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Isolation of Hemicellulose from Wood Chips via Extraction with Kraft Green Liquor

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Chemical Research in Chinese Universities 2010年第4期26卷 667-671页

作者： SUN Hui xu Ying-kai xu guo-zhi Department of Material Science and Engineering China National Center for Quality Supervison ＆ Test of Plastic Products Beo＇ing Technology and Business University Beijing 100048 P. R. China Department of Surgery University of Pittsburg 3459 Fifth Avenue Pittsburgh PA USA

The present paper covers the extraction of hemicelluloses from woods, i.e., Eucalyptus Globulus, white fir and Douglas fir via green liquor pretreatment and alkali post-treatment with sodium hydroxide. The effects of such extraction conditions as extraction time, temperature on the yields of hemicellulose and the degree of deliginification were investigated. Sugar analyses using Dionex indicate that xylose, glucose and mannose are the main sugar types present in the hemicellulose from Eucalyptus. Other sugar components such as arabinose and galactose were also found in Dogulas fir hemicellulose. The highest yield of hemicellulose was 8.4% for Eucalyptus extracted with green liquor at 130 ℃ for 3.5 h. Further sodium hydroxide extraction for 5 h gave a hemicellulose yield of about 20%. The use of green liquor for the extraction of wood hemicellulose is believed to be the first attempt.

关键词： Hemicellulose Lignin Wood Green liquor Alkali extraction

Quantitative ^(31)P NMR Analysis of Lignocellulosic Materials in Ionic Liquids

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Chemical Research in Chinese Universities 2010年第3期26卷 488-490页

作者： SUN Hui xu Ying-kai xu guo-zhi Department of Materials Science and Engineering National Center for Quality Supervision and Test of Plastic Products Beijing Technology and Business University Beijing 100048 P R. China Department of Surgery University of Pittsburgh Pennsylvania 15213 USA

In an effort to utilize NMR technique for the analysis of the structural components of wood and biomasses such as lignin, we made a comparative study of lignin contents of several types of lignocellulosie materials both before and after enzymatic hydrolyses. To this end, Eucalyptus Globulus, Norway spruce thermomeehanieal pulp（TMP） corn stover and Eucalyptus kraft pulp were ball-milled and treated with cellulase to prepare materials with high lignin contents. These materials were analyzed via ^31p NMR in ionic liquids. The results show that the contents of various functional groups for the lignocellulosic materials after enzymatic hydrolyses are generally in agreement with those from their corresponding enzymatic mild acidolysis liginins（EMALs）, indicating that ^31p NMR analysis of lignocellulosic materials in ionic liquids is a promising method for quantitative characterization of lignocellulosic materials.

关键词： Structural characterization ^31p NMR Enzymatic mild acidolysis lignin(EMAL)

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辽河口地区浮游植物群落时空分布特征

东北水利水电 2024年第1期42卷 36-40,72页

作者：王金海徐志国内蒙古兴安盟水利事业发展中心内蒙古兴安盟137400 水利部松辽水利委员会吉林长春130021

浮游植物可作为鱼产潜力估算的重要依据,在水域生态系统的上行效应和下行效应中发挥重要的作用,浮游植物的时空分布对环境因子有着重要的指示作用。本文针对2015年平水期和丰水期的大辽河、双台子河、大凌河及绕阳河浮游植物进行了定性... 详细信息

浮游植物可作为鱼产潜力估算的重要依据,在水域生态系统的上行效应和下行效应中发挥重要的作用,浮游植物的时空分布对环境因子有着重要的指示作用。本文针对2015年平水期和丰水期的大辽河、双台子河、大凌河及绕阳河浮游植物进行了定性与定量采样分析,通过对浮游植物时空分布的研究,间接反应出了河口营养时空分布状态,有助于提升河口环境管理的科学决策水平,可为我国河口海域的生态监测和管理等提供参考。

关键词：辽河口浮游植物丰水期平水期时空分布

Immobilization of Bovine Serum Albumin on Poly(ether ether ketone) for Surface Biocompatibility Improvement

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Chemical Research in Chinese Universities 2012年第2期28卷 353-357页

