外资进入与省域国内国际双重价值链嵌入——新发展格局下的理论与经验分析

外资对构建以国内大循环为主体、国内国际双循环相互促进的新发展格局至关重要。本文从马克思主义政治经济学理论和大国发展经济学视角出发,分析了外资在畅通国内大循环和深度融入国际外循环体系中的重要作用。此外,文章基于2007—2017年30个省域贸易增加值分解数据,揭示了省域国内国际双重价值链关联特征,并进一步实证检验了外资进入对省域国内国际双重价值链嵌入的影响和作用机制,并拓展了制度质量和信息化水平的分析情境。研究发现:第一,总体上,各省域对国内价值链和全球价值链的嵌入程度具有显著异质性。外资的进入提升了省域在国内国际双重价值链中的嵌入程度,且国际资本的进入在推动国内大循环构建与发展的同时更能推动国内各省域同国际外循环的价值链分工合作。第二,机制分析发现,外资进入主要通过生产率效应和示范带动效应促进省域同全球价值链的关联,以及通过外部冲击效应提升省域对国内价值链的嵌入程度。第三,异质性分析表明,外资进入对省域国内国际双重价值链关联的影响在东中西部间存在明显的地理区域差异,且在“一带一路”倡议提出以后,外资对省域国内国际双重价值链嵌入的促进效应得到了进一步提升。第四,进一步拓展制度和信息化情境分析发现,制度质量和信息化水平的提升能够正向调节外资进入对省域国内国际双重价值链关联的作用效应。此外,基于制度质量的二分法,产权制度和契约制度在激励外资与省域双重价值链关联关系的强度方面存在明显差异。

Model Predictive Current Control with Adaptive-adjusting Timescales for PMSMs

A model predictive current control(MPCC)with adaptive-adjusting method of timescales for permanent magnet synchronous motors(PMSMs)is proposed in this paper to improve the dynamic response and prediction accuracy in transient-state,while lessening the computational burden and improving the control performance in steady-state.The timescale characteristics of different parts of MPCC,such as signal sampling,prediction calculation,control output,model error correction,are analyzed,and the algorithm architecture of MPCC with multi-timescale is proposed.The difference between reference and actual speed,and the change rate of actual speed are utilized to discriminate the transient state of speed change and load change,respectively.Adaptive-adjusting method of control period and prediction stepsize are illustrated in detail after operation condition discrimination.Experimental results of a PMSM are presented to validate the effectiveness of proposed MPCC.In addition,comparative evaluation of single-step MPCC with fixed timescale and proposed MPCC is conducted,which demonstrates the superiority of proposed control strategy.

Study on Extraction Technology of Theabrownine from Liubao Tea and Its Antioxidant Activity

[ Objective] This study aimed to provide theoretical reference for the extraction of theabrownine from Liubao tea, determination of the biological activity, and development and utilization of theabrownine. [Method] Orthogonal experimental design was adopted to investigate the effects of solid-liquid ratio, extraction temperature, extraction duration, and extraction frequency on the yield of theabrownine extracted from Liubao tea. The extraction technology was optimized, and the antioxidant activity of theabrownine was analyzed. [ Result] The results showed that extraction frequency and extraction temperature had significant effects on the yield of theabrownine extracted from Liubao tea, while solid-liquid ratio and extraction duration had no significant effect. The optimal conditions for extracting theabrownine from Liubao tea were determined as follows ： solid-liquid ratio was 1 ： 30, extraction temperature was 100℃, extraction duration was 80 min, and extraction frequency was 4 times. Under these conditions, the yield of theabrownine reached 22.92%. Results of antioxidant activity determination showed that hydroxyl radical-scavenging activity of theabrownine was as high as 74%, and the scavenging effects was significantly higher than that of Vitamin C under low concentrations; nitroso-scavenging activity of theabrownine reached 73%, with no significant difference from that of Vitamin C; superoxide anion free radical-scavenging activity of theabrownine could be above 60%, which was lower than that of Vitamin C. [Condusion] Liubao tea contains abundant theabrownine that has relatively high antioxidant activity with good prospects in antioxidant application, which lays solid foundation for in-depth development of Liubao tea.

