An empirical model of the environmental effect of FDI in host countries: Analysis based on Chinese panel data

From the 1970's, Foreign Direct Investment (FDI) flowed into host countries. With the development of economy in host countries the environment deteriorated. The overall goal of this paper is to estimate whether the impacts of FDI positive or negative on environment in host countries. To meet this overall goal, it is constructed a simultaneous system with data of 28 provinces in China (1992-2008). This system supposes the pollution indicators to be determined by economic scale, industrial composition and pollution density of a province, in which pollution density is created to estimate the environmental effect of FDI more exactly than traditional technological character. Also the domestic and foreign capital is tried to distinguish to make the pollution source clear. Based on a panel data of 28 provinces (1992-2008) with the three-stage least squares (3sls) estimator, the results of the system show that with the domestic investment, the environmental effect is positive, which means that FDI increases pollution emission. The direct environmental effect of FDI, which does not include domestic investment, is different decided by various pollution indicators. --FDI,pollution emission, host countries

The Panel Co-integration Analysis between the Logistics Industry and Economics Growth in China

Abstract: Along with the recently rapid development in China, the logistics development is also accelerating. The effect of logistics is more and more important in Chinese economy. A lot of articles about the relationship between them are qualitative analysis. The thesis introduces the panel model and the theory of panel co-integration, studies and confirms the panel co-integration between logistics industry and economics growth in china from 1978 to 2008. And on FMOLS it makes positive correlation between logistics supply and demand and economics growth in china. Key words: Logistics; Economics Growth; Panel co-integratio

Enhancing Heat Transfer in Internal Combustion Engine by Applying Nanofluids

Nanofluids exhibit novel properties including significant heat transfer properties that make them potentially useful in internal combustion engine cooling. However, although there is a substantial number of mechanisms proposed, modeling works related to their enhanced thermal conductivity, systematic mechanisms, or models that are suitable for nanofluids are still lacked. With molecular dynamics simulations, thermal conductivities of nanofluids with various nanoparticles have been calculated. Influence rule of various factors for thermal conductivity of nanofluids has been studied. Through defining the ratio of thermal conductivity enhancement by nanoparticle volume fraction, Κ, the impacts of nanoparticle properties for thermal conductivity are further evaluated. Furthermore, the ratio of energetic atoms in nanoparticles, E, is proposed to be an effective criterion for judging the impact of nanoparticles for the thermal conductivity of nanofluids. Mechanisms of heat conduction enhancement are investigated by MD simulations. Altered microstructure and movements of nanoparticles in the base fluid are proposed to be the main reasons for thermal conductivity enhancement in nanofluids. Both the static and dynamic mechanisms for heat conduction enhancement in nanofluids have been considered to establish a prediction model for thermal conductivity. The prediction results of the present model are in good agreement with experimental results

H19 potentiates let-7 family expression through reducing PTBP1 binding to their precursors in cholestasis

Cholestasis induces the hepatic long non-coding RNA H19, which promotes the progression of cholestatic liver fibrosis. However, microRNAs that are dysregulated by H19 during cholestasis remain elusive. Using miRNA-sequencing analysis followed by qPCR validation, we identified marked upregulation of eight members of the let-7 family in cholestatic livers by bile duct ligation (BDL) and H19 overexpression. In particular, the expression of let-7a-1/7d/7f-1 was highly induced in H19-BDL livers but decreased in H19KO-BDL livers. Interestingly, H19 decreased the nuclear let-7 precursors as well as the primary transcripts of let-7a-1/7d/7f-1 levels in BDL mouse livers. Bioinformatics, RNA pull-down, and RNA immunoprecipitation (RIP) assays revealed that the crucial RNA-binding protein polypyrimidine tract-binding protein 1 (PTBP1), an H19 interaction partner, interacted with the precursors of let-7a-1 and let-7d and suppressed their maturation. Both PTBP1 and let-7 expression was differentially regulated by different bile acid species in hepatocyte and cholangiocyte cells. Further, H19 negatively regulated PTBP1's mRNA and protein levels but did not affect its subcellular distribution in BDL mouse livers. Moreover, we found that H19 restrained but PTBP1 facilitated the bioavailability of let-7 miRNAs to their targets. Taken together, this study revealed for the first time that H19 promoted let-7 expression by decreasing PTBP1's expression level and its binding to the let-7 precursors in cholestasis