作者： SUN Hui CHEN Rui-chao LI Ang xu guo-zhi School of Materials Science and Mechanical Engineering Beijing Technology and Business UniversityBeijing 100048P R.China

UV-induced graft polymerization of acrylic acid（AA） on poly（ether ether ketone）（PEEK） films was carried out to introduce ―COOH for the subsequent immobilization of bovine serum albumin（BSA）.BSA was introduced on PEEK surface based on the condensation reaction between ―NH 2 and ―*** modified surface（PEEK-BSA） was characterized by energy-disperse spectrometry（EDS）,X-ray photoelectron spectroscopy（XPS）,water contact angle measurement and UV spectrum *** contact angle was found to decrease from 104° for the virgin PEEK films to 63° for the BSA-immobilized PEEK films,demonstrating a significant improvement of surface ***,the appearance of nitrogen on PEEK film confirmed by XPS and EDS indicates the immobilization of BSA on PEEK surface.

关键词： Poly(ether ether ketone)(PEEK) UV-grafting Bovine serum albumin immobilization

Numerical simulation on a film-cooled rotating model with 30° injection holes

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航空动力学报 2010年第7期25卷 1443-1453页

作者： YANG Bin xu guo-qiang TAO zhi DING Shui-ting WU Hong-wei National Key Laboratory of Science and Technology on Aero-Engines School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

The flow and heat transfer characteristics were numerically investigated on a film cooling model under different rotating operating *** computational model was originated from the mid-span section of a typical turbine rotor with two rows of 14 staggered injection holes angled 30° both on the suction surface and pressure surface,and the flow through the coolant plenum and all the hole-pipes were resolved as a part of the computational domain by specifying the coolant mass flux in the *** computations primarily focus on under-standing the rotational effect on film cooling performance in mechanism research *** the present study,the Reynolds number(Re) based on mainstream velocity and injection hole diameter varied from 1835.5 to 5507.4,and the averaged blowing ratio(M) ranges of 0.5 to *** show that the coolant will move on to the high-radius locations near the suction and pressure surfaces due to the strong centrifugal effect,which leads to the decrease in adiabatic effectiveness *** discharge coefficients(Cd),on the pressure surface,are much higher than that on the suction surface under a given operating *** addition,the critical values of angular speed which represent the equilibrium of centrifugal force and Coriolis force near the pressure surface are also presented.

关键词： film cooling rotating adiabatic effectiveness heat transfer discharge coefficient

Incorporating Lasso Regression to Physics-Informed Neural Network for Inverse PDE Problem

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 385-399页

作者： Meng Ma Liu Fu xu guo zhi Zhai National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an710049China Department of Electrical and Computer Engineering University of Massachusetts LowellLowellMA 01854USA

Partial Differential Equation(PDE)is among the most fundamental tools employed to model dynamic *** PDE modeling methods are typically derived from established knowledge and known phenomena,which are time-consuming and ***,discovering governing PDEs from collected actual data via Physics Informed Neural Networks(PINNs)provides a more efficient way to analyze fresh dynamic systems and establish *** study proposes Sequentially Threshold Least Squares-Lasso(STLasso),a module constructed by incorporating Lasso regression into the Sequentially Threshold Least Squares(STLS)algorithm,which can complete sparse regression of PDE coefficients with the constraints of l0 *** further introduces PINN-STLasso,a physics informed neural network combined with Lasso sparse regression,able to find underlying PDEs from data with reduced data requirements and better *** addition,this research conducts experiments on canonical inverse PDE problems and compares the results to several recent *** results demonstrated that the proposed PINN-STLasso outperforms other methods,achieving lower error rates even with less data.

关键词： Physics-informed neural network inverse partial differential equation Lasso regression scientific machine learning

A Local Tb Theorem for Square Functions and Parabolic Layer Potentials

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1941-1966页

作者： zhi Dan WANG guo Ming ZHANG School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816P.R.China Frontiers Science Center for Nonlinear Expectations Ministry of EductionResearch Center for Mathematics and Interdisciplinary SciencesShandong UniversityQingdao266237P.R.China

In this paper,we give a locally parabolic version of Tb theorem for a class of vector-valued operators with off-diagonal decay in L^(2) and certain quasi-orthogonality on a subspace of L^(2),in which the testing functions themselves are also *** an application,we establish the boundedness of layer potentials related to parabolic operators in divergence form,defined in the upper half-space Rn+2+:={(x,t,λ)∈R^(n+1)×(0,∞)},with uniformly complex elliptic,L^(∞),t,λ-independent coefficients,and satisfying the De Giorgi/Nash estimates.

