CIIS President Meets with UN General Assembly Co-Chairs of Intergovernmental Negotiations on Security Council Reform

On February 28,CIIS President Chen Bo,along with scholars in relevant fields,met with Co-chairs of the Intergovernmental Negotiations on the United Nations Security Council Reform of the 78th session of the UN General Assembly,Permanent Representative of Kuwait to the UN Tareq M.A.M.Albanai and Permanent Representative of Austria to the UN Alexander Marschik.

Evaluation of frictional pressure drop correlations for air-water and air-oil two-phase flow in pipeline-riser system

Accurate prediction of the frictional pressure drop is important for the design and operation of subsea oil and gas transporting system considering the length of the pipeline. The applicability of the correlations to pipeline-riser flow needs evaluation since the flow condition in pipeline-riser is quite different from the original data where they were derived from. In the present study, a comprehensive evaluation of 24prevailing correlation in predicting frictional pressure drop is carried out based on experimentally measured data of air-water and air-oil two-phase flows in pipeline-riser. Experiments are performed in a system having different configuration of pipeline-riser with the inclination of the downcomer varied from-2°to-5°to investigated the effect of the elbow on the frictional pressure drop in the riser. The inlet gas velocity ranges from 0.03 to 6.2 m/s, and liquid velocity varies from 0.02 to 1.3 m/s. A total of885 experimental data points including 782 on air-water flows and 103 on air-oil flows are obtained and used to access the prediction ability of the correlations. Comparison of the predicted results with the measured data indicate that a majority of the investigated correlations under-predict the pressure drop on severe slugging. The result of this study highlights the requirement of new method considering the effect of pipe layout on the frictional pressure drop.

Pressure transient characteristics of non-uniform conductivity fractured wells in viscoelasticity polymer flooding based on oil-water two-phase flow

Polymer flooding in fractured wells has been extensively applied in oilfields to enhance oil recovery.In contrast to water,polymer solution exhibits non-Newtonian and nonlinear behavior such as effects of shear thinning and shear thickening,polymer convection,diffusion,adsorption retention,inaccessible pore volume and reduced effective permeability.Meanwhile,the flux density and fracture conductivity along the hydraulic fracture are generally non-uniform due to the effects of pressure distribution,formation damage,and proppant breakage.In this paper,we present an oil-water two-phase flow model that captures these complex non-Newtonian and nonlinear behavior,and non-uniform fracture characteristics in fractured polymer flooding.The hydraulic fracture is firstly divided into two parts:high-conductivity fracture near the wellbore and low-conductivity fracture in the far-wellbore section.A hybrid grid system,including perpendicular bisection(PEBI)and Cartesian grid,is applied to discrete the partial differential flow equations,and the local grid refinement method is applied in the near-wellbore region to accurately calculate the pressure distribution and shear rate of polymer solution.The combination of polymer behavior characterizations and numerical flow simulations are applied,resulting in the calculation for the distribution of water saturation,polymer concentration and reservoir pressure.Compared with the polymer flooding well with uniform fracture conductivity,this non-uniform fracture conductivity model exhibits the larger pressure difference,and the shorter bilinear flow period due to the decrease of fracture flow ability in the far-wellbore section.The field case of the fall-off test demonstrates that the proposed method characterizes fracture characteristics more accurately,and yields fracture half-lengths that better match engineering reality,enabling a quantitative segmented characterization of the near-wellbore section with high fracture conductivity and the far-wellbore section with low fracture conductivity.The novelty of this paper is the analysis of pressure performances caused by the fracture dynamics and polymer rheology,as well as an analysis method that derives formation and fracture parameters based on the pressure and its derivative curves.

Simulation of Two-Phase Flowback Phenomena in Shale Gas Wells

The gas-water two-phaseflow occurring as a result of fracturingfluidflowback phenomena is known to impact significantly the productivity of shale gas well.In this work,this two-phaseflow has been simulated in the framework of a hybrid approach partially relying on the embedded discrete fracture model(EDFM).This model assumes the region outside the stimulated reservoir volume(SRV)as a single-medium while the SRV region itself is described using a double-medium strategy which can account for thefluid exchange between the matrix and the micro-fractures.The shale gas adsorption,desorption,diffusion,gas slippage effect,fracture stress sensitivity,and capillary imbibition have been considered.The shale gas production,pore pressure distribution and water saturation distribution in the reservoir have been simulated.The influences of hydraulic fracture geometry and nonorthogonal hydraulic fractures on gas production have been determined and discussed accordingly.The simulation results show that the daily gas production has an upward and downward trend due to the presence of a large amount of fracturingfluid in the reservoir around the hydraulic fracture.The smaller the angle between the hydraulic fracture and the wellbore,the faster the daily production of shale gas wells decreases,and the lower the cumulative production.Nonplanar fractures can increase the control volume of hydraulic fractures and improve the production of shale gas wells.

