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Eukaryotic Translation Initiation Factors Shape RNA Viruses Resistance in Plants 被引量:3
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作者 Jannat Shopan Xiaolong Lv +2 位作者 Zhongyuan Hu Mingfang Zhang Jinghua Yang 《Horticultural Plant Journal》 2020年第2期81-88,共8页
Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis require... Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis requires host cellular factors for translating their viral RNAs, and for regulating their replication and cell to cell systemic movement. Therefore, the viruses are dependent on cellular translation factors. Mutations in the gene encoding eIF4E and eIF4G or their isoforms, eIFiso4 E, eIFiso4 G and eIF2Bβ have been mapped as a source of plant potyvirus while other genus of plant virus recessive resistance genes in many species are originated from these loci. Some of other plant translation factors, such as eIF3,eIF4 A-like helicases, eEF1A and eEF1B, which are required in interacting with viral RNAs and regulating various aspects of the infection cycle,have also been identified. Here, we summarized the mechanisms utilized by RNA viruses of eukaryotic plants and the essential roles of e IFs in virus infection. Moreover, we discussed the potential of e IFs as a target gene in the development of genetic resistance to viruses for crop improvement. This review highlighted newly revealed examples of abnormal translational strategies and provided insights into natural host resistance mechanisms that have been linked to 3 cap-independent translational enhancer activity. 展开更多
关键词 EUKARYOTIC translation initiATION factor genome EDITING 3 cap-independent TRANSLATIONAL ENHANCER virus resistance
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Fatigue Resistance in Engineering Components:A Comprehensive Review on the Role of Geometry and Its Optimization
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作者 Ibrahim T.Teke Ahmet H.Ertas 《Computer Modeling in Engineering & Sciences》 2025年第7期201-237,共37页
Fatigue failure continues to be a significant challenge in designing structural and mechanical components subjected to repeated and complex loading.While earlier studies mainly examined material properties and how str... Fatigue failure continues to be a significant challenge in designing structural and mechanical components subjected to repeated and complex loading.While earlier studies mainly examined material properties and how stress affects lifespan,this review offers the first comprehensive,multiscale comparison of strategies that optimize geometry to improve fatigue performance.This includes everything from microscopic features like the shape of graphite nodules to large-scale design elements such as fillets,notches,and overall structural layouts.We analyze and combine various methods,including topology and shape optimization,the ability of additive manufacturing to finetune internal geometries,and reliability-based design approaches.A key new contribution is our proposal of a standard way to evaluate geometry-focused fatigue design,allowing for consistent comparison and encouraging validation across different fields.Furthermore,we highlight important areas for future research,such as incorporating manufacturing flaws,using multiscale models,and integrating machine learning techniques.This work is the first to provide a broad geometric viewpoint in fatigue engineering,laying the groundwork for future design methods that are driven by data and centered on reliability. 展开更多
