浙江出口商品结构竞争力实证分析

全球金融危机引发的国际市场需求萎缩恶化了浙江的出口贸易环境,进一步使浙江出口商品的结构问题显现出来。分析了后危机时代浙江出口的总体情况、浙江出口商品的结构及浙江出口商品竞争力发展趋势。并对如何优化浙江出口商品结构提出了对策建议。

结构转换与高质量发展

通过加快结构转换促进高质量发展,一直是中国经济政策追求的目标。文章使用面板分位数回归模型,利用全球150个国家的增长数据,检验了经济结构转换促进高质量发展的假说。研究发现,高结构转换率对经济增长率有一定的抑制效应,但对全要素生产率表现出显著的促进效应。基于不同收入组别的异质性检验表明,在中等收入国家中,高结构转换率对经济增长率的抑制效应以及对全要素生产率的促进效应,均比其他收入组别的国家更强烈,内生性和稳健性检验进一步验证了上述结果。由此表明,加速经济结构转换虽然会造成一定程度的"结构性减速",但有利于促进全要素生产率的提升,通过发挥结构转换中的存量优化和增量创新作用,有助于推进中国经济的高质量发展。文章的研究结果为构建现代经济体系、加快实现高质量发展提供了决策参考依据。

浙江省外贸竞争力测度与分析——基于全国的比较研究

文章首先分析了浙江省外贸发展状况,然后采用贸易竞争力指数、显性比较优势指数、出口商品结构转换率指标,对浙江省外贸竞争力水平进行测度并与全国比较,最后对提升浙江省外贸竞争力提出了一些建议。

青海外贸竞争力分析及对策研究

对外贸易是经济增长的助推器。外贸竞争力的强弱,成为衡量一国或地区经济发展和产业升级的关键所在。本文运用贸易竞争指数、国际市场占有率、出口商品结构转换率三个显示性指标对青海外贸竞争力及其影响因素进行分析,并对如何提升青海外贸竞争力提出了相应的对策建议。

安徽省外贸竞争力分析及对策研究

经济全球化进程的不断加快,使外贸对经济的推动作用越来越显著。外贸竞争力的强弱,直接影响到一国或地区的出口创汇和经济发展。本文运用国际市场占有率、贸易竞争指数、出口商品结构转换率三个指标,对安徽省外贸出口竞争力现状及其影响因素进行了分析,提出了提升安徽省外贸竞争力的相关对策。

山西对外贸易国际竞争力的现状与提升途径

在利用国际市场占有率、出口商品结构转换率、显示性比较优势指数、贸易竞争指数等外贸竞争力评价指标,具体分析山西对外贸易国际竞争力现状的基础上,分析了山西对外贸易国际竞争力不强的原因,并进而提出实施对外贸易国际化导向战略,全面提升山西对外贸易国际竞争力的途径。

东北地区外贸竞争力的现状与提升途径探析

利用国际市场占有率、贸易竞争指数和出口商品结构转换率等外贸竞争力评价指标、具体分析了东北地区外贸竞争力的现状,得出改革开放后东北地区的外贸竞争力虽然得到了提升,但提升速度不快、外贸整体水平不高的结论,分析了其原因,提出了相应的对策建议。

上海高新技术产业的国际竞争力相关指标分析

入世以后，中国高新技术产品进出口迅猛增加，本文主要分析了上海高新技术产业的相关数据，利用竞争力指标得出一些结论？

A novel ring vibrating gyroscope based on side piezo-electrodes

Solid-state wave gyroscope is one kind of high-performance vibrating gyroscopes. The present work develops a new type of solid-state wave gyroscope—a ring vibrating gyroscope driven by piezo-electrodes located on the sidewall of the structure. It has advantages of large vibrating amplitude, high energy conversion efficiency and compact structure. The working principle of the piezoelectric ring vibrating gyroscope is based on the inertia effect of the standing wave in the axisymmetric resonator caused by Coriolis force. The finite element method(FEM) analysis has been implemented to characterize the ring type resonator. The prototypal gyroscope was manufactured and has been trimmed by mechanical way. The harmonic response of the ring vibrating gyroscope has been tested. The resonating frequency of the ring type resonator is 3715.6 Hz and the frequency split of the two working modes before trimming was about 5 Hz and was reduced to sub-0.01 Hz after trimming procedure. The Q-factor of the ring type resonator was 2504. Then, the turntable experiment was implemented. The measured scale factor k is 9.24 m V/[(°)·s] and the full scale range of the gyroscope is larger than ±300(°)/s.

Weight and Efficiency Optimized DC/DC Converter Based on Multiple Interleaved Channels

Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.

Improving the performance of inverted organic solar cells by adjusting the concentration of precursor solution of Al-doped ZnO

Al-doped ZnO(AZO) has been used as an electron transport and hole blocking buffer layer in inverted organic solar cells(IOSCs). In this paper, the AZO morphology, optical and structural properties and IOSCs performance are investigated as a function of precursor solution concentration from 0.1 mol/L to 1.0 mol/L. We demonstrate that the device with 0.1 mol/L precursor concentration of AZO buffer layers enhances the short-circuit current and the fill factor of IOSCs simultaneously. The resulting device shows that the power conversion efficiency is improved by 35.6% relative to that of the 1.0 mol/L device, due to the improved surface morphology and transmittance(300–400 nm) of AZO buffer layer.

