检索结果-南通市图书馆

Thermodynamic studies on gas-based reduction of vanadium titano-magnetite pellets

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 822-830页

作者： jun-wei chen Yang Jiao Xi-dong Wang Department of Energy and Resources Engineering College of Engineering Peking University

Numerous studies have focused on the reduction thermodynamics of ordinary iron ore;by contrast, the literature contains few thermodynamic studies on the gas-based reduction of vanadium titano-magnetite (VTM) in mixed atmospheres of H2, CO, H2O, CO2, and N2. In this paper, thermodynamic studies on the reduction of oxidized VTM pellets were systematically conducted in an atmosphere of a C–H–O system as a reducing agent. The results indicate that VTM of an equivalent valence state is more difficult to reduce than ordinary iron ore. A reduction equilibrium diagram using the C–H–O system as a reducing agent was obtained;it clearly describes the reduction process. Experiments were performed to investigate the effects of the reduction temperature, the gas composition, and two types of iron ores on the reduction of oxidized VTM pellets. The results show that the final reduction degree increases with increasing reduction temperature, increasing molar ratio of H2/(H2 + CO), and decreasing H2O, CO2, and N2 contents. In addition, the reduction processes under various conditions are discussed. All of the results of the reduction experiments are consistent with those of theoretical thermodynamic analysis. This study is expected to provide valuable thermodynamic theory on the industrial applications of VTM.

关键词： vanadium titano-magnetite gas-based reduction C-H-O system thermodynamics

Research on the Swing of the Body of Two-Joint Robot Fish

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2008年第2期5卷 159-165页

作者： Ying-xiang Liu wei-shan chen jun-kao Liu School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 P. R. China

The disadvantages caused by the swing of a fish body were analyzed. The coordinate system of a two-joint robot fish was built. The hydrodynamic analysis of robot fish was developed. The dynamic simulation of a two-joint robot fish was carried out with the ADAMS software. The relationship between the swing of fish body and the mass distribution of robot fish, the relationship between the swing of fish body and the swing frequency of tail, were gained. The impact of the swing of fish body on the kinematic parameters of tail fin was analyzed. Three methods to restrain the swing of fish body were presented and discussed.

关键词： robot fish swing of fish body hydrodynamic analysis dynamic simulation

Effect of Oxygen Partial Pressure on Phase Equilibria and Liquidus in CaO-Al_2O_3-FeO_x System

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2012年第11期19卷 8-12页

作者： WANG Nan HUANG wei-jun chen Shuai-chao chen Min School of Materials and Metallurgy Northeastern University Shenyang 110819 Liaoning China

A high temperature equilibration experiment was carried out to investigate the effect of oxygen partial pres- sure on the phase equilibria and liquidus in CaO-Al2O3- FeOx system with the intermediate oxygen partial pressures of 10.13 Pa and 1.01 × 10^-3 Pa. The equilibrated phases and their compositions of the quenched samples were analyzed by using SEM/EPMA （Scanning Electron Microscope/Electron Probe Micro Analysis） and XRD （X Ray Diffraction）. The phase equilibrium results include two cases, the two phase coexistence and the three-phase coexistence in the high Al2O3 region with oxygen partial pressure of either 10.13 Pa or 1.01 × 10^-3 Pa. Effects of oxygen partial pressure and temperature on the liquidus along the primary phase fields of CaO · Al2O3 and CaO · 2Al2O3 were nota hle. With the decrease of oxygen partial pressure, the liquid area expands and the liquidus of CaO · Al2O3 and CaO · 2Al2O3 primary fields moves to the Al2O3-FeOx region. On the other hand, the liquid area of CaO Al2O3-FeOx sys tem extends extremely to the high Al2O3 region with the temperature increasing from 1 400 to 1 500℃, especially at lower oxygen partial pressure. The present experiment results are in good agreement with the calculated ones by FactSage.

关键词： oxygen partial pressure liquidus phase equilibrium CaO-Al2O3 FeOx system

Extensive cutaneous metastasis of recurrent gastric cancer:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第22期9卷 6575-6581页

作者： jun-wei chen Long-Zhi Zheng De-He Xu wei Lin Department of Clinical Medicine The School of Clinical MedicineFujian Medical UniversityFuzhou 350000Fujian ProvinceChina Department of Clinical Medicine The Affiliated Hospital of Putian UniversityPutian 351100Fujian ProvinceChina Department of Gastrointestinal Surgery The Affiliated Hospital of Putian UniversityPutian 351100Fujian ProvinceChina

