Interdigitation means mutual nappe structures which might result from the low-angle thrusting during the collision betWeen tWo continental blocks. It is well developed in the coveting strata of Laochang-Laba district,...Interdigitation means mutual nappe structures which might result from the low-angle thrusting during the collision betWeen tWo continental blocks. It is well developed in the coveting strata of Laochang-Laba district, Lancang, Yunnan Province ( Fig. 1).展开更多
Two Zn（II） coordination polymers, namely [Zn2（bpy）（aobtc）（H2O）2]·2H2O（1） and [Zn2（bpy）（aobtc）（H2O）]·4H2O（2）（bpy = 4,4＇-bipyridine, H4 aobtc = 3,3＇,5,5＇-azoxybenzenetetracarboxylic acid...Two Zn（II） coordination polymers, namely [Zn2（bpy）（aobtc）（H2O）2]·2H2O（1） and [Zn2（bpy）（aobtc）（H2O）]·4H2O（2）（bpy = 4,4＇-bipyridine, H4 aobtc = 3,3＇,5,5＇-azoxybenzenetetracarboxylic acid） have been hydrothermally synthesized through tuning the p H value of the reaction system（1, C（26）H（22）N（4）O（13）Zn2, Mr = 729.21; 2, C（26）H（24）N4O（14）Zn2, Mr = 747.23）, and their structures have been determined by single-crystal X-ray diffraction analyses. Compound 2 has been further characterized by infrared spectra（IR）, elemental analyses, thermal analyses and powder X-ray diffraction（PXRD） analyses. Additionally, the photoluminescence of 2 is also discussed. The structure demonstrates that the crystal of 2 belongs to the triclinic system, space group P1 with a = 8.41494（18）, b = 9.59838（19）, c = 17.6477（3） ？, α = 91.5098（16）, β = 98.1439（17）, γ = 90.4323（17）°, V = 1410.44（5） ^3, Z = 2, ρcalc = 1.759 g/cm^3, μ = 2.819 mm-1, F（000） = 760.0, R = 0.0311 and w R = 0.0839（I 〉 2σ（I））. Compound 1 shows a two-dimensional monolayer while compound 2 displays a novel 2D double-layered network constructed from monolayer motifs, which is similar to the single layer in 1. Further, each bilayer motif in 2 is interdigitated by two others in a parallel fashion to yield an unusual 2D → 3D interdigitated framework.展开更多
In plants, cortical microtubules anchor to the plasma membrane in arrays and play important roles in cell shape. However, the molecular mechanism of microtubule binding proteins, which connect the plasma membrane and ...In plants, cortical microtubules anchor to the plasma membrane in arrays and play important roles in cell shape. However, the molecular mechanism of microtubule binding proteins, which connect the plasma membrane and cortical microtubules in cell morphology remains largely unknown. Here, we report that a plasma membrane and microtubule duallocalized IQ67 domain protein, IQD21, is critical for cotyledon pavement cell(PC) morphogenesis in Arabidopsis. iqd21 mutation caused increased indentation width, decreased lobe length, and similar lobe number of PCs, whereas IQD21 overexpression had a different effect on cotyledon PC shape. Weak overexpression led to increased lobe number, decreased indentation width, and similar lobe length, while moderate or great overexpression resulted in decreased lobe number, indentation width, and lobe length of PCs. Live-cell observations revealed that IQD21 accumulation at indentation regions correlates with lobe initiation and outgrowth during PC development. Cell biological and genetic approaches revealed that IQD21 promotes transfacial microtubules anchoring to the plasma membrane via its polybasic sites and bundling at the indentation regions in both periclinal and anticlinal walls. IQD21 controls cortical microtubule organization mainly through promoting Katanin 1-mediated microtubule severing during PC interdigitation. These findings provide the genetic evidence that transfacial microtubule arrays play a determinant role in lobe formation, and the insight into the molecular mechanism of IQD21 in transfacial microtubule organization at indentations and puzzle-shaped PC development.展开更多
Performance of the proton exchange membrane fuel cell(PEMFC)is appreciably affected by the channel geometry.The branching structure of a plant leaf and human lung is an efficient network to distribute the nutrients in...Performance of the proton exchange membrane fuel cell(PEMFC)is appreciably affected by the channel geometry.The branching structure of a plant leaf and human lung is an efficient network to distribute the nutrients in the respective systems.The same nutrient transport system can be mimicked in the flow channel design of a PEMFC,to aid even reactant distribution and better water management.In this work,the effect of bio-inspired flow field designs such as lung and leaf channel design bipolar plates,on the performance of a PEMFC was examined experimentally at various operating conditions.A PEMFC of 49 cm2 area,with a Nafion 212 