关键词 Fatigue resistance geometry optimization topology optimization microstructural geometry additive manufacturing crack initiation multiaxial fatigue reliability-based design raster orientation notch effect defect morphology fatigue life prediction
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Effect of initial deposition behavior on properties of electroless Ni-P coating on ZK60 and ME20 magnesium alloys 被引量:3
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作者 Li FENG You-wei ZHANG +6 位作者 Chen WEN Si-zhen LI Jia-feng LI De CHENG Jing-ying BAI Qing-xin CUI Li-gong ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第8期2307-2322,共16页
The composition of magnesium alloys is greatly associated with initial deposition behavior of electroless Ni-P coatings.Thus,the initial deposition behavior of electroless Ni–P coatings on ZK60 and ME20 alloys was in... The composition of magnesium alloys is greatly associated with initial deposition behavior of electroless Ni-P coatings.Thus,the initial deposition behavior of electroless Ni–P coatings on ZK60 and ME20 alloys was investigated.The results indicated that differences in the alloy compositions significantly influenced the initial deposition process and the adhesive strength,corrosion resistance,and crystal structure.The initial deposition of coatings on ZK60 and ME20 alloys preferentially occurred on the precipitates.The precipitates in ZK60 alloy had higher chemical activity after HF activation and controlled the initial deposition rate of the coating.The initial deposition rate of the coating on ME20 alloy mainly depended on the density of the Mg F2 film formed by HF activation rather than on the precipitates.Owing to differences in the initial deposition process,the coating on ZK60 alloy had higher adhesive strength and better corrosion resistance than that on ME20 alloy.The coatings on ZK60 and ME20 alloys mainly had crystalline structures,and the coating on ME20 alloy had also a slight microcrystalline structure. 展开更多
关键词 ZK60 magnesium alloys ME20 alloys electroless Ni plating initial deposition adhesive strength corrosion resistance
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High expression of autophagy-related gene EIF4EBP1 could promote tamoxifen resistance and predict poor prognosis in breast cancer 被引量:1
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作者 Shan Yang Tian-Li Hui +6 位作者 Hao-Qi Wang Xi Zhang Yun-Zhe Mi Meng Cheng Wei Gao Cui-Zhi Geng Sai-Nan Li 《World Journal of Clinical Cases》 SCIE 2023年第20期4788-4799,共12页
BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP... BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP1) plays critical roles in the tumorigenesis and progression of BC. However, the expression and mechanism of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients are still unclear.AIM To investigate the expression and functions of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients.METHODS High-throughput sequencing data of breast tumors were downloaded from the Gene Expression Omnibus database. Differential gene expression analysis identified EIF4EBP1 to be significantly upregulated in cancer tissues. Its prognostic value was analyzed. The biological function and related pathways of EIF4EBP1 was analyzed. Subsequently, the expression of EIF4EBP1 was determined by real-time reverse transcription polymerase chain reaction and western blotting. Cell Counting Kit-8 assays, colony formation assay and wound healing assay were used to understand the phenotypes of function of EIF4EBP1.RESULTS EIF4EBP1 was upregulated in the TAM-resistant cells, and EIF4EBP1 was related to the prognosis of BC patients. Gene Set Enrichment Analysis showed that EIF4EBP1 might be involved in Hedgehog signaling pathways. Decreasing the expression of EIF4EBP1 could reverse TAM resistance, whereas overexpression of EIF4EBP1 promoted TAM resistance.CONCLUSION This study indicated that EIF4EBP1 was overexpressed in the BC and TAM-resistant cell line, which increased cell proliferation, invasion, migration and TAM resistance in BC cells. 展开更多
关键词 Breast cancer Eukaryotic translation initiation factor 4E binding protein 1 TAMOXIFEN resistance Prognosis BIOINFORMATICS
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ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer
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作者 Yang-kai JIANG Yu-jun SHUAI +7 位作者 Hua-min DING Hui ZHANG Chao HUANG Liang WANG Jia-yin SUN Wen-jie WEI Xing-yuan XIAO Guo-song JIANG 《Current Medical Science》 SCIE CAS 2023年第3期560-571,共12页
Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladde... Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladder cancer patients.AT-rich interaction domain 1A(ARID1A)gene mutation occurs frequently in bladder cancer;however,the role of CDDP sensitivity in BC has not been studied.Methods We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology.IC50 determination,flow cytometry analysis of apoptosis,and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A.qRT-PCR,Western blotting,RNA interference,bioinformatic analysis,and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC.Results It was found that ARID1A inactivation was associated with CDDP resistance in BC cells.Mechanically,loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3(EIF4A3)through epigenetic regulation.Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399(circ0008399),a novel circular RNA(circRNA)identified in our previous study,which,to some extent,showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells.Importantly,EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP.Conclusion Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3. 展开更多
