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The calculation of equivalence factor for ecological footprints in China: a methodological note
Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU
《环境科学与工程前沿(英文)》 2015年 第9卷 第6期 页码 1015-1024 doi: 10.1007/s11783-014-0670-0
关键词: ecological footprint equivalence factor net primary production biological capacity land types
通过一个等价雷诺数揭示层流到湍流的转捩区域 Article
陈晓东
《工程(英文)》 2019年 第5卷 第3期 页码 576-579 doi: 10.1016/j.eng.2018.09.013
Flow transition from laminar to turbulent mode (and vice versa)—that is, the initiation of turbulence—is one of the most important research subjects in the history of engineering. Even for pipe flow, predicting the onset of turbulence requires sophisticated instrumentation and/or direct numerical simulation, based on observing the instantaneous flow structure formation and evolution. In this work, a local Reynolds number equivalence γ (ratio of local inertia effect to viscous effect) is seen to conform to the Universal Law of the Wall, where γ = 1 represents a quantitative balance between the abovementioned two effects. This coincides with the wall layer thickness (y+ = 1, where y+ is the dimensionless distance from the wall surface defined in the Universal Law of the Wall). It is found that the characteristic of how the local derivative of γ against the local velocity changes with increasing velocity determines the onset of turbulence. For pipe flow, γ ≈ 25, and for plate flow, γ ≈ 151.5. These findings suggest that a certain combination of γ and velocity (nonlinearity) can qualify the source of turbulence (i.e., generate turbulent energy). Similarly, a re-evaluation of the previous findings reveals that only the geometrically narrow domain can act locally as the source of turbulence, with the rest of the flow field largely being left for transporting and dissipating. This understanding will have an impact on the future large-scale modeling of turbulence.
基于动态等值及数值积分灵敏度的快速紧急控制策略计算 Research Articles
Yi-fan GAO, Jian-quan WANG, Tan-nan XIAO, Dao-zhuo JIANG
《信息与电子工程前沿(英文)》 2019年 第20卷 第8期 页码 1119-1132 doi: 10.1631/FITEE.1700389
Experimental evaluation of a 35 kVA downdraft gasifier
Ashok Jayawant Rao KECHE, Gaddale AMBA PRASAD RAO
《能源前沿(英文)》 2013年 第7卷 第3期 页码 300-306 doi: 10.1007/s11708-013-0247-9
关键词: biomass gasification producer gas equivalence ratio total particulate matter conversion efficiency of gasifier
Xiang LI, Wenzheng ZHANG, Zhong HUANG, Dehao JU, Li HUANG, Mingzhi FENG, Xingcai LU, Zhen HUANG
《能源前沿(英文)》 2019年 第13卷 第3期 页码 483-493 doi: 10.1007/s11708-019-0631-1
关键词: marine engine natural gas methane turbulent jet ignition (TJI) pre-chamber
Pengxing YI,Peng HUANG,Tielin SHI
《机械工程前沿(英文)》 2016年 第11卷 第4期 页码 388-402 doi: 10.1007/s11465-016-0404-z
Wind turbine gearbox (WTG), which functions as an accelerator, ensures the performance and service life of wind turbine systems. This paper examines the distinctive modal properties of WTGs through finite element (FE) and experimental modal analyses. The study is performed in two parts. First, a whole system model is developed to investigate the first 10 modal frequencies and mode shapes of WTG using flexible multi-body modeling techniques. Given the complex structure and operating conditions of WTG, this study applies spring elements to the model and quantifies how the bearings and gear pair interactions affect the dynamic characteristics of WTGs. Second, the FE modal results are validated through experimental modal analyses of a 1.5 WM WTG using the frequency response function method of single point excitation and multi-point response. The natural frequencies from the FE and experimental modal analyses show favorable agreement and reveal that the characteristic frequency of the studied gearbox avoids its eigen-frequency very well.