Flotillin-2 is an acrosome-related protein involved in mouse spermiogenesis

Spermatogenesis is a complex process of terminal differentiation by which mature sperms are generated,and it can be divided into three phases：mitosis,meiosis and spermiogenesis.In a previous study,we established a series of proteomic profiles for spermatogenesis to understand the regulation of male fertility and infertility.Here,we further investigated the localization and the role of flotillin-2 in spermiogenesis.Flotillin-2 expression was investigated in the testis of male CD1 mice at various developmental stages of spermatogenesis by using Western blotting,immunohistochemistry and immunofluorescence.Flotillin-2 was knocked down in vivo in three-week-old male mice using intratesticular injection of small inhibitory RNA（siRNA）,and sperm abnormalities were assessed three weeks later.Flotillin-2 was expressed at high levels in male germ cells during spermatogenesis.Flotillin-2 immunoreactivity was observed in pachytene spermatocytes as a strong dot-shaped signal and in round spermatids as a sickle-shaped distribution ahead of the acrosome.Immunofluorescence confirmed flotillin-2 was localized in front of the acrosome in round spermatids,indicating that flotillin-2 was localized to the Golgi apparatus.Knockdown of flotillin-2 in vivo led to a significant increase in head sperm abnormalities isolated from the cauda epididymis,compared with control siRNA-injected testes.This study indicates that flotillin-2 is a novel Golgi-related protein involved in sperm acrosome biogenesis.

Driving Range Parametric Analysis of Electric Vehicles Driven by Interior Permanent Magnet Motors Considering Driving Cycles

This paper presents parametric analysis of driving range of electric vehicles driven by V-type interior permanent magnet motors aiming at maximum driving range,i.e.,minimal total energy consumption of the motors over a driving cycle.Influence of design parameters including tooth width,slot depth,split ratio(the ratio of inner diameter to outer diameter of the stator),and V-type magnet angle on the energy consumption of the motors and driving range of electric vehicles over a driving cycle is investigated in detail.The investigation is carried out for two typical driving cycles with different characteristics to represent different conditions:One is high-speed,low-torque cycle-Highway Fuel Economy Test and the other is low-speed,high-torque cycle-Artemis Urban Driving Cycle.It shows that for both driving cycles,the same parameters may have different influence on the energy consumption of the motors,as well as driving range of electric vehicles.

Development of an Analytical Method for Evaluating the Catalytic Active Sites of Titanium Silicalite Zeolite

A simple, quick, sensitive, accurate and precise method has been developed for evaluating the catalytic active sites of titanium silicalite-1 (TS-1). The catalytic active sites of titanium silicalite zeolite depend on the effectively active species (EAS) in TS-1 which react with specific substrates quickly. However, the EAS was hard to be evaluated with conventional instruments and techniques in the past. In this paper, the EAS was formed in TS-1 upon interaction with H2O2, and its presence could be confirmed by UV-vis spectroscopy which has an absorption peak at 385 nm. The absorbance at 385 nm was found to be linearly related to time, and when the absorbance and the increasing rate of absorbance (k) increased, the catalytic performance of TS-1 enhanced.

Clinical observation of rh-endostatin combined with chemotherapy as first line treatment for metastatic colorectal cancer

