检索结果-南通市图书馆

On the comparison of particle regeneration technique and volume adaptive scheme in the compressible flow based on smoothed particle hydrodynamics

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2022年第3期34卷 408-421页

作者： ming-kang li Shuai Zhang Yu-Xiang Peng A-Man Zhang College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Nanhai Institute of Harbin Engineering University Sanya572024China School of Marine Engineering and Technology Sun Yat-sen UniversityZhuhai519082China

The collapse of a cavitation bubble is an interesting topic and it has many applications in the engineering *** to its compressible nature,the modelling of a cavitation bubble is not easy by the Lagrangian method,like the smoothed particle hydrodynamics(SPH),as there is large variation of particle ***,there are two kinds of method that have been proposed to deal with this problem:the particle regeneration technique(PRT)and the volume adaptive scheme(VAS).They have all been validated via several numerical tests of compressible flow in the past *** is based on totally different concept,the ultimate simulation results and properties may ***,we intend to compare these two methods based on the Riemann-based SPH solver with monotone upwind-centered scheme for conservation laws(MUSCL)reconstruction via several numerical *** characteristics of these two methods are discussed and the applicable scope for them are also commented for further usage.

关键词： Compressible flow smoothed particle hydrodynamics(SPH) particle regeneration technique(PRT) volume adaptive scheme(VAS)

Tribological behaviour of biomedical Ti–Zr-based shape memory alloys

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

Rare Metals 2017年第6期36卷 478-484页

作者： Wen-Tao Qu Xu-Guang Sun Bi-Fei Yuan kang-ming li Zhen-Guo Wang Yan li School of Mechanical Engineering Xi'an Shiyou UniversityXi'an 710065 China School of Materials Science and Engineering Beihang University Beijing 100191 China Key Laboratory of Aerospace Materials and Performance(Ministry of Education) Beihang University Beijing 100191China

The tribological behaviour of Ti-30Zr, Ti-20Zr-10Nb and Ti-19Zr-10Nb-1Fe alloys was investigated using reciprocating friction and wear tests. X-ray diffraction（XRD） results indicate that Ti-30Zr, Ti-20Zr-10Nb and Ti-19Zr-10Nb-1Fe alloys are composed of hexagonal a＇-martensite, orthorhombic a＇＇-martensite and bcc β phases,respectively. Ti-30Zr alloy has the highest hardness of HV（273.1 ± 9.3）, while Ti-20Zr-10Nb alloy exhibits the lowest hardness of HV（235.2 ± 20.4） among all the *** tribological results indicate that Ti-30Zr alloy shows the best wear resistance among these alloys, corresponding to the minimum average friction coefficient of 0.052 and the lowest wear rate of 6.4x10^-4mm3·N^-1·m^-1. Ti-20Zr-10Nb alloy displays better wear resistance than Ti-19Zr-10Nb-1Fe alloy, because the iron oxide is easy to fall off and less Nb2O5 films form on the worn surface of the *** and abrasive wear in association with adhesive wear are the main wear mechanism of these alloys.

关键词： Biomedical material Shape memory alloyTi-Zr Tribology

Autonomous multi-drone racing method based on deep reinforcement learning

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu kang Jian DI ming li Yunbo ZHAO Yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： autonomous multi-drone racing deep reinforcement learning Markov game racing drone sim-to-real

Benefits of intra-operative systemic chemotherapy during curative surgery in patients with locally advanced gastric cancer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2013年第18期126卷 3493-3498页

作者： MENG Qing-bin YU Jian-chun MA Zhi-qiang kang Wei-ming ZHOU li YE Xin Department of General Surgery Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China

