检索结果-南通市图书馆

Comparative pyrolysis kinetics of heavy oil and its SARA fractions using distributed activation energy model

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2023年第5期20卷 3231-3239页

作者： Qing-An Xiong yu-ming zhang Pei Qiao Guo-Tong Li Jia-Zhou Li Wei zhang College of Mechanical and Transportation Engineering China University of PetroleumBeijing102249China

The pyrolysis behaviors of Qingdao vacuum residue(QD-VR)and its SARA(saturates,aromatics,reins,and asphaltenes)fractions were evaluated by thermo-gravimetric with mass spectrometer(TG-MS).The pyrolysis kinetics were determined by Friedman,one-parallel and four-parallel distributed activation energy model(DAEM),*** results indicated that the pyrolysis behavior of QD-VR was similar to that of *** saturates,the release of H_(2),CH_(4),CO,and CO_(2) occurred in 80-400℃,while the temperature range for QD-VR and other fractions is 200-800℃.The average activation energy(Ea)via Friedman method was 179.72 kJ/mol and increased with the conversion ***-parallel Gaussian DAEM was more suitable to describe the pyrolysis process of the single SARA fractions,while four-parallel Gaussian DAEM was more suitable to describe the pyrolysis process of heavy ***,comparing the weighted E_(a) from one-parallel(227.64 kJ/mol)and four-parallel Gaussian DAEM(204.63 kJ/mol),the results suggested that during pyrolysis process of heavy oil,there was an interaction between the SARA fractions,which could reduce the E_(a) of heavy oil ***,during heavy oil pyrolysis,resins and asphaltenes could increase the E_(a) of saturates and aromatics,while saturates and aromatics could decrease the E_(a) of resins and asphaltenes.

关键词： Heavy oil Pyrolysis kinetics SARA fractions DAEM

Micro-positron emission tomography imaging of angiogenesis based on ^(18)F-RGD for assessing liver metastasis of colorectal cancer

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2021年第4期20卷 345-351页

作者： ming-yu zhang Hui-Jie Jiang Hao Jiang Rong-Jun zhang Zhen-Chang Wang Department of Nuclear Medicine Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Department of Radiology The Second Affiliated Hospital of Harbin Medical UniversityHarbin 150086China Jiangsu Institute of Nuclear Medicine Wuxi 214063China Department of Radiology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China

Background:Positron emission tomography (PET) imaging is a non-invasive method to visualize and quantify the tumor *** study aimed to explore the feasibility of ^(18)F-AIF-NOTA-E[PEG_(4-c)(RGDfk)]_(2) (denoted as ^(18)F-RGD) PET quantitative parameters to distinguish the angiogenesis in colorectal cancer (CRC) mice which has different metastatic ***:Twenty Lo Vo and twenty LS174T of CRC liver metastases animal models were established by implantation of human CRC cell lines via intrasplenic ***-based micro-PET imaging of animal model was performed and the uptake of ^(18)F-RGD tracer in the tumor tissues was quantified as tumor-to-liver maximum or mean standardized uptake value (SUVmax or SUVmean) *** correlation was used to analyze the relationship between radioactive parameters and tumor ***:The SUVmax and SUVmean ratios of Lo Vo model were significantly higher than those of LS174T in both liver metastasis and primary tumor lesions (P<0.05).A significant difference was observed in both vascular endothelial growth factor (VEGF) and Ki67 expressions between Lo Vo and LS174T primary tumors (P<0.05).The tumor-to-liver SUVmax or SUVmean ratio of ^(18)F-RGD showed a moderate correlation with VEGF expression (r=0.5700,P=0.001 and r=0.6657,P<0.001,respectively),but the SUVmean ration showed a weak correlation with Ki67 expression (r=0.3706,P<0.05).The areas under the receiver operating characteristic (ROC) curves of ^(18)F-RGD SUVmean ratio,SUVmax ratio for differentiating Lo Vo from LS174T tumor were 0.801 and 0.759,***:The tumor-to-liver SUVmean ratio of ^(18)F-RGD was a promising image parameter for the process of monitoring tumor angiogenesis in CRC xenograft mice model.

关键词： RGD peptide Positron emission tomography Colorectal liver metastases Vascular endothelial growth factor

Methods for Thickness Determination of SiC Homoepilayers by Using Infrared Reflectance Spectroscopy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 240-243页

作者： LI Zhi-yun SUN Ji-Wei zhang yu-ming zhang Yi-Men TANG Xiao-Yan Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi'an 710071

Infrared reflectance spectra have been widely used to measure layer thickness based either on calculation or on curve fitting, and two traditional methods for thickness determination have been studied. Considering the disadvantages of those two methods, we propose a new fitting model based on the fitting of the fringe order difference. In comparison with the measured results, the new fitting model shows its superiority not only for its stable and accurate results which have great agreement with the results from SEM, but also for its simple and quick fitting process.

