Estimating the impact of transport efficiency on trade costs: Evidence from Chinese agricultural traders

Using a unique survey data on agricultural traders in China in 2004, this study provides direct evidence on significance of interregional transport costs and their key determinants. Our major findings are as follows: (1) the trade barriers within China are dominated by transport-related costs but not artificial barriers, approximated by tolls and fines; (2) Labor and fuels costs are the most significant component of transport costs; (3) road quality is very important for transportation efficiency. Our results indicate that if increasing transport speed by 1 km per hour now, the fuel costs and total direct transportation costs for Chinese traders would reduce by 1.3% and 0.7% respectively.Transportation Costs, China, Agricultural Traders, Infrastructure, International Relations/Trade,

Consumer Willingness to Pay for Preservative-Free Food: The Case of Beijing

Consumers are facing a trade-off between the benefits of an increase in the length of the shelf life of food, such as low food costs, and the potential health damages caused by food preservatives. However, few studies in the current literature place emphasis on food preservatives, neither from a scientific perspective nor from an economic perspective. This causes a lot of controversies about government regulations. By constructing a theoretical framework and using a survey of 293 customers from 25 supermarkets in Beijing, this paper studies the consumer attitude towards food preservatives and attempts to fill the gap in the current literature. The main findings include that food price, and consumers' age and income are important for the willingness to pay (WTP) for 'preservative-free food' in Beijing. In particular, food price and consumer incomes are positively correlated with the WTP and there might be an inverted U-shaped relationship between age and WTP. This study indicates that consumers in Beijing are willing to pay a very high premium for preservative-free food 62% for preservative-free Mooncakes compared to conventional ones

Estimating transport costs and trade barriers in China: Direct evidence from Chinese agricultural traders

Using a unique survey data on agricultural traders in China in 2004, this study provides direct evidence on the significance of inter-regional trade barriers and their key components. Our major findings are as follows. (1) The trade barriers within China are fairly small, accounting for about 20 percent of trade value. (2) Transport and non-transport costs respectively contribute 42% and 58% to the trade barriers. (3) Labor and transport-related taxes are the two largest proportions of total transport costs, and respectively accounts for 35% and 30%. (4) Artificial trade barriers created by the government are not sizable as we perceived. (5) Road quality is crucial for reducing transport costs within China: Increasing transport speed by 1 km per hour, the total transport costs for Chinese agricultural traders would decrease by 0.6 percent mainly due to improved fuel-burning efficiency and reduced labor requirement

A FPC-ROOT Algorithm for 2D-DOA Estimation in Sparse Array

To improve the performance of two-dimensional direction-of-arrival (2D DOA) estimation in sparse array, this paper presents a Fixed Point Continuation Polynomial Roots (FPC-ROOT) algorithm. Firstly, a signal model for DOA estimation is established based on matrix completion and it can be proved that the proposed model meets Null Space Property (NSP). Secondly, left and right singular vectors of received signals matrix are achieved using the matrix completion algorithm. Finally, 2D DOA estimation can be acquired through solving the polynomial roots. The proposed algorithm can achieve high accuracy of 2D DOA estimation in sparse array, without solving autocorrelation matrix of received signals and scanning of two-dimensional spectral peak. Besides, it decreases the number of antennas and lowers computational complexity and meanwhile avoids the angle ambiguity problem. Computer simulations demonstrate that the proposed FPC-ROOT algorithm can obtain the 2D DOA estimation precisely in sparse array

Selection Method for Kernel Function in Nonparametric Extrapolation Based on Multicriteria Decision-Making Technology

Selecting the most appropriate kernel function to extrapolate a load set is the paramount step in compiling load spectrum, as it affects the results of nonparametric extrapolation largely. Aiming at this issue, this paper provides a new approach in selecting kernel function for the nonparametric extrapolation. To solve the complexity and uncertainty of nonparametric extrapolation, characteristics of four kernel functions and their effects on the results are explained in the “from-to” diagram obtained by rainflow counting. Multicriteria decision-making (MCDM) is then applied to solve the selection problem of kernel function. To evaluate the dispersion degrees of the mean and amplitude of a load set accurately, their range, standard deviation, and interquartile range are selected as the evaluation criteria. The weight of each criterion, which represents the impact degree on the selection of the kernel function, is calculated separately using the eigenvector and entropy method. The comprehensive weights are obtained by applying the optimization theory and Jaynes’ maximum entropy principle. Finally, the importance of each criterion is discussed according to their calculated comprehensive weights, and the selection method for kernel functions is obtained, which is illustrated by extrapolating the output torque of the power split device of hybrid electrical vehicles

Characterization of blaOxA-23 gene regions in isolates of Acinetobacter baumannii