membrane with a 40%catalyst loading of 0.4 mg·cm-2 on the anode side and also 0.6 mg·cm-2 on the cathode side is assembled by incorporating the bio-inspired channel bipolar plate,and was tested on a programmable fuel-cell test station.The impact of the working parameters like reactants’relative humidity(RH),back pressure and fuel cell temperature on the performance of the fuel cell was examined;the operating pressure remains constant at 0.1 MPa.It was observed that the best performance was attained at a back pressure of 0.3 MPa,75°C operating temperature and 100%RH.The three flow channels were also compared at different operating pressures ranging from 0.1 MPa to 0.3 MPa,and the other parameters such as operating temperature,RH and back pressure were set as 75°C,100%and 0.3 MPa.The experimental outcomes of the PEMFC with bio-inspired channels were compared with the experimental results of a conventional triple serpentine flow field.It was observed that among the different flow channel designs considered,the leaf channel design gives the best output in terms of power density.Further,the experimental results of the leaf channel design were compared with those of the interdigitated leaf channel design.The PEMFC with the interdigitated leaf channel design was found to generate 6.72%more power density than the non-interdigitated leaf channel design.The fuel cell with interdigitated leaf cha展开更多
In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can gene...In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can generate high-intensity THz pulses(a)those with large-aperture dipoles and(b)those with interdigitated electrodes.We will first describe the principles of THz generation from PCAs.The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized.We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with widebandgap semiconductor substrates.Then,we will explain the evolution of LAPCA with interdigitated electrodes,which allows one to reduce the photoconductive gap size,and thus obtain higher bias fields while applying lower voltages.We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by ampli-fied lasers.Finally,we will discuss the future perspectives of THz pulse generation using LAPCAs.展开更多
In the design of the finger-overlap envelope according to the envelope of wavelet func-tion, it is concluded that the pulse-response function of the interdigital transducer (IDT) for surface acoustic wave (SAW) is ide...In the design of the finger-overlap envelope according to the envelope of wavelet func-tion, it is concluded that the pulse-response function of the interdigital transducer (IDT) for surface acoustic wave (SAW) is identical to the wavelet function. SAW type of the wavelet-transform ele-ment is manufactured. A new method of using two wavelet-transform elements to manufacture the reconstruction element of the wavelet transform is proposed. The sources of the element error are analyzed, and the methods for reducing the error are put forward. SAW type of the wavelet trans-formation element and its reconstruction element have the following three characteristics: (i) the implementing methods of the wavelet transform element and its reconstruction element are simple, and free of complicated mathematical algorithms of the wavelet transform; (ii) because one of SAW element is fast, the response velocities of SAW type of the wavelet transform element and its reconstruction element are also fast; (iii) the costs of the wavelet transform element and its recon-struction element are low, so the elements may be manufactured in a large quantity.展开更多
Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative dist...Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi- nylidene fluoride （PVDF） transducer is designed to realize the mode selection of gnided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.展开更多
Flexible pressure sensors have attracted great attention due to their potential in the wearable devices market and in particular in human-machine interactive interfaces.Pressure sensors with high sensitivity,wide meas...Flexible pressure sensors have attracted great attention due to their potential in the wearable devices market and in particular in human-machine interactive interfaces.Pressure sensors with high sensitivity,wide measurement range,and low-cost are now highly desired for such practical applications.In the present investigation,an ultrasensitive pressure sensor with wide measurement range has been successfully fabricated.Carbon nanotubes(CNTs)(uniformly sprayed on the surface of paper)comprise the sensitivity material,while lithographed interdigital electrodes comprise the substrate.Due to the