Abstract:
At present, the most commonly used method to calculate recoverable reserves of shale gas reservoirs is the production decline curve method, which is only applicable to the production wells with decreasing production. For the production wells with constant productions, the material balance method could be used to calculate the recoverable reserves, but it does not consider the particularity of shale gas reservoirs. Under this circumstance, this paper deduces a new calibration method for recoverable reserves of shale gas reservoirs with double porosity medium. The method is based on the material balance equation, which has a wide application range. The method cannot only calculate the recoverable reserves and recoveries of free gas in fractures, but also calculate recoverable reserves and recoveries of free gas and adsorbed gas in the matrix. The calculated results show that the free gas in the shale gas reservoir is mainly in the fractures. The recovery of the free gas in the fractures is relatively high and the recovery of the free gas and adsorbent gas in the matrix is rather low. Gas reservoir recovery and recoverable reserves are more sensitive to abandonment pressure, therefore, in the production process, the reduction of the abandonment pressure of gas reservoir should be attempted. The matrix porosity, the adsorption phase density and the crack compression coefficient have a greater effect on the recovery rate. And the study of these parameters needs to be strengthened in order to obtain more accurate parameters.

Abstract:
This paper probes into the prospect of introducing learner autonomy and teacher autonomy in the context of EFL education. Starting with some basic definitions of autonomy, learner autonomy and teacher autonomy, the paper explores the roles played by both learner and teacher in the process of cultivating autonomy and presents eight practical stages in the integration of learner autonomy and teacher autonomy in order to carry the point of being autonomous in EFL education. Key words: Learner autonomy; Teacher autonomy; EFL education Résumé Cet sondes texte de la perspective de l'introduction de l'autonomie des apprenants et de l'autonomie des enseignants dans le contexte de l'éducation d’EFL. En commen ant par quelques définitions de base de l'autonomie autonomie de l'apprenant, et l'autonomie des enseignants, le document examine le r le joué par des apprenants et des enseignants dans le processus de cultiver l'autonomie et présente huit étapes pratiques dans l'intégration de l'autonomie des apprenants et de l'autonomie des enseignants en vue de porter le point d'être autonome dans l'éducation EFL. Mots clés: Autonomie de l'apprenant; Autonomie des enseignants; Education d’EFL

Abstract:
In wireless sensor networks (WSNs), cooperative communication represents a potential candidate to combat the effects of channel fading by exploiting diversity gain achieved via cooperation among the relays nodes. However, for the energy-constrained WSN, to what extent cooperative communication can save energy consumption for a successful packet transmission is still unknown. Energy efficiency of cooperation and direct transmission schemes in WSN is studied and compared in this paper. The expressions of energy efficiency of the two schemes are derived, respectively. The numerical results reveal that for the small distance separation between the source and destination nodes, the direct transmission scheme is more energy efficient than cooperation and the relay location, packet size, and modulation level have important effects on energy efficiency. At last, energy efficiency maximization for the cooperative communication system is achieved by optimizing both the packet size and modulation level jointly.

Abstract:
In wireless sensor networks (WSNs), cooperative communication represents a potential candidate to combat the effects of channel fading by exploiting diversity gain achieved via cooperation among the relays nodes. However, for the energy-constrained WSN, to what extent cooperative communication can save energy consumption for a successful packet transmission is still unknown. Energy efficiency of cooperation and direct transmission schemes in WSN is studied and compared in this paper. The expressions of energy efficiency of the two schemes are derived, respectively. The numerical results reveal that for the small distance separation between the source and destination nodes, the direct transmission scheme is more energy efficient than cooperation and the relay location, packet size, and modulation level have important effects on energy efficiency. At last, energy efficiency maximization for the cooperative communication system is achieved by optimizing both the packet size and modulation level jointly.