关键词 AT-rich interaction domain 1A hsa_circ_0008399 eukaryotic translation initiation factor 4A3 cisplatin resistance bladder cancer
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Treatment Initiation among Patients with Multidrug Resistant Tuberculosis in Bhopal District, India
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作者 Hemant Deepak Shewade Arun M. Kokane +9 位作者 Akash Ranjan Singh Manoj Verma Malik Parmar Sanjay Singh Chahar Manoj Tiwari Sheeba Naz Khan Mukesh Nagar Sanjai Kumar Singh Pradeep Kumar Mehra Ajay M. V. Kumar 《Journal of Tuberculosis Research》 2017年第4期237-242,共6页
Revised national tuberculosis control programme in India has limited co-hort-wise information about what happens to patients diagnosed with multidrug resistant TB (MDR-TB). We determined the pre-treatment loss to foll... Revised national tuberculosis control programme in India has limited co-hort-wise information about what happens to patients diagnosed with multidrug resistant TB (MDR-TB). We determined the pre-treatment loss to follow-up (non-initiation of treatment by programme within 6 months of diagnosis) and time from diagnosis to treatment initiation in Bhopal district, central India (2014). Pre-treatment loss to follow-up was 13% (0.95 CI: 7%, 23%), not significantly different from the national estimates (18%) and median time to initiate treatment was seven days, lower than that reported elsewhere in the country. Bhopal was performing well with reference to time to treatment initiation in programmatic settings. 展开更多
关键词 MULTIDRUG-resistANT TUBERCULOSIS Operational Research Pre-Treatment Attrition Diagnosis and TREATMENT Pathway initial Loss to FOLLOW-UP
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始锻温度对6082-0.3RE建筑用铝合金性能的影响
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作者 冯玉苗 《锻压技术》 北大核心 2026年第3期59-65,共7页
为探究始锻温度对6082-0.3RE建筑用铝合金性能的影响规律,在多种始锻温度下对6082-0.3RE铝合金进行单向拔长锻造试验,进而对该合金的力学性能、耐腐蚀性能以及耐磨性能进行测试与分析。研究发现,随着始锻温度从420℃提高至500℃,6082-0.... 为探究始锻温度对6082-0.3RE建筑用铝合金性能的影响规律,在多种始锻温度下对6082-0.3RE铝合金进行单向拔长锻造试验,进而对该合金的力学性能、耐腐蚀性能以及耐磨性能进行测试与分析。研究发现,随着始锻温度从420℃提高至500℃,6082-0.3RE铝合金的力学性能、耐腐蚀性与耐磨性均呈现先提高后下降的趋势。与420℃始锻温度相比,当始锻温度提升至480℃时,6082-0.3RE铝合金的性能得到显著改善,屈服强度、抗拉强度和断后伸长率分别提升了51 MPa、56 MPa和5.2%,腐蚀电位正向偏移了0.226 V,同时腐蚀电流密度降低了15.86μA·cm^(-2),经过30 min磨损测试后磨损体积减少了26.35×10^(-3)mm^(3)。综合各项性能指标,6082-0.3RE铝合金的最佳始锻温度为480℃。 展开更多
关键词 6082-0.3RE铝合金 始锻温度 力学性能 耐腐蚀性能 耐磨损性能
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Simultaneous knockout of multiple eukaryotic translation initiation factor 4E genes confers durable and broad-spectrum resistance to potyviruses in tobacco 被引量:1
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作者 Yong Liu Shuo Wang +7 位作者 Danyang Zhao Chenglu Zhao Haiqin Yu Jianmin Zeng Zhijun Tong Cheng Yuan Zhenghe Li Changjun Huang 《aBIOTECH》 2025年第2期232-248,共17页
