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Pretreating and normalizing metabolomics data for statistical analysis

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Genes & Diseases 2024年第3期11卷 188-205页

作者： jun Sun Yinglin xia Division of Gastroenterology and Hepatology Department of MedicineDepartment of Microbiology/ImmunologyUIC Cancer CenterUniversity of Illinois ChicagoJesse Brown VA Medical Center Chicago(537)ChicagoIL 60612USA Division of Gastroenterology and Hepatology Department of MedicineUniversity of Illinois ChicagoChicagoIL 60612USA

Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological *** is emerging as a powerful tool generally for pre-cision ***,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and ***,metabo-lomics data are very ***/pretreating and normalizing procedures on metabolomics data are usually required before statistical *** this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data *** discuss the advantages and limitations of each *** choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis *** then provide the perspective of their applications in the microbiome and metabolome research.

关键词： Data centering and scaling Data normalization Data transformation Missing values MS-Baseddata preprocessing NMRData preprocessing Outliers Preprocessing/pretreatment

Hybrid Neural Network Model for RH Vacuum Refining Process Control

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Journal of Iron and Steel Research International 2004年第1期11卷 12-16页

作者： ZHANGChun-xia WANGBao-jun ZHOUShi-guang LIULiu XUJing-bo LINLi-ping ZHANGCheng-fu CentralIronandSteelResearchInstitute Beijing100081China WuhanIronandSteel（Group）Co Wuhan430080China PekingUniversity Beijing100080China

A hybrid neural network model,in which RH process(theoretical)model is combined organically with neural network(NN)and case-base reasoning(CBR),was *** CBR method was used to select the operation mode and the RH operational guide parameters for different steel grades according to the initial conditions of molten steel,and a three-layer BP neural network was adopted to deal with nonlinear factors for improving and compensating the limitations of technological model for RH process control and end-point *** was verified that the hybrid neural network is effective for improving the precision and calculation efficiency of the model.

关键词： RH vacuum refining process process control model hybrid neural network

Determination of the draft force for different subsoiler points using discrete element method

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International Journal of Agricultural and Biological Engineering 2016年第3期9卷 81-87页

作者： Li bo xia Rui Liu Fanyi Chen jun Han Wenting Han Bing College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling712100China

Generally,a subsoiler is comprised of a shank and a *** point shape has a significant effect on the draft force of a *** this study,the draft force of subsoilers with four different points were compared under the speed of 0.8 m/s and the depth of 350 mm in the soil *** Element Method(DEM)was applied in simulating the working process of the *** stiffness of soil particles used in DEM was calibrated by comparing the simulated draft force of a standard arc-shaped subsoiler with the *** calibrated soil particle stiffness was 1.1×104 N/*** validated model was then used to compare the draft force of subsoilers with four different points under the same condition in the *** showed that different points would cause different draft *** subsoiler with short chisel point caused the smallest draft force(2885 N)while the point with short face and wings had the largest force(4474 N).The relative errors of the simulated results were less than 4%,which proved that DEM was an effective way for predicting the draft force of *** velocity field and contact force filed could show the movement of soil around the subsoiler.

关键词： subsoiler point shape draft force chisel point DEM conservation tillage

Quantizations of the W-Algebra W（2, 2）

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Acta Mathematica Sinica,English Series 2011年第4期27卷 647-656页

作者： jun bo LI School of Mathematics and Statistics Changshu Institute of Technology Changshu 215500 P. R. China Department of Mathematics University of Science and Technology of China Hefei 230026 P. R. China Department of Mathematics Tongji University Shanghai 200092 P. R. China

We quantize the W-algebra W（2,2）, whose Verma modules, Harish-Chandra modules, irreducible weight modules and Lie bialgebra structures have been investigated and determined in a series of papers recently.

关键词： Quantization the W-algebra W(2 2) quantum groups Lie bialgebras

Porosity of gas shale:Is the NMR-based measurement reliable?

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Petroleum Science 2022年第2期19卷 509-517页

作者： Peng Zhao bo He bo Zhang jun Liu Key Laboratory of Deep Underground Science and Engineering(Ministry of Education) College of Architecture and EnvironmentSichuan UniversityChengduSichuan 610065China Institute of New Energy and Low-Carbon Technology Sichuan UniversityChengduSichuan 610065China Institute of Science and Technology China Three Gorges CorporationBeijing100038China

Aiming at obtaining an accurate porosity of gas shale,various approaches are ***,nuclear magnetic resonance(NMR),being treated as a kind of new-developed technique,possesses the representative ***,as a booming technique,the reliability of NMR-based porosity of shale is not exactly *** on NMR device,this work measured the porosity of shale experiencing different water soaking time,accordingly,judging the reliability of NMR-based *** indicate the NMR outcomes vary with the water soaking time,making a doubt about the objectivity of NMRbased porosity in reflecting the real shale ***,some supplementary means were adopted to verify the water soaking-induced variation in the pore system of shale sample,which intensities the suspicion if the NMR-based porosity is reliable or *** sum up,this work considers that the NMR-based porosity of shale is not reliable enough when water is used as the ***,this work also offers some suggestions on how to enhance the reliability of NMR-based porosity of shale ***,this work selects a fresh perspective to analyze the NMR approach in determining shale porosity,which is hopefully helpful in promoting the development of NMR technique in the shale-related field.

