检索结果-南通市图书馆

Numerical investigation of flow over a two-dimensional square cylinder with a synthetic jet generated by a bi-frequency signal

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第10期43卷 1569-1584页

作者： yiran lu Yuan QU Jiangsheng WANG Jinjun WANG Fluid Mechanics Key Laboratory of Education Ministry Beihang UniversityBeijing 100191China

The flow around a square cylinder with a synthetic jet positioned at the rear surface is numerically investigated with the unsteady Reynolds-averaged Navier-Stokes(URANS)*** of the typical sinusoidal wave,a bi-frequency signal is adopted to generate the synthetic *** bi-frequency signal consists of a basic sinusoidal wave and a high-frequency *** with various amplitudes of the high-frequency component are *** is found that synthetic jets actuated by bi-frequency signals can realize better drag reduction with lower energy consumption when appropriate parameter sets are applied.A new quantity,i.e.,the actuation efficiency Ae,is used to evaluate the controlling *** actuation efficiency Ae reaches its maximum of 0.2668 when the amplitude of the superposed high-frequency signal is 7.5%of the basic *** vortex structures and frequency characteristics are subsequently analyzed to investigate the mechanism of the optimization of the bi-frequency *** the synthetic jet is actuated by a single-frequency signal with a characteristic velocity of 0.112 m/s,the wake is *** alternative deflection of vortex pairs and the peak at half of the excitation frequency in the power spectral density(PSD)function are *** the bi-frequency cases with the same characteristic velocity,the wake gradually turns to be symmetrical with the increase in the amplitude of the high-frequency ***,the deflection of the vortex pairs and the peak at half of the excitation frequency gradually disappear as well.

关键词： synthetic jet flow control signal superposition vortex dynamics

淮北平原雨天与非雨天小麦和大豆潜水蒸发模拟研究

在线全文

学校读者我要写书评

暂无评论

水文 2024年第1期44卷 17-25页

作者：卢怡然王怡宁李靖瑄周超方晶晶高佩孙博河海大学水文水资源与水利工程科学国家重点实验室江苏南京210098 南京水利科学研究院江苏南京210029 昆明理工大学津桥学院建筑工程学院云南昆明650106 安徽省水利科学研究院安徽蚌埠233000

为揭示淮北平原雨天和非雨天作物生长期不同阶段潜水蒸发规律,本文利用五道沟水文实验站1998—2020年长系列实验资料,采用非线性拟合方法,模拟砂姜黑土冬小麦和夏大豆生长期潜水蒸发随埋深的变化,提出雨天非雨天潜水蒸发计算拟合模型,... 详细信息

为揭示淮北平原雨天和非雨天作物生长期不同阶段潜水蒸发规律,本文利用五道沟水文实验站1998—2020年长系列实验资料,采用非线性拟合方法,模拟砂姜黑土冬小麦和夏大豆生长期潜水蒸发随埋深的变化,提出雨天非雨天潜水蒸发计算拟合模型,进而得出作物生育期雨天非雨天临界埋深。结果表明,冬小麦雨天初始生长期与成熟期潜水蒸发随埋深的增大而递减,呈指数函数关系;快速发育期和生育中期潜水蒸发随埋深的增大呈先增后减的趋势,呈复合函数关系;非雨天各生长期潜水蒸发均随埋深的增大而递减,呈指数函数关系,临界埋深在2.34~3.91 m;夏大豆雨天和非雨天各生长期潜水蒸发量均随埋深的增大而递减,呈指数函数或幂函数关系,临界埋深在2.10~3.80 m,拟合模型R2为0.83~0.98,RMSE在0.0519~0.2624mm/d,能较准确预测作物雨天非雨天生长期不同阶段浅水蒸发量。

关键词：雨天非雨天潜水蒸发临界埋深五道沟水文实验站

Biomass-derived porous carbon highly efficient for removal of Pb(Ⅱ) and Cd(Ⅱ)

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2019年第4期4卷 414-423页

作者： Anqi Wang Zhikeng Zheng Ruiqi Li Di Hu yiran lu Huixia luo Kai Yan Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology School of Environmental Science and EngineeringSun Yat-Sen University135 Xingang Xi RoadGuangzhou 510275China School of Engineering Brown UniversityProvidenceRI 02906United States School of Material Science and Engineering Sun Yat-Sen University135 Xingang Xi RoadGuangzhou 510275China

The utilization of abundant and renewable biomass to fabricate advanced functional materials is considered a promising route for environmental ***,Lignin-based porous carbon with layered graphene-like structure(LPC)is successfully synthesized and applied to efficiently remove Pb(Ⅱ)and Cd(Ⅱ).The as-synthesized LPC materials are systematically characterized and these results show that LPC has a porous graphene-like structure,facilitating the diffusion and immobilization of heavy metal *** influence of different reaction parameters(solution pH,initial concentration of metal ions,contact time and adsorbent amount)on the adsorption performance is investigated in *** results demonstrate that LPC can achieve superior adsorption capacities of 250.5 mg·g^-1 for Pb(Ⅱ)and 126.4 mg·g^-1 for Cd(Ⅱ),which are far superior to the previously reported ***-second order kinetics model and Freundlich isotherm model describe the adsorption process ***,the exhausted LPC can be regenerated easily and exhibits the removal efficiency of 96%and 92%for Pb(Ⅱ)and Cd(Ⅱ)after five continuous runs,*** study shows a sustainable strategy for the design of porous carbon material from na?ve biomass and highlights the great potential in wastewater treatment.