关键词： THICKNESS measurement SILICON carbide INFRARED spectroscopy CURVE fitting COMPARATIVE studies SCANNING electron microscopy

Diversity analysis of soil dematiaceous hyphomycetes from the Yellow River source area:Ⅰ

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第10期9卷 829-834页

作者： Hao-qin PAN Jin-feng yu yue-ming WU Tian-yu zhang Hong-feng WANG Mycological Laboratory Department of PlantPathology Shandong Agricultural University Tai＇an 271018 China

Twenty-four soil samples of eight ecosystem-types around the Yellow River source area were investigated for the number and specific composition of soil dematiaceous hyphomycetes by dilution plate technique. And then the co-relationship between genus species of soil dematiaceous hyphomycetes and ecosystem-types was analyzed. The results show that the amount and species distribution of soil dematiaceous hyphomycetes had an obvious variability in different ecosystem-types, and that the dominant genus species varied in the eight ecosystem-types studied, with Cladosporium being the dominant genus in seven of the eight ecosystem-types except wetland. The index of species diversity varied in different ecosystem-types. The niche breadth analysis showed that Cladosporium had the highest niche breadth and distributed in all ecosystem-types, while the genera with a narrow niche breadth distributed only in a few ecosystem-types. The results of niche overlap index analysis indicated that Stachybotrys and Torula, Doratomyces and Scolecobasidium, Cladosporium and Chrysosporium had a higher niche overlap, whereas Arthrinium and Gliomastix, Phialophora and Doratomyces, Oidiodendron and Ulocladium had no niche overlap.

关键词： Yellow River source area Ecosystems Fungal species diversity Soil dematiaceous hyphomycetes Niche breadth Niche overlap

Correlations of the expression of Cx43,SCFFBXW7,p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in colon cancer tissues

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2025年第1期17卷 207-213页

作者： Rong-Gang Luan ming-Da Liu Zi-Feng Deng Cong-Lan Lu Mei-Ling yu ming-yu zhang Rong Liu Ran An You-Liang Yao Dong-Bei Guo Yong-Xing zhang Lei Zhao Department of Gastrointestinal Surgery Air Force Hospital of Eastern TheaterAnhui Medical UniversityNanjing 230032Jiangsu ProvinceChina State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics School of Public HealthXiamen UniversityXiamen 361102Fujian ProvinceChina Trauma Surgery Air Force Hospital of Eastern TheaterAnhui Medical UniversityNanjing 230032Jiangsu ProvinceChina Department of Orthopaedics Air Force Hospital of Eastern TheaterAnhui Medical UniversityNanjing 230032Jiangsu ProvinceChina

BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ***,reduced expression results in a loss of this capacity to facilitate cyclin E *** ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical *** To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon *** Expression levels of Cx43,SCFFBXW7,p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their *** Positive rate of Cx43,SCFFBXW7,p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%*** expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node ***43 and SCFFBXW7(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCFFBXW7 and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon *** Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCFFBXW7,thereby influencing the ubiquitination and degradation of cyclin E1.

关键词： Colon cancer Cx43 SCFFBXW7 Phosphorylation of cyclin E1 Sites of cyclin E1 Correlation analysis

Targeted inductive heating of nanomagnets by a com- bination of alternating current （AC） and static magnetic fields

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第2期8卷 600-610页

作者： ming Ma yu zhang Xuli Shen Jun Xie Yan Li Ning Gu ing 210096 China

The conversion of electromagnetic energy into heat by nanomagnets has the potential to be a powerful, non-invasive technique for cancer therapy by hyperthermia and hyperthermia-based drug release, while temperature controllability and targeted heating are challenges to developing applications of such magnetic inductive hyperthermia. This study was designed to control the hyperthermia position and area using a combination of alternating current （AC） and a static magnetic field. MnZn ferrite （MZF） nanoparticles which exhibited excellent hyperthermia properties were first prepared and characterized as an inductive heating mediator. We built model static magnetic fields simply using a pair of permanent magnets and studied the static magnetic field distributions by measurements and numerical simulations. The influence of the transverse static magnetic fields on hyperthermia properties was then investigated on MZF magnetic fluid, gel phantoms and SMMC-7721 cells in vitro. The results showed a static magnetic field can inhibit the temperature rise of MZF nanoparticles in an AC magnetic field. But in the uneven static magnetic field formed by a magnet pair with repelling poles face-to-face, the heating area can be restricted in a central low static field; meanwhile the side effects of hyperthermia can be reduced by a surrounding high static field. As a result we can position the hyperthermia area, protect the non-therapeutic area, and reduce the side effects lust by using a well-designed combination of AC and static field.