BACKGROUND Cutaneous metastasis is a rare event associated with poor prognosis for gastric cancer and has been rarely reported in the *** SUMMARY A 69-year-old male patient who had undergone salvage gastrectomy and a few courses of adjuvant chemotherapy 3 mo earlier for recurrent gastric cancer developed widespread cutaneous *** to the patient’s intolerance to further adjuvant chemotherapy,he was placed in hospice care and expired 1 mo *** the literature,gastric cancers are rarely reported as the primary malignancies for cutaneous ***,thus,provide an update on a case review published in 2014 by reviewing 10 more case reports dated from 2014 to *** average age for the new group of patients was 59.4±*** percent of the patients presented with cutaneous lesions and advanced gastric cancer synchronously while 70%developed cutaneous metastases 1.3 years to 14 years after the initial treatment for primary gastric *** percent of the patients received either local excision or chemo±radiation therapy to treat their cutaneous *** This report highlights cutaneous metastasis as a late and untreatable metastasis of gastric cancer.

关键词： Cutaneous metastasis Gastric stump cancer Remnant gastrectomy D2 dissection Signet ring cell carcinoma Case report

Sorbitol induces flower bud formation via the MADS-box transcription factor EjCAL in loquat

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 Integrative Plant Biology 2023年第5期65卷 1241-1261页

作者： Hong-Xia Xu Dong Meng Qing Yang Ting chen Meng Qi Xiao-Ying Li Hang Ge jun-wei chen Institute of Horticulture Zhejiang Academy of Agricultural SciencesHangzhou 310021China Beijing Advanced Innovation Center for Tree Breeding by Molecular Design Beijing Forestry UniversityBeijing 100000China College of Forestry Beijing Forestry UniversityBeijing 100083China

Sorbitol is an important signaling molecule in fruit trees. Here, we observed that sorbitol increased during flower bud differentiation(FBD) in loquat(Eriobotrya japonica Lindl.). Transcriptomic analysis suggested that bud formation was associated with the expression of the MADS-box transcription factor(TF) family gene, EjCAL. RNA fluorescence in situ hybridization showed that EjCAL was enriched in flower primordia but hardly detected in the shoot apical meristem. Heterologous expression of EjCAL in Nicotiana benthamiana plants resulted in early FBD. Yeast-one-hybrid analysis identified the ERF12 TF as a binding partner of the EjCAL promoter. Chromatin immunoprecipitation-PCR confirmed that EjERF12 binds to the EjCAL promoter, and β-glucuronidase activity assays indicated that EjERF12 regulates EjCAL *** loquat trees with sorbitol promoted flower bud formation and was associated with increased expression of EjERF12 and EjCAL. Furthermore, we identified EjUF3GaT1 as a target gene of EjCAL and its expression was activated by EjCAL. Function characterization via overexpression and RNAi reveals that EjUF3GaT1 is a biosynthetic gene of flavonoid hyperoside. The concentration of the flavonoid hyperoside mirrored that of sorbitol during FBD and exogenous hyperoside treatment also promoted loquat bud formation. We identified a mechanism whereby EjCAL might regulate hyperoside biosynthesis and confirmed the involvement of EjCAL in flower bud formation in planta. Together,these results provide insight into bud formation in loquat and may be used in efforts to increase yield.

关键词： EjCAL flower bud differentiation hyperoside loquat sorbitol

Cloning, expression and chitin-binding activity of two peritrophin-like protein genes in the common cutworm, Spodoptera fitura

在线全文

学校读者我要写书评

暂无评论

Insect Science 2014年第4期21卷 449-458页

作者： wei-jun chen Li-Xia Huang Dan Hu Li-Yan Liu jun Gu Li-Hua Huang Qi-Li Feng Guangdong Provincial Key Laboratory of Biotechnology for Plant Development School of Life Sciences South China Normal UniversityGuangzhou China

Insect midgut secretes a semi-permeable peritrophic membrane （PM）, which plays important roles in protecting the midgut and helping with food digestion. The lep- idopteran larvae produce type 1 PM, which is degraded when insects develop into the metamorphic stages. However, the underlying mechanism is unclear. In the present study, two peritrophin-like proteins （peritrophin-57 and 37） were identified from the midgut expression sequence tag library and transcriptome of the common cutworm, Spodoptera litura. The temporal and spatial expression patterns and responses to the induction of 20- hydroxyecdysone （20E） and starvation were examined by real-time quantitative polymerase chain reaction according to their common sequence region. The chitin-binding activity was also studied using a competitor, calcofluor. The open reading frames are 1 554 and 1 020 bp, respectively. They shared four highly conserved peritrophin-A domains and were ex- pressed only in the midgut rather than in the other tissues, including fat body, epidermis, Malpighian tube and hemolymph. Their transcriptional expression could only be detected at the larval stages rather than in eggs, prepupae, pupae and adults. The purified protein of peritrophin-37 bound to chitin in a dose-dependent manner. These results indicate that the two proteins are peritrophins, the structural components of PM. In addition, the messenger RNA levels of the two peritrophins were significantly down-regulated by 20E injection, whereas feeding/starvation had no effect on the expression. These findings suggest that the increase of20E titer may be an important factor which controls the degradation of PM during metamorphosis.

