检索结果-南通市图书馆

Microstructure and ablation behavior of Zr-based ultra-high-temperature gradient composites

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第9期34卷 2889-2899页

作者： Qing-hua LIU Tian TIAN Wei SUN hong-bo zhang Xiang XIONG State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China National Key Laboratory of Science and Technology on High-strength Structural Materials Central South UniversityChangsha 410083China

To obtain high-performance Zr-based ultra-high-temperature composites,Zr-based ultra-high-temperature gradient composites were prepared by changing the laying method of the infiltrant via reactive melt *** effects of different infiltrant laying methods on the microstructure and ablative properties of Zr-based ultrahigh-temperature gradient composites were *** results showed that the gradient structure of the Zr-based ultrahigh-temperature gradient composites differed when the composition ratio of the infiltrant was *** the thicknesses of the Zr/Mo/Si layers were 6/4/12 mm and 8/2/12 mm,the SiMoZrC solid solution content in the samples increased and decreased along the infiltration direction,*** gradient samples were ablated in an oxyacetylene flame at 3000°C for 40 *** ablation resistance of the sample was the highest when the infiltrant was a powder and the thickness of the Zr/Mo/Si layer was 6/4/12 mm.

关键词： reactive melt infiltration ceramic-matrix composites gradient material microstructure ablation property

Establishment of a prognosis predictive model for liver cancer based on expression of genes involved in the ubiquitin-proteasome pathway

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Oncology 2024年第3期15卷 434-446页

作者： Hua Li Yi-Po Ma Hai-Long Wang Cai-Juan Tian Yi-Xian Guo hong-bo zhang Xiao-Min Liu Peng-Fei Liu Department of Endoscopy Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center for CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin 300060China Department of Critical Care Medicine Dingzhou City People’s HospitalDingzhou 073000Hebei ProvinceChina Department of Oncology Tianjin Academy of Traditional Chinese Medicine Affiliated HospitalTianjin 300120China Tianjin Marvel Medical Laboratory Tianjin Marvelbio Technology Co.LtdTianjin 300180China Department of Intelligent Technology Tianjin Yunquan Intelligent Technology Co.LtdTianjin 300381China Department of Oncology Tianjin Huanhu HospitalTianjin 300350China

BACKGROUND The ubiquitin-proteasome pathway(UPP)has been proven to play important roles in *** To investigate the prognostic significance of genes involved in the UPP and develop a predictive model for liver cancer based on the expression of these *** In this study,UPP-related E1,E2,E3,deubiquitylating enzyme,and proteasome gene sets were obtained from the Kyoto Encyclopedia of Genes and Genomes(KEGG)database,aiming to screen the prognostic genes using univariate and multivariate regression analysis and develop a prognosis predictive model based RESULTS Five genes(including autophagy related 10,proteasome 20S subunit alpha 8,proteasome 20S subunit beta 2,ubiquitin specific peptidase 17 like family member 2,and ubiquitin specific peptidase 8)were proven significantly correlated with prognosis and used to develop a prognosis predictive model for liver *** training,validation,and Gene Expression Omnibus sets,the overall survival differed significantly between the high-risk and low-risk *** expression of the five genes was significantly associated with immunocyte infiltration,tumor stage,and postoperative recurrence.A total of 111 differentially expressed genes(DEGs)were identified between the high-risk and low-risk groups and they were enriched in 20 and 5 gene ontology and KEGG *** division cycle 20,Kelch repeat and BTB domain containing 11,and DDB1 and CUL4 associated factor 4 like 2 were the DEGs in the E3 gene set that correlated with *** We have constructed a prognosis predictive model in patients with liver cancer,which contains five genes that associate with immunocyte infiltration,tumor stage,and postoperative recurrence.

关键词： Liver cancer Ubiquitin-proteasome pathway Prognosis prediction Gene expression Immune infiltration

Blended skip entry guidance for low-lifting lunar return vehicles

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

Acta Mechanica Sinica 2014年第6期30卷 973-982页

作者： Zong-Fu Luo hong-bo zhang Guo-Jian Tang College of Aerospace Science and Engineering National University of Defense Technology

A skip entry guidance algorithm blending numerical predictor-corrector and nominal trajectory tracking is presented for lunar return *** guidance is decoupled into longitudinal and lateral channels.A piecewise bank-vs-energy magnitude profile and a sign profile are adopted in the skip phase.A magnitude parameter is used to adjust the predicted downrange,and a pseudo-crossrange at the beginning of the final phase is selected as the lateral control *** biases of both channels are nullified by a false position iteration *** on-line estimation and modeling method is introduced to compensate for aerodynamic and atmospheric uncertainties.A nominal trajectory for the final phase is generated based on actual reenter conditions,and the obtained nominal trajectory is tracked by a linear feedback law.A lateral corridor is used to manage the lateral *** proposed guidance algorithm is assessed using three-degree-of-freedom Monte Carlo analyses,and the results show a satisfactory and robust performance under highly stressful dispersions.

