检索结果-南通市图书馆

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第2期31卷 377-388页

作者： Tao Pan Hong-chun Zhu Zhou-hua Jiang hua-bing Li Rui Zhang Hao Feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh techniques.The results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width increase.Meanwhile,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium analysis.As melt rate increases,both the molten pool depth and the mushy width increase.It is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the mold.The nonlinear increment in sensible heat leads to a nonlinear increase in the mushy width.In addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then increases.When melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time

Zinc glycine chelate ameliorates DSS‑induced intestinal barrier dysfunction via attenuating TLR4/NF‑κB pathway in meat ducks

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 Animal Science and Biotechnology 2024年第2期15卷 765-778页

作者： Yaqi Chang Ke Wang Guangmang Liu hua Zhao Xiaoling Chen Jingyi cai Gang Jia Institute of Animal Nutrition Key Laboratory for Animal Disease‑Resistance Nutrition of ChinaMinistry of EducationSichuan Agricultural UniversityChengdu 611130SichuanChina

Background Zinc glycine chelate(Zn-Gly)has anti-inflammation and growth-promoting properties;however,the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown.Three-hundred 1-day-old ducks were divided into 5 groups(6 replicates and 10 ducks per replicate)in a completely randomized design:the control and dextran sulfate sodium(DSS)groups were fed a corn-soybean meal basal diet,and experimental groups received supplements of 70,120 or 170 mg/kg Zn in form of Zn-Gly.The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15–21,and the control group received normal saline.The experiment lasted 21 d.Results Compared with DSS group,70,120 and 170 mg/kg Zn significantly increased body weight(BW),villus height and the ratio of villus to crypt,and significantly decreased the crypt depth of jejunum at 21 d.The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining.Compared with control,the content of intestinal permeability marker D-lactic acid(D-LA)and fluxes of fluorescein isothiocyanate(FITC-D)in plasma of DSS group significantly increased,and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes.Compared with control,contents of plasma,jejunum endotoxin and jejunum pro-inflammatory factors IL-1β,IL-6 and TNF-αwere significantly increased in DSS group,and were significantly decreased by 170 mg/kg Zn supplementation.Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10,IL-22 and sIgA and IgG in jejunum.Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum,and decreased gene and protein expression of CLDN-2 compared with DSS group.The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA.Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8

关键词： Cherry Valley ducks Growth performance Gut inflammation Intestinal barrier Zn-Gly

Identification and Characteristics Analysis of Micro-Seismic Signals in the Haima Seep Area

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第1期35卷 288-291页

作者： Xiangchun Wang bing Nie Zhiyu Wu Weiwei Wang hua Chen China University of Geosciences Beijing 100083China CNOOC China Limited Shenzhen BranchShenzhen 518000China Guangzhou Marine Geological Survey Guangzhou 511458China CNOOC China Limited Shanghai BranchShanghai 200335China

INTRODUCTION.In recent years,with the steady development of offshore energy exploration technology,submarine gas seepage sites,and their products are gradually being identified and analyzed.The submarine cold seep is a seepage phenomenon in which hydrocarbon gases stored deep in the seafloor are transported to seawater by gushing or seepage under the action of tectonic compression(Roy et al.,2019;Tinivella and Giustiniani,2016).

关键词： submarine Seismic offshore

Mirizzi syndrome:Problems and strategies

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 234-240页

作者： Jun Wu Shuang-Yong cai Xu-Liang Chen Zhi-Tao Chen Shao-hua Shi Department of Hepatobiliary and Pancreatic Surgery People’s Hospital of Jiulongpo DistrictChongqing 400050China Department of Hepatobiliary and Pancreatic Surgery Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310003China

Mirizzi syndrome is a serious complication of gallstone disease.It is caused by the impacted stones in the gallbladder neck or cystic duct.One of the features of Mirizzi syndrome is severe inflammation or dense fibrosis at the Calot’s triangle.In our clinical practice,bile duct,branches of right hepatic artery and right portal vein clinging to gallbladder infundibulum are often observed due to gallbladder infundibulum adhered to right hepatic hilum.The intraoperative damage of branches of right hepatic artery occurs more easily than that of bile duct,all of which are hidden pitfalls for surgeons.Magnetic resonance cholangiopancreatography(MRCP)and endoscopic retrograde cholangiopancreatography(ERCP)are the preferable tools for the diagnosis of Mirizzi syndrome.Anterograde cholecystectomy in Mirizzi syndrome is easy to damage branches of right hepatic artery and bile duct due to gallbladder infundibulum adhered to right hepatic hilum.Subtotal cholecystectomy is an easy,safe and definitive approach to Mirizzi syndrome.When combined with the application of ERCP,a laparoscopic management of Mirizzi syndrome by well-trained surgeons is feasible and safe.The objective of this review was to highlight its existing problems:(1)low preoperative diagnostic rate,(2)easy to damage bile duct and branches of right hepatic artery,and(3)high concomitant gallbladder carcinoma.Meanwhile,the review aimed to discuss the possible therapeutic strategies:(1)to enhance its preoperative recognition by imaging findings,and(2)to avoid potential pitfalls during surgery.

