汉代的关、关市和关禁制度

秦始皇统一中国为国内民族贸易的发展创造了有利的条件。“汉兴,开关梁,驰山泽之禁”,汉族与周边少数民族的贸易往来日暂频繁,至汉武帝即位后,更出现了空前活跃的盛况。然而多年来论者对此似有所忽略,至今尚无专门的研究。笔者不揣谫陋,拟从古代关的设置入手,考察一下汉代民族贸易的主要形式——关市贸易和关禁制度,以此向识者请教。

关于加强边防专业教员队伍建设的几点思考

目前,在公安武警院校系统里,教员队伍的建设问题越来越引起人们的普遍重视。然而,专业教员人才的短缺、补充渠道的不畅,一直是令人困惑的问题。

UNITED STABILIZING SCHEME FOR EDGE DELAY IN OPTICAL BURST SWITCHED NETWORKS

A novel scheme, namely united stabilizing scheme for edge delay, is introduced in optical burst switched networks. In the scheme, the limits of burst length and assembly time are both set according to certain qualifications. For executing the scheme, the conception for unit input bit rate is introduced to improve universality, and the assembly algorithm with a buffer safety space under the self-similar traffic model at each ingress edge router is proposed. Then, the components of burst and packet delay are concluded, and the equations that limits of burst length and assembly time should satisfy to stabilize the burst edge delay under different buffer offered loads are educed. The simulation results show that united stabilizing scheme stabilizes both burst and packet edge delay to a great extent when buffer offered load changes from 0.1 to 1, and the edge delay of burst and packet are near the limit values under larger offered load, respectively.

Nucleation potency prediction of LaB_6 with E2EM model and its influence on microstructure and tensile properties of Al-7Si-0.3Mg alloy

The edge-to-edge matching(E2EM)crystallographic model was used to predict the orientation relationships(ORs)between LaB6 and Al.Three different possible ORs can be predicted between LaB6 and Al,which are(100)Al||(100)LaB6,[001]Al||[001]LaB6;(110)Al||(110)LaB6,[001]Al||[001]LaB6;and(111)Al||(111)LaB6,[011]Al||[011]LaB6.The prediction results are perfectly confirmed through TEM analysis and prove the nucleation potency of LaB6.The refining efficacy of Al-2La-1B refiner and its influence on the tensile properties were investigated in the as-cast Al-7Si-0.3Mg alloy.According to the results,LaB6 has higher nucleation potency than TiB2,leading to better grain refining efficacy of Al-2La-1B refiner in the as-cast Al-7Si-0.3Mg alloy.Regarding the mechanical performances,tensile properties of the as-cast Al-7Si-0.3Mg casting alloy are prominently improved after addition of Al-2La-1B refiner,due to the refined microstructures.

An Approach for Enabling Intelligent Edge Gateway Based on Microservice Architecture in Cloud Manufacturing

Cloud manufacturing has become a reality. It requires sensing and capturing heterogeneous manufacturing resources and extensive data analysis through the industrial internet. However,the cloud computing and serviceoriented architecture are slightly inadequate in dynamic manufacturing resource management. This paper integrates the technology of edge computing and microservice and develops an intelligent edge gateway for internet of thing(IoT)-based manufacturing. Distributed manufacturing resources can be accessed through the edge gateway,and cloud-edge collaboration can be realized. The intelligent edge gateway provides a solution for complex resource ubiquitous perception in current manufacturing scenarios. Finally,a prototype system is developed to verify the effectiveness of the intelligent edge gateway.

A comparative analysis of multi-output frontier models

Recently, there have been more debates on the methods of measuring efficiency. The main objective of this paper is to make a sensitivity analysis for different frontier models and compare the results obtained from the different methods of estimating multi-output frontier for a specific application. The methods include stochastic distance function frontier, stochastic ray frontier, and data envelopment analysis. The stochastic frontier regressions with and without the inefficiency effects model are also com-pared and tested. The results indicate that there are significant correlations between the results obtained from the alternative estimation methods.

Boundary States and Correlation Functions of Tricritical Ising Model from Coulomb-Gas Formalism

We consider the minimal conformaJ model describing the tricritical Ising model on the disk and on the upper half plane. Using the coulomb-gas formalism we determine its consistents boundary states as well as its one-point and two-point correlation functions.