关键词: wind turbine gearbox modal analysis finite element analysis modal frequency bearing equivalence
Role of the forkhead transcription factor FOXO-FOXM1 axis in cancer and drug resistance
null
《医学前沿(英文)》 2012年 第6卷 第4期 页码 376-380 doi: 10.1007/s11684-012-0228-0
The forkhead transcription factors FOXO and FOXM1 have pivotal roles in tumorigenesis and in mediating chemotherapy sensitivity and resistance. Recent research shows that the forkhead transcription factor FOXM1 is a direct transcriptional target repressed by the forkhead protein FOXO3a, a vital downstream effector of the PI3K-AKT-FOXO signaling pathway. Intriguingly, FOXM1 and FOXO3a also compete for binding to the same gene targets, which have a role in chemotherapeutic drug action and sensitivity. An understanding of the role and regulation of the FOXO-FOXM1 axis will impact directly on our knowledge of chemotherapeutic drug action and resistance in patients, and provide new insights into the design of novel therapeutic strategy and reliable biomarkers for prediction of drug sensitivity.
关键词: FOXO3a FOXM1 transcription factor cancer drug resistance tumorigenesis
LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes
Shiguo XIAO; Shaohong LI
《结构与土木工程前沿(英文)》 2022年 第16卷 第7期 页码 871-881 doi: 10.1007/s11709-022-0863-8
关键词: slope stability safety factor failure criterion least square support vector machine
lncR-GAS5 upregulates the splicing factor to impair endothelial autophagy, leading to atherogenesis
《医学前沿(英文)》 2023年 第17卷 第2期 页码 317-329 doi: 10.1007/s11684-022-0931-4
关键词: lncR-GAS5 miR-193-5p splicing factor SRSF10 autophagy atherogenesis
《结构与土木工程前沿(英文)》 2021年 第15卷 第4期 页码 877-894 doi: 10.1007/s11709-021-0756-2
关键词: bridges multi-lane factor traffic load lane load disparity multi-truck presence weigh-in-motion data
Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG
《化学科学与工程前沿(英文)》 2009年 第3卷 第3期 页码 272-281 doi: 10.1007/s11705-009-0023-x
关键词: stirred tank numerical simulation precipitation shape factor crystal kinetics
The formation mechanism and the influence factor of residual stress in machining
null
《机械工程前沿(英文)》 2014年 第9卷 第3期 页码 265-269 doi: 10.1007/s11465-014-0311-0
Residual stresses generated in cutting process have important influences on workpiece performance. The paper presents a method of theoretical analysis in order to explicate the formation mechanism of residual stresses in cutting. An important conclusion is drawn that the accumulated plastic strain is the main factor which determines the nature and the magnitude of surface residual stresses in the workpiece. On the basis of the analytical model for residual stress, a series of simulations for residual stress prediction during cutting AISI 1045 steel are implemented in order to obtain the influences of cutting speed, depth of cut and tool edge radius on surface residual stress in the workpiece. And these influences are explained from the perspective of formation mechanism of residual stress in cutting. The conclusions have good applicability and can be used to guide the parameters selection in actual production.
关键词: residual stress analytical model strain plastic cutting parameter
null
《医学前沿(英文)》 2017年 第11卷 第3期 页码 403-409 doi: 10.1007/s11684-017-0522-y
Tissue factor pathway inhibitor (TFPI) is the main inhibitor of tissue factor-mediated coagulation. TFPI is expressed by endothelial and smooth muscle cells in the vasculature. Endothelium-derived TFPI has been reported to play a regulatory role in arterial thrombosis. However, the role of endogenous TFPI in vascular smooth muscle cells (VSMCs) in thrombosis and vascular disease development has yet to be elucidated. In this TFPIFlox mice crossbred with Sma–Cre mice were utilized to establish TFPI conditional knockout mice and to examine the effects of VSMC-directed TFPI deletion on development, hemostasis, and thrombosis. The mice with deleted TFPI in VSMCs (TFPISma) reproduced viable offspring. Plasma TFPI concentration was reduced 7.2% in the TFPISma mice compared with TFPIFlox littermate controls. Plasma TFPI concentration was also detected in the TFPITie2 (mice deleted TFPI in endothelial cells and cells of hematopoietic origin) mice. Plasma TFPI concentration of the TFPITie2 mice was 80.4% lower (P<0.001) than that of the TFPIFlox mice. No difference in hemostatic measures (PT, APTT, and tail bleeding) was observed between TFPISma and TFPIFlox mice. However, TFPISma mice had increased ferric chloride–induced arterial thrombosis compared with TFPIFlox littermate controls. Taken together, these data indicated that endogenous TFPI from VSMCs inhibited ferric chloride–induced arterial thrombosis without causing hemostatic effects.
