检索结果-南通市图书馆

journal of Materials Science & Technology 2023年第7期138卷 70-79页

作者： ji-Chang Ren junjun Zhou christopher j.butch Zhigang Ding Shuang Li Yonghao Zhao Wei Liu Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Biomedical Engineering Nanjing UniversityNanjing 210023China

Searching for single-phase solid solutions(SPSSs)in high-entropy alloys(HEAs)is a prerequisite for the intentional design and manipulation of microstructures of alloys in vast composition ***,to date,reported SPSS HEAs are still rare due to the lack of reliable guiding principles for the synthesis of new SPSS ***,we demonstrate an ensemble machine-learning method capable of discovering SPSS HEAs by directly predicting quinary phase diagrams based only on atomic composition.A total of 2198 experimental structure data are extracted from as-sputtered quinary HEAs in the literature and used to train a random forest classifier(termed AS-RF)utilizing bagging,achieving a prediction accuracy of 94.6%compared with experimental *** AS-RF model is then utilized to predict 224 quinary phase diagrams including∼32,000 SPSS HEAs in Cr-Co-Fe-Ni-Mn-Cu-Al composition *** extrapolation capability of the AS-RF model is then validated by performing first-principle calculations using density functional theory as a benchmark for the predicted phase transition of newly predicted ***,interpretation of the AS-RF model weighting of the input parameters also sheds light on the driving forces behind HEA formation in sputtered systems with the main contributors being:valance electron concentration,work function,atomic radius difference and elementary symmetries.

关键词： High entropy alloys Phase structures Machine learning Density functional theory

Asymmetric Schottky Contacts in van der Waals Metal-Semiconductor-Metal Structures Based on Two-Dimensional janus Materials

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 2020年第1期2020卷 1108-1115页

作者： jia Liu ji-Chang Ren Tao Shen Xinyi Liu christopher j.butch Shuang Li Wei Liu Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Department of Biomedical Engineering Nanjing UniversityNanjingChina Blue Marble Space Institute of Science SeattleWashingtonUSA

Physical and electronic asymmetry plays a crucial role in rectifiers and other devices with a directionally variant current-voltage(I-V)*** strategies for practically creating asymmetry in nanoscale components have been demonstrated,but complex fabrication procedures,high cost,and incomplete mechanistic understanding have significantly limited large-scale applications of these *** this work,we present density functional theory calculations which demonstrate asymmetric electronic properties in a metal-semiconductor-metal(MSM)interface composed of stacked van der Waals(vdW)*** MoSSe has an intrinsic dipole due to its asymmetric structure and,consequently,can act as either an n-type or p-type diode depending on the face at the interior of the stacked structure(SeMoS-SMoS ***-SMoS).In each configuration,vdW forces dominate the interfacial interactions,and thus,Fermi level pinning is largely *** transport calculations show that not only does the intrinsic dipole cause asymmetric I-V characteristics in the MSM structure but also that different transmission mechanisms are involved across the S-S(direct tunneling)and S-Se interface(thermionic excitation).This work illustrates a simple and practical method to introduce asymmetric Schottky barriers into an MSM structure and provides a conceptual framework which can be extended to other 2D janus semiconductors.

关键词： Schottky asymmetric dipole

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

Encapsulating maytansinoid in pH-sensitive nanocarriers:The importance of using extremely potent cytotoxic agents and fast release for nanomedicine to achieve tumor elimination

在线全文

学校读者我要写书评

暂无评论

Nano Research 2019年第8期12卷 1959-1966页

作者： Bo Dai Xingyu Wu christopher j. butch jianquan Wang Ziyang Wang Yisheng Wang Shuming Nie Qian Lu Yiqing Wang Yitao Ding Drum Tower Clinical Medical College Nanjing Medical UniversityNanjing 210008China Department of Biomedical Engineering College of Engineering and Applied SciencesNanjing UniversityNanjing 210008China Department of Biomedical Engineering University of Illinois at Urbana-ChampaignIllinois 61801USA

The clinical translation of nanomedicine is hindered by the low delivery efficiency, and consequently drug concentration in tumor sites falls short of the therapeutic effective range which leads to poor clinical outcomes. One important lesson learned from the development of antibody-drug-conjugates (ADCs) is that to achieve significant clinical benefits, extremely potent cytotoxic agents and cleavable linkers should be used. By encapsulating maytansinoid, AP3, which is 100-1,000 times more potent than most conventional small molecule anticancer drugs, in pH-sensitive acetalated dextran-polyethylene glycol (PEG)(ADP) nanocarriers, even with only 1% drug loading, we were able to eradicate tumors in 50% of tested animals with negligible side effects, while free AP3 only showed marginal efficacy and severe liver damages. This study suggests that besides improving the low efficiency of nano-delivery systems, the potency of drug to be delivered is also critical to the clinical outcomes of nanomedicine. Our results also showed that ADP nanoparticles (NPs) were able to expand the narrow therapeutic window of maytansinoids in a similar manner to the ADCs.