关键词： Mirizzi syndrome Bile duct injury Artery injury Surgical treatment Subtotal cholecystectomy

Accurate characterization of bubble mixing uniformity in a circular region using computational geometric theory

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 149-159页

作者： Hui Sun Jianxin Xu Shibo Wang Guangcheng cai hua Wang Wuliang Yin State Key Laboratory ofComplex Nonferrous Metal Resources Clean Utilization Kunming University ofScience and TechnologyKunming650093China bFaulty of Metallurgical and Energy Engineering Kunming University ofScience and TechnologyKunming650093China Faculty of Science Kunming University ofScience and TechnologyKunming650500China Department of Elec.and Electronic Engineering.University of Manchester ManchesterM139PL UK

The present study proposes a novel method based on the geometric theory for measuring the distribution of bubble swarms in the circular region of a direct-contact heat exchanger.It was determined that the mixing is uniform when the average distance between the bubble swarms in the unit circular region is approximately 0.9054,which is the standard reference value.The effect of sample size(i.e.,the number of bubbles)on mixing uniformity was investigated to determine the optimal sample size.It was verified that the metric's accuracy and stability were higher with a sample size of 155.Accordingly,it was proposed to increase the sample size by filling irregular bubbles using a segmentation method,which enabled a further accurate assessment of the mixing uniformity.The mixing uniformity of bubble swarms in the circular region and its maximum internal connection with the square region was accurately quantified.It was revealed that the relative average error increased by approximately 3.47% due to information loss.The proposed method was demonstrated to be rotationally invariant.The present study provided novel insights into evaluating mixing uniformity,which would guide enhanced heat transfer and the effective evaluation of the spatiotemporal characteristics of transient mixing in circular regions or the cross-sections of chemical transport pipelines.

关键词： Direct-contact heat exchanger Circular region Bubble swarm Distribution uniformity AD-Circle method

Comprehensive analysis of the potential pathogenesis of COVID-19 infection and liver cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第2期16卷 436-457页

作者： Yao Rong Ming-Zheng Tang Song-hua Liu Xiao-Feng Li Hui cai First Clinical Medical College Gansu University of Chinese MedicineLanzhou 730000Gansu ProvinceChina General Surgery Clinical Medical Center Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Key Laboratory of Molecular Diagnostics and Precision Medicine for Surgical Oncology in Gansu Province Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina NHC Key Laboratory of Diagnosis and Therapy of Gastrointestinal Tumor Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina

BACKGROUND A growing number of clinical examples suggest that coronavirus disease 2019(COVID-19)appears to have an impact on the treatment of patients with liver cancer compared to the normal population,and the prevalence of COVID-19 is significantly higher in patients with liver cancer.However,this mechanism of action has not been clarified.Gene sets for COVID-19(GSE180226)and liver cancer(GSE87630)were obtained from the Gene Expression Omnibus database.After identifying the common differentially expressed genes(DEGs)of COVID-19 and liver cancer,functional enrichment analysis,protein-protein interaction network construction and scree-ning and analysis of hub genes were performed.Subsequently,the validation of the differential expression of hub genes in the disease was performed and the regulatory network of transcription factors and hub genes was constructed.RESULTS Of 518 common DEGs were obtained by screening for functional analysis.Fifteen hub genes including aurora kinase B,cyclin B2,cell division cycle 20,cell division cycle associated 8,nucleolar and spindle associated protein 1,etc.,were further identified from DEGs using the“cytoHubba”plugin.Functional enrichment analysis of hub genes showed that these hub genes are associated with P53 signalling pathway regulation,cell cycle and other functions,and they may serve as potential molecular markers for COVID-19 and liver cancer.Finally,we selected 10 of the hub genes for in vitro expression validation in liver cancer cells.CONCLUSION Our study reveals a common pathogenesis of liver cancer and COVID-19.These common pathways and key genes may provide new ideas for further mechanistic studies.