关键词： Porous carbon Layered structure Heavy metals Adsorption kinetics Recyclability

Chemotherapy induces breast cancer stem cell enrichment through repression of glutathione S-transferase Mu

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第2期11卷 528-531页

作者： Jing He yiran Yu Yilin He Jie He Guangyu Ji Haiquan lu The Second Hospital and Advanced Medical Research Institute Cheeloo College of MedicineShandong UniversityJinanShandong 250012China Department of Nursing The First Affiliated Hospital of Shandong First Medical UniversityJinanShandong 250014China School of Medicine Xinjiang Medical UniversityUrumqiXinjiang 830054China School of Medicine Binzhou Medical UniversityYantaiShandong 264003China Oncology Department Jinan Zhangqiu District People's HospitalJinanShandong 250200China Key Laboratory for Experimental Teratology of the Ministry of Education Cheeloo College of MedicineShandong UniversityJinanShandong 250012China Center for Reproductive Medicine Shandong UniversityJinanShandong 250012China

Triple-negative breast cancer(TNBC)has aggressive characteristics as exemplified by the high risk of recurrence,metastasis,and patient mortality.1 Cytotoxic chemotherapy may reduce tumor burden initially,but leave behind chemo-resistant breast cancer stem cells(BCSCs)that lead to tumor recurrence and metastasis.2 Chemotherapy induces BCsC enrichment through the activation of glutathione biosynthesis pathways,which increases intracellular glutathione levels and specifies the BCSC phenotype through complicated downstream signaling pathways.3 Glutathione S-transferases(GSTs),a superfamily(which contains seven cytosolic classes:Alpha,Kappa,Mu,Omega,Pi,Theta,and Zeta,and one microsomal class MGSTs)of phase Il enzymes that catalyze the conjugation of glutathione with electrophilic compounds,play a critical role in detoxification and chemotherapy resistance of cancer ***,the role of GSTs in the regulation of BCSCs is largely elusive.

关键词： chemotherapy breast metastasis

Numerical investigation of efficient synthetic jets generated by multiple-frequency actuating signals

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 2022年第1期38卷 70-80页

作者： yiran lu Jiangsheng Wang Jinjun Wang Key Laboralory of Fluid Mechanics(Bejjing University of Aeronautics and Astronautics) Ministry of EducationBejing 100191China

The synthetic jets generated by multiple-frequency actuating signals composed of a basic sinusoidal wave and a superposed high-frequency signal is investigated by two-dimensional simulation in the present *** effect of the frequency and amplitude of the high-frequency signal on the synthetic jet in the quiescent flow is investigated in detail with stroke length ratio L and Reynolds number Re_(U0)kept as *** is found that,with the high-frequency signal superposed,the vortex pairs induced by the synthetic jets are strengthened and *** distance that the vortex pairs can propagate downstream is also *** entrainment of the synthetic jets is thus enhanced as *** optimal design is reached when the frequency ratio,defined as the ratio between the superposed signal frequency and the basic signal frequency,is fixed at f^(+)=*** this optimal frequency ratio,the jet entrainment increases monotonously with the amplitude of the high-frequency signal.

关键词： Synthetic jet Jet entrainment Signal superposition Vortex pairs

A comparison of statistical learning of naturalistic textures between DCNNs and the human visual hierarchy

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

Science China(Technological Sciences) 2024年第8期67卷 2310-2318页

作者： lu XinCheng YUAN ZiQi ZHANG YiChi AI HaiLin CHENG SiYuan GE yiran FANG Fang CHEN NiHong Department of Psychological and Cognitive Sciences Tsinghua UniversityBeijing 100084China IDG/McGovern Institute for Brain Research Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health Peking UniversityBeijing 100871China Key Laboratory of Machine Perception(Ministry of Education) Peking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Peking UniversityBeijing 100871China IDG/McGovern Institute for Brain Research Peking UniversityBeijing 100871China State Key Laboratory of Brain and Cognitive Science Institute of PsychologyChinese Academy of SciencesBeijing 100101China

The visual system continuously adapts to the statistical properties of the environment. Existing evidence shows a close resemblance between deep convolutional neural networks(CNNs) and primate visual stream in neural selectivity to naturalistic textures above the primary visual processing stage. This study delves into the mechanisms of perceptual learning in CNNs,focusing on how they assimilate the high-order statistics of natural textures. Our results show that a CNN model achieves a similar performance improvement as humans, as manifested in the learning pattern across different types of high-order image statistics. While L2 was the first stage exhibiting texture selectivity, we found that stages beyond L2 were critically involved in learning. The significant contribution of L4 to learning was manifested both in the modulations of texture-selective responses and in the consequences of training with frozen connection weights. Our findings highlight learning-dependent plasticity in the mid-to-high-level areas of the visual hierarchy. This research introduces an AI-inspired approach for studying learning-induced cortical plasticity, utilizing DCNNs as an experimental framework to formulate testable predictions for empirical brain studies.

