rarely considered in numerical simulations of high rockfill dams. This study intends to develop a reasonable and practical constitutive model for rockfill materials to overcome the above problems.

The effects of anisotropy and grain crushing are comprehensively considered by the spatial position of the reference state line. After the improved generalized plasticity model for rockfill materials (referred to as the PZR model) is developed and verified by laboratory tests, it is used with the finite element method to simulate the stress–strain behaviors of the Nuozhadu high core rockfill dam.

The simulated results agree well with the laboratory tests data and the situ monitoring data, verifying the reliability and practicability of the developed PZR model.

A new anisotropic state parameter is proposed to reflect the nonmonotonic variation in the strength as the major principal stress direction angle varies. This advantage is verified by the simulation of a set of conventional triaxial tests with different inclination angles of the compaction plane. 2) This is the first time that the elastoplastic model is verified by the situ monitoring data of high core rockfill dams. The numerical simulation results show that the PZR model can well reflect the stress–strain characteristics of rockfill materials in high core rockfill dams and is better than the traditional EB model.

The purpose of this study is to solve the key problem of the residual stress of strip in buckling and deviation during the continuous annealing process (CAP).

Considering the one-to-one correspondence between deformation and residual stress, the strip was divided into multiple elements. To obtain the total deformation of each element, the influence model of some factors on the deformation of steel strip element was established. Then, according to the constitutive equation of residual stress and deformation, and the deformation coordination relation between strip elements, a set of calculation model, which is suitable for residual stress of strip during CAP was established, the model precision was verified by finite element method simulation, and the influences on residual stress of strip were also analyzed.

The weighted calculation of comparison between analytical results and simulation shows that the accuracy of the analytical method is within 10 per cent, which fully meets the requirements.

The different residual stress of steel strip can be displayed quickly and intuitively in the synchronous process segment according to this model, which is of great importance to the prevention of strip buckling and deviation.

The aim of this paper was to study the initial corrosion behavior of copper in the substations of Zhanjiang and Zhuhai.

The copper exposed at the substation of Guangdong coastal region in southern China for up to 12 months. The rust layer formed on the copper has been examined by scanning electron microscopy, X-ray energy spectrum, X-ray diffraction and electrochemical polarization techniques.

The corrosion weight loss of copper at Zhanjiang exposure site is a little more serious than that at Zhuhai exposure site in every exposure period. The corrosion products of copper have different changes in color and composition at the two exposure sites. The tensile strength of copper has a slight decrease after one-year exposure.

The atmospheric exposure experiments of copper in the substations of Zhanjiang and Zhuhai have been adopted for the first time. The corrosion behavior of copper was investigated, and it can provide reference for material selection of the substation.

More and more statistics have repeatedly shown that as the economic development has entered the New Normal, the Chinese fiscal system has experienced tremendous changes. Although chance cannot be ruled out, much of those changes indicate trends, and they can even be said to be the result of the law of economic development. These trends and changes have repeatedly demonstrated that, as a reflection and an inevitable result of the economic developing speed shift, structural adjustment and energy conversion, the Chinese fiscal system, far from the conventional operating state, has progressed on a new path. The paper aims to discuss this issue.

This paper systematically analyzes several new trends and changes in the Chinese fiscal system under the New Normal. First, revenue growth has experienced a sharp downward trend, while the tax elasticity coefficient has declined rapidly. Second, fiscal expenditure has risen against the tendency, while the rigidity of expenditure has kept on increasing.

Considering the present fiscal and taxation system reform with the analysis above, it can be seen that if the reform’s progress for the past two years is slower than expected – thus, preventing the effects of all aspects from a timely achievement – then, in the recent period, the agreement on the fiscal and taxation system reform will be reached and challenges entirely different from the past, including sharp slowdown in revenue growth rate, fiscal expenditure rising against trend and increases in fiscal deficit and government debts will be faced. The factors encouraging the reform are gathering gradually. The growth of the strength to push the reform forward is speeding up. And the pace of the reform in relevant areas is quickening.

In the face of those trends and changes, on the one hand, the authors should deeply understand and accurately grasp them through a comprehensive summary and systematic analysis. On the other hand, a series of conventional ideas, thoughts and strategies should be adjusted comprehensively and duly. Taking a train of new ideas, thoughts and strategies, the authors ought to actively adapt to and initiate a new Chinese fiscal structure under the New Normal of China’s economy.

The purpose of this paper is to study the corrosion behavior of Q235 steel in the bentonite-based resistance-reducing agent (RRA) with different infiltration rates of underground water.

The corrosion behavior of the steel in underground water was assessed by weight loss experiment, electrochemical impedance spectroscopy and polarization curve.

The results showed that the corrosion rate of the steel in the RRA pastes was much lower than that in the original acidic soil. The underground water infiltration slightly accelerated the corrosion rate of the steel in the RRA pastes, but the acceleration role is weak. The bentonite-based RRA can be compatibly applied in the acidic soil.

The bentonite-based RRA can significantly reduce the corrosion rate of the steel and is suitable to compatibly apply in the acidic soil.