交通基础设施结构对城乡收入差距的空间溢出效应研究

为探究交通基础设施作为一项公共品对缩小城乡收入差距的贡献程度,以二元经济发展理论,新古典经济学理论为基础,运用空间自相关,空间误差模型,在我国2005-2017年30个省级行政区(除西藏)的面板数据基础上,引入交通基础设施密度作为核心解释变量,从空间的视角探讨,交通基础设施对于改善城乡收入差距的贡献程度。实证结果显示:公路交通基础设施的建设有助于缩小城乡收入差距,其中,一级公路,三级公路对于收入差距存在正向溢出,二级公路存在负向溢出,高速公路影响并不明显;铁路基础设施则与之相反。结果表明:优化交通基础设施的投建结构对于缩小城乡收入差距存在重要的现实意义,随着资本边际收益不断递减以及人口红利优势的逐渐消失,合理分配交通基础设施投资支出对于推动经济增长向效率方向转型变得日益迫切。

交通基础设施对经济增长影响的实证研究——基于动态面板数据模型

基于2004~2013年省际面板数据,运用动态面板数据模型进行分析,研究交通基础设施密度和交通基础设施投资与经济增长的关系,结果表明交通基础设施密度与交通基础设施投资对经济增长有正向促进作用。通过比较,交通基础设施密度东部产出弹性最大,而交通基础设施投资西部产出弹性最大。

试论浸胶帆布布面麻点解决措施

本文首先详细分析了浸胶帆布概论,并且充分结合布料测试技术,在此基础条件上,进一步总结出布面麻点形成原理以及实验流程。

A New Extension Theory-based Production Operation Method in Industrial Process

To explore the problems of dynamic change in production demand and operating contradiction in production process, a new extension theory-based production operation method is proposed. The core is the demand requisition, contradiction resolution and operation classification. For the demand requisition, the deep and comprehensive demand elements are collected by the conjugating analysis. For the contradiction resolution, the conflict between the demand and operating elements are solved by the extension reasoning, extension transformation and consistency judgment. For the operating classification, the operating importance among the operating elements is calculated by the extension clustering so as to guide the production operation and ensure the production safety. Through the actual application in the cascade reaction process of high-density polyethylene (HDPE) of a chemical plant, cases study and comparison show that the proposed extension theory-based production operation method is significantly better than the traditional experience-based operation method in actual production process, which exploits a new way to the research on the production operating methods for industrial process.

Celebration’s Urban Environment, Sustainable by the Joy of Living

Besides arguments like fighting against dispersed urbanization, improving economies of infrastructure and preserving natural resources, another measure to sustainability is the delight of people in staying together with others sharing a well-designed urban landscape. Analyzing the Celebration’s urban setting is highlighted how some design firms are turning to reclaim the types of urbanism and traditional American architecture, representing the wish for reinforcing the daily vicinity relationships. As a matter of sustainability, it mentioned aspects of vehicular accessibility and the population density which is higher in Celebration than that in other suburban towns in USA. Attention is given both to the management of natural landscape and the role of the entrepreneur to construct a town in a so fragile soil. The relationship between community and sustainability is highlighted, leading to the idea of building spaces to become places, capable to convey the feeling of joy of living.

Confined State and Electronic Transport in an Artificial Graphene-Based Tunnel Junction

Artificial graphene structures embedded in semiconductors could open novel routes for studies of electron interactions in 1ow-dimensional systems. We propose a way to manipulate the transport properties of massless Dirac fermions in an artificial graphene-based tunnel junction. Velocity-modulation control of electron wave propagation in the different regions can be regarded as velocity barriers. Transmission probability of electron is affected profoundly by this velocity barrier. We find that there is no confinement for Dirac electron as the velocity ratio ζ is less than 1, but when the velocity ratio is larger than 1 the confined state appears in the continuum band. These localized Dirac electrons may lead to the decreasing of transmission probability.

New key-stream generation scheme based on Henon chaotic system

As known to all that Henon chaotic system is not appropriate for generating the key-streams because it has non-uniformly distributed output signal, a new key-stream generation scheme based on Henon chaotic system is presented. In order to get the key-streams with good statistics and long enough cycle length, a specific method for dividing the enon attractor into numerous non-overlapping sub-regions, and a new one-to-one mapping strategy between the divided sub-regions and elements of dynamically generated matrix consisting of O＇s and l＇s are proposed. Experimental results demonstrate that the generated key-streams are with long enough cycle length and very sensitive to the initial values and secret keys. For example, key-streams with the cycle length of 10^32 can easily be obtained. Moreover, even if the fluctuation to the initial values or secret keys is as small as 10^- 14 uncorrelated key-streams will be generated. Experimental results also demonstrate that the generated key-streams have good randomness and they can pass all the standard criteria specified in FIPS PUB 140^-2 with no less than 98%.