Objective To analyze the efficacy and safety of Rh-endostatin combined with chemotherapy in the treatment of metastatic colorectal cancer.Methods All 60 metastatic colorectal cancer patients were divided into the test group(n = 30) and the control group(n = 30). The control group was treated with chemotherapy regime FOLFOX4(Oxaliplatin + Fluorouracil + Calcium Levofolinate), the test group was treated by Endostar combined with FOLFOX4 scheme.Results The response rates were 53.3% in test group and 36.7% in control group respectively(P < 0.05), the disease control rate were 83.3% and 73.3%(P < 0.05). The median progression-free survival in test group and control group were 7.3 months versus 5.3 months(P < 0.05) and median overall survival were 11.6 months versus 9.3 months(P < 0.05). Among 27 cases of liver metastases were sub group analysis, difference on the test group and the control group response rate(RR) and disease control rate(DCR) had statistical significance(P < 0.05), but difference on progression free survival(PFS) and overall survival(OS) had no statistical significance(P > 0.05). The major toxicities were myelosuppression, gastrointestinal symptoms, neurotoxicity, most in grade I-II. After chemotherapy, quality of life(QOL) of patients were more improved than before treatment. After treatment the carcino embryonie antigen(CEA) and caner antigent 199(CA199) levels decreased obviously, furthermore, the test group decreased more obviously than the control group. Conclusion Rh-endostatin combined with chemotherapy in the treatment of metastatic colorectal cancer is safer and effective, and also improves PFS.

Evaluation of Uncertainty for Determination of Stevioside Content in Fermented Milk by HPLC

[Objectives]The paper was to establish an evaluation method for the uncertainty of stevioside(including stevioside,rebaudioside A,rebaudioside B,rebaudioside C,rebaudioside F,Dulcoside A,rubusoside and steviolbioside)content determination in fermented milk based on HPLC.[Methods]The mathematical model of stevioside content and the propagation rate of uncertainty were established,and the sources of uncertainty were analyzed.[Results]The uncertainty mainly came from four main aspects,including standard uncertainty u(C)introduced by solution concentration C,standard uncertainty u(V)introduced by sample volume V,standard uncertainty u(m)introduced by sample mass m weighing and standard uncertainty u(f_(rep))introduced by measurement repeatability of stevioside content after sample dissolution and constant volume.The uncertainty estimation table and fishbone chart of stevioside content X determination were established.The relative synthetic standard uncertainty of stevioside content was obtained,and the standard uncertainty was extended to form the measurement result of stevioside content and its uncertainty report.[Conclusions]The evaluation results can be directly applied to the daily practical detection work.

Message from Editors

THE More Electric Aircraft(MEA)/All Electric Aircraft(AEA)system is being widely recognized as the future for the aerospace industry to meet the power demands of increasing electric loads,reduce aircraft emissions,improve fuel economy,and lower the cost of the total system.

Effect of Rural Social Pension Insurance on Total Retail Sales of Consumer Goods

Based on data of 31 provinces of China in 2019 collected from the National Bureau of Statistics,this paper explores the impact of the number of urban employees’endowment insurance on the total retail sales of social consumer goods in different provinces in China.Taking the population,per capita disposable income,per capita life expectancy,and regional per capita GDP of each province as the variables,this paper establishes regression models to do the empirical research.The results show that:(1)The increase of the number of urban employees’old-age insurance has a significant positive impact on residents’consumption.The wider the coverage of old-age insurance,the more it can enhance the consumption confidence of the residents.(2)Due to the economic development,the level of urbanization has been greatly improved,leading to an increased birth rate and total population,and thus consumption has been driven.Therefore,the increase of the total population has a significant positive effect on the increase of the total retail sales of social consumer goods.(3)The increase of per capita disposable income has insignificant impact on the increase of total retail sales of social consumer goods due to residents’debt,the rise of house prices,the rapid widening of income gap between different groups,and the difficulty of meeting the various needs of people.(4)Although the increase of life expectancy per capita will lead to the decrease of total retail sales of social consumer goods,this decrease is not significant.(5)Per capita GDP will lead to a small increase in the total retail sales of social consumption.Finally,based on the above conclusions,some suggestions to stimulate consumption are given.

