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cerberus Fossae, Mars: The case for Dike Intrusion-related Formation and Modification

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Acta Geologica Sinica(English Edition) 2016年第S1期90卷 173-174页

作者： Amanda L.nahm Matthew w.PENDLETON Simon A.KATTENHORN German Aerospace center (DLR) University of Idaho Earth consultants International University of Alaska Anchorage

cerberus Fossae(cF)is a large fracture system on Mars that extends for more than 1200 *** structures,or fossae,are southeast of,and oriented approximately radially to,the large shield volcano Elysium ***

关键词： Burr cerberus Fossae Mars cF

Graben on the Lunar Nearside: Do Dikes Lie Beneath?

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Acta Geologica Sinica(English Edition) 2016年第S1期90卷 175-176页

作者： Amanda L.nahm German Aerospace center (DLR)

On the Moon,tectonic structures are concentrated on the nearside,spatially associated with the maria(e.g.,watters and Johnson,2010),or basalt-filled impact *** graben(or rilles)are long,narrow troughs up to

关键词： Graben on the Lunar Nearside Do Dikes Lie Beneath

Effect of different water supply on morphology, growth and physiological characteristics of Salix psammophila seedlings in Maowusu sandland, china

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Journal of Environmental Sciences 2001年第4期13卷 411-417页

作者： Xiao, c.-w. Lab. Quantitative Vegetation Ecol. Institute of Botany Chinese Academy of Sciences Beijing 100093 China

Response pattern was investigated for seedlings of Salix psammophila, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. The growth characters, in terms of plant height, stem diameter, total branch number, total leaf number and area, total bifurcation ratio, total branch lenght and branch number, branch lenght, leaf number and leaf area of each branch order, and leaf, branch and root biomass significantly increased when water supply increased. That water supply had significant effect on biomass allocation showed different investment pattern of biomass resource of the seedlings grown under different water supply treatments. Stomatal density of abaxial leaf surface decreased, and stomatal apparatus length and width of adaxial and abaxial leaf surface increased with the increase of water supply, while Stomatal density of adaxial leaf surface was not affected by water supply. water supply obviously affected the diumal changes of photosynthetic rate, and the photosynthetic rate of the seedlings showed strongly midday depression grown under the 157.5 mm water supply, but not grown under higher water supply. Additionally the assimilation-light response curves and flourescence efficiency more showed that water supply improve photosynthesis capacity. Finally, S. psammophila seedlings stood out by their slow growth and relatively high investments in root growth in order to reduce tissue losing rate and consumption of water resource for keeping water balance under water stress. The seedlings that grown under rich water supply did by their fast growth and relatively high investments in branch and leaf growth in order to improve the power of capturing light energy for higher photosynthesis.

关键词： Biomass Fluorescence Morphology Photosynthesis Physiology Plants (botany) Precipitation (chemical) Seed Tissue

Measurement and Prediction of Insertion Force for the Mosquito Fascicle Penetrating into Human Skin

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Journal of Bionic Engineering 2009年第2期6卷 143-152页

作者： X Q Kong c w wu State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of Technology

Mosquitoes are exceptional in their ability to pierce into human skin with a natural ultimate painless microneedle, named fascicle. Here the structure of the Aedes albopictus mosquito fascicle is obtained using a Scanning Electron Microscope (SEM), and the whole process of the fascicle inserting into human skin is observed using a high-speed video imaging technique. Direct measurements of the insertion force for mosquito fascicle to penetrate into human skin are reported. Results show that the mosquito uses a very low force (average 18 μN) to penetrate into the skin. This force is at least three orders of magnitude smaller than the reported lowest insertion force for an artificial microneedle with an ultra sharp tip to insert into the human skin. In order to understand the piercing mechanism of mosquito fascicle tip into human multilayer skin tissue, a numerical simulation is conducted to analyze the insertion process using a nonlinear finite element method. A good agreement occurs between the numerical results and the experimental measurements.

