多层微波集成电路中微带线层间互连仿真

针对多层微波集成电路设计的微带线层间互连问题，介绍了垂直通孔互连、垂直带条互连和层耦合过渡互连三种高性能的互连方法，并且采用三维电磁仿真软件HFSS对这三种互连结构进行了建模和仿真。仿真结果表明，垂直通孔互连和垂直带条互连在0.1～25 GHz的频宽范围内，回波损耗S11<-20 dB，插入损耗S21>-1 dB，互连性能优良，而层耦合过渡互连在20～68 GHz内回波损耗S11 <-20 dB，插入损耗S21>-1 dB，具有在毫米波频段实现互连的潜力。     

一种基于SIR结构的三通带带通滤波器

应用双指耦合结构和枝节加载谐振器（Stub-loaded Resonator，SLR）实现了一款基于阶梯阻抗谐振器（Stepped Impedance Resonator，SIR）的滤波器。该滤波器具有3个通带，带外抑制较好，工作频段提高。通过调整阻抗比可调节第二、三通带的谐振频率；SLR结构能够增加通带数量；SLR结构和双指耦合结构均能改善滤波器的S参数。HFSS软件仿真表明，3个通带的中心频率分别为3.5 GHz、6.6 GHz、9.2 GHz，对应的分数带宽分别为5.7%、3%、2%，S11分别为-18 dB、-22 dB、-24 dB，通带内的S21分别为-1.8 dB、-1 dB、-1 dB。电路的测量结果与仿真结果较为吻合。该滤波器在5G通信的低频段具有应用前景。     

我国石油税制与公司税收筹划对地方税收的影响分析——以石油城克拉玛依为例

我国石油税制改革始终都是在确保国家石油安全的基础上展开的,但在改革的过程中却造成了国家与石油企业、中央税收与地方税收之间的利益冲突。利益冲突的产生既有石油税制方面的原因,也有石油企业总部经济的原因,还有国家始终掌控油品定价权方面的原因。文章旨在建立框架模型并通过实际事例和数据,解释石油企业、中央税收与地方税收之间的利益冲突,并说明我国现行石油税制以及石油公司税收筹划是如何对地方税收产生影响的。     

China’s Agricultural Policy Transition: Impacts of Recent Reforms and Future Scenarios

This article reviews recent developments in China’s agricultural domestic support policy, especially the transition from taxing farmers and agriculture to providing direct subsidies to grain production and purchased inputs. A model‐based quantitative analysis on the effects of these policy changes is presented. Simulation results suggest that recent policy changes have achieved the declared policy goals of increasing grain production and boosting farm income. Much of the increase in grain production and farm income can be attributed to higher per unit return to arable land, land reallocation to grain production and extra agricultural employment triggered by the policy changes. Based on the assumption that China’s public assistance to agriculture and farmers will continue and rise, two hypothetical future scenarios are simulated. Using all the support permitted under WTO de minimis limits with existing instruments, China’s policy will increase grain production, change trade patterns seemingly contrary to China’s comparative advantage, increase rural employment and significantly increase farm income (by more than 12%). If, however, decoupled instruments are applied to raise China’s agricultural domestic support to the same level, China’s agricultural production and trade will remain unchanged, rural employment remain stable, but farm income will be increased by nearly 15%.     

Tariff Preferences,WTO Negotiations and the LDCs: The Case of the ‘Everything But Arms’ Initiative

By assessing the impact of the recently adopted ‘Everything But Arms’ (EBA) initiative of the EU on the Least Developed Countries (LDCs) and by showing how further multilateral trade liberalisations erode the EBA preferences and impact the LDCs, this paper attempts to uncover the LDCs’ difficult positions in the WTO trade negotiations. Due to its limited product coverage and previous preferences granted by the EU, welfare impacts of the EBA on the LDCs are shown to be small and the bulk of these gains are associated with the ‘sensitive’ products that are subject to gradual liberalisations. Moreover, these small gains are likely to disappear if the EU conducts trade policy reforms in fulfilling its WTO obligations, resulting in an actually worse‐off situation for the LDCs. Extending the analysis to a multilateral trade liberalisation scenario reinforces the above results that the LDCs may well lose due to preference erosion and higher world market prices. It concludes that other development assistance measures from developed countries should be made available to the LDCs to ease their dependency on trade preferences and to foster their supply capacities. The LDCs themselves should attempt to integrate the duty and quota‐free market access status contained in the EBA into a binding WTO agreement to secure a stable trading environment. But more importantly, in order to solve the difficulties at the root these countries should actively engage in reforming their own trade policies.     

一种SIR结构的超宽带带通滤波器

提出了一种基于阶梯阻抗谐振器（Step Impedance Resonator,SIR）结构的具有平行耦合微带线的超宽带（Ultra-wideband,UWB）带通滤波器。滤波器采用孔径补偿技术设计,在地面上蚀刻两个矩形槽,以增强顶层微带线之间的耦合。为了优化S参数并改善带外的抑制,在谐振器中采用了缺陷微带结构（Defective Microstrip Structure,DMS）。仿真结果表明,滤波器的通带范围为2.3~6.1 GHz,中心频率为4.2 GHz,分数带宽（Fractional Bandwidth,FBW）大于90.4%;插入和回波损耗分别优于-1 dB和-10 dB;通带中群延迟的变化范围为0.4~0.6 ns,滤波器的线性度良好。该滤波器可用于5G通信系统。     

Government budget,public-sector wages and capital taxes in a small open economy: A Hong Kong case

This paper examines the welfare implications of adjustments in public-sector wages and capital tax rates for a small open economy in a general equilibrium setting. The individually and jointly optimal wage and tax policies are derived and interpreted. Facing reductions in land sales and falls in foreign interest rates, a cut in public workers' pay is needed to make their wage comparable to the private sector and a hike in capital taxes is recommended for a budgetary consideration. Using a computable general equilibrium model for Hong Kong, we numerically evaluate the various optimal policies which not only confirm the theoretical results but also provide quantitative estimates of the optimal policy variables.     

《论语》对学生教育工作的启示

孔子是中国古代教育的第一人,反映在《论语》中的他的许多教育原则对当代高校学生教育管理工作起着积极的指导作用,有许多方面更是值得学生工作者在实际工作中予以借鉴。     

旅游地形象遮蔽理论在经济林产业研究中的应用——以四川越西与汉源贡椒产业为例

应用旅游地形象遮蔽理论初步构建了经济林产业形象遮蔽的理论,界定了经济林产业形象遮蔽的概念、内涵,探讨了其发生机制,并以四川越西和汉源贡椒产业为例,分析了产业形象遮蔽发生的机制,初步论证了旅游地形象遮蔽理论在经济林产业形象中应用的可行性与合理性。     

一种SLR结构陷波宽带滤波器的设计

在枝节加载谐振器（Stub-loaded Resonator,SLR）的理论基础上设计了一种陷波宽带滤波器,应用于3.0~6.7 GHz频段。该滤波器由一个倒T形短路枝节加载谐振器（Short SLR,SSLR）和一个基于半波长SIR基本结构的阶跃阻抗枝节加载谐振器（Stepped Impedance SLR,SISLR）构成。与传统陷波滤波器相比,该滤波器没有采用传统的缺陷地结构或缺陷微带结构,其陷波特性由SISLR与SSLR耦合所致,能够实现更好的设计灵活性。对电路进行了仿真和实物制作,仿真结果表明,插入损耗和回波损耗分别优于0.3 dB和12.2 dB,陷波的中心频率位于5.8 GHz,其分数带宽为6.8%。测试结果与仿真结果基本一致,体现了良好的电路性能。