We have develoPed a simPle and economical method f0r Chlamydia trachomatisdetecting, called microtiter plate hybridization (PCR-MPH), which may replace stan-dard PCR. This method is similar to that of an ELISA. Brithe...We have develoPed a simPle and economical method f0r Chlamydia trachomatisdetecting, called microtiter plate hybridization (PCR-MPH), which may replace stan-dard PCR. This method is similar to that of an ELISA. Brithe, the PCR productslabeled at the 5'termini with biotin were hybridized with probes immobilized on a mi-crotiter well, and the bound PCR products were detected by streptavidin-c0njugatedenzymes followed by color development. Two inprovements have been made in immobi-lizing the probe to the microtiter wells, in terms of increasing both immobility and hy-bridization deciency. One is that singleustranded (ss )DNA, without the complemen-tary strand, is used. The other is that instead of a single copy, a tandem array of theprobe is used for immobilization and hybridization. Using of ssDNA containing abouta 5O-rePeat array of a relevant sequence as an immobilized probe, the sensitivity in-creased 1O-fold over that of a single oligonucleotide unit. We also found that the hy-brldizatlon condltions such as time, temPerature, and solution composition could be simplthed. The advantages of this microtiter plate-hybridization method for routinepathogens detecting are a short time assay, easy processing of large numbers of sansples, and the potential for automation.展开更多
This paper introduces a novel fiat plate solar collector (FPC) using micro heat pipe array (MHPA) as a key element. To analyze the thermal transfer behavior of flat plate solar collector with micro heat pipe array...This paper introduces a novel fiat plate solar collector (FPC) using micro heat pipe array (MHPA) as a key element. To analyze the thermal transfer behavior of flat plate solar collector with micro heat pipe array (MHPA-FPC), an indoor experiment for thermal transfer characteristic of MHPA applied to FPC was conducted by using an electrical heating film to simulate the solar radiation. Different cooling water flow rates, cooling water temperatures, slopes, and contact thermal resistances be- tween the condenser of MHPA and the heat exchanger were tested at different heating powers. The experimental results in- dicate that MHPA-FPC exhibits the enhanced heat transfer capability with increased cooling water flow rate and temperature. Total thermal resistance has a maximum decline of approximately 10% when the flow rate increases from 180 to 360 L h-1 and 38% when the cooling water temperature increases from 20~C to 40~C. When the inclination angle of MHPA-FPC ex- ceeds 30~, the slope change has a negligible effect on the heat transfer performance of MHPA-FPC. In addition, contact thermal resistance significantly affects the heat transfer capability of MHPA-FPC. The total thermal resistances lowers to nearly half of the original level when contact material between the condenser of MHPA and the heat exchanger changes from conductive silicone to conductive grease. These results could provide useful information for the optimal design and operation of MHPA-FPC.展开更多
Electron beam welding (EBW) is a fusion welding process in which a beam of high-velocity electrons is applied to two materials to be joined. It is a complex high-temperature metallurgical process, and the quality of...Electron beam welding (EBW) is a fusion welding process in which a beam of high-velocity electrons is applied to two materials to be joined. It is a complex high-temperature metallurgical process, and the quality of welding may deteriorate because of defects caused by improper welding parameters, especially in the EBW of thickened aluminum alloy plate. Ultrasonic phased array(UPA) technology has been applied more widely in the field of nondestructive testing because of its ability of effectively controlling the shape and direction of the emitted ultrasonic beam. In present research, a specimen with EBW seam on thickened aluminum plate was tested with a linear array ultrasonic phased array probe, and a large number of B-scan images of the weld were acquired by electronic scanning in probe combined with the mechanical scanning of the probe along the weld direction. This large number of B-scan images were stacked to construct the volume data, with which the 3D image of the weld discontinuities were reconstructed, and the 3D visualization was realized. More details about weld discontinuities' spatial distribution and orientation were revealed, and this approach also made the results of non-destructive ultrasonic testing more easily to understand.展开更多
The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, th...The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing.展开更多
A metallic interconnect plate with a flow channel array is one of the most important elements in a solid oxide fuel cell(SOFC). Electrochemical machining(ECM) is considered to be an adoptable technology for fabricatin...A metallic interconnect plate with a flow channel array is one of the most important elements in a solid oxide fuel cell(SOFC). Electrochemical machining(ECM) is considered to be an adoptable technology for fabricating flow channels in an interconnect plate on account of its efficiency and low cost. With respect to the traditional electrolyte flow mode in ECM cross-channel array, the electrolyte usually flows from one side to the opposite side of the rectangular processing area. However, obvious flow marks are typically formed at the bottom of channels perpendicular to the flow. According to multiphysical simulation analysis, the low electrolyte velocity in the channels perpendicular to the flow leads to uneven distribution of electrolyte products. To improve the uniformity of the flow field, two new electrolyte flow modes, “two-in and two-out” and “three-in and one-out”, are proposed. By adding one or two additional electrolyte inlets to the sides of the traditional flow field, the electrolyte flow velocity in the channels perpendicular to the traditional flow will be increased. Corresponding simulations and experiments were performed and the results showed that the “three-in and one-out” flow mode can produce a flatter bottom surface for the cross-channel array. Parameter optimization experiments for the preferred flow mode were undertaken and the optimal flow field parameters were determined.展开更多
Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible s...Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.展开更多
文摘We have develoPed a simPle and economical method f0r Chlamydia trachomatisdetecting, called microtiter plate hybridization (PCR-MPH), which may replace stan-dard PCR. This method is similar to that of an ELISA. Brithe, the PCR productslabeled at the 5'termini with biotin were hybridized with probes immobilized on a mi-crotiter well, and the bound PCR products were detected by streptavidin-c0njugatedenzymes followed by color development. Two inprovements have been made in immobi-lizing the probe to the microtiter wells, in terms of increasing both immobility and hy-bridization deciency. One is that singleustranded (ss )DNA, without the complemen-tary strand, is used. The other is that instead of a single copy, a tandem array of theprobe is used for immobilization and hybridization. Using of ssDNA containing abouta 5O-rePeat array of a relevant sequence as an immobilized probe, the sensitivity in-creased 1O-fold over that of a single oligonucleotide unit. We also found that the hy-brldizatlon condltions such as time, temPerature, and solution composition could be simplthed. The advantages of this microtiter plate-hybridization method for routinepathogens detecting are a short time assay, easy processing of large numbers of sansples, and the potential for automation.