关键词： biomimetic microneedle mosquito fascicle mechanics penetration

Effect of suction change on water content and total volume of an expansive clay

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 699-706页

作者： ZHAN Liang-tong cHEN Ping NG c.w.w. ~ Department of civil Engineering Zhejiang University Hangzhou 310027 China Department of civil Engineering Zhejiang Sci- Tech University Hangzhou 310018 China Department of civil Engineering Hong Kong University of Science and Technology Hong Kong China

A laboratory study was carried out on both natural and compacted specimens to investigate the complex soil-water interaction in an unsaturated expansive clay. The laboratory study includes the measurement of soil-water characteristic curves, 1D free swelling tests, measurement of swelling pressure and shrinkage tests. The test results revealed that the air-entry value of the natural specimen was quite low due to cracks and fissures present. The hydraulic hysteresis of the natural specimen was relatively insignificant as compared with the compacted specimen. within a suction range 0 to 500 kPa, a bilinear relationship between free swelling strain (or swelling pressure) and initial soil suction was observed for both the natural and compacted specimens. As a result of over-consolidation and secondary structures such as cementation and cracks, the natural specimens exhibited significant lower swelling (or swelling pressure) than the compacted specimen. The change of matric suction exerts a more significant effect on the water phase than on the soil skeleton for this expansive clay.

关键词： Expansive soil water content Suction Swelling Shrinkage

Is a nanorod (or nanotube) with a lower Young’s modulus stiffer? Is not Young’s modulus a stiffness indicator?

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 712-724页

作者： Lim c. w. Department of Building and construction City University of Hong Kong

It has been a known fact in classical mechanics of materials that Young’s modulus is an indicator of material stiffness and materials with a higher Young’s modulus are stiffer. At the nanoscale, within the scope and under specific circumstances described in this paper, however, a nanorod (or a nanotube) with a smaller Young’s modulus (smaller stress-strain rate) is stiffer. In such a scenario, Young’s modulus is not a stiffness indicator for nanostructures. Furthermore, the nonlocal stress-strain rate is dependent on types of load, boundary conditions and location. This is likely to be one of the many possible reasons why numerous experiments in the past obtained significantly varying values of Young’s modulus for a seemingly identical nanotube, i.e. because the types of loading and/or boundary conditions in the experiments were different, as well as at which point the property was measured. Based on the nonlocal elasticity theory and within the scope of material and geometric linearity, this paper reports the strange and hitherto unrealized effect that a nanorod (or a nanotube) with a lower Young’s modulus (smaller stress-strain rate) indicates smaller extension in tensile analysis. Similarly, it is also predicted that a nanorod (or a nanotube) with a lower Young’s modulus results in smaller bending deflection, higher critical buckling load, higher free vibration frequency and higher wave propagation velocity, which are at all consequences of a stiffer nanostructure.

关键词： nanorod nanotube nonlocal stress nonlocal elasticity stiffness tensile Young’s modulus

On the truth of nanoscale for nanobeams based on nonlocal elastic stress field theory:equilibrium,governing equation and static deflection

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Applied Mathematics and Mechanics(English Edition) 2010年第1期31卷 37-54页

作者： c. w. LIM Department of Building and construction City University of Hong Kong

This paper has successfully addressed three critical but overlooked issues in nonlocal elastic stress field theory for nanobeams：（i） why does the presence of increasing nonlocal effects induce reduced nanostructural stiffness in many, but not consistently for all, cases of study, i.e., increasing static deflection, decreasing natural frequency and decreasing buckling load, although physical intuition according to the nonlocal elasticity field theory first established by Eringen tells otherwise？（ii） the intriguing conclusion that nanoscale effects are missing in the solutions in many exemplary cases of study, e.g., bending deflection of a cantilever nanobeam with a point load at its tip; and （iii） the non-existence of additional higher-order boundary conditions for a higher-order governing differential equation. Applying the nonlocal elasticity field theory in nanomechanics and an exact variational principal approach, we derive the new equilibrium conditions, do- main governing differential equation and boundary conditions for bending of nanobeams. These equations and conditions involve essential higher-order differential terms which are opposite in sign with respect to the previously studies in the statics and dynamics of nonlocal nano-structures. The difference in higher-order terms results in reverse trends of nanoscale effects with respect to the conclusion of this paper. Effectively, this paper reports new equilibrium conditions, governing differential equation and boundary condi- tions and the true basic static responses for bending of nanobeams. It is also concluded that the widely accepted equilibrium conditions of nonlocal nanostructures are in fact not in equilibrium, but they can be made perfect should the nonlocal bending moment be replaced by an effective nonlocal bending moment. These conclusions are substantiated, in a general sense, by other approaches in nanostructural models such as strain gradient theory, modified couple stress models and experim

