检索结果-南通市图书馆

Theoretical analysis and numerical simulation of mechanical energy loss and wall resistance of steady open channel flow

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

Journal of Hydrodynamics 2016年第3期28卷 489-496页

作者：刘士和薛娇 School of Water Resources and Hydropower Engineering Wuhan University

The mechanical energy loss and the wall resistance are very important in practical engineering. These problems are investigated through theoretical analysis and numerical simulation in this paper, The results are as follows. （1） A new mechanical energy equation for the total flow is obtained, and a general formula for the calculation of the mechanical energy loss is proposed. （2） The general relationship between the wall resistance and the mechanical energy loss for the steady channel flow is obtained, the simplified form of which for the steady uniform channel flow is in consistent with the formula used in Hydraulics deduced by 7r theorem and dimensional analysis. （3） The steady channel flow over a backward facing step with a small expansion ratio is numerica- lly simulated, and the mechanical energy loss, the wall resistance as well as the relationship between the wall resistance and the mechanical energy loss are calculated and analyzed.

关键词： channel flow energy equation mechanical energy loss resistance

BURDEN OF ABNORMAL heMATOPOIETIC CLONE IN PATIENTS WITH MYELODYSPLASTIC SYNDROMES

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Sciences Journal 2006年第2期21卷 99-103页

作者： Hua-quan Wang Zong-hong Shao Jun shi Yan-ran Cao Hong liu Jie Bai Mei-feng Tu Li-ming Xing Zhen-zhu Cui shi-he liu Jun Sun Hai-rong Jia Tian-ying Yang the First Department of hematology Institute of Hematology ＆ Blood Diseases HospitalChinese Academy of Medical Sciences ＆ Peking Union Medical College Tianjin 300020 Department of hematology and Oncology General Hospital Tianjin Medical University Tianjin 300052

Objective To investigate the role of the burden of abnormal hematopoietic clone in the development of myelodysplastic syndromes (MDS). Methods The ratio of the bone marrow cells with abnormal chromosomes to the total counted bone marrow cells was regarded as the index of MDS clone burden. The disease severity related parameters including white blood cell count, hemoglobin, platelet count, lactate dehydrogenase level, bone marrow blast, myeloid differentiation index, micromegakaryocyte, transfusion, interleukin-2, tumor necrosis factor (TNF), CD4^+ and CD8^+ T cells of MDS patients were assayed, and the correlations between those parameters and MDS clone burden were also analyzed. Results The clone burden of MDS patients was 67.4%±36.2%. MDS clone burden positively correlated with bone marrow blasts (r = 0.483, Phemoglobin level (r=-0.445, Phe number of blasts, hemoglobin, and erythrocytes in high clone burden (>50%) and low clone burden (≤50%) groups were 7.78%±5.51% and 3.45%±3.34%, 56.06±14.28 g/L and 76.40±24.44 g/L, (1.82±0.48)×10~ 12 /L and (2.32±0.66)×10~ 12 /L, respectively (all Phe serum level of interleukin-2 of MDS patients (6.29±3.58 ng/mL) was significantly higher than normal control (3.11±1.40 ng/mL, Phe serum level of TNF of MDS patients and normal control group were 2.42±1.79 ng/mL and 1.68±0.69 ng/mL, respectively. The ratio of CD4 to CD8 was higher in high clone burden MDS patients (1.90±0.52) than that in low clone burden patients (0.97±0.44, Phe quantitive clonal karyotype abnormalities and deficient T cell immunity are important parameters for evaluating MDS severity and predicting its progression.

关键词： myelodysplastic syndromes karyotype T lymphocyte

Low‑Temperature Oxidation Induced Phase Evolution with Gradient Magnetic heterointerfaces for Superior Electromagnetic Wave Absorption

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第1期17卷 191-204页

作者： Zizhuang he Lingzi shi Ran Sun Lianfei Ding Mukun he Jiaming Li Hua Guo Tiande Gao Panbo liu School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710129People’s Republic of China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase ***,accordion-shaped Co/Co_(3)O_(4)@N-doped carbon nanosheets(Co/Co_(3)O_(4)@NC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation *** results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial ***,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic ***,the synthesized Co/Co_(3)O_(4)@NC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon *** design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption.