Background There is little information on the impact of intra-operative systemic chemotherapy on gastric cancer. The aim of this study was to identify prognostic factors in patients with locally advanced gastric cancer and undergoing curative resection, with a focus on evaluating survival benefits and tolerance of intra-operative systemic chemotherapy. Methods We retrospectively analyzed clinicopathological data for 264 consecutive patients who underwent curative resection for gastric cancer at Peking Union Medical College Hospital from January 2002 to January 2007. Survival curves were plotted using the Kaplan-Meier method and compared using log-rank tests. Univariate and multivariate analyses were performed with the Cox proportional hazard model. Results Patients who received intra-operative systemic chemotherapy had higher 5-year overall survival and 5-year disease-free survival rates （P=-0.019 and 0.010, respectively） than patients who did not receive intra-operative systemic chemotherapy. In the subgroup analysis, systemic intra-operative chemotherapy benefited the 5-year overall survival and disease-free survival rates for patients with cancer of stage pTNM IB-IIIB, but not stage pTNM IIIC. Patients who received intra-operative systemic chemotherapy in combination with post-operative chemotherapy had higher 5-year overall survival and 5-year disease-free survival rates （P=0.046 and 0.021, respectively） than patients who only received postoperative chemotherapy. However, the difference in these rates between patients who received only intra-operative systemic chemotherapy and patients who only received curative surgery was not statistically significant （P=0.150 and 0.170, respectively）. Multivariate analyses showed that intra-operative systemic chemotherapy was a favorable prognostic factor for the overall survival and disease-free survival rates （P =0.048 and 0.023, respectively）. No grade 4 toxicities related to intra-operative systemic chemotherapy were reco

关键词： stomach neoplasms chemotherapy gastrectomy survival rate

高强韧性轮辋用490CL车轮钢焊接开裂失效分析

在线全文

学校读者我要写书评

暂无评论

包钢科技 2024年第1期50卷 41-46页

作者：杨维宇康利明勤牧张智刚郭玉刚内蒙古包钢钢联股份有限公司技术中心内蒙古包头014010 内蒙古包钢钢联股份有限公司营销中心内蒙古包头014010

采用闪光对焊制成的490CL车轮钢轮辋在扩口成型工序,从焊缝处开裂失效。通过宏观、微观断口形貌观察,化学成分和力学性能检测,显微组织检验,显微硬度测试及能谱成分分析,对高强韧性轮辋用490CL车轮钢焊接开裂原因进行分析。结果表明,焊... 详细信息

采用闪光对焊制成的490CL车轮钢轮辋在扩口成型工序,从焊缝处开裂失效。通过宏观、微观断口形貌观察,化学成分和力学性能检测,显微组织检验,显微硬度测试及能谱成分分析,对高强韧性轮辋用490CL车轮钢焊接开裂原因进行分析。结果表明,焊缝开裂处存在一定面积的以氧化锰为主的焊接“灰斑”,降低了焊缝塑性,导致焊接好的轮辋在扩口成型时从焊缝融合线处开裂。从降低闪光留量、增加顶锻压强等方面调整焊接工艺参数,改善轮辋用490CL车轮钢焊缝质量,轮辋成型时焊缝开裂比率从1.5%降低至0.3%。

关键词： 490CL车轮钢轮辋焊接开裂显微组织显微硬度断口形貌

Recovery and in-situ reduction of precious metals by graphdiyne and graphdiyne oxide for antibacterial use

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1747-1757页

作者： ming-Ji Jiang Ya-Na Zhang ling-Shen Meng Jing kang Yong-Jun li Alideertu Dong College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot010021China Engineering Research Center of Dairy Quality and Safety Control Technology Ministry of EducationInner Mongolia UniversityHohhot010021China Department of Chemistry University of ZurichCH-8057ZurichSwitzerland Laboratory of Organic Solids and Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing100190China

Based on the in-situ self-reduction and chemical stability,graphdiyne(GDY)and graphdiyne oxide(GDYO)are used as trapping agents to investigate the ability for recovering Au^(3+),Ag^+,and Pd^(2+)under different pH values and interfering *** strong acidity at pH=1,these two agents demonstrate high select recovery towards the three precious metal ions,which could be insitu reduced to nanoparticles(NPs).In addition,superparamagnetic Fe_(3)O_(4)NPs are deposited on the surfaces of GDY and *** magnetic responses enable GDYFe_(3)O_(4)to recover precious metals conveniently and efficiently by the aid of an external magnetic *** study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus(1×10^(5)colony-forming unit(CFU)·mL^(-1)),and the antibacterial rates are 100%.This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications.