关键词： Local Tb theorems Calderon-Littlewood-Paley family Parabolic layer potentials Carleson measure estimates

SEMI-IMPLICIT SPECTRAL DEFERRED CORRECTION METHODS BASED ON SECOND-ORDER TIME INTEGRATION SCHEMES FOR NONLINEAR PDES

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Journal of Computational Mathematics 2024年第1期42卷 111-133页

作者： Ruihan guo Yan xu School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China

In[20],a semi-implicit spectral deferred correction(SDC)method was proposed,which is efficient for highly nonlinear partial differential equations(PDEs).The semi-implicit SDC method in[20]is based on first-order time integration methods,which are corrected iteratively,with the order of accuracy increased by one for each additional *** this paper,we will develop a class of semi-implicit SDC methods,which are based on second-order time integration methods and the order of accuracy are increased by two for each additional *** spatial discretization,we employ the local discontinuous Galerkin(LDG)method to arrive at fully-discrete schemes,which are high-order accurate in both space and *** experiments are presented to demonstrate the accuracy,efficiency and robustness of the proposed semi-implicit SDC methods for solving complex nonlinear PDEs.

关键词： Spectral deferred correction method Nonlinear PDEs Local discontinuous Galerkin method Second-order scheme

Expression and significant roles of the long non-coding RNA CASC19/miR-491-5p/HMGA2 axis in the development of gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第8期16卷 3559-3584页

作者： Li-Xiang Zhang Pan-Quan Luo zhi-Jian Wei A-Man xu Tao guo Department of Gastroenterology The First Affiliated Hospital of Anhui Medical UniversityHefei 230031Anhui ProvinceChina Anhui Provincial Key Laboratory of Digestive Disease Hefei 230031Anhui ProvinceChina Department of General Surgery The First Affiliated Hospital of Anhui Medical UniversityHefei 230031Anhui ProvinceChina Anhui Public Health Clinical Center Hefei 230000Anhui ProvinceChina

BACKGROUND Gastric cancer(GC)is a common malignant tumor,long non-coding RNA and microRNA(miRNA)are important regulators that affect tumor proliferation,metastasis and chemotherapy resistance,and thus participate in tumor ***19 is a new bio-marker which can promote tumor invasion and ***,the mechanism by which CASC19 affects the progression of GC through miRNA is not *** To explore the role of the CASC19/miR-491-5p/HMGA2 regulatory axis in *** To explore the expression and prognosis of CASC19 in GC through clinical samples,and investigate the effects of inhibiting CASC19 on the proliferation,migration,invasion and other functions of GC cells through cell counting Kit-8(CCK-8),ethynyldeoxyuridine,Wound healing assay,Transwell,Western blot and flow cytometry *** effect of miR-491-5p and HMGA2 in GC were also *** regulatory relationship between CASC19 and miR-491-5p,miR-491-5p and HMGA2 were validated through Dual-luciferase reporter gene assay and reverse transcription *** CCK-8,Transwell,Wound healing assay,flow cytometry and animal experiments verify the role of CASC19/miR-491-5p/HMGA2 regulatory *** The expression level of CASC19 is related to the T stage,N stage,and tumor size of *** of the expression of CASC19 can inhibit the ability of proliferation,migration,invasion and EMT conversion of GC cells,and knocking down the expression of CASC19 can promote the apoptosis of GC *** the expression of miR-491-5p can inhibit the proliferation of GC cells,miR-491-5p mimics can inhibit EMT conversion,and promote the apoptosis of GC cells,while decreasing the expression of miR-491-5p can promote the proliferation and EMT conversion and inhibit the apoptosis of GC *** expression of HMGA2 in GC tissues is higher than that in adjacent *** the same time,the expression level of HMGA2 is related to the N and T stages of the *** the level of HMGA2 can pr

关键词： Gastric cancer Long non-coding RNA CASC19 miR-491-5p HMGA2 Prognosis