Difference in Unbalanced Magnetic Force of Fractional-Slot PM Machines between Internal and External Rotor Topologie

This paper presents a comparative investigation into unbalanced magnetic force(UMF)of asymmetric permanent magnet machines without rotor eccentricities,particularly focusing on the difference between internal-and external-rotor topologies.The asymmetric field distribution results in radial and tangential asymmetric force waves.Although the radial and tangential stresses are in different direction,the UMF components they produce are nearly aligned.The UMF from asymmetric radial force wave can be additive or subtractive to that from asymmetric tangential force wave.Investigation shows that for the same pole slot number combination,if the UMFs due to radial and tangential force waves are additive in internal rotor machine,they are subtractive in the external rotor counterpart,and vice versa.Investigation reveals a general rule determining whether additive or cancelling:for a UMF produced by any two field harmonics,they are additive if the higher order is produced by the outer part outside the airgap,but cancelling if the higher order is produced by the inner part.Therefore,for a machine with pole number 2p=3k+1,they are additive if it is an external-rotor machine,but otherwise subtractive.On the other hand,for a machine with pole number 2p=3k-1,they are subtractive if it is an external-rotor machine,but otherwise additive.For the UMF due to armature reaction only,they are subtractive for external-rotor machines,but otherwise additive.The investigation is carried out by an analytical model and validated by finite element analysis.

Message from Editors

ELECTRICAL machine systems have found extensive applications,for which various machine topologies have been proposed in the recent years.Performance analysis and optimal design with theoretical methods and multi-field finite element methods are key issues for developing high-end products.Meanwhile,control strategies linked with specific machine topologies and design considerations are rather beneficial for the electrical machine systems,in the aspects of energy efficiency,output smoothness,control precision,dynamic response,and many others.

长江经济带企业家创业精神的时空分异与影响因素

在新型城镇化与“大众创业、万众创新”的战略背景下,剖析城市层面企业家创业精神的内在规律对于科学构建创业支持体系,推动城市高质量发展具有重要意义。在创业生态系统理论的基础上,提出企业家创业精神的分析框架,并针对长江经济带这一重要的战略区域,运用城市面板数据和空间计量模型方法,实证探究了创业生态系统对企业家创业精神的影响。研究发现(:1)长江经济带城市中,企业家创业精神的空间分布与空间增长趋势均存在明显的空间分异特征,总体上空间集聚态势不断增强(;2)本城市创业生态系统对企业家创业精神产生了差异化影响。市场环境、政府规模、研发支持、基础设施等因素的影响得到证实,但金融资本、人力资本的影响不显著(;3)邻近城市创业生态系统对本城市的空间溢出效应不容忽视。其中市场环境、政府规模、基础设施等以负向效应为主,研发能力则以正向效应为主(;4)研究进一步从经济带区域空间结构调整、城市创业生态系统建设等方面,提出完善创业支持体系的对策建议。

随机参考价格影响下带成本约束的库存系统

本文深入探讨了制造商在考虑随机参考价格效应的情况下,对生产和定价做出最佳决策的问题。我们将其表述为随机控制问题,目的是在成本约束下最大化净利润函数。首先,为了解决约束优化问题,我们可以利用拉格朗日乘子方法将其转换为无约束问题。通过动态规划方法和粘性解方法,本文研究结果揭示了无约束问题的值函数是汉密尔顿–雅可比–贝尔曼(HJB)方程的唯一粘性解。然而,HJB方程难以得到显式解,我们利用有限差分理论和随机递归算法建立了合适的数值近似方案。我们证明了HJB方程的有限差分方案的收敛性,并证明了该方案的解收敛于HJB方程的解。此外,我们通过确定适当的拉格朗日乘子,在约束问题的最优解和无约束问题的最优解之间建立联系。最后,我们进行了数值实验并分析了关键参数的灵敏度。我们的实验结果可以为制造商提供库存和定价的参考。

技能强国战略背景下高职院校体育院系专业技能认证与培训体系研究

本文旨在构建和完善高职院校体育院系的专业技能认证与培训体系,以提升学生的专业技能和就业竞争力。研究首先分析了当前体育专业教育面临的挑战和行业需求,基于此,提出了一套综合性的培训内容,包括基础理论知识、专项技能训练、教学法与训练法、体育管理与营销、健康教育与促进以及科研方法与实践。针对培训方法,研究强调了理论与实践相结合、项目化学习、师生共研、信息技术应用、创新创业、实习与实践以及国际交流与合作的重要性。通过实施这一体系,旨在培养学生的综合素质,增强其适应未来体育行业发展的能力。