Recessive resistance mediated by mutations in the eukaryotic translation initiation factor 4E(eIF4E),has proven effective against diverse potyviruses and is extensively utilized in breeding programs.However,the rise o... Recessive resistance mediated by mutations in the eukaryotic translation initiation factor 4E(eIF4E),has proven effective against diverse potyviruses and is extensively utilized in breeding programs.However,the rise of resistance-breaking(RB)strains and emerging potyviral species necessitates the development of more durable and broad-spectrum resistance strategies.In this study,our field survey in Yunnan,China,identified potato virus Y(PVY)RB isolates,as well as the prevalence of tobacco vein banding mosaic virus(TVBMV)and chilli veinal mottle virus(ChiVMV),in tobacco carrying the recessive va locus,which lacks the eIF4E1-S susceptibility gene,due to a chromosomal deletion.Protein interaction and viral infection assays demonstrated that both eIF4E1-S and eIFiso4E-T are used by PVY RB as susceptibility factors for infection,with the combined inactivation of these genes confering durable resistance.Similarly,the knockout of eIFiso4E-S,in the va genetic background,provided effective resistance to TVBMV and reduced susceptibility to ChiVMV.Notably,pyramiding mutations in eIFiso4E-S and eIFiso4E-T,in va tobacco,generated plants exhibiting robust,broad-spectrum resistance,to all three viruses,without compromising plant development.These findings underscore the potential of stacking eIF4E mutations to engineer durable,broad-spectrum resistance to potyviruses in tobacco,offering a promising strategy for crop improvement. 展开更多
关键词 Eukaryotic translation initiation factor 4E Recessive resistance POTYVIRUS Gene editing Durable resistance Broad-spectrum resistance
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抽滤法测定活性污泥比阻的影响因素研究
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作者 张梦杰 张永强 申凯 《河南化工》 2026年第3期28-30,共3页
探讨了抽滤脱水中污泥浓度、过滤压力、过滤介质的性质和开始计时时滤液的起始体积等对污泥比阻的影响。结果表明,可压缩性污泥的比阻随压力的增大而增大,而不可压缩性污泥的比阻基本不受压力的影响。污泥比阻随着污泥浓度的增加而增大... 探讨了抽滤脱水中污泥浓度、过滤压力、过滤介质的性质和开始计时时滤液的起始体积等对污泥比阻的影响。结果表明,可压缩性污泥的比阻随压力的增大而增大,而不可压缩性污泥的比阻基本不受压力的影响。污泥比阻随着污泥浓度的增加而增大,随过滤介质阻抗的增大而增大;污泥比阻还与开始计时时的滤液起始体积有关,起始体积不同时,测得的比阻也不同,但其变化没有特定的规律。 展开更多
关键词 污泥比阻 压力 污泥浓度 过滤介质 滤液起始体积
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基于Deform-3D的锻压温度对304不锈钢法兰管耐磨性影响的模拟分析
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作者 崔海源 马骏驰 +5 位作者 高焱 李润涛 吴宇星 罗飞 赵永涛 徐平 《河南工程学院学报(自然科学版)》 2026年第1期25-29,共5页
为降低实验成本并验证有限元模拟在304不锈钢法兰管锻压过程及耐磨性分析中的有效性,基于Deform-3D软件,模拟了1100~1190℃始锻温度和760~880℃终锻温度组合下的法兰管锻压成型过程及室温耐磨性。结果表明,始锻温度1160℃与终锻温度860... 为降低实验成本并验证有限元模拟在304不锈钢法兰管锻压过程及耐磨性分析中的有效性,基于Deform-3D软件,模拟了1100~1190℃始锻温度和760~880℃终锻温度组合下的法兰管锻压成型过程及室温耐磨性。结果表明,始锻温度1160℃与终锻温度860℃组合下,法兰管的耐磨性达到全局最佳。当始锻温度降至1145℃时,法兰管耐磨性接近最佳,其对应的终锻温度拓宽至840~880℃,表明在此始锻温度下更易通过控制终锻温度获得耐磨性优良的制品。耐磨性变化主要源于锻压温度调控的微观组织协同作用:温度影响晶粒尺寸和晶界碳化物析出行为,二者共同决定了材料表面塑性变形抗力,进而影响法兰管耐磨性。模拟得到的磨损体积变化趋势与文献实验结果吻合,表明模拟方法能有效分析法兰管锻压过程并预测其耐磨性。 展开更多
关键词 始锻温度 终锻温度 耐磨性 有限元分析
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PVA和VAE对碱矿渣隧道防火涂料抗风振性能的影响
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作者 黄国雄 《福建建筑》 2026年第1期65-69,共5页
在风吸振动情况下,碱矿渣隧道防火涂料(ASF)与衬砌良好的粘结性能,对保障隧道防火功能至关重要。采用自制的振动试验装置,通过改变聚乙烯醇(PVA)(0%~2.6%)和可再分散乳胶粉(VAE)(0%~4.2%)的掺量进行试验,测定了ASF初始粘结强度、风吸振... 在风吸振动情况下,碱矿渣隧道防火涂料(ASF)与衬砌良好的粘结性能,对保障隧道防火功能至关重要。采用自制的振动试验装置,通过改变聚乙烯醇(PVA)(0%~2.6%)和可再分散乳胶粉(VAE)(0%~4.2%)的掺量进行试验,测定了ASF初始粘结强度、风吸振动下的破坏时间和粘结强度损失率等指标,并结合微观电镜和孔结构分析其机理。试验结果表明,随着PVA掺量的增加,ASF抗风振性能先提高后降低;随着VAE掺量的增加,ASF抗风振性能提高。采用了1.3%PVA和2.1%VAE的ASF,其初始粘结强度为0.312 MPa、风吸振动下破坏时间为35min、30min时的粘结强度损失率为50.9%,可将其在工程中推广应用。 展开更多