关键词： Gas shale Low-field NMR Porosity measurement Low-temperature nitrogen adsorption

Stability and Instability of Schwarzschild-AdS for the Nonlinear Einstein-Klein-Gordon System

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Acta Mathematicae Applicatae Sinica 2022年第4期38卷 778-812页

作者： Feng-xia LIU bo-Ling GUO Institute of Artificial Intelligence Beihang UniversityBeijing 100083China Institute of Applied Physics and Computational Mathematics Beijing 100088China

In this paper,we study the global behavior of solutions to the spherically symmetric(it means that the problem is 2+2 framework)coupled Nonlinear-Einstein-Klein-Gordon(NLEKG)system in the presence of a negative cosmological *** prove the well posedness of the NLEKG system in the Schwarzschild-AdS spacetimes and that the Schwarzschild-AdS spacetimes(the trivial black hole solutions of the EKG system for whichφ=0 identically)are asymptotically *** perturbations of Schwarzschild-AdS initial data again lead to regular black holes,with the metric on the black hole exterior approaching a SchwarzschildAdS *** argument on the black hole exterior,with the redshift effect and weighted Hardy inequalities playing the fundamental role in the *** integrated decay and pointwise decay estimates are obtained.

关键词： nonlinear-Einstein-Klein-Gordon equation schwarzschild-AdS spacetime well-posedness bootstrap

Retinal stem cells transplantation combined with copolymer-1 immunization reduces interferon-gamma levels in an experimental model of glaucoma

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International Journal of Ophthalmology(English edition) 2011年第6期4卷 594-598页

作者： xia Zhou xiao-bo xia Department of Ophthalmology Xiangya Hospital of Central South University Changsha 410006 Hunan Province China

AIM: To explore the effect of immunization with copolymer-1 (COP-1) and retinal stem cells (RSCs) transplantation on interferon-gamma (IFN-gamma) levels in a rat experimental glaucoma model. METHODS: An experimental glaucoma was induced by argon laser photocoagulation of the episcleral veins and limbal plexus in the right eye of rats. Immediately following glaucoma induction, rats were immunized with COP-1. RSCs were cultured and transplanted intravitreally into the eyes of glaucoma model animals 1 week post-laser treatment. Six experimental groups were used: COP-1/RSC, PBS/RSC, COP-1/PBS, PBS/PBS, glaucoma model group, and a normal control group. The concentration of IFN-gamma in aqueous humor (AH) and serum was measured by enzyme-linked immunosorbent assay (ELISA) in each of the six groups. Retinal ganglion cell (RGC) survival was assessed by quantifying apoptosis using Hoechst staining. RESULTS: Concentrations of IFN-gamma in AH and serum of rats that had undergone glaucoma induction were higher than those of non-induced control rats. The concentrations of IFN-gamma in AH and serum of the COP-1/RSCs treated group were determined to be 2371.9ng/L and 710.9ng/L, respectively, which were significantly lower than those in the other treated groups (P<0.05). In fact, IFN-gamma levels in the dual treated group were reduced to background levels. The COP-1/RSC group had lower number of apoptotic RGCs than the other three experimental groups (P<0.05). CONCLUSION: The reduced levels of IFN-gamma in AH and serum of the COP-1/RSC group may be related to synergistic effects between RSCs transplantation and COP-1 immune modulation. It is likely that the lower levels of IFN-gamma prevented RGCs glaucomatous apoptasis.

关键词： glaucoma interferon-gamma RSC transplantation COP-1 immunization

Thermal Transport through Solid-Liquid Interface:Effect of the Interfacial Coupling and Nanostructured Surfaces

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Journal of Thermal Science 2022年第4期31卷 1167-1179页

作者： LI Haiyang WANG jun xia Guodong MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy Conversion Beijing University of TechnologyBeijing 100124China

The solid-liquid interfacial thermal transport depends on the physical properties of the interfaces,which have been studied extensively in open ***,the fundamental understanding on the mechanism of the solid-liquid interfacial thermal transport is far from *** the present paper,heat transfer through solid-liquid interfaces is studied based on the non-equilibrium molecular dynamics *** is shown that the interfacial heat transfer can be enhanced by increasing interfacial coupling strength or introducing the nanostructured *** underlying mechanism of the interfacial thermal transport is analyzed based on the calculation results of the heat flux distribution,potential mean force,and the vibrational density of states at the interfacial *** is found that the interfacial thermal transport is dominated by the kinetic and virial contributions in the interface *** enhancement of the interfacial heat transfer can be attributed to the fluid adsorption on the solid surface under a strong interfacial interaction or by the nanostructured solid surfaces,which reduce the mismatch of the vibrational density of states at the solid-liquid interface region.

关键词： solid-liquid interface molecular dynamics simulation thermal resistance nanostructure

Design of wideband graded-index antireflection coatings at oblique light incidence

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Chinese Physics B 2012年第1期21卷 199-203页

作者： Zhang jun-Chao Fang Ming Jin Yun-xia He Hong-bo Key Laboratory of Material Science and Technology for High Power Lasers Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Graduate University of Chinese Academy of Sciences Beijing 100049China

We suggest a design method of graded-refractive-index （GRIN） antireflection （AR） coating for s-polarized or p- polarized light at off-normal incidence. The spectrum characteristic of the designed antireflection coating with a quintic effective refractive-index profile for a given state of polarization has been discussed. In addition, the genetic algorithm was used to optimize the refractive index profile of the GRIN antireflection for reducing the mean reflectance of s- and p-polarizations. The average reflectance loss was reduced to only 0.04% by applying optimized GRIN AR coatings onto BK7 glass over the wavelength range from 400 to 800 nm at the incident angle of θo = 70°.

关键词： antireflection coatings oblique incidence graded-refractive-index profile genetic algo-rithm