关键词： COVID-19 Liver cancer Differentially expressed genes Hub genes Pathogenesis

Hepatic perivascular epithelioid cell tumors:The importance of preoperative diagnosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第13期30卷 1926-1933页

作者： Shuai Yan Jia-Jie Lu Lin Chen Wei-hua cai Jin-Zhu Wu Department of Medical School Nantong UniversityNantong 226300Jiangsu ProvinceChina Department of Hepatobiliary Surgery Affiliated Nantong Hospital 3 of Nantong UniversityNantong 226006Jiangsu ProvinceChina Nantong Institute of Liver Disease Affiliated Nantong Hospital 3 of Nantong UniversityNantong 226006Jiangsu ProvinceChina

Accurate preoperative diagnosis is highly important for the treatment of perivascular epithelioid cell tumors(PEComas)because PEComas are mainly benign tumors and may not require surgical intervention.By analyzing the causes,properties and clinical manifestations of PEComas,we summarize the challenges and solutions in the diagnosis of PEComas.

关键词： Hepatic perivascular epithelioid cell tumors Liver Preoperative diagnosis Angiomyolipomas Mesenchymal tissue-derived tumors

Concept, configuration, and application of on-board nanogrids for use in electric vehicles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Technological Sciences 2024年第7期67卷 2053-2073页

作者： ZHAO bing LI Yong WU Fang WAN JiangHu cai JiuQing YANG HaiTao LIU Fang College of Electrical and Information Engineering Hunan University Wuhan Second Ship Design and Research Institute School of Automation Central South University

Against the backdrop of increasingly serious climate change, researchers are attempting to extend macroscale carbon reduction research to smaller scales. With the rapid development and widespread application of electric vehicles(EVs), an effective approach for carbon reduction based on EVs has the potential to be developed. To coordinate and manage the EV platform in diverse application scenarios, the concept of an on-board nanogrid(OBNG), in which a nanogrid is combined with the EV, is proposed and defined, and the characteristics summarized. A configuration that includes a physical layer with the on-board hardware system; an information layer for logical control, energy management, and communication coordination; and an application layer that can cope with different working environments is proposed. A detailed introduction to the basic architecture and management mode of each layer is provided along with information concerning the relevant technologies for coordinated operation. New ideas and approaches to improve the existing performance are proposed, and finally, combined with a background of smart and low-carbon cities, major application scenarios are envisioned.

关键词： electric vehicle nanogrid energy management hybrid energy storage power electronics converter

Probing the Gamma-Ray Emission Region of Five TeV Flat Spectrum Radio Quasars

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 158-171页

作者： Hu-bing Xiao Hai-Tao Cao Rui Xue Jin-Ting cai Ge-Ge Wang Marina Manganaro Shao-hua Zhang Zhi-Hao Ouyang Li-Ping Fu Jun-Hui Fan Shanghai Key Lab for Astrophysics Shanghai Normal University School of Information Engineering Department of Physics Zhejiang Normal University College of Mathematics and Physics Guangxi Minzu University Key Laboratory of Cosmology and Astrophysics (Liaoning) College of Sciences Northeastern University Department of Physics University of Rijeka Center for Astrophysics Guangzhou University Key Laboratory for Astronomical Observation and Technology of Guangzhou Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province

The location of γ-ray emission of blazars remains a contested topic, inspiring the development of numerous investigative techniques to address this issue. In this work, we analyzed Fermi γ-ray light curves in the GeV and MeV bands, employing the discrete cross-correlation function method to discern time lags between the two bands.For 4C +21.35, Ton 599, B2 1420+32, and PKS 1510-089, we identified a time lag spanning several days, while for PKS 1441+25, the time lag was not statistically found. The results imply that the soft photons necessary for inverse Compton scattering predominantly originate from the dusty torus in the first four sources, whereas for PKS1441+25, they seem to be sourced mainly from the broad-line region. Further analysis of the opacity(τγγ) and the GeV spectra study supports the conclusion that the location of the dissipation region must be beyond the BLR to avoid significant absorption. Notably, for PKS 1441+25, the emission region is also posited to lie outside yet proximate to the BLR. The parameters of describing the emission region were obtained by fitting broadband spectral energy distribution with contemporaneous observation data. Our findings suggest that for the five TeV FSRQs, during Te V flaring events, the jet appears to maintain an equilibrium between the energy density of the magnetic field and that of the particles for all investigated sources, with the exceptions of 4C +21.35 and PKS1441+25. In terms of the overall jet power, particle energy is the dominant contributor, and the observed blazar radiation cannot be solely attributed to the magnetic field, except in the case of 4C +21.35. Consequently,magnetic reconnection is unlikely to be the primary mechanism behind particle acceleration in these systems.

关键词： galaxies: active galaxies: jets gamma-rays: galaxies