关键词： CNN perceptual learning naturalistic texture psychophysics

Effect of fracture fluid flowback on shale microfractures using CT scanning

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 426-436页

作者： Jiale He Zhihong Zhao yiran Geng Yuping Chen Jianchun Guo Cong lu Shouyi Wang Xueliang Han Jun Zhang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China Drilling Test Engineering Department of Longdong Oil and Gas Development Company Changqing OilfieldPetroChina Company LimitedQingyang745000China Tight Oil and Gas Exploration and Development Project Department PetroChina Southwest Oil and Gas Field CompanyChengdu610056China No.11 Oil Production Plant Changqing Oilfield CompanyPetroChina Company LimitedQingyang745000China

The field data of shale fracturing demonstrate that the flowback performance of fracturing fluid is different from that of conventional reservoirs,where the flowback rate of shale fracturing fluid is lower than that of conventional *** the early stage of flowback,there is no single-phase flow of the liquid phase in shale,but rather a gas-water two-phase flow,such that the single-phase flow model for tight oil and gas reservoirs is not *** this study,pores and microfractures are extracted based on the experimental results of computed tomography(CT)scanning,and a spatial model of microfractures is ***,the influence of rough microfracture surfaces on the flow is corrected using the modified cubic law,which was modified by introducing the average deviation of the microfracture height as a roughness factor to consider the influence of microfracture surface *** flow in the fracture network is simulated using the modified cubic law and the lattice Boltzmann method(LBM).The results obtained demonstrate that most of the fracturing fluid is retained in the shale microfractures,which explains the low fracturing fluid flowback rate in shale hydraulic fracturing.

关键词： Shale Flowback of fracturing fluid Microfracture Lattice Boltzmann method(LBM)

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

日本殖民统治时期的台湾爱国文人连横

抗日战争研究 2005年第2期 218-229页

作者：吕一燃中国社会科学院中国边疆史地研究中心

连横是一个不屈服于日本殖民统治的热爱祖国的知识分子。他身处日本侵略者残暴殖民统治的环境中,坚持民族气节,勇敢地拿起手中的笔,写下了许多歌颂反对日本割占台湾而英勇牺牲的英雄的诗文。他用毕生精力捍卫、保护和宣传中华民族传统文... 详细信息

连横是一个不屈服于日本殖民统治的热爱祖国的知识分子。他身处日本侵略者残暴殖民统治的环境中,坚持民族气节,勇敢地拿起手中的笔,写下了许多歌颂反对日本割占台湾而英勇牺牲的英雄的诗文。他用毕生精力捍卫、保护和宣传中华民族传统文化,以抵制日本推行的同化政策。他呕心沥血地写下了不朽名著《台湾通史》和其他著作,为的是要让台湾人民永远记住自己的祖国和民族,以及台湾宝岛被日本割占的历史。他身居台湾,心向祖国,关心祖国的发展和前途。他既痛恨日本侵略者,也痛恨专制腐败出卖台湾的清政府。他崇拜孙中山等民族革命者,同时痛斥窃国大盗袁世凯。他一生最大的愿望是,抗日战争胜利,光复台湾。

关键词：殖民统治时期连横中华民族传统文化日本侵略者文人爱国《台湾通史》知识分子热爱祖国民族气节同化政策台湾人民抗日战争清政府革命者孙中山袁世凯

在线全文

学校读者我要写书评

暂无评论

试论唐文标与台湾新诗批评

华文文学 2020年第6期 74-80页

作者：鲁怡然四川大学文学与新闻学院

唐文标20世纪70年代新诗批评围绕"文学应该为谁而写"和"文学应该怎样写"两个问题展开,对台湾现代诗逃避现实、崇尚艺术至上所衍生的一系列弊端进行了较为彻底的检讨和清算,掀起了现代诗论战。他以横扫一切的气势彻底地否定了台湾现代诗... 详细信息

唐文标20世纪70年代新诗批评围绕"文学应该为谁而写"和"文学应该怎样写"两个问题展开,对台湾现代诗逃避现实、崇尚艺术至上所衍生的一系列弊端进行了较为彻底的检讨和清算,掀起了现代诗论战。他以横扫一切的气势彻底地否定了台湾现代诗的价值和意义,尽管他的不少观点有失客观,但却不失为问路之石,成功激起了台湾现代诗坛的一潭浑水。

关键词：唐文标台湾现代诗新诗批评。