关键词: arterial thrombosis conditional knockout mice tissue factor pathway inhibitor vascular smooth muscle cells
Fibroblast growth factor 21: a novel metabolic regulator from pharmacology to physiology
null
《医学前沿(英文)》 2013年 第7卷 第1期 页码 25-30 doi: 10.1007/s11684-013-0244-8
Fibroblast growth factor 21 (FGF21) is a member of the fibroblast growth factor family. It actually functions as endocrine hormones but does not regulate cell growth and differentiation. It is demonstrated that FGF21 acts on multiple tissue to coordinate carbohydrate and lipid metabolism, including enhancing insulin sensitivity, decreasing triglyceride concentrations, causing weight loss, ameliorating obesity-associated hyperglycemia and hyperlipidemia. Moreover, FGF21 also plays important roles in some physiological processes, such as fasting and feeding, growth hormone axis and thermogenic function of brown adipose tissue. Clinical relevance of FGF21 in humans is still unclear, and the basis and consequences of increased FGF21 in metabolic disease remain to be determined. Both the pharmacological actions and physiological roles make FGF21 attractive drug candidates for treating metabolic disease, but some questions remain to be answered. This article concentrates on recent advances in our understanding of FGF21.
关键词: FGF21 metabolism pharmacology physiology clinical relevance
Optimized human factor IX expression cassettes for hepatic-directed gene therapy of hemophilia B
null
《医学前沿(英文)》 2015年 第9卷 第1期 页码 90-99 doi: 10.1007/s11684-015-0390-2
Gene therapy provides a potential cure for hemophilia B, and significant progress has been achieved in liver-directed gene transfer mediated by adeno-associated viral vectors. Recent clinical trials involving the use of a self-complementary adeno-associated virus serotype 8-human codon-optimized factor IX (AAV8-hFIXco) vector demonstrated encouraging efficacy with hFIX expression stabilized at 1% to 6% of normal level in patients, but safety concerns related to high vector doses are still present. Thus, further improvement of AAV vectors and hFIX expression cassette may positively contribute to the ultimate success of hemophilia B gene therapy. In this study, to obtain a higher expression level of hFIX that potentiates the coagulant capacity of recipients, human FIX expression vector was optimized by upgrading the codon adaption index and adjusting the GC content, inserting a Kozak sequence (GCCACC), and introducing a gain-of-function mutation, R338L (FIX Padua). The efficiency of the published and the presently constructed cassettes was compared through in vivo screening. In addition, the regulatory elements that control the FIX gene expression in these cassettes were screened for liver-specific effectiveness. Among all the constructed cassettes, scAAV-Pre-hFIXco-SIH-R338L, which was the construct under the control of the prothrombin enhancer and prealbumin promoter, resulted in the highest level of coagulant activity, and the expression levels of two constructed cassettes (scAAV-Chi-hFIXco-SIH-R338L and scAAV-Pre-hFIXco-SIH-R338L) were also higher than that of the published cassette (scAAV-LP1-hFIXco-SJ). In summary, our strategies led to a substantial increase in hFIX expression at the protein level or a remarkably elevated coagulant activity. Thus, these reconstructs of hFIX with AAV vector may potentially contribute to the creation of an efficacious gene therapy of hemophilia B.
关键词: factor IX hemophilia B liver-specific regulatory elements hydrodynamic gene transfer
标题 作者 时间 类型 操作
The calculation of equivalence factor for ecological footprints in China: a methodological note
Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU
期刊论文
Experimental evaluation of a 35 kVA downdraft gasifier
Ashok Jayawant Rao KECHE, Gaddale AMBA PRASAD RAO
期刊论文
methane/air mixtures with multiple orifices in a large bore constant volume chamber: effect of air-fuel equivalence
Xiang LI, Wenzheng ZHANG, Zhong HUANG, Dehao JU, Li HUANG, Mingzhi FENG, Xingcai LU, Zhen HUANG
期刊论文
Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine
Pengxing YI,Peng HUANG,Tielin SHI
期刊论文
LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes
Shiguo XIAO; Shaohong LI
期刊论文
lncR-GAS5 upregulates the splicing factor to impair endothelial autophagy, leading to atherogenesis
期刊论文
A practical multi-lane factor model of bridges based on multi-truck presence considering lane load disparities
期刊论文
Numerical investigation of the influence of kinetics and shape factor on barium sulfate precipitation
Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG
期刊论文
Endogenous tissue factor pathway inhibitor in vascular smooth muscle cells inhibits arterial thrombosis
null
期刊论文