112 research outputs found
Review of Financial Pressure
Different from foreign capital markets, china’s domestic capital markets are special, which also determines that the research on financial pressure starts from the reform of state-owned enterprises, and draws lessons from the relevant theories of financial risk and financial fraud, thus gradually forming a more diversified research results
Study of decay with perturbative QCD approach
The -exchange process is studied
with the perturbative QCD approach. Three kinds of wave functions for
meson and two forms of wave functions for charmonium are considered. It is
estimated that branching ratios for ,
, , decays are the order of
, , , , respectively, where the largest
uncertainty is from wave functions. There is a possibility for measuring these
decay in the near future.Comment: 17 pages, revtex4, accepted by EPJ
An Object-Oriented Classification Method on High resolution Satellite Data
ABSTRACT:To traditional moderate or low resolution satellite data, the data processing or information detecting is only on a per-pixel basis because of the impacts to geometric accuracy of spatial resolution, Thereby only the spectral information is used for the classification. High spatial resolution sensors involves a general increase of spatial information and the accuracy of results may decrease on a per-pixel basis. In order to realise the full potential of the VHR image data, An object-oriented image analysis is implemented with the software eCognition. It is based on fuzzy logic, allows the integration of different object featrues, such as spectral values, shape and texture. In this paper we analysis an object-oriented classification method using QuickBird panchromatic and multispectral data on the test area of the PuDong New district of ShangHai.The analysis includes two parts: first dividing the image data into segments and then classifying the segments by means of fuzzy approach of nearest neighbour classifier
Nitrogen-doped carbon nanotubes coated with zinc oxide nanoparticles as sulfur encapsulator for high-performance lithium/sulfur batteries
Nitrogen-doped carbon nanotubes coated with zinc oxide nanoparticles (ZnO@NCNT) were prepared via a sol–gel route as sulfur
encapsulator for lithium/sulfur (Li/S) batteries. The electrochemical properties of the S/ZnO@NCNT composite cathode were evaluated
in Li/S batteries. It delivered an initial capacity of 1032 mAh·g−1 at a charge/discharge rate of 0.2C and maintained a reversible
capacity of 665 mAh·g−1 after 100 cycles. The coulombic efficiency of the cathode remains unchanged above 99%, showing
stable cycling performance. X-ray photoelectron spectroscopy analysis confirmed the formation of S–Zn and S–O bonds in the
composite. This indicates that an enhanced cycling and rate capability of the S/ZnO@NCNT composite could be ascribed to advantages
of the ZnO@NCNT matrix. In the composite, the active ZnO-rich surfaces offer a high sulfur-bonding capability and the
NCNT core acts as a conductive framework providing pathways for ion and electron transport. The as-prepared S/ZnO@NCNT
composite is a promising cathode material for Li/S batteries
Gated recurrent unit neural network (GRU) based on quantile regression (QR) predicts reservoir parameters through well logging data
The prediction of reservoir parameters is the most important part of reservoir evaluation, and porosity is very important among many reservoir parameters. In order to accurately measure the porosity of the core, it is necessary to take cores for indoor experiments, which is tedious and difficult. To solve this problem, this paper introduces machine learning models to estimate porosity through logging parameters. In this paper, gated recurrent unit neural network based on quantile regression method is introduced to predict porosity. Porosity measurement is implemented by taking cores for indoor experiments. The data is divided into training set and test set. The logging parameters are used as the input parameters of the prediction model, and the porosity parameters measured in the laboratory are used as the output parameters. Experimental results show that the quantile regression method improves the accuracy of the gated recurrent unit neural network, and the RMSE (Root Mean Square Error) of the unoptimized GRU neural network is 0.1774, after optimization, the RMSE is 0.1061. By comparing with the most widely used BP neural network, the accuracy of the method proposed in this paper is much higher than that of BP neural network. This shows that the gated recurrent neural network method based on quantile regression is excellent in predicting reservoir parameters
Short-term and medium-term clinical outcomes of laparoscopic-assisted and open surgery for colorectal cancer: a single center retrospective case-control study
BACKGROUND: Laparoscopic procedure is a rapid developed technique in colorectal surgery. In this investigation we aim at assessing the diversities of short-term and medium-term clinical outcomes of laparoscopic-assisted versus open surgery for colorectal cancer. METHODS: A total number of 519 patients with non-metastatic colorectal cancer were enrolled for this study. The patients underwent either laparoscopic-assisted surgery (LAP) (n = 254) or open surgery (OP) (n = 265). Surgical techniques, perioperative managements and clinical follow-ups were standardized. Short-term perioperative data and medium-term recurrence and survival were compared and analyzed between the two groups. RESULTS: There were no differences in perioperative parameters between the two groups except in regards to a trend of faster recovery in laparoscopic procedures. There was no statistically significant difference in postoperative complications, reoperation rate, or perioperative mortality. Statistically significant differences in a faster return of gastrointestinal function and shorter hospital stay were identified in favor of laparoscopic-assisted resection. In colon and rectal cancer cases separately, the overall survival, cancer-free survival and recurrence rate were similar in two groups. There was also no tendency of significant differences in overall survival, cancer-free survival and recurrence in stage I-II and stage III patients in two cancer categories between the two groups, respectively. pT, lymph node metastasis, and clinical stage were independent predictors of overall death risk, while pT, pN, lymph node metastasis and clinical stage were found to be the independent predictors of recurrence risk in enrolled patients database. CONCLUSIONS: Laparoscopic-assisted procedure has more benefits on postoperative recovery, while has the same effects on medium-term recurrence and survival compared with open surgery in the treatment of non-metastatic colorectal cancer
Experimental study on working capacity of carbon canister based on Euro VI
In order to study the gasoline working capacity and durability of the carbon canister, the gasoline working capacity test of the carbon canister was conducted under different test conditions. The results showed that the gasoline working capacity of the canister carbon decreased with the increase of fuel vapor loading rate. The fuel vapor volume ratio of the inlet has little effect on the gasoline working capacity. After 300 gasoline working capacity test cycles, the working capacity of butane decreased by about 20%. The fuel vapor adsorption amount in first cycle of each carbon canister is far greater than the desorption amount in first cycle, and also far greater than the adsorption and desorption amount in the subsequent cycles, which indicated that a large amount of fuel vapor occupied the active sites after the first use of the carbon canister and cannot desorb
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