Arbitrary High-Order Fully-Decoupled Numerical Schemes for Phase-Field Models of Two-Phase Incompressible Flows

Due to the coupling between the hydrodynamic equation and the phase-field equation in two-phase incompressible flows,it is desirable to develop efficient and high-order accurate numerical schemes that can decouple these two equations.One popular and efficient strategy is to add an explicit stabilizing term to the convective velocity in the phase-field equation to decouple them.The resulting schemes are only first-order accurate in time,and it seems extremely difficult to generalize the idea of stabilization to the second-order or higher version.In this paper,we employ the spectral deferred correction method to improve the temporal accuracy,based on the first-order decoupled and energy-stable scheme constructed by the stabilization idea.The novelty lies in how the decoupling and linear implicit properties are maintained to improve the efficiency.Within the framework of the spatially discretized local discontinuous Galerkin method,the resulting numerical schemes are fully decoupled,efficient,and high-order accurate in both time and space.Numerical experiments are performed to validate the high-order accuracy and efficiency of the methods for solving phase-field models of two-phase incompressible flows.

Numerical Simulation of Oil-Water Two-Phase Flow in Low Permeability Tight Reservoirs Based on Weighted Least Squares Meshless Method

In response to the complex characteristics of actual low-permeability tight reservoirs,this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs,considering complex boundary shapes.Utilizing radial basis function point interpolation,the method approximates shape functions for unknown functions within the nodal influence domain.The shape functions constructed by the aforementioned meshless interpolation method haveδ-function properties,which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells.Moreover,the meshless method offers greater flexibility and freedom compared to grid cell discretization,making it simpler to discretize complex geometries.A variational principle for the flow control equation group is introduced using a weighted least squares meshless method,and the pressure distribution is solved implicitly.Example results demonstrate that the computational outcomes of the meshless point cloud model,which has a relatively small degree of freedom,are in close agreement with those of the Discrete Fracture Model(DFM)employing refined grid partitioning,with pressure calculation accuracy exceeding 98.2%.Compared to high-resolution grid-based computational methods,the meshless method can achieve a better balance between computational efficiency and accuracy.Additionally,the impact of fracture half-length on the productivity of horizontal wells is discussed.The results indicate that increasing the fracture half-length is an effective strategy for enhancing production from the perspective of cumulative oil production.

Identifying the enhancement mechanism of Al/MoO_(3) reactive multilayered films on the ignition ability of semiconductor bridge using a one-dimensional gas-solid two-phase flow model

Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics device.Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices.In this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) RMFs.In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this model.It is found that the exothermal reaction in RMFs improved the ignition performance of SCB.In the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low temperature.In addition,it made up for pressure loss in the gas phase.During the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise continuously.This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

A Note on an Order Level Inventory Model with Varying Two-Phased Demand and Time-Proportional Deterioration

The main purpose of this paper is to generalize the effect of two-phased demand and variable deterioration within the EOQ (Economic Order Quantity) framework. The rate of deterioration is a linear function of time. The two-phased demand function states the constant function for a certain period and the quadratic function of time for the rest part of the cycle time. No shortages as well as partial backlogging are allowed to occur. The mathematical expressions are derived for determining the optimal cycle time, order quantity and total cost function. An easy-to-use working procedure is provided to calculate the above quantities. A couple of numerical examples are cited to explain the theoretical results and sensitivity analysis of some selected examples is carried out.

Cultural Barriers to International Business Negotiations

Studies in international business negotiation acquire unprecedented significance,as globalization closely connects various business fields into a dynamic whole.Cultural factors play a vital role in international business negotiation.This paper begins with a brief introduction to business negotiation,international business negotiation and significance of cultural barriers to international business negotiation.It then explores two fundamental cultural differences of China and western countries:value differences and thinking-pattern differences,which pose cultural barriers.The author then puts forward three strategies to help remove the cultural barriers and achieve successful negotiations.

Proxemic Communication and Negotiation

Communication is not just verbal. This paper concentrates on the three areas of nonverbal communication that will most likely affect contract negotiations, that is proxemic communication, using available space, distance form or proximity to other people, and territorial control. Based on this, the paper tends to provide certain strategies to promote the negotiation.

The Application of Non-verbal Communication Strategies in International Business Negotiations

As the economic globalization deepens, trades among nations are steadily increasing. Therefore, the international business negotiations become more and more significant. In the process of negotiations, the application of appropriate strategies is necessary for negotiators to reach an agreement smoothly. However, the non-verbal communication plays an important role to some extent in real international business negotiations. This article tends to explore the application of non-verbal strategies in the international business negotiations.

Cultural Differences in International Business Negotiation

Different countries have different cultures.Currently,the world is developing quickly in the age of economic globalization.Business contacts among nations get increasingly close,which has brought more and more opportunities to deal with businesses.Actually,international business negotiation is the most important part of international business,meanwhile,cultural differences have many influence on international business negotiation,such as languages,manners,time,thinking,value and attitudes and so on.Analyzing their differences is a good way to find out some effective ways to avoid or mitigate the adverse impacts the cross-cultural elements might produce on international business negotiation.