“一带一路”EPC项目投标阶段的税务风险管理——以X公司投资越南光伏电站为例

"一带一路"倡议下"走出去"企业税务风险管控十分重要。本文以X公司投资越南光伏电站EPC项目为例,详细分析了当前我国企业参与"一带一路"建设中EPC项目投标阶段的涉税风险,并对如何防范税收风险提出了几点建议。

Smart dielectric materials for next-generation electrical insulation

Smart dielectric materials with bioinspired and autonomous functions are expected to be designed and fabricated for nextgeneration electrical insulation.Similar to organisms,such dielectrics with selfadaptive,selfreporting,and selfhealing capabilities can be employed to avoid,diagnose,and repair electrical damage to prevent catastrophic failure and even a blackout.Compared with traditional dielectrics,the utilization of smart materials not only increases the stability and durability of power apparatus but also reduces the costs of production and manufacturing.In this review,researches on selfadaptive,selfreporting,and selfhealing dielectrics in the field of electrical insulation,and illuminating studies on smart polymers with autonomous functions in other fields are both introduced.The principles,methods,mechanisms,applications,and challenges of these materials are also briefly presented.

New guaiane-type sesquiterpenoid dimers from Artemisia atrovirens and their antihepatoma activity

Leading by cytotoxicity against HepG2 cells,bioactivity-guided fractionation of the EtOAc fraction from Artemisia atrovirens led to the isolation of 18 new guaianolide dimers,artematrolides A-R and lavandiolides A,B,C,H,and J.Eight compounds(1,4,10,12,13,and 19-21) were unambiguously confirmed by the single-crystal X-ray diffraction analyses,and the others were elucidated based on IR,UV,HRESIMS,1 D and 2 D NMR experiments,and comparison of the experimental and calculated ECD data.Structurally,all of them were [4+2] Diels-Alder adducts of two monomeric guaianolides.The isolates were evaluated for their cytotoxicity against three human hepatoma cell lines,and 19 compounds demonstrated cytotoxicity against HepG2,SMMC-7721,and Huh7 cell lines.Especially,compounds 1,12,14,and 15 exhibited cytotoxicity with IC50 values of 4.4,3.8,7.6,and 6.7 μmol/L(HepG2),9.6,4.6,6.6,and 6.0 μmol/L(SMMC-7721),and 7.6,4.5,6.9,and 5.6 μmol/L(Huh7),respectively.Notably,compound 12 showed the most promising activity against three human hepatoma cell lines and dose-dependently inhibited cell migration and invasion,induced G2/M cell cycle arrest and cell apoptosis in HepG2 cells,down-regulated the expression of BCL-2 and PARP-1,and activated PARP-1 to up-regulate the expression of cleaved-PARP-1.

Adaptive gradient-based source and mask co-optimization with process awareness

We develop a source and mask co-optimization framework incorporating the minimization of edge placement error(EPE)and process variability band(PV Band)into the cost function to compensate simultaneously for the image distortion and the increasingly pronounced lithographic process conditions.Explicit differentiable functions of the EPE and the PV Band are presented,and adaptive gradient methods are applied to break symmetry to escape suboptimal local minima.Dependence on the initial mask conditions is also investigated.Simulation results demonstrate the efficacy of the proposed source and mask optimization approach in pattern fidelity improvement,process robustness enhancement,and almost unaffected performance with random initial masks.

The First Case of New Variant COVID-19 Originating in the United Kingdom Detected in a Returning Student—Shanghai Municipality,China,December 14,2020

On December 14,2020,a 23-year-old female returning from the United Kingdom(UK)via airplane was tested by the laboratory of Shanghai Customs using nose swab to test for coronavirus disease 2019(COVID-19).At 20:30 on December 14,Shanghai CDC received notification from the Shanghai Customs that the patient tested positive for COVID-19.By 22:00,the patient was transported by ambulance from the isolation point to the fever clinic of Jiading District Central Hospital.Due to travel history from the UK and abnormalities in nucleic acid test results.