关键词： Skip entry guidance Numerical predictorcorrector Low-lifting vehicle Lunar return mission Bank profile

IPS observation system for the Miyun 50m radio telescope and its commissioning observation

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2012年第7期12卷 857-864页

作者： Xin-Ying Zhu Xi-Zhen zhang hong-bo zhang De-Qing Kong Hui-Peng Qu National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Beijing Institute of Tracking and Telecommunications Technology Beijing 100094 China

Ground-based observation of Interplanetary Scintillation （IPS） is an impor- tant approach for monitoring solar wind. A ground-based IPS observation system has been newly implemented on a 50 m radio telescope at Miyun station, managed by the National Astronomical Observatories, Chinese Academy of Sciences. This observa- tion system has been constructed for the purpose of observing solar wind speed and the associated scintillation index by using the normalized cross-spectrum of a simul- taneous dual-frequency IPS measurement. The system consists of a universal dual- frequency front-end and a dual-channel multi-function back-end specially designed for IPS. After careful calibration and testing, IPS observations on source 3C 273B and 3C 279 have been successfully carried out. The preliminary observation results show that this newly-developed observation system is capable of performing IPS observa- tion. The system＇s sensitivity for IPS observation can reach over 0.3 Jy in terms of an IPS polarization correlator with 4 MHz bandwidth and 2 s integration time.

关键词： instrument - interplanetary scintillation -- telescope -- radio astron-omy

CO Clouds around SNR G21.8-0.6 and G32.8-0.1

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 705-711页

作者： Jian-Jun Zhou Xi-Zheng zhang hong-bo zhang Jarken Esimbek Ju-Yong zhang Bing-Gang Ju National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 National Astronomical Observatories / Urumqi Observatory Chinese Academy of Sciences Urumqi 830011 Graduate School of Chinese Academy of Sciences Beijing 100049 Qinghai Station of Purple Mountain Observatory Chinese Academy of Sciences Delingha 817000

We made the first CO（1-0） mapping to SNR G21.8-0.6 and SNR G32.8-0.1, both associated with OH 1720MHz maser. Based on the morphological correspondence and velocity and position agreement between the radio remnant an... 详细信息

关键词： ISM clouds -- ISM individual (G21.8-0.6, G32.8-0.1 ) -- ISM molecules -- masers -- supernova remnants

Mechanical thrombectomy for acute occlusion of the posterior inferior cerebellar artery: 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10期9卷 2268-2273页

作者： hong-bo zhang Pian Wang Yan Wang Jiang-hong Wang Zheng Li Rong Li Department of Neurology Chengdu Fifth People's HospitalChengdu 611130Sichuan ProvinceChina

BACKGROUND Mechanical thrombectomy(MT)has been demonstrated to be useful for the treatment of ischemic stroke in patients with large vessel ***,recanalization by MT is not recommended for distal vessels such as second-order branches of the middle cerebral artery and posterior inferior cerebellar artery(PICA).Because of the small size and tortuosity of these arteries,the risks of using the available endovascular devices outweigh the benefits of ***,MT appears to be effective in patients with primary distal vessel occlusion in eloquent areas,those with a high National Institutes of Health Stroke Scale score,and those ineligible for recombinant tissue plasminogen activator ***,we report the use of MT for treating acute occlusion of the PICA using a directaspiration first-pass technique(ADAPT).CASE SUMMARY In this case,the patient received acute occlusion of the PICA with ADAPT when right internal carotid artery stenting was *** With the introduction of advanced endovascular devices,MT may now be a feasible treatment for acute occlusion of the PICA.

关键词： Posterior inferior cerebellar artery Mechanical thrombectomy Ischemic stroke Carotid artery stent Neurovascular interventions Case report

Gravitational Deformation Measurement Method for the Main Reflector and Sub-reflector of the 70 m Antenna by Laser Scanner

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

Research in Astronomy and Astrophysics 2022年第9期22卷 1-9页

作者： Lian-bo Fu Jian-Jun Liu Wei Yan De-Qing Kong Xin Ren Chen-Di Liu hong-bo zhang Key Laboratory of Lunar and Dep Space Exploration National Astronomical ObservatoriesChinese Academy of SciencesBejing 100101China Urunaivreyr of Chinese Academy of Sciences Beijing 100049China

Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement resulting from the factors of wind, temperature, and gravity, among which the effect of gravity is especially pronounced. In this work, a three-dimensional laser scanner was employed to measure the main reflector and subreflector gravitational deformation of the Tianjin 70 m antenna at different elevation angles. Here, we solved the antenna main reflector deformation and sub-reflector displacement, and analyzed the deformation law of the antenna under the action of gravity. A new measurement method of antenna main reflector deformation and subreflector displacement is realized by mutual verification of the measured results and theoretical simulations. This method will help to improve the antenna performance and provide a reference to optimize the design of largeaperture antennas.