关键词： hyperthermia magnetic nanoparticles static magnetic field alternating magnetic field MnZn ferrite

Ultrasonic Nebulization Extraction Coupled with Gas Chromatography-Mass Spectrometry for Analysis of Volatile Components in Traditional Chinese Patent Medicine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2011年第2期27卷 203-207页

作者： LIANG yue WANG Lu WANG Zi-ming yu Cui zhang Han-qi SHI yu-hua College of Chemistry Jilin University Changchun 130012 P. R. China

The ultrasonic nebulization extraction（UNE） was developed and applied to the extraction of volatile components from traditional Chinese patent medicine Xiaoyao Pills. Several parameters of ultrasonic nebulization extraction including the sample particle size, solvent volume, extraction time and ultrasonic power were studied and selected. As a result, 2.4 g of sample with particle size of 80 mesh was extracted with 15 mL of n-hexane for 20 min at an ultrasonic power of 35 W. The volatile components were analyzed by gas chromatography-mass spectrometry （GC-MS） under the optimal conditions and 57 compounds were identified. The precision, repeatability and stability of the proposed method were also studied. Compared with ultrasonic-assisted extraction（UAE） and hydrodistillation（HD） extraction, the proposed method is more efficient, faster and easier to be operated at room temperature with smaller sample and energy consumption. It is suggested that the ultrasonic nebulization extraction can be used as a novel alternative method for the extraction of volatile components from traditional Chinese patent medicine.

关键词： Ultrasonic nebulization extraction Gas chromatography-mass spectrometry Volatile component Traditional Chinese patent medicine

Simulation of SiC radiation detector degradation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第1期28卷 300-305页

作者： Hai-Li Huang Xiao-Yan Tang Hui Guo Yi-Men zhang yu-Tian Wang yu-ming zhang School of Microelectronics Xidian University Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices Xidian University

Simulation on the degradation of 4H-SiC Schottky detector was carried out using ISE TCAD, and the limit of the driftdiffusion analytical model was discussed. Two independent defect levels, rather than a pair of specific carrier lifetime, were induced to describe Z1/2 defects in simulation to calculate the charge collection efficiency versus bias voltage. Comparison between our calculation and the reported experimental results shows that an acceptable agreement was achieved, proving the feasibility of regarding Z1/2 defect as two individual defect levels. Such a treatment can simplify the simulation and may help to further investigate the detector degradation.

关键词： 4H-SiC detector degradation simulation Z1/2 defect

Electric transport properties and temperature stability of magnetoresistance of composite system between La_(8/9)Sr_(1/45)Na_(4/45)MnO_3 and Sb_2O_3

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第4期32卷 363-368页

作者： Gui-Ying Wang Yong-Gang Tang Qi-Xiang Song ming-yu zhang Zhen-Sheng Peng Anhui Key Laboratory of Spintronic and Nano-materials Research School of Mechanical and Electronic Engineering Suzhou University

The samples ofLa8/9Sr1/45Na4/45MnO3 （LSNMO）/x/2（Sb2O3） were prepared by the solid-state reaction method. The electric transport properties and the temperature stabil-ity of magnetoresistance （MR） of the samples were studied through the measurements of X-ray diffraction patterns, resistivity-temperature （ρ-T） curves, mass magnetization-temperature （σ-T） curves, and magnetoresistance-temper-ature （MR-T） curves. The results indicate that the p-Tcurves of the original material LSNMO show two peaks, and the phenomenon of two peaks of ρ-T curves disappears for the composite samples, which can be explained by a competition between surface-phase resistivity induced by boundary-dependent scattering and body-phase resistivity induced by paramagnetism-ferromagnetism transition. For all the sam-ples in the low temperature range, MR increases continu-ously with the decrease of temperature, which shows a characteristic of low-field magnetoresistance. However, MR basically keeps the same in the high temperature range. The paramagnetism-ferromagnetism transition is observed in the high temperature range due to a composite between perov-skite manganite and insulator, which can enhance the tem-perature of MR appearance in the high temperature range and make it to appear near room temperature. For the sample with x = 0.12, MR remains constant at the value of 7.5 % in the temperature range of 300-260 K, which achieves a tem-perature stability of MR near room temperature. In addition,for the sample with x = 0.16, MR is above 6.8 % in the high temperature range of 318-252 K （△T = 66 K）. MR almost remains constant in this temperature range, which favors the practical application of MR.

关键词： Electric transport property Temperaturestability of magnetoresistance Two-phase composite Perovskite manganite