Three vertex degree correlations of fixed act-size collaboration networks

A rate equation approach was presented for the exact computation of the three vertex degree correlations of the fixed act-size collaboration networks.Measurements of the three vertex degree correlations were based on a rate equation in the continuous degree and time approximation for the average degree of the nearest neighbors of vertices of degree k,with an appropriate boundary condition.The rate equation proposed can be generalized in more sophisticated growing network models,and also extended to deal with related correlation measurements.Finally,in order to check the theoretical prediction,a numerical example was solved to demonstrate the performance of the degree correlation function.

Application of grey relational analysis in sheet metal forming for multi-response quality characteristics

The theory of grey systems is a new technique for performing prediction, relational analysis and decision making in many areas. In this paper, the use of grey relational analysis for optimizing the square hole flanging process parameters with considerations of the multiple response (the average flanging height, regular flanging and maximum strain) is introduced. Various flanging parameters, such as the blank inner radius rb, blank inner width B0, are considered. An orthogonal array is used for the experimental design. Multiple response values are obtained using finite element analysis (FEA). Optimal process parameters are determined by the grey relational grade obtained from the grey relational analysis for multi-performance characteristics (flanging height, regular flanging and maximum strain). Analysis of variance (ANOVA) for the grey relational grade is implemented. The results showed good agreement with the experiment result. Grey relational analysis can be applied in multiple response optimi-zation designs.

Controversy of International Carbon-motivated Border Tax Adjustment and Its Impact on China's Manufacturing Industries

Carbon-motivated border tax adjustment （BTA） aims to compensate for the loss of competitiveness of carbon intensive products due to carbon dioxide abatement actions. Based on the analysis of the international background of carbon-motivated BTAs, this paper discusses the fundamental motivation leading to US policy transformation, the potential impacts of the policy on China＇s manufacturing industries, and the compatibility of the policy to WTO rules. Carbon-motivated BTAs violate the fundamental principle of the UNFCCC, and potentially conflict with the core WTO principle of non-discrimination reflected in the GATT Articles 1 and III. However, Article XX of the GATT may be applicable. Thus, the author suggests several measures to alleviate the impacts of carbon-motivated BTAs, and puts forward countermeasures based on carbon consumption per capita.

Multi-level CO_(2) fluxes over Beijing megacity with the eddy covariance method

Based on five years of eddy covariance measurements at multiple levels(47,140,and 280 m)of Beijing's 325-m meteorological tower,the exchange process of CO_(2) fluxes between the atmosphere and urban surface were investigated.As a result of the total vehicle control policy from 2011 in Beijing,the growth rate of annual total CO_(2) flux at 140 m is 7.8% from 2008-2010 but 2.3%from 2010-2012.With the minimum vegetation cover and largest population density,the 5-yr average annual total CO_(2) flux at 140 m is largest(6.41 kg C m^(−2) yr^(−1)),compared with that at 47 m(5.78 kg C m^(−2) yr^(−1))and 280 m(3.99 kg C m^(−2) yr^(−1)).With regards to annual total CO_(2) fluxes in Beijing,vehicle numbers and population are the main controlling factors.The measured CO_(2) fluxes were highly dependent on land cover/use in the prevailing wind direction.The CO_(2) fluxes at three layers all correlated positively with road fraction,with the R2 values being 0.69,0.57,and 0.54(P<0.05),respectively.The decreasing fraction of vegetation caused an increasing of the annual total CO_(2) flux,and there was an exponential relationship between them.The annual total CO_(2) fluxes were larger with higher population density.

A Kind of Atomic Coherent State as a Two-Mode Squeezed State

We find that a kind of atomic coherent state, formed as exp[ ξJ＋-ξJ-]｜00〉,when the SU（2） generators J± are taken as Fan＇s form J＋=（1/2）（α1-α2）（α1-α2）,J-=（1/2）（α1＋α2）（α1＋α2）,and J0=（1/2）（α1α2-α1α2）,is simultaneously a two-mode squeezed state. We analyse this squeezed state＇s physical properites, such as the cross- correlation function, the Wigner function, and its marginal distribution as well as the Husimi function.

Proposal and Analyses of Resonant Bilateral Converter Employing Simple Zero Current Switches

With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.