关键词： telescopes techniques:radar astronomy planets and satellites:detection

Effects of proteinase A on cultivation and viability characteristics of industrial Saccharomyces cerevisiae WZ65

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第10期10卷 769-776页

作者： hong-bo zhang Hai-feng zhang Qi-he CHEN Hui RUAN Ming-liang FU Guo-qing HE Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

Proteinase A （PrA）, encoded by PEP4 gene, is a key enzyme in the vacuoles of Saccharomyces cerevisiae. We characterized the effects of PrA on cell growth and glucose metabolism in the industrial S. cerevisiae WZ65. It was observed that the lag phase of cell growth of partial PEP4 gene deletion mutant （36 h） and PrA-negative mutant （48 h） was significantly extended, compared with the wild type strain （24 h）（P〈0.05）, but PrA had no effect on glucose metabolism either under shaking or steady state cultivations. The logistic model was chosen to evaluate the effect of PrA on S. cerevisiae cell growth, and PrA was found to promote cell growth against insufficient oxygen condition in steady state cultivation, but had no effect in shaking cultivation. The effects of glucose starvation on cell growth of partial PEP4 gene deletion strain and PrA-negative mutant were also evaluated. The results show that PrA partial deficiency increased the adaption ofS. cerevisiae to unfavorable nutrient environment, but had no effect on glucose metabolism under the stress of low glucose. During heat shock test, at 60 ℃ the reduced cell viability rate （RCVR） was 10% for the wild type S. cerevisiae and 90% for both mutant strains （P〈0.01）, suggesting that PrA was a negative factor for S. cerevisiae cells to survive under heat shock. As temperatures rose from 60 ℃ to 70℃, the wild type S. cerevisiae had significantly lower relative glucose consumption rate （RGCR）（61.0% and 80.0%） than the partial mutant （78.0% and 98.5%） and the complete mutant （80.0% and 98.0%）（P〈0.05）, suggesting that, in coping with heat shock, cells of the PrA mutants increased their glucose consumption to survive. The present study may provide meaningful information for brewing industry; however, the role of PrA in industrial S. cerevisiae physiology is complex and needs to be further investigated.

关键词： Proteinase A (PrA) PEP4 gene Saccharomyces cerevisiae WZ65 Cell metabolism Viability

Construction of recombinant industrial Saccharomyces cerevisiae strain with bglS gene insertion into PEP4 locus by homologous recombination

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第7期9卷 527-535页

作者： Qiang zhang Qi-he CHEN Ming-liang FU Jin-ling WANG hong-bo zhang Guo-qing HE Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

The bglS gene encoding endo-1,3-1,4-β-glucanase from Bacillus subtil＆ was cloned and sequenced in this study. The bglS expression cassette, including PGK1 promoter, bglS gene fused to the signal sequence of the yeast mating pheromone a-factor （MFals）, and ADH1 terminator with G418-resistance as the selected marker, was constructed. Then one of the PEP4 allele of Saccharomyces cerevisiae WZ65 strain was replaced by bglS expression cassette using chromosomal integration of polymerase chain reaction （PCR）-mediated homologous recombination, and the bglS gene was expressed simultaneously. The recombinant strain S. cerevisiae （SC-βG） was preliminarily screened by the clearing hydrolysis zone formed after the barley β-glucan was hydrolyzed in the plate and no proteinase A （PrA） activity was measured in fermenting liquor. The results of PCR analysis of genome DNA showed that one of the PEP4 allele had been replaced and bglS gene had been inserted into the locus of PEP4 gene in recombinant strains. Different endo-1,3-1,4-β-glucanase assay methods showed that the recombinant strain SC-βG had high endo-1,3-1,4-β-glucanase expression level with the maximum of 69.3 U/（h·ml） after 60 h of incubation. Meanwhile, the Congo Red method was suitable for the determination of endo-1,3-1,4-β-glucanase activity during the actual brewing process. The current research implies that the constructed yeast strain could be utilized to improve the industrial brewing property of beer.

关键词： Endo-1 3-1 4-β-glucanase (bglS) Gene replacement Homologous recombination Bacillus subtilis PEP4 gene Saccharomyces cerevisiae