~1H nuclear magnetic resonance-based metabolomic study on efficacy of Qingrehuatan decoction against abundant phlegm-heat syndrome in young adults with essential hypertension

OBJECTIVE; To observe the influence of Qingrehuatan decoction （QRHT） on serum metabolic profile in young essential hypertension （YEH） patients with abundant phlegm-heat syndrome and provide a basis for treatment with the decoction. METHODS： Twelve male YEH patients were randomly selected and serum samples were collected for examination before and after 4 weeks of thetreatment with QRHT. Twelve healthy males were randomly selected and their serum samples were collected as a control. All serum samples were detected using metabolomic technology with 1H nuclear magnetic resonance. Differences in metabo- lites were studied by principal component analysis and partial least squares-discriminate analysis, which produced scores and Ioadings plots.RESULTS： After 4 weeks of treatment, serum substances could be distinguished between the YEH patients with abundant phlegm-heat syndrome and the control patients. The specific serum endogenous metabolites tended to improve after the treatment. QRHT can appropriately increase the levels of glucose, lactic acid, citric acid, high-density lipoprotein, phosphatidylcholine, glycerophosphate choline, hydroxybutyrate, alanine, and glutamate. QRHT could also decrease the levels of low-density lipoprotein/very low-density lipoprotein, lipids, N-acetyl glycoprotein, and O-acetyl glycoprotein.CONCLUSION： QRHT can effectively ameliorate metabolic disorders in YEH Patients with abundant phlegmheat syndrome. 1H NMR-based metabolo- mic technology can provide an objective basis for the treatment of YEH patients with abundant phlegm-heat syndrome using QRHT.

An magnetic resonance-based plasma metabonomic investigation on abnormal Savda in different complicated diseases

OBJECTIVE： To provide existence of abnormal potential evidence for the Savda, we assessed host metabonomic responses and dynamic changes oc- curring in various diseases using 1H nuclear mag- netic resonance （NMR）-based metabonomics. METHODS： Plasma samples taken from patients with complicated diseases with abnormal Savda （n= 140, including 35 cases each of diabetes, asthma, breast cancer, and cervical carcinoma） and from healthy controls （n=35） were analyzed by ~H NMR （600 MHz）, and the spectral profiles were analyzed by multivariate analysis using orthogonal projec- tion to latent structure with discriminant analysis. RESULTS： Supervised modeling of the data provid- ed very good discrimination between patients and healthy controls. Compared with ,the healthy controls, the patient groups with different disease con- ditions displayed similar metabolic changes, characterized by lower creatine, creatinine, lactate, and amino acid levels （including isoleucine, leucine, va- line, alanine, and 1-methylhistidine） and higher lip- id levels （very low-density lipoproteins and unsatu- rated lipids）. Additionally, cancer patients （breast and cervical） showed decreased myo-inositol, a-glucose, and 13-glucose, and increased pyruvate and carnitine in plasma. CONCLUSION： The data indicate that decreased ox- idative defense, liver function abnormalities, amino acid deficiencies, and energy metabolism disorders are common characteristics of complicated diseas- es, which may be related to the formation of abnor- mal Savda.

Wavelength conversion based on nonlinear polarization rotation in gain transparent SOA

We describe an all-optical wavelength conversion scheme for 1310 nm to 1550 nm based on nonlinear polarization rotation in a gain-transparent semiconductor optical amplifier （GT-SOA） which brings in the assistant light to improve the property of the converted light. From the SOA carder density equations, the 1310 nm-to-1550 nm wavelength conversion scheme is analyzed by the Jones matrix. The phase shift between TE and TM modes and the converted light are simulated at bit rate of 30 Gbit/s. We also analyze the influence of the input signal power, the injected current and the assistant light power on the extinction ratio of the converted li~,ht.