Unjust Decision Making Resulting in Marginalization of the Powerless Prostitution Community in Silir-Semanggi of Solo

The city government of Solo has made a decision that street vendors operating in the city＇s Revolution Monument in Banjarsari Square for years must be relocated to the new built traditional market, called Pasar Notoharjo. This study utilized ethnographic methods, a combination of methods including observation, in-depth interview, focus group and the unobtrusive method including collecting written information. The study showed that the decision of Solo city government which tended to privilege street vendors＇ interests resulted in the life chance of prostitution was deteriorated and marginalized. The city government has accommodated street vendors＇ demand to remove ,the organized prostitution community operating in Silir-Semanggi of Solo since 1960s as one of requirements for their relocation to this area, where the new built traditional market with more than one thousand kiosks was provided for street vendors. The procuresses＇ demand to obtain their rights of the land they occupied for more than 20 years on behalf of their legal ownership failed due to administrative, bureaucratic and legal obstacles. Prostitutes were inhumanly chased away by the city government apparatuses in collaboration with the police from the site of operation in 2006 and it resulted that the social and economic lives of procuresses and prostitutes got worse since their prostitution activities in this location were totally forbidden and unfinished. Both procuresses and prostitutes were marginalized because they did not have links to the powerful stakeholder who were able to protect their rights. Their health was in danger because the city government＇s concern to their activities was limited in particularly since 1998 when the location was formally closed by Solo mayor of the new order.

IMPROVEMENT TO THE EVAPORATION DUCT MODEL BY INTRODUCING NONLINEAR SIMILARITY FUNCTIONS IN STABLE CONDITIONS

Modified refractivity (M) profile is an important parameter to describe the atmospheric refraction environment,as well as a key factor in uniquely evaluating electromagnetic propagation effects.In order to improve the model-derived M profile in stable (especially very stable) conditions,three nonlinear similarity functions,namely BH91,CB05,SHEBA07,are introduced in this paper to improve the original Babin_V25 model,and the performances of these modified models are verified based on the hydrometeorological observations from tower platforms,which are finally compared with the original Babin_V25 model and Local_HYQ92 model.Results show that introducing nonlinear similarity functions can significantly improve the model-derived M profile;especially,the newly developed SHEBA07 functions manage to reduce the predicted root mean square (rms) differences of M and M slope (for both 0-5m and 5-40m) by 64.5%,16.6%,and 60.4%,respectively in stable conditions.Unfortunately,this improved method reacts little on the evaporation duct height;in contrast,Local_HYQ92 model is capable of reducing the predicted rms differences of M,M slope (for both 0-5m and 5-40m),and evaporation duct height by 76.7%,40.2%,83.7%,and 58.0% respectively.Finally,a new recommendation is made to apply Local_HYQ92 and Babin_SHEBA07 in very stable conditions considering that M slope is more important than evaporation duct height and absolute M value in uniquely determining electromagnetic propagation effects.

The Development of Hip-Hop Dance Culture in China

Hip-hop dance originated in the Black neighborhood of New York popular global youth cultures in an unprecedented fashion. As in the 1970s and developed as one of the most a global youth culture, it was introduced to China's Mainland 30 years ago, underwent a series of rises and falls, and gradually transformed into a local scene under the influence of neighboring countries and regions. As hip-hop dance localizes in China, it has incorporated local ingredients such as Chinese traditional culture. Meanwhile, its function such as bodybuilding is also strengthened but the features such as competitiveness are weakened. The localization of hip-hop dance in China's Mainland reflects the globalization of the youth culture, which is featured by local hybridity, multicultural interactions, and conflicting interdependence with public media and commerce. This trend endows the global youth culture with a richer and more complex style and also shows that youth play an active part in generating the new forms and new styles of youth culture.

Leak detection in pipelines by exclusively frequency domain method

A further development of exclusively inverse frequency domain method for leak detection in pipelines is presented and validated.The location and leakage can be determined by analyzing the difference of transient water head response between the simulated and measured data in frequency domain.The transient signals are generated by portion sharp closure of a valve from the small constant opening and it needs only a few meters of water.The discrete boundary conditions and observation data are both transformed in frequency domain by Laplace transform.Example in numerical simulation is studied for demonstration of this approach.The application of the method to an experimental pipeline confirms the analysis and illustrates successful detection of the single pipeline leak.The precalibration approach is presented to minimize the effect of data and model error and it splits the method into two parts.One uses data from a known state to fit the parameters of the model and the other uses data from the current state for the fitting of leak parameters using the now calibrated model.Some important practical parameters such as wave speed,friction in steady and unsteady state and the adaptability of the method are discussed.It was found that the nonlinearity errors associated with valve boundary condition could be prevented by consideration of the induced flow perturbation curve shape.