关键词 碱矿渣 隧道防火涂料 初始粘结强度 粘结强度损失率 抗风振性能
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Eukaryotic initiation factor 5A2 and human digestive system neoplasms 被引量:4
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作者 Qing-Bin Meng Jing-Jing Peng +3 位作者 Zi-Wei Qu Xiao-Min Zhu Zhang Wen Wei-Ming Kang 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2019年第6期449-458,共10页
Eukaryotic initiation factor 5A2(eIF5A2),as one of the two isoforms in the family,is reported to be a novel oncogenic protein that is involved in multiple aspects of many types of human cancer.Overexpression or gene a... Eukaryotic initiation factor 5A2(eIF5A2),as one of the two isoforms in the family,is reported to be a novel oncogenic protein that is involved in multiple aspects of many types of human cancer.Overexpression or gene amplification of EIF5A2 has been demonstrated in many cancers.Accumulated evidence shows that eIF5A2 initiates tumor formation,enhances cancer cell growth,increases cancer cell metastasis,and promotes treatment resistance through multiple means,including inducing epithelial–mesenchymal transition,cytoskeletal rearrangement,angiogenesis,and metabolic reprogramming.Expression of eIF5A2 in cancer correlates with poor survival,advanced disease stage,as well as metastasis,suggesting that eIF5A2 function is crucial for tumor development and maintenance but not for normal tissue homeostasis.All these studies suggest that eIF5A2 is a useful biomarker in the prediction of cancer prognosis and serves as an anticancer molecular target.This review focuses on the expression,subcellular localization,post-translational modifications,and regulatory networks of eIF5A2,as well as its biochemical functions and evolving clinical applications in cancer,especially in human digestive system neoplasms. 展开更多
关键词 EUKARYOTIC translation initiATION factor 5A2 HYPUSINE MODIFICATION ACETYLATION MODIFICATION Drug resistance Cancer THERAPEUTICS
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Initial stiffness and moment resistance of reinforced joint with end-plate connection
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作者 Sufang WANG Yiyi CHEN 《Frontiers of Structural and Civil Engineering》 SCIE EI 2009年第4期345-351,共7页
In beam-to-column joint with bolted end-plate connection,the structural details of column flange reinforced by backing plate and column web panel reinforced by supplementary plate are analyzed.The joint is divided int... In beam-to-column joint with bolted end-plate connection,the structural details of column flange reinforced by backing plate and column web panel reinforced by supplementary plate are analyzed.The joint is divided into some basic components,and the initial stiffness of each component is obtained.Especially,the initial stiffness of reinforced components is drawn by theoretical model and finite element analysis.The initial stiffness of reinforced joint