Graphene-based Li-ion hybrid supercapacitors with ultrahigh performance

There is a growing demand for hybrid supercapacitor systems to overcome the energy density limitation of existing-generation electric double layer capacitors （EDLCs）, leading to next generation-Ⅱ supercapacitors with minimum sacrifice in power density and cycle life. Here, an advanced graphene-based hybrid system, consisting of a graphene-inserted Li4Ti5O12 （LTO） composite anode （G-LTO） and a three-dimensional porous graphene-sucrose cathode, has been fabricated for the purpose of combining both the benefits of Li-ion batteries （energy source） and supercapacitors （power source）. Graphene-based materials play a vital role in both electrodes in respect of the high performance of the hybrid supercapacitor. For example, compared with the theoretical capacity of 175 mA-h.g-1 for pure LTO, the G-LTO nanocomposite delivered excellent reversible capacities of 207, 190, and 176 mA·1h·g-1 at rates of 0.3, 0.5, and 1 C, respectively, in the potential range 1.0-2.5 V vs. Li/Li＋; these are among the highest values for LTO-based nano- composites at the same rates and potential range. Based on this, an optimized hybrid supercapacitor was fabricated following the standard industry procedure; this displayed an ultrahigh energy density of 95 Wh·kg-1 at a rate of 0.4 C （2.5 h） over a wide voltage range （0-3 V）, and still retained an energy density of 32 Wh·kg-1 at a high rate of up to 100 C, equivalent to a full discharge in 36 s, which is exceptionally fast for hybrid supercapacitors. The excellent performance of this Li-ion hybrid supercapacitor indicates that graphene-based materials may indeed play a significant role in next-generation supercapacitors with excellent electrochemical performance.

4H-Si C monolithic Darlington transistors with slight current gain drop at high collector current density

Profit from high current gain features, 4 H-Si C power Darlington transistor has the capacity for handling high current transmission. In this paper, monolithic Darlington transistors were fabricated using a simultaneous formation process for both n-type(emitter) and p-type(base) ohmic contact. The isolated device shows current gain of 1061 and 823 with collector current density(JC) increasing from 200 to 800 A/cm2, exhibiting a slight current gain drop at high JC. By extracting the interface state density(Dit) between Si O2 and p-type 4 H-Si C, it is found that this advantage owes to the improvement of the shallow bulk minority carrier lifetime in base region. Furthermore, ISE-TCAD(technology computer aided design) simulation was carried out to study the relationship between base minority lifetime and the current gain, from which the total base minority lifetime is estimated to be 48 ns. The open base breakdown voltage(BVCEO) is 850 V at a leakage current of 2 μA due to the electric filed crowding at the isolation bottom between drive bipolar junction transistor(BJT) and output BJT. To solve this, non-isolated devices were also fabricated with improved BVCEOof 2370 V, indicating the superior potential of 4 H-Si C monolithic Darlington transistors for high power application, while the current gain is deceased to 420, which needs further improvement.

Happy together？ Avoidance of conspecifics by gregarious mussels

Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often explained by its preferences for conspecifics, though direct evidence for such preferences has been rather limited so far. We studied the reactions of zebra mussels to con- specifics, hypothesizing that they may either be attracted to one another or form aggregations only in the absence of alternative attachment sites, in Experiment 1, we tested mussel tendency to detach from existing druses depending on druse size （2-25 individuals） and substratum type （soft： sand; hard： glass）. Mussels detached significantly more often on the hard substratum and from larger druses compared to soft substratum and smaller druses, respectively. This indicates that mussels tended to avoid conspecifics at high density, particularly when alternative substratum was available. In Experiment 2, we tested the responses of single mussels to distant （3 or 15cm） conspecifics （0, 3, 15 individuals per 2.51 tank） on the sandy substratum. The presence of conspecifics, regardless of their distance and density, resulted in single unattached mussels staying more often in their initial positions. Mussels did not move preferentially towards or away from the conspecifics. Thus, even on unsuitable substratum mussels were not attracted by conspecifics and probably exhibited an avoidance reaction by reducing their movement. This suggests that dense mussel aggregations are formed due to the lack of available alternative attachment sites rather than due to their preferences for conspecifics.

A higher performance dye-sensitized solar cell based on the modified PMII/EMIMBF_4 binary room temperature ionic liquid electrolyte

Additives and iodine(I_2) are used to modify the binary room temperature ionic liquid(RTIL) electrolyte to enhance the photovoltaic performance of dye-sensitized solar cells(DSSCs). The short-circuit current density(JSC) of 17.89 m A/ cm2, open circuit voltage(VOC) of 0.71 V and fill factor(FF) of 0.50 are achieved in the optimal device. An average photoelectric conversion efficiency(PCE) of 6.35% is achieved by optimization, which is over two times larger than that of the parent device before optimization(2.06%), while the maximum PCE can reach up to 6.63%.