关键词： Magnetic heterointerfaces Phase evolution Interfacial polarization Magnetic coupling Electromagnetic wave absorption

在线全文

学校读者我要写书评

暂无评论

发达国家农地流转的经验和启示

经济问题 2017年第3期45卷 62-65,106页

作者：吕世辰贺静刘慧山西师范大学政法学院山西临汾041004

发达国家是指在第二次世界大战之前经济发展水平和技术水平较高的国家。农地流转是指农业用地全要素的关系变动。运用文献研究和理论研究的方法,论述了发达国家农地流转的研究意义、发达国家农地流转的经验以及对我国的启示,指出农地所... 详细信息

发达国家是指在第二次世界大战之前经济发展水平和技术水平较高的国家。农地流转是指农业用地全要素的关系变动。运用文献研究和理论研究的方法,论述了发达国家农地流转的研究意义、发达国家农地流转的经验以及对我国的启示,指出农地所有权、承包权和经营权三权分置是我国党和政府对农地流转理论的重大创新。

关键词：发达国家农地流转三权分置经验和启示

The effects of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents:a meta-analysis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1513-1520页

作者： Xueyun Shao Longfei he Yangyang liu Physical Education School Shenzhen UniversityShenzhenGuangdong ProvinceChina Shenzhen Institute of Neuroscience ShenzhenGuangdong ProvinceChina

Brain-derived neurotrophic factor is a crucial neurotrophic factor that plays a significant role in brain health. Although the vast majority of meta-analyses have confirmed that exercise interventions can increase brain-derived neurotrophic factor levels in children and adolescents, the effects of specific types of exercise on brain-derived neurotrophic factor levels are still controversial. To address this issue, we used meta-analytic methods to quantitatively evaluate, analyze, and integrate relevant studies. Our goals were to formulate general conclusions regarding the use of exercise interventions, explore the physiological mechanisms by which exercise improves brain health and cognitive ability in children and adolescents, and provide a reliable foundation for follow-up research. We used the Pub Med, Web of Science, Science Direct, Springer, Wiley Online Library, Weipu, Wanfang, and China National Knowledge Infrastructure databases to search for randomized controlled trials examining the influences of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents. The extracted data were analyzed using Review Manager 5.3. According to the inclusion criteria, we assessed randomized controlled trials in which the samples were mainly children and adolescents, and the outcome indicators were measured before and after the intervention. We excluded animal experiments, studies that lacked a control group, and those that did not report quantitative results. The mean difference(MD;before versus after intervention) was used to evaluate the effect of exercise on brain-derived neurotrophic factor levels in children and adolescents. Overall, 531 participants(60 children and 471 adolescents, 10.9–16.1 years) were included from 13 randomized controlled trials. heterogeneity was evaluated using the Q statistic and I^(2) test provided by Review Manager software. The meta-analysis showed that there was no heterogeneity among the studies(P = 0.67,

关键词： adolescents brain-derived neurotrophic factor children exercise meta-analysis randomized controlled trials

3D Printing of Tough Hydrogel Scaffolds with Functional Surface Structures for Tissue Regeneration

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 18-45页

作者： Ke Yao Gaoying Hong Ximin Yuan Weicheng Kong Pengcheng Xia Yuanrong Li Yuewei Chen Nian liu Jing he Jue shi Zihe Hu Yanyan Zhou Zhijian Xie Yong he State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Liangzhu Laboratory Zhejiang UniversityHangzhou 310027People’s Republic of China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Stomatology Hospital School of StomatologyZhejiang University School of MedicineHangzhou 310027People’s Republic of China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001People’s Republic of China Institute of Digital Medicine Nanjing First HospitalNanjing Medical UniversityNanjing 210006People’s Republic of China

Hydrogel scaffolds have numerous potential applications in the tissue engineering ***,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical *** by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this ***,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent ***,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell ***,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT *** experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.

关键词： 3D printing Tough hydrogel scaffold Functional surface structure Tissue regeneration Biomaterials

T cell interactions with microglia in immune-inflammatory processes of ischemic stroke

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1277-1292页

作者： Yuxiao Zheng Zilin Ren Ying liu Juntang Yan Congai Chen Yanhui he Yuyu shi Fafeng Cheng Qingguo Wang Changxiang Li Xueqian Wang School of Traditional Chinese Medicine Beijing University of Chinese MedicineBeijingChina Library Beijing University of Chinese MedicineBeijingChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