Background/purposeTo investigate the characterization of blaOxA-23 gene regions in isolates of Acinetobacter baumannii from Taizhou Municipal Hospital.MethodsFifty-nine non-repetitive, multiresistant (including imipenem-resistant) isolates of A. baumannii were recovered from clinical infections in hospitalized patients from January 2010 to August 2011 in Taizhou Municipal Hospital (affiliated with Taizhou University) in China. These isolates were genotyped using pulsed-field gel electrophoresis (PFGE). blaOxA-23 β-lactamase and associated genetic structures were analyzed using polymerase chain reaction (PCR), and recombination plasmids were analyzed by BamHI- or SacI- restriction enzyme digestion; predicted promoter structures of blaOxA-23 genes were determined and compared using protein-protein BLAST analysis.ResultsFifteen out of 59 isolates expressing imipenem-resistant A. baumannii clinical isolates acquired either a blaOxA-23 β-lactamase gene. A new gene cluster (ISAba1-blaOxA-23-AMP) with three previously identified transposons (Tn2006, Tn2007, and Tn2008) and one previously identified gene cluster (ISAba1- blaOxA-23) was found in the isolates. Recombination plasmids were analyzed by restriction enzyme digestion.ConclusionOur results indicate that pattern A was the most prevalent molecular type based on PFGE, and that different clones might be widespread with a majority of ISAba1-blaOxA-23 clonal lineages in the 15 PCR positive isolates of A. baumannii in the hospital

Fluctuating Two-state Light Harvesting In A Photosynthetic Membrane

The mechanism by which light is converted into chemical energy in a natural photosynthetic system has drawn considerable research interest. Using fluorescence spectroscopy and microscopic imaging, we have observed fluctuating intermolecular protein fluorescence resonant energy transfers (FRET) among light-harvesting proteins I and II (LH1 and LH2) in bacterial photosynthetic membranes. Using two-channel, FRET, photon-counting detection and a novel, two-dimensional cross-correlation function amplitude-mapping analysis, we revealed fluorescence intensity and spectral fluctuations of donor (LH2) and acceptor (LH1) fluorescence involving FRET. Our results suggest that there are dynamic coupled and noncoupled states of the light-harvesting protein assemblies in photosynthetic membranes. The light-harvesting complex assembly under ambient conditions and under water involves dynamic intermolecular structural fluctuations that subsequently disturb the degree of energy transfer coupling between proteins in the membrane. Such intrinsic and dynamic heterogeneity of the native photosynthetic membranes, often submerged under the overall thermally induced spectral fluctuations and not observable in an ensemble-averaged measurement, likely plays a critical role in regulating the light-harvesting efficiency of the photosynthetic membranes

Nitrogen-doped micropores binder-free carbon-sulphur composites as the cathode for long-life lithium-sulphur batteries

Nitrogen-doped micropores-contained carbon nanofibres (NMCNFs) were prepared by carbonizing ZIF-8 grown in liquid-phase along with electrospinning. When NMCNFs act as sulphur host materials in lithium–sulphur batteries, NMCNFs can retard the shuttle effect and dissolution of polysulfides through the synergic action of effective physical confinement to micropores and nitrogen surface chemical absorption. NMCNFs show a capacity up to 636 mAh g−1 after 500 cycles against Li anode

Parameter Optimization of a Discrete Scattering Model by Integration of Global Sensitivity Analysis Using SMAP Active and Passive Observations

Active and passive microwave signatures respond differently to the land surface and provide complementary information on the characteristics of the observed scenes. The objective of this paper is to explore the synergy of active radar and passive radiometer observations at the same spatial scale to constrain a discrete radiative transfer model, the Tor Vergata (TVG) model, to gain insights into the microwave scattering and emission mechanisms over grasslands. The TVG model can simultaneously simulate the backscattering coefficient and emissivity with a set of input parameters. To calibrate this model, in situ soil moisture and temperature data collected from the Maqu area in the northeastern region of the Tibetan Plateau, interpolated leaf area index (LAI) data from the Moderate Resolution Imaging Spectroradiometer LAI eight-day products, and concurrent and coincident Soil Moisture Active Passive (SMAP) radar and radiometer observations are used. Because this model needs numerous input parameters to be driven, the extended Fourier amplitude sensitivity test is first applied to conduct global sensitivity analysis (GSA) to select the sensitive and insensitive parameters. Only the most sensitive parameters are defined as free variables, to separately calibrate the active-only model (TVG-A), the passive-only model (TVG-P), and the active and passive combined model (TVG-AP). The accuracy of the calibrated models is evaluated by comparing the SMAP observations and the model simulations. The results show that TVG-AP can well reproduce the backscattering coefficient and brightness temperature, with correlation coefficients of 0.87, 0.89, 0.78, and 0.43 and root-mean-square errors of 0.49 dB, 0.52 dB, 7.20 K, and 10.47 K for σ HH⁰ , σ VV⁰ , TBH, and TBV, respectively. In contrast, TVG-A and TVG-P can only accurately model the backscattering coefficient and brightness temperature, respectively. Without any modifications of the calibrated parameters, the error metrics computed from the validation data are slightly worse than those of the calibration data. These results demonstrate the feasibility of the synergistic use of SMAP active radar and passive radiometer observations under the unified framework of a physical model. In addition, the results demonstrate the necessity and effectiveness of applying GSA in model optimization. It is expected that these findings can contribute to the development of model-based soil moisture retrieval methods using active and passive microwave remote sensing data