synergistic effects of CNT’s high specific surface area,paper’s porous structure,interdigital electrodes’efficient contact with CNT,our pressure sensor realizes a wide measurement range from 0 to 140 kPa and exhibits excellent stability through 15,000 cycles of testing.For the paper-based CNT film/interdigitated structure(PCI)pressure sensor,the connection area between the sensitive material and interdigital electrodes dominates in the lowpressure region,while internal change within the sensitive materials plays the leading role in the high-pressure region.Additionally,the PCI pressure sensor not only displays a high sensitivity of 2.72 kPa–1(up to 35 kPa)but also can detect low pressures,such as that exerted by a resting mung bean(about 8 Pa).When attached to the surface of a human body,the pressure sensor can monitor physiological signals,such as wrist movement,pulse beats,or movement of throat muscles.Furthermore,the pressure sensor array can identify the spatial pressure distribution,with promising applications in humanmachine interactive interfaces.展开更多
Rapid screening of foodborne pathogens is of great significance to ensure food safety.A microfluidic biosensor based on immunomagnetic separation,enzyme catalysis and electrochemical impedance analysis was developed f...Rapid screening of foodborne pathogens is of great significance to ensure food safety.A microfluidic biosensor based on immunomagnetic separation,enzyme catalysis and electrochemical impedance analysis was developed for rapid and sensitive detection of S.typhimurium.First,the bacterial sample,the magnetic nanoparticles(MNPs)modified with capture antibodies,and the enzymatic probes modified with detection antibodies and glucose oxidase(GOx)were simultaneously injected into the microfluidic chip,followed by mixing and incubation to form MNP-bacteria-probe sandwich complexes.Then,glucose with high impedance was injected into the chip and catalyzed by the GOx on the complexes into hydrogen peroxide with high impedance and gluconic acid with low impedance,which was finally measured using the low-cost interdigitated microelectrode and the electrochemical impedance analyzer to determine the target bacteria.Under the optimal conditions,this biosensor could quantitatively detect S.typhimurium at the concentrations from 1.6×10^(2) CFU/m L to 1.6×10^(6) CFU/m L in 1 h with the low detection limit of 73 CFU/m L.Besides,this biosensor was demonstrated with good feasibility for practical applications by detecting the S.typhimurium spiked chicken meat samples.展开更多
Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a ...Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.展开更多
基金This note is one of research fruits of the Project 9487002, supported by the National Natural Science Foundation of China.
文摘Interdigitation means mutual nappe structures which might result from the low-angle thrusting during the collision betWeen tWo continental blocks. It is well developed in the coveting strata of Laochang-Laba district, Lancang, Yunnan Province ( Fig. 1).
基金Financially supported by the National Natural Science Foundation of China(No.21571149)the Program for Chongqing Excellent Talents in University,the Fundamental Research Funds for the Central Universities(XDJK2013A027,XDJK2016C101)the Open Foundation of Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education(338080045)
文摘Two Zn（II） coordination polymers, namely [Zn2（bpy）（aobtc）（H2O）2]·2H2O（1） and [Zn2（bpy）（aobtc）（H2O）]·4H2O（2）（bpy = 4,4＇-bipyridine, H4 aobtc = 3,3＇,5,5＇-azoxybenzenetetracarboxylic acid） have been hydrothermally synthesized through tuning the p H value of the reaction system（1, C（26）H（22）N（4）O（13）Zn2, Mr = 729.21; 2, C（26）H（24）N4O（14）Zn2, Mr = 747.23）, and their structures have been determined by single-crystal X-ray diffraction analyses. Compound 2 has been further characterized by infrared spectra（IR）, elemental analyses, thermal analyses and powder X-ray diffraction（PXRD） analyses. Additionally, the photoluminescence of 2 is also discussed. The structure demonstrates that the crystal of 2 belongs to the triclinic system, space group P1 with a = 8.41494（18）, b = 9.59838（19）, c = 17.6477（3） ？, α = 91.5098（16）, β = 98.1439（17）, γ = 90.4323（17）°, V = 1410.44（5） ^3, Z = 2, ρcalc = 1.759 g/cm^3, μ = 2.819 mm-1, F（000） = 760.0, R = 0.0311 and w R = 0.0839（I 〉 2σ（I））. Compound 1 shows a two-dimensional monolayer while compound 2 displays a novel 2D double-layered network constructed from monolayer motifs, which is similar to the single layer in 1. Further, each bilayer motif in 2 is interdigitated by two others in a parallel fashion to yield an unusual 2D → 3D interdigitated framework.