can be obtained by assembling the initial stiffness of each component.The design moment resistance of column flange reinforced by backing plate is deduced based on yield line method,and the design moment resistances of other components are deduced based on present codes.The design moment resistance of the reinforced joint is then determined by the minimum of the design moment resistances of all components.By comparison with the results of finite element calculation,it is verified that the method to calculate the initial stiffness of reinforced joint is accurate enough to be used to estimate the rigid behavior of the joint and to make parametric study. 展开更多
关键词 steel structure end-plate connection backing plate supplementary web plate initial stiffness moment resistance
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锻造温度对新型机械模具钢高温性能的影响 被引量:2
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作者 尹久 程兴国 《锻压技术》 北大核心 2025年第4期1-6,24,共7页
4Cr5MoSiV1NbSr作为一种新型模具钢具有较佳的应用前景。为了研究锻造温度对4Cr5MoSiV1NbSr模具钢高温性能的影响,选择始锻温度为1000~1250℃和终锻温度为700~950℃,在500℃高温环境下对锻后模具钢进行磨损试验和氧化试验。结果表明:始... 4Cr5MoSiV1NbSr作为一种新型模具钢具有较佳的应用前景。为了研究锻造温度对4Cr5MoSiV1NbSr模具钢高温性能的影响,选择始锻温度为1000~1250℃和终锻温度为700~950℃,在500℃高温环境下对锻后模具钢进行磨损试验和氧化试验。结果表明:始锻温度从1000℃增加至1250℃时,4Cr5MoSiV1NbSr模具钢试样的高温耐磨损和抗高温氧化性能均呈先升高后降低的趋势;终锻温度从700℃增加至950℃时,4Cr5MoSiV1NbSr模具钢试样的高温耐磨损和抗高温氧化性能均先升高后基本不变。与1000℃始锻相比,1150℃始锻的Cr5MoSiV1NbSr模具钢试样高温磨损体积减小63.7%、高温氧化单位面积质量增重减小57.3%。与700℃终锻相比,900℃终锻的Cr5MoSiV1NbSr模具钢试样高温磨损体积减小74.5%、高温氧化单位面积质量增重减小66.7%。 展开更多
关键词 始锻温度 终锻温度 4Cr5MoSiV1NbSr模具钢 高温耐磨损性能 抗高温氧化性能
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基于多尺度模型的装配式框架抗连续倒塌性能分析
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作者 张望喜 陈冬冬 +3 位作者 胡帅 张瑾熠 张倚天 易伟建 《西安建筑科技大学学报(自然科学版)》 北大核心 2025年第6期791-800,共10页
为探究周边框架约束作用对框架“初始受损区域”抗连续倒塌性能的影响,采用多尺度建模的方法,以层数、柱失效位置为变量,研究现浇混凝土(RC)空间框架和装配整体式混凝土(PC)空间框架“初始受损区域”的抗连续倒塌性能.结果表明:底层角... 为探究周边框架约束作用对框架“初始受损区域”抗连续倒塌性能的影响,采用多尺度建模的方法,以层数、柱失效位置为变量,研究现浇混凝土(RC)空间框架和装配整体式混凝土(PC)空间框架“初始受损区域”的抗连续倒塌性能.结果表明:底层角柱失效和底层边柱失效工况下,多层空间框架梁机制阶段最大相对抗力大于单层空间框架,多层PC空间框架梁机制抗力比多层RC空间框架下降更快;底层边柱失效工况下,PC空间框架压拱机制比相应RC框架更早结束,抗力下降更快;在此基础上结合规范和既有研究,分别对底层角柱和底层边柱失效工况下的梁机制阶段和压拱机制阶段的抗力计算方法进行了修正. 展开更多
关键词 多尺度模型 装配整体式框架 抗连续倒塌 周边框架约束 初始受损区域
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考虑螺栓预紧力及嵌缝宽度影响的管片接头抗弯特性研究
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作者 石钰锋 周宇航 +3 位作者 胡梦豪 张涛 黄匀 魏纲 《铁道科学与工程学报》 北大核心 2025年第12期5473-5486,共14页
盾构隧道管片环向接头构造复杂,现有承载理论在接头嵌缝构造、连接螺栓、初始预紧力等参数上多采用简化处理或依据经验确定,使管片接头抗弯特性尚不明确。为此,建立综合考虑初始预紧力、混凝土抗压承载极限及嵌缝构造的管片接头承载全... 盾构隧道管片环向接头构造复杂,现有承载理论在接头嵌缝构造、连接螺栓、初始预紧力等参数上多采用简化处理或依据经验确定,使管片接头抗弯特性尚不明确。为此,建立综合考虑初始预紧力、混凝土抗压承载极限及嵌缝构造的管片接头承载全过程解析理论模型,采用数值模拟验证理论的准确性,进一步探明初始预紧力、嵌缝间距等对管片接头初始抗弯刚度、抗弯承载极限等抗弯特性的影响。研究结果表明:所建管片接头受力全过程解析模型可用于分析任意荷载作用下接头的力学状态,且理论与数值结果吻合度较高;无预紧力时,正、负弯矩接头的初始抗弯刚度分别为7580、6190(kN·m)/rad,抗弯承载极限分别为173 kN·m、43.7 kN·m,差异明显,说明接头内缘嵌缝间距过大不利于负弯矩承载;相较于无预紧力时,螺栓预紧力的施加可显著提高接头抗弯刚度及承载性能,仅施加2 kN螺栓预紧力,正、负弯矩接头的初始抗弯刚度提升了494%和7%,抗弯承载极限提升了637%和203.2%,但预紧力过大也会导致管片局部屈服,经研究可知南昌地铁制式管片的较优初始预紧力在200 kN左右;随外缘嵌缝间距的增大,接头抗弯承载极限呈先增大后减小的趋势,在嵌缝间距3 mm左右达到最大,间距大于6 mm后大幅下降,表明接头外缘嵌缝间距存在一个可充分发挥管片接头抗弯性能的较优区间。研究结果可为进一步发展盾构隧道管片接头承载理论和抗弯特性影响分析提供参考。 展开更多