关键词： metamorphosis peritrophic membrane peritrophin starvation 20-hydroxyecdysone

Adaptive Output-feedback Regulation for Nonlinear Delayed Systems Using Neural Network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2008年第1期5卷 103-108页

作者： wei-Sheng chen jun-Min Li Department of Applied Mathematics,Xidian University,Xi′an 710071,PRC Department of Applied Mathematics Xidian University Xi’an PRC

A novel adaptive neural network （NN） output-feedback regulation algorithm for a class of nonlinear time-varying timedelay systems is proposed. Both the designed observer and controller are independent of time delay. Different from the existing results, where the upper bounding functions of time-delay terms are assumed to be known, we only use an NN to compensate for all unknown upper bounding functions without that assumption. The proposed design method is proved to be able to guarantee semi-global uniform ultimate boundedness of all the signals in the closed system, and the system output is proved to converge to a small neighborhood of the origin. The simulation results verify the effectiveness of the control scheme.

关键词： Adaptive neural network (NN) output-feedback nonlinear time-delay systems backstepping

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2023年第20期29卷 3168-3184页

作者： Jia-Lin Wu jun-Yang Luo Zai-Bo Jiang Si-Bo Huang Ge-Run chen Hui-Ying Ran Qi-Yue Liang Ming-Sheng Huang Li-Sha Lai jun-wei chen Department of Interventional Radiology The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630Guangdong ProvinceChina The First Clinical Medical College Guangdong Medical UniversityZhanjiang 524000Guangdong ProvinceChina Zhongshan School of Medicine Sun Yat-sen UniversityGuangzhou 510080Guangdong ProvinceChina Department of Radiology Guangzhou First People's HospitalSchool of MedicineSouth China University of TechnologyGuangzhou 510010Guangdong ProvinceChina

BACKGROUND The efficacy of conversion therapy for patients with unresectable hepatocellular carcinoma(HCC)is a common clinical *** To analyse the prognostic factors of overall survival(OS)in patients with unresectable HCC who received conversion *** One hundred and fifty patients who met the inclusion criteria were enrolled and divided into a training cohort(n=120)and a validation cohort(n=30).Using the independent risk factors in the training cohort,a nomogram model was constructed to predict OS for patients treated with transarterial chemoembolization following hepatic *** nomogram was internally validated with the bootstrapping *** predictive performance of nomogram was assessed by Harrell’s concordance index(C-index),calibration plot and timedependent receiver operating characteristic curves and compared with six other conventional HCC staging *** Multivariate Cox analysis identified that albumin,blood urea nitrogen,gamma-glutamyl transpeptidase to platelet ratio,platelet to lymphocyte ratio,macrovascular invasion and tumour number were the six independent prognostic factors correlated with OS in nomogram *** C-index in the training cohort and validation cohort were 0.752 and 0.807 for predicting OS,which were higher than those of the six conventional HCC staging systems(0.563 to 0.715 for the training cohort and 0.458 to 0.571 for the validation cohort).The calibration plots showed good consistency between the nomogram prediction of OS and the actual observations of *** curve analyses indicated satisfactory clinical *** a total nomogram score of 196,patients were accurately classified into low-risk and high-risk ***,we have deployed the model into online calculators that can be accessed for free at https://***/DynNomapp/.CONCLUSION The nomogram achieved optimal individualized prognostication of OS in HCC patients who received conversion ther

关键词： Hepatocellular carcinoma Conversion therapy Nomogram Inflammation Transarterial chemoembolization

Formability enhancing of AZ31 magnesium alloy sheets by differential speed rollingFormability enhancing of AZ31 magnesium alloy sheets by differential speed rollingFormability enhancing of AZ31 magnesium alloy sheets by differential speed rollingFormability enhancing of AZ31 magnesium alloy sheets by differential speed rolling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料科学与工程（中英文版） 2008年第7期2卷 38-43页

作者： XIA wei-jun chen Ji-hua chen Ding School of Materials Science and Engineering Hunan UniversityChangsha 410082China