关键词： nanomedicine drug delivery maytansinoid extremely potent drug pH-sensitive nanocarrier

Studying turbulence structure near the wall in hydrodynamic flows:An approach based on the Schur decomposition of the velocity gradient tensor

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 2022年第5期34卷 806-825页

作者： christopher j.Keylock School of Architecture Building and Civil EngineeringLoughborough UniversityLeicestershireUK

The Schur decomposition of the velocity gradient tensor(VGT)is an alternative to the classical Cauchy-Stokes decomposition into rotation rate and strain rate ***,there have been several strands of work that have employed this decomposition to examine the physics of turbulence dynamics,including approaches that combine the Schur and Cauchy-Stokes *** are briefly reviewed before the latter approach is set *** partitions the rotation rate and strain rate tensors into normal/local and non-normal/non-local *** then study the relation between the VGT dynamics and ejection-sweep events in a channel flow *** show that the sweeps in particular exhibit novel behaviour compared with either the other quadrants,or the flow in general,with a much-reduced contribution to the dynamics from the non-normal terms above the viscous *** particular,the reduction in the production term that is the interaction between the non-normality and the normal straining reduces in the log-layer as a consequence of an absence of alignment between the non-normal vorticity and the strain rate *** have been early forays into using the Schur transform approach for subgrid-scale modelling in large-eddy simulation(LES)and this would appear to be an exciting way forward.

关键词： Turbulence channel flow velocity gradient tensor Schur decomposition

Development process for a higher capacity Propsetter~ system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Mining Science and Technology 2018年第1期28卷 121-126页

作者： christopher j.Brown Product Development-Strata Worldwide LLC

As longwall tailgate support technologies continue to be developed and improved, strata worldwide has worked to design and manufacture a revised Propsetter to provide additional support capacity and enable applications at greater mine *** support is targeted for tailgate applications, however, it can also be utilized for roof support in various types of mining *** paper describes the design changes for enhancing the support capacity of the Propsetter to more closely align its performance with other support technologies currently being employed in longwall *** changes to each design aspect of the Propsetter was key to successfully improving the roof support's load capacity while maintaining controlled *** the load capacity would allow a mine to improve support efficiency with a smaller, less intrusive support compared to support alternatives and reduce the cost per foot of supported *** target support capacity was 711–890 k N at 50 mm of deformation to more closely match the performance of competing tailgate supports such as the 610 mm-diameter CAN~.To achieve this goal, changes were made to all design aspects of the Propsetter: diameter, wedge cut depth and angle, pod size, and confinement *** results from the NIOSH Mine Roof Simulator verified that these design changes were successful in increasing the capacity of the Propsetter to the 711–890 k N range at fifty mms of deformation.

关键词： Propsetter Can Longwall mining Tailgate roof support Controlled deformation

Plasma-catalysis: Is it just a question of scale?

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2019年第2期13卷 264-273页

作者： j.christopher Whitehead School of Chemistry The University of ManchesterManchester M13 9PLUK

The issues of describing and understanding the changes in performance that result when a catalyst is placed into plasma are discussed. The different chemical and physical interactions that result and how their combination might produce beneficial results for the plasma-catalytic processing of different gas streams are outlined with particular emphasis being placed on the different range of spatial and temporal scales that must be considered both in experiment and modelling. The focus is on non-thermal plasma where the lack of thermal equilibrium creates a range of temperature scales that must be considered. This contributes in part to a wide range of inhomogeneity in different properties such as species concentrations and electric fields that must be determined experimentally by in situ methods and be incorporated into modelling. It is concluded that plasmacatalysis is best regarded as conventional catalysis perturbed by the presence of a discharge, which modifies its operating conditions, properties and outcomes often in a very localised way. The sometimes used description "plasma-activated catalysis" is an apt one.

关键词： plasma catalysis plasma-activated catalysis non-thermal plasma CO2 conversion

Endocasts-the direct evidence and recent advances in the study of human brain evolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第9期17卷 993-1002页

作者： christopher j.Norton 86011-4099 AZ Beijing 100044 China Flagstaff Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Laboratory of Quaternary Paleontology Northern Arizona University USA

Brain evolution is one of the most important aspects of human evolution,usually studied through *** of fossil hominid endocasts allows inferences on functional anatomy,physiology,and *** this paper,we describe the general features of endocast studies and review some of the major topics in *** are:absolute and relative brain size evolution;brain shape variation;brain asymmetry and lateralization;middle meningeal vessels and venous sinuses;application of computed tomography and virtual imaging;the history of Chinese brain endocast *** particular,this review emphasizes endocast studies on Chinese hominin fossils.

关键词： endocast human fossil brain evolution cranial capacity human evolution

Structural subgrid-scale modeling for large-eddy simulation: A review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2016年第4期32卷 567-578页

作者： Hao Lu christopher j.Rutland School of Energy and Power Engineering Huazhong University of Science and Technology Engine Research Center Mechanical EngineeringUniversity of Wisconsin-Madison

Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.

关键词： turbulence turbulent viscosity priori dissipation posteriori scalar A review scales Reynolds

An In Vivo Experimental Validation of a Computational Model of Human Foot

在线全文

学校读者我要写书评

暂无评论

journal of Bionic Engineering 2009年第4期6卷 387-397页

作者： christopher j.Nester David Howard Centre for Health Sport and Rehabilitation Sciences ResearchUniversity of Salford Salford M5 4WTUK

Reliable computational foot models offer an alternative means to enhance knowledge on the biomechanics of human foot. Model validation is one of the most critical aspects of the entire foot modeling and analysis *** paper presents an in vivo experiment combining motion capture system and plantar pressure measure platform to validate a three-dimensional finite element model of human *** Magnetic Resonance Imaging(MRI)slices for the foot modeling and the experimental data for validation were both collected from the same volunteer *** validated components included the comparison of static model predictions of plantar force,plantar pressure and foot surface deformation during six loading conditions,to equivalent measured *** the whole experiment,foot surface deformation,plantar force and plantar pressure were recorded simultaneously during six different loaded standing *** predictions of the current FE model were in good agreement with these experimental results.

关键词： human foot computational model plantar pressure