Some insects and animals, such as bugs, grasshoppers and tree frogs, realize their efficient adhesion mechanism to glass surface, wall and ceiling by injecting a wetting liquid thin film into the pad-substrate contact...Some insects and animals, such as bugs, grasshoppers and tree frogs, realize their efficient adhesion mechanism to glass surface, wall and ceiling by injecting a wetting liquid thin film into the pad-substrate contact area. Their ability to control adhesion (attaching or detaching from a surface) is in many cases connected to the contact geometry and surface patterns of their attachment pads. This paper focuses on the dependence of the capillary adhesion (wet adhesion) on the micro patterns of the bio-adhesive pads. The objective is to reveal the possible mechanism for a bio-adhesive pad to control capillary force through adjusting its micro-scale surface pattern and topography. A capillary adhesion force model is built up taking account of the combined role of micro-dimple geometry as well as the wetting behavior of the confined liquid thin film. Calculated results of the apparent contact angle on the regularly micro-dimpled surfaces are compared with and in good agreement with the experimental measurements. Simulation of the capillary adhesion force reveals that it is controllable in a large mag- nitude by adjusting a dimensionless surface pattern parameter k defined as a/(a+b), where a is the dia- meter of micro dimple, and (a+b) is the side length of one pattern cell. When adjusting the parameter k more than 0.75, the capillary adhesion force could be switchable from attractive to repulsive. This effect of micro patterns on the interfacial capillary force is proved to be dominant when the pad-substrate clearance decreases to the nano/micrometer scale. These results indicate that a controllable and switchable capillary adhesive mechanism might be utilized by a living insect or animal to realize its stable adhesion and quick releasing movement through adjusting the micro-pattern topography of its bio-adhesive pad.展开更多
Here we describe a plasmon-enhanced fluorescence substrate based on poly（methyl methacrylate） （PMMA）-coated, large-area Au@Ag nanorod arrays. The use of a PMMA medium enables precise control of the competition bet...Here we describe a plasmon-enhanced fluorescence substrate based on poly（methyl methacrylate） （PMMA）-coated, large-area Au@Ag nanorod arrays. The use of a PMMA medium enables precise control of the competition between enhancing and quenching processes as a function of the distance between Au@Ag nanorods and dye molecules. At the optimal PMMA layer thickness of 56 nm （for which the distance between nanopartides and dye molecules is 16 nm）, a maximum enhancement of fluorescence of up to N 27 times is measured. The competition mechanism between enhancing and quenching processes depends on the thickness of the PMMA layer, which has been confirmed by consistent experimental and theoretical modeling results. Notab136 the micropatterned metal-enhanced fluorescence （MEF） substrate exhibits high uniformity and reproducibility. The simple spin-coating process described herein provides an attractive, scalable, and low-cost strategy to produce uniform and reproducible large-area MEF substrates that can potentially be used in many fields, such as biochips, diagnostics, and photonics.展开更多
本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的...本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的测量研究。在FIB-EB双束系统下记录切槽前后制斑微区的图像,利用数字图像相关法计算切槽后的位移,结合InglisMuskhelishvili理论公式可计算得到残余应力。文中研究了不同温度及保温时间对残余应力释放的影响规律。结果表明,残余应力随保温时间的增长释放速度逐渐减小,最后残余应力趋于稳定值。同时,温度越高,残余应力释放越彻底,800℃下近乎完全释放。该工艺具有适用性好,效率高等优点,可望在材料微区变形测量中得到进一步应用。展开更多
The wedge strip anode （WSA） has been widely used in 2-D positiomsensitive detectors. A circular WSA with an effective diameter of 52 mm is successfully coupled to a tripe gas electron multiplier （GEM） detector thr...The wedge strip anode （WSA） has been widely used in 2-D positiomsensitive detectors. A circular WSA with an effective diameter of 52 mm is successfully coupled to a tripe gas electron multiplier （GEM） detector through a simple resistive layer. A spatial resolution of 440 μm （FWHM） is achieved for a 10 kVp X-ray using 1 atm Ar：CO2=70：30 gas. The simple electronics of only three channels makes it very useful in applications strongly requiring simple interface design, e.g. sealed tubes and high pressure detectors.展开更多
This paper sets out to demonstrate that scraping of the flat dorsal surface of human dermis with a scalpel blade and cell plating without centrifugation can lead to the recognition and identification of the individual...This paper sets out to demonstrate that scraping of the flat dorsal surface of human dermis with a scalpel blade and cell plating without centrifugation can lead to the recognition and identification of the individual packing micro pattern of dermal reticular fibroblasts at confluence. The characteristic alignment of papillary and reticular fibroblasts at right angles to each other led to the positive identification of reticular fibroblasts. A non-enzymatic means of sub-culturing (passaging), which yields fully functional, healthy cells with normal, phenotypic morphology is also described. Implications for published subcutaneous wound healing studies are discussed as well as the confluent reticular fibroblast configuration, interpreted as ananatomic site identity code,which may be the address of a specific fibroblast gene pattern expression.展开更多
基金the National Natural Science Foundation of China(Nos.11972215,12072174,12172189,52111540269)the National Key R&D Program of China(Nos.2022YFC2402600,2018FYA0305800)the China Postdoctoral Science Foundation(No.2021M701907).