基金supported by funding from the National Natural Science Foundation of China (31970730, 32170721)。
文摘In plants, cortical microtubules anchor to the plasma membrane in arrays and play important roles in cell shape. However, the molecular mechanism of microtubule binding proteins, which connect the plasma membrane and cortical microtubules in cell morphology remains largely unknown. Here, we report that a plasma membrane and microtubule duallocalized IQ67 domain protein, IQD21, is critical for cotyledon pavement cell(PC) morphogenesis in Arabidopsis. iqd21 mutation caused increased indentation width, decreased lobe length, and similar lobe number of PCs, whereas IQD21 overexpression had a different effect on cotyledon PC shape. Weak overexpression led to increased lobe number, decreased indentation width, and similar lobe length, while moderate or great overexpression resulted in decreased lobe number, indentation width, and lobe length of PCs. Live-cell observations revealed that IQD21 accumulation at indentation regions correlates with lobe initiation and outgrowth during PC development. Cell biological and genetic approaches revealed that IQD21 promotes transfacial microtubules anchoring to the plasma membrane via its polybasic sites and bundling at the indentation regions in both periclinal and anticlinal walls. IQD21 controls cortical microtubule organization mainly through promoting Katanin 1-mediated microtubule severing during PC interdigitation. These findings provide the genetic evidence that transfacial microtubule arrays play a determinant role in lobe formation, and the insight into the molecular mechanism of IQD21 in transfacial microtubule organization at indentations and puzzle-shaped PC development.
文摘Performance of the proton exchange membrane fuel cell(PEMFC)is appreciably affected by the channel geometry.The branching structure of a plant leaf and human lung is an efficient network to distribute the nutrients in the respective systems.The same nutrient transport system can be mimicked in the flow channel design of a PEMFC,to aid even reactant distribution and better water management.In this work,the effect of bio-inspired flow field designs such as lung and leaf channel design bipolar plates,on the performance of a PEMFC was examined experimentally at various operating conditions.A PEMFC of 49 cm2 area,with a Nafion 212 membrane with a 40%catalyst loading of 0.4 mg·cm-2 on the anode side and also 0.6 mg·cm-2 on the cathode side is assembled by incorporating the bio-inspired channel bipolar plate,and was tested on a programmable fuel-cell test station.The impact of the working parameters like reactants’relative humidity(RH),back pressure and fuel cell temperature on the performance of the fuel cell was examined;the operating pressure remains constant at 0.1 MPa.It was observed that the best performance was attained at a back pressure of 0.3 MPa,75°C operating temperature and 100%RH.The three flow channels were also compared at different operating pressures ranging from 0.1 MPa to 0.3 MPa,and the other parameters such as operating temperature,RH and back pressure were set as 75°C,100%and 0.3 MPa.The experimental outcomes of the PEMFC with bio-inspired channels were compared with the experimental results of a conventional triple serpentine flow field.It was observed that among the different flow channel designs considered,the leaf channel design gives the best output in terms of power density.Further,the experimental results of the leaf channel design were compared with those of the interdigitated leaf channel design.The PEMFC with the interdigitated leaf channel design was found to generate 6.72%more power density than the non-interdigitated leaf channel design.The fuel cell with interdigitated leaf cha
文摘In this paper,we review the past and recent works on generating intense terahertz(THz)pulses from photoconductive antennas(PCAs).We will focus on two types of large-aperture photoconductive antenna(LAPCA)that can generate high-intensity THz pulses(a)those with large-aperture dipoles and(b)those with interdigitated electrodes.We will first describe the principles of THz generation from PCAs.The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized.We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with widebandgap semiconductor substrates.Then,we will explain the evolution of LAPCA with interdigitated electrodes,which allows one to reduce the photoconductive gap size,and thus obtain higher bias fields while applying lower voltages.We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by ampli-fied lasers.Finally,we will discuss the future perspectives of THz pulse generation using LAPCAs.