关键词： bending effective nonlocal bending moment nanobeam nanomechanics,nanoscale nonlocal elastic stress strain gradient

Asymptotic analysis of a vibrating cantilever with a nonlinear boundary

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Science china(Physics,Mechanics & Astronomy) 2009年第9期52卷 1414-1422页

作者： c. w. LIM Department of Building and construction City University of Hong Kong

Nonlinear vibration of a cantilever in a contact atomic force microscope is analyzed via an asymptotic approach. The asymptotic solution is sought for a beam equation with a nonlinear boundary condition. The steady-state responses are determined in primary resonance and subharmonic resonance. The relations between the response amplitudes and the excitation frequencies and amplitudes are derived from the solvability condition. Multivaluedness occurs in the relations as a consequence of the nonlinearity. The stability of steady-state responses is analyzed by use of the Lyapunov linearized stability theory. The stability analysis predicts the jumping phenomenon for certain parameters. The curves of the response amplitudes changing with the excitation frequencies are numerically compared with those obtained via the method of multiple scales. The calculation results demonstrate that the two methods predict the same varying tendencies while there are small quantitative differences.

关键词： asymptotic analysis vibration nonlinear boundary condition beam contact

Silicon-based metal-organic frameworks(SiMOFs)for immunogenic cell death in cancer therapy

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Nano Research 2025年第1期18卷 628-641页

作者： Min Han Zishan chen Shiying Zhou Zunde Liao Xiangting Yi Yao He Yiling Zhong Kam w.Leong college of Pharmacy State Key Laboratory of Bioactive Molecules and Druggability AssessmentJinan UniversityGuangzhou 511443China Department of Biomedical Engineering Columbia UniversityNew YorkNY 10027USA Institute of Functional Nano and Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China

Silicon-based nanomaterials,known for their unique properties and favorable biocompatibility,significantly impact sectors like energy,electronics,and ***,metalorganic frameworks(MOFs)have emerged as promising candidates for biomedicine,characterized by adjustable chemical composition,high porosity,and ***,the combination of silicon with MOFs to create silicon-based MOF nanostructures(SiMOFs)remains ***,we establish a diverse library of SiMOFs with various nanostructures,including flower-like,capsule-like,hexagonal snowflake-like,and necklace-like morphologies via microwave-assisted *** SiMOFs,with their spacious interiors,are ideal for drug *** are used to load drugs and create drug-loaded SiMOFs(e.g.,SiFeO).SiFeO exhibits excellent photothermal effects and high reactive oxygen species(ROS)generation capacity,enabling synergistic treatments involving chemochemodynamic-photothermal *** approach efficiently triggers immunogenic cell death(IcD)and demonstrates excellent antitumor efficacy in *** staining reveals that the synergistic therapy can modulate the tumor microenvironment(TME)by reducing M2-phenotype macrophages,increasing the activation of antigen-presenting cells(APcs),enhancing the infiltration of cD4^(+)and cD8^(+)T cells,elevating Granzyme B production,and decreasing the presence of immunosuppressive regulatory T cells(Tregs).consequently,drug-loaded SiMOFs-mediated combination therapy effectively reverses the immunosuppressive TME and activates robust antitumor immune responses by inducing IcD in tumor cells,ultimately achieving superior anticancer efficacy.

关键词： silicon-based nanomaterials nanocarriers immunogenic cell death antitumor immune responses