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50575123, 50730007)PPP Project from CSC and DAADGerman Research Foundation (DFG) (Grant No. SFB622) (Y.H. Liu and S.I.-U. Ahmed)
文摘Some insects and animals, such as bugs, grasshoppers and tree frogs, realize their efficient adhesion mechanism to glass surface, wall and ceiling by injecting a wetting liquid thin film into the pad-substrate contact area. Their ability to control adhesion (attaching or detaching from a surface) is in many cases connected to the contact geometry and surface patterns of their attachment pads. This paper focuses on the dependence of the capillary adhesion (wet adhesion) on the micro patterns of the bio-adhesive pads. The objective is to reveal the possible mechanism for a bio-adhesive pad to control capillary force through adjusting its micro-scale surface pattern and topography. A capillary adhesion force model is built up taking account of the combined role of micro-dimple geometry as well as the wetting behavior of the confined liquid thin film. Calculated results of the apparent contact angle on the regularly micro-dimpled surfaces are compared with and in good agreement with the experimental measurements. Simulation of the capillary adhesion force reveals that it is controllable in a large mag- nitude by adjusting a dimensionless surface pattern parameter k defined as a/(a+b), where a is the dia- meter of micro dimple, and (a+b) is the side length of one pattern cell. When adjusting the parameter k more than 0.75, the capillary adhesion force could be switchable from attractive to repulsive. This effect of micro patterns on the interfacial capillary force is proved to be dominant when the pad-substrate clearance decreases to the nano/micrometer scale. These results indicate that a controllable and switchable capillary adhesive mechanism might be utilized by a living insect or animal to realize its stable adhesion and quick releasing movement through adjusting the micro-pattern topography of its bio-adhesive pad.
文摘Here we describe a plasmon-enhanced fluorescence substrate based on poly（methyl methacrylate） （PMMA）-coated, large-area Au@Ag nanorod arrays. The use of a PMMA medium enables precise control of the competition between enhancing and quenching processes as a function of the distance between Au@Ag nanorods and dye molecules. At the optimal PMMA layer thickness of 56 nm （for which the distance between nanopartides and dye molecules is 16 nm）, a maximum enhancement of fluorescence of up to N 27 times is measured. The competition mechanism between enhancing and quenching processes depends on the thickness of the PMMA layer, which has been confirmed by consistent experimental and theoretical modeling results. Notab136 the micropatterned metal-enhanced fluorescence （MEF） substrate exhibits high uniformity and reproducibility. The simple spin-coating process described herein provides an attractive, scalable, and low-cost strategy to produce uniform and reproducible large-area MEF substrates that can potentially be used in many fields, such as biochips, diagnostics, and photonics.
基金National Natural Science Foundation of China(50872077)Innovation Team Fundation of Shaanxi University of Science and Technology(TD09-05)Graduate Innovation Foundation of Shaanxi University of Technology(SUST-A04)
文摘本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的测量研究。在FIB-EB双束系统下记录切槽前后制斑微区的图像,利用数字图像相关法计算切槽后的位移,结合InglisMuskhelishvili理论公式可计算得到残余应力。文中研究了不同温度及保温时间对残余应力释放的影响规律。结果表明,残余应力随保温时间的增长释放速度逐渐减小,最后残余应力趋于稳定值。同时,温度越高,残余应力释放越彻底,800℃下近乎完全释放。该工艺具有适用性好,效率高等优点,可望在材料微区变形测量中得到进一步应用。
基金Supported by National Natural Science Foundation of China (10735020, 11075026)
文摘The wedge strip anode （WSA） has been widely used in 2-D positiomsensitive detectors. A circular WSA with an effective diameter of 52 mm is successfully coupled to a tripe gas electron multiplier （GEM） detector through a simple resistive layer. A spatial resolution of 440 μm （FWHM） is achieved for a 10 kVp X-ray using 1 atm Ar：CO2=70：30 gas. The simple electronics of only three channels makes it very useful in applications strongly requiring simple interface design, e.g. sealed tubes and high pressure detectors.
文摘This paper sets out to demonstrate that scraping of the flat dorsal surface of human dermis with a scalpel blade and cell plating without centrifugation can lead to the recognition and identification of the individual packing micro pattern of dermal reticular fibroblasts at confluence. The characteristic alignment of papillary and reticular fibroblasts at right angles to each other led to the positive identification of reticular fibroblasts. A non-enzymatic means of sub-culturing (passaging), which yields fully functional, healthy cells with normal, phenotypic morphology is also described. Implications for published subcutaneous wound healing studies are discussed as well as the confluent reticular fibroblast configuration, interpreted as ananatomic site identity code,which may be the address of a specific fibroblast gene pattern expression.