Effect of grinding wheel on the dynamic performance of high-speed spindle system with an improved FE model

The grinding wheel is a key factor which should be considered in the process of predicting the dynamic performance of the high-speed spindle system. Currently, most research is mainly focuses on shaft and bearing using Timoshenko’s beam and Jones’ bearing model. In this research, considering the effect of grinding wheel on the dynamic behavior of the high-speed motorized spindle system, a dynamic model of spindle system has been established by utilizing the finite element method (FEM). The model is improved by optimizing the relevant parameters of spindle system and validated by measuring FRF using impact hammer test. The reported results are well matched (maximum error is 5 %). Using the improved model, the effect of grinding wheel on the critical speeds, mode shapes, centrifugal force and gyroscopic effects of spindle system are analyzed. In addition, the impact of different diameters, materials and fixed methods of grinding wheel on the dynamic property of spindle system are also carried out. The result shows the affect of grinding wheel and design guideline of the spindle and grinding wheel

Study of experimental modal analysis method of machine tool spindle system

Dynamic properties of the machine tools especially the spindle systems contribute greatly to the reliability of the machine tools. The increasing use of modal analysis as a standard tool to estimate the dynamic modal parameters means that both experienced and inexperienced analysts are faced with new challenges: uncertainty about the accuracy of results. Therefore, the key requirement for experimental modal analysis is a reliable, efficient and accurate experimental method in spindle system analysis. Several processes, such as reference and response selection in modal test however would make the system identification process for structural dynamics inaccurate. To investigate the results accuracy when applying experimental modal analysis on machine tool spindle, this work hence further studied the experimental setup itself based on the reference and response selection. The reference selection and reference optimization method is developed for the accuracy and efficiency improving purpose. First, by comparing results from different reference quantity and direction test, the method to select reference points is studied. Then the modal parameters are verified by the complex mode indicator functions and finite element analysis to study the influence of the reference on the modal analysis accuracy. Next, improved algorithm of response points optimization is developed based on the MAC matrix to minimize the number and location of measuring response points. Lastly, the general standard and method to select the reference and response points are put forward. The approach setting-up the experimental impact test provides reliable and accurate results and can reduce the testing time at the same time

The Improvement of 3D Traveltime Tomographic Inversion Method

As 3D high-precision seismic exploration is more and more widely used in seismic data acquisition, traveltime tomographic inversion based on first arrivals is developed from 2D to 3D. However, magnanimity data of 3D traveltime inversion brings about the problem of data storage; the absence of first arrivals with near offset reduces the precision of shallow layer; the utilization of prior information, such as small refraction and micro-logging data, can improve the precision of 3D traveltime inversion. Therefore, we make some improvements in 3D traveltime inversion method. We take compression storage for large and sparse matrix, propose virtual receivers technology, and add prior information to tomographic inversion linear equations. The application in 3D real data indicates that the improvements can effectively improve 3D traveltime tomographic inversion.Key words: 3D seismic exploration; 3D traveltime inversion method; 3D traveltime tomographic inversio

First Arrival Time Auto-Picking Method Based on Multi-Time Windows Energy Ratio

First arrival time auto-picking technique plays an important role in seismic exploration. It is widely used in shallow layer tomography and static correction. Conventional method that based on sliding time windows energy ratio is not stable. Here a new method based on multi-time windows energy ratio is proposed. Combining with automatic quality control and phase-domain first arrival estimation technique, our method performs perfectly on seismic records of normal S/N ratio. In the computational process of conventional sliding time windows energy ratio method, first arrivals are often determined by the maximum energy ratio of two adjacent sliding time windows. It is well known that for low S/N ratio data the conventional picking is not effective, and for high S/N ratio data weak reflections are hardly detected. The reason is that first arrival time does not correspond to the maximum energy ratio. Meanwhile conventional method sometime picks local secondary extreme of energy ratio. The new method of multi-time windows energy ratio method takes both maximum and local secondary extreme in consideration. Hence new method promotes the stability and accuracy of first arrival picking. Combined with automatic quality control and phase-domain first arrival estimation, the new method performs well in its application in the middle part of Dzungarian Basin(Northwest China)