基金financially supported by the Natural Science Foundation of Beijing(Grant No.Z1004020201201)the Opening Funds of State Key Laboratory of Building Safety and Build Environment of China(Grant No.BSBE 2011-07)
文摘This paper introduces a novel fiat plate solar collector (FPC) using micro heat pipe array (MHPA) as a key element. To analyze the thermal transfer behavior of flat plate solar collector with micro heat pipe array (MHPA-FPC), an indoor experiment for thermal transfer characteristic of MHPA applied to FPC was conducted by using an electrical heating film to simulate the solar radiation. Different cooling water flow rates, cooling water temperatures, slopes, and contact thermal resistances be- tween the condenser of MHPA and the heat exchanger were tested at different heating powers. The experimental results in- dicate that MHPA-FPC exhibits the enhanced heat transfer capability with increased cooling water flow rate and temperature. Total thermal resistance has a maximum decline of approximately 10% when the flow rate increases from 180 to 360 L h-1 and 38% when the cooling water temperature increases from 20~C to 40~C. When the inclination angle of MHPA-FPC ex- ceeds 30~, the slope change has a negligible effect on the heat transfer performance of MHPA-FPC. In addition, contact thermal resistance significantly affects the heat transfer capability of MHPA-FPC. The total thermal resistances lowers to nearly half of the original level when contact material between the condenser of MHPA and the heat exchanger changes from conductive silicone to conductive grease. These results could provide useful information for the optimal design and operation of MHPA-FPC.
基金supported by the National Natural Science Foundation of China(Grant No.51575134 and 51175113)
文摘Electron beam welding (EBW) is a fusion welding process in which a beam of high-velocity electrons is applied to two materials to be joined. It is a complex high-temperature metallurgical process, and the quality of welding may deteriorate because of defects caused by improper welding parameters, especially in the EBW of thickened aluminum alloy plate. Ultrasonic phased array(UPA) technology has been applied more widely in the field of nondestructive testing because of its ability of effectively controlling the shape and direction of the emitted ultrasonic beam. In present research, a specimen with EBW seam on thickened aluminum plate was tested with a linear array ultrasonic phased array probe, and a large number of B-scan images of the weld were acquired by electronic scanning in probe combined with the mechanical scanning of the probe along the weld direction. This large number of B-scan images were stacked to construct the volume data, with which the 3D image of the weld discontinuities were reconstructed, and the 3D visualization was realized. More details about weld discontinuities' spatial distribution and orientation were revealed, and this approach also made the results of non-destructive ultrasonic testing more easily to understand.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 10304012).
文摘The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing.
基金co-supported by the Joint Funds of the Natural Science Foundation of China and Guangdong Province(No.U1601201)the Natural Science Foundation of Jiangsu Province(No.BK20192007)the National Natural Science Foundation of China for Creative Research Groups(No.51921003)。
文摘A metallic interconnect plate with a flow channel array is one of the most important elements in a solid oxide fuel cell(SOFC). Electrochemical machining(ECM) is considered to be an adoptable technology for fabricating flow channels in an interconnect plate on account of its efficiency and low cost. With respect to the traditional electrolyte flow mode in ECM cross-channel array, the electrolyte usually flows from one side to the opposite side of the rectangular processing area. However, obvious flow marks are typically formed at the bottom of channels perpendicular to the flow. According to multiphysical simulation analysis, the low electrolyte velocity in the channels perpendicular to the flow leads to uneven distribution of electrolyte products. To improve the uniformity of the flow field, two new electrolyte flow modes, “two-in and two-out” and “three-in and one-out”, are proposed. By adding one or two additional electrolyte inlets to the sides of the traditional flow field, the electrolyte flow velocity in the channels perpendicular to the traditional flow will be increased. Corresponding simulations and experiments were performed and the results showed that the “three-in and one-out” flow mode can produce a flatter bottom surface for the cross-channel array. Parameter optimization experiments for the preferred flow mode were undertaken and the optimal flow field parameters were determined.
基金the National Natural Science Foundation of China(Nos.21701022 and51690161)the Fundamental Research Funds for the Central Universities(Nos.N182505037 and N182410001)+2 种基金the Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001)the Liao Ning Revitalization Talents Program(No.XLYC1807214)the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.201910145260)。
文摘Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.