文摘In the design of the finger-overlap envelope according to the envelope of wavelet func-tion, it is concluded that the pulse-response function of the interdigital transducer (IDT) for surface acoustic wave (SAW) is identical to the wavelet function. SAW type of the wavelet-transform ele-ment is manufactured. A new method of using two wavelet-transform elements to manufacture the reconstruction element of the wavelet transform is proposed. The sources of the element error are analyzed, and the methods for reducing the error are put forward. SAW type of the wavelet trans-formation element and its reconstruction element have the following three characteristics: (i) the implementing methods of the wavelet transform element and its reconstruction element are simple, and free of complicated mathematical algorithms of the wavelet transform; (ii) because one of SAW element is fast, the response velocities of SAW type of the wavelet transform element and its reconstruction element are also fast; (iii) the costs of the wavelet transform element and its recon-struction element are low, so the elements may be manufactured in a large quantity.
基金This project is supported by National Natural Science Foundation of China (No. 60404017)Municipal Natural Science Foundation of Beijing, China (No.4052008)Plan of Excellent People Cultivation of Beijing, China (No. 20051D0501506)
文摘Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi- nylidene fluoride （PVDF） transducer is designed to realize the mode selection of gnided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.
基金the funding support from the National Natural Science Foundation of China (51605449, 51675493 and 51705476)Shanxi “1331 Project” Key Subject Construction (1331KSC)
文摘Flexible pressure sensors have attracted great attention due to their potential in the wearable devices market and in particular in human-machine interactive interfaces.Pressure sensors with high sensitivity,wide measurement range,and low-cost are now highly desired for such practical applications.In the present investigation,an ultrasensitive pressure sensor with wide measurement range has been successfully fabricated.Carbon nanotubes(CNTs)(uniformly sprayed on the surface of paper)comprise the sensitivity material,while lithographed interdigital electrodes comprise the substrate.Due to the synergistic effects of CNT’s high specific surface area,paper’s porous structure,interdigital electrodes’efficient contact with CNT,our pressure sensor realizes a wide measurement range from 0 to 140 kPa and exhibits excellent stability through 15,000 cycles of testing.For the paper-based CNT film/interdigitated structure(PCI)pressure sensor,the connection area between the sensitive material and interdigital electrodes dominates in the lowpressure region,while internal change within the sensitive materials plays the leading role in the high-pressure region.Additionally,the PCI pressure sensor not only displays a high sensitivity of 2.72 kPa–1(up to 35 kPa)but also can detect low pressures,such as that exerted by a resting mung bean(about 8 Pa).When attached to the surface of a human body,the pressure sensor can monitor physiological signals,such as wrist movement,pulse beats,or movement of throat muscles.Furthermore,the pressure sensor array can identify the spatial pressure distribution,with promising applications in humanmachine interactive interfaces.
文摘Rapid screening of foodborne pathogens is of great significance to ensure food safety.A microfluidic biosensor based on immunomagnetic separation,enzyme catalysis and electrochemical impedance analysis was developed for rapid and sensitive detection of S.typhimurium.First,the bacterial sample,the magnetic nanoparticles(MNPs)modified with capture antibodies,and the enzymatic probes modified with detection antibodies and glucose oxidase(GOx)were simultaneously injected into the microfluidic chip,followed by mixing and incubation to form MNP-bacteria-probe sandwich complexes.Then,glucose with high impedance was injected into the chip and catalyzed by the GOx on the complexes into hydrogen peroxide with high impedance and gluconic acid with low impedance,which was finally measured using the low-cost interdigitated microelectrode and the electrochemical impedance analyzer to determine the target bacteria.Under the optimal conditions,this biosensor could quantitatively detect S.typhimurium at the concentrations from 1.6×10^(2) CFU/m L to 1.6×10^(6) CFU/m L in 1 h with the low detection limit of 73 CFU/m L.Besides,this biosensor was demonstrated with good feasibility for practical applications by detecting the S.typhimurium spiked chicken meat samples.
基金The Hong Kong Polytechnic University for the funding support(Nos.1-YW1B,G-YBV2,and G-UACC).
文摘Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.