New E-Commerce Model Based on Multi-Agent Automated Negotiation

A new multi-agent automated negotiation model is developed and evaluated, in which two competitive agents, such as the buyer and seller, have firm deadlines and incomplete information about each other. The negotiation is multi-dimensional in different cases. The model is discussed in 6 kinds of cases with different price strategies, warrantee strategies and time strategies. The model improves the model of Wooldridge and that of Sycara to a certain extent. In all possible situations, the optimal negotiation strategy is analyzed and presented, and an e-commerce model based on multi-agent automated negotiation model is also illustrated for the e-commerce application in the future.

RESEARCH ON NEGOTIATION-BASED PARTNER SELECTION APPROACH

The key problem in the construction of virtual enterprises (VEs) is how toselect appropriate partners. The negotiation-based approach is proposed to support partner selectionin the construction of VEs. The negotiation model is discussed from three main aspectsrespectively, i.e., negotiation protocol, negotiation goal and negotiation decision-making model.And the generic mathematical description of the negotiation model is formally presented. Finally, asimple example is used to validate the approach's availability.

Metropolitan Pollution Reduction by Intelligent Negotiation

This paper discusses the issue of pollution reduction in metropolises by means of intelligent negotiation in multi-agent systems. For situations of complete information, it gives a stochastic hill-climbing search algorithm for computing the pollution-reduction solutions; For situations of incomplete information, it puts forward a genetic algorithm for computing the best solutions for every plants subjectively and proposes market-mechanism-based algorithm for computing the emission-redistribution solutions objectively. Key words intelligent negotiation - game theory - pollution reduction - genetic algorithm CLC number TP 391.1 Foundation item: Supported by the National 863 Project (2002AA134020-04)Biography: HAN Wei (1975-) male, Ph.D. candidate, research direction: MAS and Electronic Commercial.

A METHOD OF TASK ALLOCATION AND AUTOMATED NEGOTIATION FOR MULTI ROBOTS

A method of task allocation and automated negotiation for multi robots was proposed. Firstly, the principles of task allocation were described based on the real capability of robot. Secondly, the model of automated negotiation was constructed, in which Least-Squares Support Vector Regression (LSSVR) was improved to estimate the opponent's negotiation utility and the robust controller of output feedback was employed to optimize the utility performance indicators. Thirdly, the protocol of negotiation and reallocation was proposed to improve the real-time capability and task allocation. Finally, the validity of method was proved through experiments.

History-based trust negotiation model

Trust negotiation （TN） is an approach to establish trust between strangers through iterative disclosure of digital credentials. Speeding up subsequent negotiations between the same negotiators is a problem worth of research. This paper introduces the concept of visiting card, and presents a history-based trust negotiation （HBTN） model. HBTN creates an account for a counterpart at the first negotiation and records valid credentials that the counterpart disclosed during each trust negotiation in his historical information base （HIB）. For the following negotiation, no more credentials need to be disclosed for both parties. HBTN speeds up subsequent negotiations between the entities that interact with each other frequently without impairing the privacy preservation.

Negotiation System of Ecological Compensation of Water Source Areas

In view of no generally accepted ecological compensation standards and methods at present,this paper discusses the introduction of the negotiation system to the process of ecological compensation for water source areas.That is,the government in water source areas and the downstream regions of river basins should confirm their respective rights and obligations and then establish their compensation standards through negotiations according to the different purposes of water use.The amount of compensation should be determined in the comprehensive consideration of the quality,quantity and compensation price of water.Through open and fair negotiations,an institutional arrangement will be set up,which can make the water source areas and the downstream regions of river basins fully express their true preferences and their independent choices on the ecological environment.

Double Learning Algorithm in Bilateral Multi-Issue Negotiation under Incomplete Information

In order to enhance the efficiency in bilateral multi-issue negotiation under incomplete information, double learning algorithm that includes Q-learning algorithm and Bayesian learning algorithm is presented. The Q-learning algorithm is used to learn the weights of issues, and the Bayesian learning algorithm is used to learn the reservation price of issues. Experiments show that the algorithm can help agents to negotiate more efficiently.

Motion Planning of Humanoid Robot for Obstacle Negotiation

The motion planning for obstacle negotiation by humanoid robot BHR-2 through stepping over or stepping on/off the wide and flat obstacle at known locations is presented. In the trajectory generation method, first the constraints of the foot motion parameters which include obstacle dimensions and the distance of obstacle from the humanoid robot is formulated. By varying the values of the constraint parameters, different types of foot motion for different obstacles can be produced. In this method, first the foot trajectory is generated, and then the waist trajectory is computed by using cubic spline interpolation without first calculating the zero moment point （ZMP） trajectory . The dynamic stability during the execution of stepping over and stepping on/off trajectories are ensured by incorporating the ZMP criterion. The effectiveness of the proposed method is confirmed by simulations and experiments on humanoid robot BHR-2.