关键词 解析模型 数值仿真 管片接头 嵌缝构造 螺栓初始预紧力 抗弯特性
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初始剪应力和循环应力方向对饱和密砂液化特性的影响
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作者 张迎宾 覃一巧 +3 位作者 张世豪 魏江涛 熊亦翔 刘永航 《岩土工程学报》 北大核心 2025年第11期2246-2254,共9页
边坡土单元体在地震荷载作用期间同时受到初始剪应力和循环应力的作用,且初始剪应力和循环应力作用方向往往不同。为探究初始剪应力和循环应力作用方向对饱和密砂液化特性的影响,对饱和密砂进行了一系列固结不排水多向循环单剪试验。试... 边坡土单元体在地震荷载作用期间同时受到初始剪应力和循环应力的作用,且初始剪应力和循环应力作用方向往往不同。为探究初始剪应力和循环应力作用方向对饱和密砂液化特性的影响,对饱和密砂进行了一系列固结不排水多向循环单剪试验。试验结果表明:饱和密砂的破坏模式主要包括循环活动性和累积塑性应变两种,破坏模式受初始剪应力大小的影响;初始剪应力的存在会降低饱和密砂的抗液化强度,但垂直加载模式下饱和密砂的抗液化强度比平行加载模式下高约5%~7%;不同加载模式下均表现出损耗能的累积速率随初始剪应力的增加而增大的现象,初始剪应力作用下饱和密砂的损耗能累积速率加快是导致其抗液化强度降低的内在原因;饱和密砂的残余孔压和损耗能的归一化曲线在对数坐标下呈现出线性关系。 展开更多
关键词 初始剪应力 抗液化强度 能量法 孔压模型 多向循环单剪试验
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超声波对紫外光固化体系耐热储存稳定性影响的研究 被引量:1
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作者 余宗萍 祁彦金 +2 位作者 吴书琴 杨鹏飞 邱凤仙 《热固性树脂》 2025年第2期61-64,共4页
将添加不同低聚物、引发剂、阻聚剂的光固化体系在超声波均质器中分别分散5、10、15 min后,测试了体系粘度,并通过红外光谱分析了体系的固化度,研究了超声波对紫外光固体系耐热储存稳定性的影响。结果表明,超声波是检测紫外光固化体系... 将添加不同低聚物、引发剂、阻聚剂的光固化体系在超声波均质器中分别分散5、10、15 min后,测试了体系粘度,并通过红外光谱分析了体系的固化度,研究了超声波对紫外光固体系耐热储存稳定性的影响。结果表明,超声波是检测紫外光固化体系热稳定性的一种快捷有效的技术手段,其对紫外光固化体系相关固化性能研究也具有重要实用价值。 展开更多
关键词 超声波 紫外光固化 低聚物 引发剂 阻聚剂 耐热性
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基于全基组测序的疑似产气荚膜梭菌食物中毒事件的病原学分析 被引量:1
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作者 余树坤 崔紫妍 +3 位作者 刘浪 谭雅心 崔洲莹 陶志阳 《中国人兽共患病学报》 北大核心 2025年第1期61-66,共6页
目的对武汉市某区一起疑似产气荚膜梭菌引起的食物中毒事件进行分子分型溯源及耐药特征性分析。方法采用FIlm Array TM检测系统和多重荧光定量PCR方法对中毒事件所涉样本进行病原菌初筛,根据初筛结果进行细菌分离培养和质谱鉴定分析,采... 目的对武汉市某区一起疑似产气荚膜梭菌引起的食物中毒事件进行分子分型溯源及耐药特征性分析。方法采用FIlm Array TM检测系统和多重荧光定量PCR方法对中毒事件所涉样本进行病原菌初筛,根据初筛结果进行细菌分离培养和质谱鉴定分析,采用荧光PCR对分离菌株进行产气荚膜梭菌6种毒力基因检测,基于全基因组测序结果分析其毒力基因、耐药基因及全基因组单核苷酸多态性遗传进化分析(wgSNPs),采用琼脂稀释法进行抗生素敏感性试验。结果共分离到10株产荚膜梭菌,其中8株来自7份肛拭子样本,1株来自粪便样本,1株来自食品样本。可疑食品产气荚膜梭菌计数为7.8×10^(6) CFU/g。10株产气荚膜分离菌株均检出plc(a)毒素基因,未检出cpe等其他5种毒素基因,证实均为A型菌产气荚膜梭菌。所有菌株对克林霉素100%耐药,对万古霉素、头孢西丁、美罗培南等抗生素几乎完全敏感。10株产气荚膜梭菌均携带tetB(P)、tetA(P)和mprF等耐药基因,其次是ermQ(70%)、ant(6)-Ib(10%)以及LnuP(10%)。wgSNPs遗传进化分析显示4株暴发菌株聚成一簇,与可疑食品来源株同属一个独立的亚分支,亲缘关系较近。结论此次食物中毒事件可能是由被产气荚膜梭菌污染的手撕鸡所致,菌株未出现多重耐药现象,但均对克林霉素耐药,需引起临床重视。 展开更多
关键词 产气荚膜梭菌 多重PCR初筛 全基因组测序 耐药基因 食物中毒
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Impact of Bubbles on Mechanical Performances in a Borosilicate Glass
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作者 LI Chengxing LI Dongfeng +2 位作者 MA Shilong QIAO Ang ZHENG Qingshuang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2025年第1期25-29,共5页
To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different porosity.By the analysis software ... To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different porosity.By the analysis software integrated within the optical microscope,the diameter and number of the bubbles on the surface of three borosilicate glasses were quantified.From the hardness and crack initiation resistance(CR),we built the relationship between the porosity and the mechanical performance of these borosilicate glasses. 展开更多
关键词 BUBBLES oxide glass HARDNESS creak initiation resistance
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