Abstract:
For controlled discrete-time stochastic processes we introduce a new class of dynamic risk measures, which we call process-based. Their main features are that they measure risk of processes that are functions of the history of the base process. We introduce a new concept of conditional stochastic time consistency and we derive the structure of process-based risk measures enjoying this property. We show that they can be equivalently represented by a collection of static law-invariant risk measures on the space of functions of the state of the base process. We apply this result to controlled Markov processes and we derive dynamic programming equations. Next, we consider partially observable processes and we derive the structure of stochastically conditionally time-consistent risk measures in this case. We establish equivalence of two approaches to such problems: history-dependent, and based on belief states, and we prove that the dynamic risk measures can be represented by a sequence of law invariant risk measures on the space of function of the observable part of the state. We also prove corresponding dynamic programming equations.

Abstract:
The orthometric height (OH) system plays a key role in geodesy, and it has broad applications in various fields and activities. Based on general relativity theory (GRT), on an arbitrary equi-geo- potential surface, there does not exist the gravity frequency shift of an electromagnetic wave signal. However, between arbitrary two different equi-geopotential surfaces, there exists the gra- vity frequency shift of the signal. The relationship between the geopotential difference and the gravity frequency shift between arbitrary two points P and Q is referred to as the gravity frequency shift equation. Based on this equation, one can determine the geopotential difference as well as the OH difference between two separated points P and Q either by using electromagnetic wave signals propagated between P and Q, or by using the Global Positioning System (GPS) satellite signals received simultaneously by receivers at P and Q. Suppose an emitter at P emits a signal with frequency f towards a receiver at Q, and the received frequency of the signal at Q is , or suppose an emitter on board a flying GPS satellite emits signals with frequency f towards two receivers at P and Q on ground, and the received frequencies of the signals at P and Q are and , respectively, then, the geopoten-tial dif- ference between these two points can be determined based on the geopotential frequen- cy shift equation, using either the gravity frequency shift ? f or ? , and the corresponding OH difference is further determined based on the Bruns’ formula. Besides, using this approach a unified world height datum system might be realized, because P and Q could be chosen quite arbitrarily, e.g., they are located on two separated continents or islands.

Abstract:
This paper discusses the scientific background and content of the ecological assessment of cities, and takes Boda, a new town in Xinjiang province, China, as a case study.

Abstract:
We analyze electron flux maps based on RHESSI hard X-ray imaging spectroscopy data for a number of extended coronal loop flare events. For each event, we determine the variation of the characteristic loop length $L$ with electron energy $E$, and we fit this observed behavior with models that incorporate an extended acceleration region and an exterior "propagation" region, and which may include collisional modification of the accelerated electron spectrum inside the acceleration region. The models are characterized by two parameters: the plasma density $n$ in, and the longitudinal extent $L_0$ of, the acceleration region. Determination of the best-fit values of these parameters permits inference of the volume that encompasses the acceleration region and of the total number of particles within it. It is then straightforward to compute values for the emission filling factor and for the {\it specific acceleration rate} (electrons s$^{-1}$ per ambient electron above a chosen reference energy). For the 24 events studied, the range of inferred filling factors is consistent with a value of unity. The inferred mean value of the specific acceleration rate above $E_0=20$ keV is $\sim10^{-2}$ s$^{-1}$, with a 1$\sigma$ spread of about a half-order-of-magnitude above and below this value. We compare these values with the predictions of several models, including acceleration by large-scale, weak (sub-Dreicer) fields, by strong (super-Dreicer) electric fields in a reconnecting current sheet, and by stochastic acceleration processes.

Abstract:
In the paper, we study the global existence of weak solution of the fully nonlinear parabolic problem (1.1)-(1.3) with nonlinear boundary conditions for the situation without strong absorption terms. Also, we consider the blow up of global solution of the problem (1.1)-(1.3) by using the convexity method.

At present, a sound intellectual property
management and service system have not been established yet in Chinese colleges
and universities. Meanwhile, the lost of existing intellectual property in
universities due to small amount, low conversion rate, low technology content
and weak brand awareness, hinders the positive effect of intellectual property
and affects its transformation and application in China. This article
introduces the current problems with intellectual property in universities and
gives some countermeasures to promote the use of intellectual property in universities
for a better regional economic service.