Direct fabrication of carbon nanotube-graphene hybrid films by a blown bubble method

Hybridization of carbon nanotubes （CNT） with graphene provides a promising means of integrating the attributes of both materials, thereby enabling widespread application. Here, we present a method to directly assemble hybrid CNT- graphene films by a blown bubble method combined with selective substrate annealing. We use polymethylmethacrylate （PMMA） as the polymeric matrix to blow bubbles containing self-assembled multi-walled CNT arrays, and then transform the bubble film into a CNT-graphene hybrid film by thermal annealing on a Cu substrate; PMMA serves as the carbon source for growing single to few-layer graphene among the CNT network until a continuously hybridized structure is formed. Compared to the bare （non-hybridized） CNT networks, the hybrid films exhibit improved electrical conductivity and structural integrity. Our method also enables the fabrication of a multi-walled CNT-Si solar cell, which has high power conversion efficiency, through the assembly of hybrid CNT-graphene structures.

Optimal extent of fluorination enabling strong temperature-dependent aggregation, favorable blend morphology and high-efficiency polymer solar cells

Temperature-dependent aggregation is a key property for some donor polymers to realize favorable bulk-heterojunction(BHJ)morphologies and high-efficiency(>10%) polymer solar cells.Previous studies find that an important structural feature that enables such temperature-dependent aggregation property is the 2nd position branched alkyl chains sitting between two thiophene units.In this report,we demonstrate that an optimal extent of fluorination on the polymer backbone is a second essential structural feature that enables the strong temperature-dependent aggregation property.We compare the properties of three structurally similar polymers with 0,2 or 4 fluorine substitutions in each repeating unit through an in-depth morphological study.We show that the non-fluorinated polymer does not aggregate in solution(0.02 mg mL^(-1) in chlorobenzene) at room temperature,which results in poor polymer crystallinity and extremely large polymer domains.On the other hand,the polymer with four fluorine atoms in each repeating unit exhibits an excessively strong tendency to aggregate,which makes it difficult to process and causes a large domain.Only the polymer with two fluorine atoms in each repeating unit exhibits a suitable extent of temperature-dependent aggregation property.As a result,its blend film achieves a favorable morphology and high power conversion efficiency.This provides another key design rationale for developing donor polymers with suitable temperature-dependent aggregation properties and thus high performance.

Porous carbon matrix-encapsulated MnO in situ derived from metalorganic frameworks as advanced anode materials for Li-ion capacitors

Conversion-type anode materials hold great potential for Li+storage applications owing to their high specific capacity,while large volume expansion and poor electrical conductivity limit their rate and cycling performances.Herein,a bimetal ZnMn-based metal-organic framework(ZnMn-MOF)is engineered for in situ conversion of MnO-encapsulated porous carbon(MnO/PC)composite.The templating and activation effects of coordinated Zn endow the converted PC matrix with a highly porous structure.This enhances the compatibility of PC matrix with MnO particles,resulting in the full encapsulation of MnO particles in the PC matrix.More significantly,the PC matrix provides enough void space to buffer the volume change,which fully wraps the MnO without crack or fracture during repeated cycling.As a result,MnO/PC shows high charge storage capability,extraordinary rate performance,and long-term cycling stability at the same time.Thus MnO/PC exhibits high delithiation capacities of 768mA h g^(-1)at 0.1Ag^(-1)and 487mA h g^(-1)at a high rate of 0.7Ag^(-1),combined with an unattenuated cycling performance after 500 cycles at 0.3Ag^(-1).More significantly,MnO/PC demonstrates a well-matched performance with the capacitive activated carbon electrode in a Li-ion capacitor(LIC)full cell.LIC demonstrates a high specific energy of 153.6W h kg^(-1)at 210W kg^(-1),combined with a specific energy of 71.8W h kg^(-1)at a high specific power of 63.0kW kg^(-1).

Giant spin torque efficiency in single-crystalline antiferromagnet MnAu films

Antiferromagnetic (AFM) materials have attracted wide attention in spin-orbit torque (SOT)-based spintronic due to its abundant spin-dependent properties and unique advantage of immunity against external field perturbations.To act as the charge-to-spin conversion source in energy-saving spintronic devices,it is of great importance for the AFM material to possess a large spin torque efficiency(ξDL).In this work,using the spin torque ferromagnetic resonance (ST-FMR) technique and a Mn2Au/Ni Fe(Py) bilayer system,we systemically study the ξDLof AFM Mn2Au films with different crystal structures.Compared with polycrystalline Mn2Au with effective ξDL<0.051,we show a much larger ξDLof~0.333 in single-crystal Mn2Au,which arises from the large spin Hall conductivity instead of electrical resistivity.Moreover,with a further contribution of interfacial effects,the effective ξDLof single-crystalline Mn2Au/Py system increases to 0.731,which is more than two times larger than the value of ~0.22 reported for the Mn2Au/CoFeB system.By utilizing the largeξDLof Mn2Au in a perpendicularly magnetized Mn Ga/Mn2Au system,energy-efficient deterministic magnetization switching with a current density at ~10^(6)A cm^(-2)is achieved.Our results reveal a significant potential of Mn2Au as an efficient SOT source and shed light on its application in future AFM material-based SOT integration technology.

Improved conversion efficiency of dye-sensitized solar cells by using novel complex nanostructured TiO_2 electrodes

A novel complex nanostructured TiO2 electrode and fabrication process were proposed and demonstrated to improve the performance of dye-sensitized solar cells(DSSCs).In the proposed process,a nanoporous TiO2 layer was firstly fabricated on the FTO(fluorine-doped tin oxide) conducting substrate by an anodization process,then a nanoparticulate TiO2 film was deposited on the nanoporous TiO2 layer by the screen printed method to form the complex nanostructured TiO2 electrode.The experiments demonstrated that the nanoporous TiO layer can enhance the light scattering,decrease the contact resistance between TiO2 electrode and FTO,and suppress the recombination of I3-ion with the injected electrons of FTO.The process variables are crucial to obtain the optimized performance of DSSCs.By adopting the optimized process,improved conversion efficiency of DSSCs was achieved at AM 1.5 sunlight.