The primary mechanism of secondary injury after cerebral ischemia may be the brain inflammation that emerges after an ischemic stroke,which promotes neuronal death and inhibits nerve tissue *** the first immune cells to be activated after an ischemic stroke,microglia play an important immunomodulatory role in the progression of the *** an ischemic stroke,peripheral blood immune cells(mainly T cells)are recruited to the central nervous system by chemokines secreted by immune cells in the brain,where they interact with central nervous system cells(mainly microglia)to trigger a secondary neuroimmune *** review summarizes the interactions between T cells and microglia in the immune-inflammatory processes of ischemic *** found that,during ischemic stroke,T cells and microglia demonstrate a more pronounced synergistic ***1,Th17,and M1 microglia can co-secrete proinflammatory factors,such as interferon-γ,tumor necrosis factor-α,and interleukin-1β,to promote neuroinflammation and exacerbate brain ***2,Treg,and M2 microglia jointly secrete anti-inflammatory factors,such as interleukin-4,interleukin-10,and transforming growth factor-β,to inhibit the progression of neuroinflammation,as well as growth factors such as brain-derived neurotrophic factor to promote nerve regeneration and repair brain *** interactions between microglia and T cells influence the direction of the subsequent neuroinflammation,which in turn determines the prognosis of ischemic stroke *** trials have been conducted on the ways to modulate the interactions between T cells and microglia toward anti-inflammatory communication using the immunosuppressant fingolimod or overdosing with Treg cells to promote neural tissue repair and reduce the damage caused by ischemic ***,such studies have been relatively infrequent,and clinical experience is still *** summary,in ischemic stroke,T cell subsets and activated micro

关键词： brain immune inflammation interaction ischemic stroke mechanism microglia neuron secondary injury T cells

Single-cell technologies: current and near future

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第01期 1-4页

作者： Chenfei Wang Qi liu Xiaohui Fan Tieliu shi Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration Ministry of EducationOrthopedics DepartmentTongji HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University Frontier Science Center for Stem Cells School of Life Sciences and TechnologyTongji University Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine Shanghai East HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University Research Institute of Intelligent Computing Zhejiang Lab Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang University National Key Laboratory of Chinese Medicine Modernization Innovation Center of Yangtze River DeltaZhejiang University Center for Bioinformatics and Computational Biology Shanghai Key Laboratory of Regulatory Biologythe Institute of Biomedical Sciences and School of Life SciencesEast China Normal University Key Laboratory of Advanced Theory and Application in Statistics and Data Science (MOE) School of StatisticsEast China Normal University

Single-cell technologies enable the indepth exploration of multiple biological hierarchies at the scale of individual cells,which have deepened our knowledge of cellular diversity, tissue organization, and overall organism function(Sun et al.,2024). In 2009, single-cell RNA sequencing(sc RNA-seq) was first developed as a powerful tool to dissect gene expression and uncover transcriptional *** the rapid advancement of technology, single-cell approaches have expanded to encompass other omics, such as genomics, epigenomics, proteomics,and metabolomics.

关键词：

同方期刊数据库

Flexible molecules dedicate to release strain of inverted inorganic perovskite solar cell

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 87-93页

作者： Hongrui Sun Sanlong Wang Pengyang Wang Yali liu Shanshan Qi Biao shi Ying Zhao Xiaodan Zhang Institute of Photoelectronic Thin Film Devices and Technology Renewable Energy Conversion and Storage Center State Key Laboratory of Photovoltaic Materials and CellsNankai University Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Haihe Laboratory of Sustainable Chemical Transformations Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)

The tensile strain in inorganic perovskite films induced by thermal annealing is one of the primary factors contributing to the inefficiency and instability of inorganic perovskite solar cells （IPSCs）,which reduces the defect formation ***,a flexible molecule 5-maleimidovaleric acid （5-MVA） was introduced as a strain buffer to release the residual strain of *** anhydride and carboxyl groups in 5-MVA interact strongly with the uncoordinated Pb2+through Lewis acid-base reaction,thus tightly“pull”the perovskite *** in-between soft carbon chain increased the structural flexibility of CsPbI2.85Br0.15perovskite materials,which effectively relieved the intrinsic internal strain of CsPbI2.85Br0.15,resisted the corrosion of external strain,and also reduced the formation of defects such as VIand *** addition,the introduction of 5-MVA improved crystal quality,passivated residual defects,and narrowed energy level ***,power conversion efficiency （PCE） of NiOxbased inverted IPSCs increased from 19.25% to 20.82% with the open-circuit voltage enhanced from 1.164 V to 1.230 *** release of strain also improved the stability of CsPbI2.85Br0.15perovskite films and devices.

关键词： Inverted inorganic perovskite solar cells Flexible molecules Strain release Crystallization Energy barrier High PCE