摘要：Coal pillar deformation is typically nonlinear and time-dependent. The accurate prediction of this defor- mation has a vital importance for the successful implementation of mining techniques. These methods have proven very important as a way to excavate coal resources from under buildings, railways, or water bodies. Elastic and visco-elastic theory are employed with a Maxwell model to formulate an analytic solution for displacement of coal pillars in room and pillar mine. These results show that the visco-elastic solution adequately predicts the coal pillar deformation over time. We conclude that the visco-elastic solution can predict the coal pillar and roadway displacement from the measured geological parameters of the conditions in situ. Furthermore, this method would be useful for mine design, coal pillar support optimization, ground subsidence prediction, and coal pillar stability analysis.

摘要：Optical manipulation of micro/nanoscale objects is of importance in life sciences,colloidal science,and *** tweezers exhibit superior manipulation capability at low optical ***,our implicit understanding of the working mechanism has limited the further applications and innovations of optothermal ***,we present an atomistic view of opto-thermo-electro-mechanic coupling in optothermal tweezers,which enables us to rationally design the tweezers for optimum performance in targeted ***,we have revealed that the non-uniform temperature distribution induces water polarization and charge separation,which creates the thermoelectric field dominating the optothermal *** further design experiments to systematically verify our atomistic *** by our new model,we develop new types of optothermal tweezers of high performance using low-concentrated ***,we demonstrate the use of new tweezers in opto-thermophoretic separation of colloidal particles of the same size based on the difference in their surface charge,which has been challenging for conventional optical *** the atomistic understanding that enables the performance optimization and function expansion,optothermal tweezers will further their impacts.

摘要：This work deals with the generation of MATLAB script files that assists the user in the design of a composite laminate to operate within safe conditions. The inputs of the program are the material properties, material limits and loading conditions. Equations based on Hooke’s Law for two-dimensional composites were used to determine the global and local stresses and strains on each layer. Failure analysis of the structure was performed via the Tsai-Wu failure theory. The output of the program is the optimal number of fibre layers required for the composite laminate, as well as the orientation of each layer.

摘要：The optimization of the scaffolds to provide a suitable matrix and accelerate the regeneration process is vital for bone tissue ***,poor mechanical and biological characteristics remain the primary challenges that must be *** example,although bredigite(Br)has shown great potential for application in bone tissue engineering,it easily fails in *** the present work,these challenges are addressed by reinforcing the Br matrix with nanosheets of graphene oxide(rGO)that have been reduced by bovine serum albumin(BSA)in order to enhance the mechanical properties and biological *** reduction of graphene oxide by BSA improves the water stability of the nanosheets and provides an electrostatic interaction between theBSA-rGO nanosheets and theBr *** high thermal conductivity of theBSA-rGO nanosheets decreases the porosity of the Br by transferring heat to the core of the ***,the addition of BSA-rGO nanosheets into the Br matrix enhances the adhesion of G-292 cells on the surface of the *** findings suggest that the tablet consisting of BSA-rGO-reinforced Br has encouraging potential for application in bone tissue engineering.

摘要：This paper presents design and development of virtual objects to be used with haptic device PHANTOM Omni for motor rehabilitation by incorporating visual and haptic feedback. Developed predominantly for augmentation of motor skill of patient, the objects could also be used for teaching and enhancing writing skill of children. The virtual objects include English alphabets, numbers, string and mazes, and games. The scheme has been evaluated on children from 11 to 14 years age. The experiment gives good results.

摘要：Thermal performance was the most important factor in the development of borehole heat exchanger utilizing geothermal energy. The thermal performance was affected by many different design parameters, such as configuration type and borehole size of geothermal heat exchanger. These eventually determined the operation and cost efficiency of the geothermal heat exchanger system. The main purpose of this work was to assess the thermal performance of geother^nal heat exchanger with variation of borehole sizes and numbers of U-tubes inside a borehole. For this, a thermal response test rig was established with line-source theory. The thermal response test was performed with in-line variable input heat source. Effective thermal conductivity and thermal resistance were obtained from the measured data. From the measurement, the effective thermal conductivity is found to have similar values for two- pair type （4 U-tubes） and three-pair type （6 U-tubes） borehole heat exchanger systems indicating similar heat transfer ability. Meanwhile, the thermal resistance shows lower value for the three-pair type compared to the two-pair type. Measured data based resistance have lower value compared to computed result from design programs. Overall comparison finds better thermal performance for the three-pair type, however, fluctuating temperature variation indicates complex flow behavior inside the borehole and requires further study on flow characteristics.

摘要：An attempt was made to optimize friction welding parameters to attain a minimum hardness at the interface and a maximum tensile strength of the dissimilar joints of AISI 304 austenitic stainless steel （ASS） and copper （Cu） alloy using response surface methodology （RSM）. Three-factor, five-level central composite design matrix was used to specify experimental conditions. Twenty joints were fabricated using ASS and Cu alloy. Tensile strength and interface hardness were measured experimentally. Analysis of variance （ANOVA） method was used to find out significant main and interaction parameters and empirical relationships were developed using regression analysis. The friction welding parameters were optimized by constructing response graphs and contour plots using design expert software. The developed empirical relationships can be effectively used to predict tensile strength and interface hardness of friction welded ASS-Cu joints at 95% confidence level. The developed contour plots can be used to attain required level of optimum conditions to join ASS-Cu alloy by friction welding process.

摘要：Due to their special anatomical and physiological features,central nervous system diseases still presented challenges,despite the fact that some advances have been made in early diagnosis and precision *** of the complexities in treating tumors is the tumor microenvironment,which includes mesenchymal stem cells(MSCs)that exhibit tumor tropism and can be used for cell ***,whether MSCs promote or suppress gliomas is still unclear,especially in glioma *** this study,a coaxial microfiber was designed to mimic the tumor microenvironment and to reveal the effect of MSCs on glioma *** fiber shell was composed of MSCs and alginate,and the core was filled with U87 MG(glioblastoma)cells and gelatin *** Shell-MSC/Core-U87 MG microenvironment improved the proliferation,survival,invasion,metastasis,and drug resistance of glioma cells,while simultaneously maintaining the stemness of glioma *** summary,coaxial extrusion bioprinted Shell-MSC/Core-U87 MG microfiber is an ideal platform for tumor and stromal cell coculture to observe tumor biological behavior in vitro.

摘要：Understanding the material flow facilitated by tool geometry in friction stir welds is challenging for quality weld production in industrial *** optimal tool shoulder and pin design combination,which plays a vital role in material flow was *** flow of plasticized material was analyzed using a marker insert *** results show that the knurling shoulder design with square and hexagonal pin design facilitated constant stability force with reference to weld length/*** uniform mixing and distribution of plasticized material were facilitated by the knurling shoulder design with square tool pin shape(TK)S(sticking length minimum)below which fragmented copper was observed.(TK)S tool facilitated higher mechanical properties for the welds,***(182 MPa)and hardness(HV 78)in stir zone.

摘要：AA5083 friction stir welds were produced using systematic experimental design, the process forces and heat input with varying parameters were studied. Helpful empirical models were developed in designing friction stir welding （FSW） tools and FSW welders. These models may be further helpful for making process parameter choice for this sort of alloy, defining welding program and control of process parameters by using computer numerical control friction stir welding welders. The results show that tool rotational speed, welding speed and tool shoulder diameter are most significant parameters affecting axial force and heat input, while longitudinal force is significantly affected by welding speed and probe diameter.