关键词： Graphdiyne In-situ reduction Recovery Precious metals Antibacterial

A strained π-extended[10]cycloparaphenylene carbon nanoring

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 171-174页

作者： kang Wei Jiayu li Wen Zhang Bing Yuan ming-De li Pingwu Du Key Laboratory of Precision and Intelligent Chemistry Anhui Laboratory of Advanced Photon Science and TechnologyDepartment of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063China

Herein,we report the facile synthesis of a highly strained hexabenzocoronene-containing carbon nanoring,cyclo[4]-paraphenylene[2]-2,11-hexabenzocoronenylene([4,2]CPHBC),as the segment of a[10,10]single-walled carbon nanotube([10,10]SWNT).[4,2]CPHBC was synthesized based on the platinummediated assembly of diborylbiphenyl and diborylhexabenzocoronene,forming a tetranuclear platinum complex,followed by reductive *** nanoring molecule was confirmed by NMR and HRMS,and its photophysical properties were studied using steady-state and time-resolved ***,the selective supramolecular host-guest interaction between[4,2]CPHBC and C_(60) was also investigated.

关键词： CPP Hexabenzocoronene Fullerene Supramolecular chemistry

Analysis on the Variation Expression of Difficult-Dissolved-Proteins of Diapause Eggs After Activating by Acid Treatment

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2008年第12期7卷 1474-1480页

作者： ZHAO Feng liN Jian-rong HUO Yong-kang MAO li-ming KONG Qing-ming XU Qiu-yun ZHONG Yang-sheng WANG Ye-yuan Department of Silk Science College of Animal Science South China Agricultural University Guangzhou 510640 P.R.China

Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs coldstored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids＇ peptide matched with those of chorion protein （Bombyx mori）. While the sequence of No. 2 protein dot had only 15 amino acids＇ peptide matched with those of heat shock protein hsp 19.9 （Bombyx mori）, and it was presumed to be an unknown protein. The difficult-dissolvedproteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.

关键词： silkworm egg acid treatment protein electrophoresis image analysis

Vertical two-dimensional WS_(2)flakes grown on flexible CNT film for excellent electrochemical performance

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 164-174页

作者： Qian Gong Jing-Yun Zou ming Ren Si-Qi Zhu Yu-Rong Zhou li-ming Zhao Jian Chen Yu-Long Wu Jiang-Tao Di li-Xing kang Qing-Wen li School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China Key Laboratory of Multifunctional Nanomaterials and Smart Systems Division of Advanced MaterialsSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application School of Physical Science and TechnologySuzhou University of Science and TechnologySuzhou 215009China

Soft electrochemical actuators that can generate mechanical motions in response to electrical stimuli can be used as artificial muscles in microscale *** electrode materials are the key component of the electrochemical actuator because they limit the ion diffusion and accumulation processes and thus affect the deformation in fast response-time and potential engineering ***-dimensional materials,such as one-dimensional(1D)CNT and two-dimensional(2D)vertically stood WS_(2),are great electrode due to their good electrochemical stability and high surface-to-volume ratios,but show limited performances when being used on their own in the actuators because of low reconstruction or low conductivity.A combination of 1D CNT and 2D WS_(2)could form a heterojunction with both high electrochemical activity and great mechanical ***,by depositing highly disordered graphene nanosheets(HDGNs)on CNT films and then WS_(2)on the formed low-dimensional nanocarbon film,a hybrid WS_(2)/HDGN/CNT film was synthesized through a multistep CVD *** grown WS_(2)nanosheets were achieved by taking advantage of HDGNs which limits CNTs ***,the volume expansion caused by the transition from WO_(3)to WS-2can force the vertical growth of WS_(2).This hybrid film shows excellent electrochemical properties,such as high specific capacitance and high rate *** actuators based on the WS_(2)/HDGN/CNT films show good actuating performance,including stability and reconfigurability.

关键词： CNT Graphene Vertically growth WS_(2) Electrochemical actuators