The Stinger PDC cutter has high rock-breaking efficiency and excellent impact and wear resistance, which can significantly increase the rate of penetration (ROP) and extend PDC bit life for drilling hard and abrasive ...The Stinger PDC cutter has high rock-breaking efficiency and excellent impact and wear resistance, which can significantly increase the rate of penetration (ROP) and extend PDC bit life for drilling hard and abrasive formation. The knowledge of force response and mechanical specific energy (MSE) for the Stinger PDC cutter is of great importance for improving the cutter's performance and optimizing the hybrid PDC bit design. In this paper, 87 single cutter tests were conducted on the granite. A new method for precisely obtaining the rock broken volume was proposed. The influences of cutting depth, cutting angle, and cutting speed on cutting force and MSE were analyzed. Besides, a phenomenological cutting force model of the Stinger PDC cutter was established by regression of experimental data. Moreover, the surface topography and fracture morphology of the cutting groove and large size cuttings were measured by a 3D profilometer and a scanning electron microscope (SEM). Finally, the rock-breaking mechanism of the Stinger PDC cutter was illustrated. The results indicated that the cutting depth has the greatest influence on the cutting force and MSE, while the cutting speed has no obvious effects, especially at low cutting speeds. As the increase of cutting depth, the cutting force increases linearly, and MSE reduces with a quadratic polynomial relationship. When the cutting angle raises from 10° to 30°, the cutting force increases linearly, and the MSE firstly decreases and then increases. The optimal cutting angle for breaking rock is approximately 20°. The Stinger PDC cutter breaks granite mainly by high concentrated point loading and tensile failure, which can observably improve the rock breaking efficiency. The key findings of this work will help to reveal the rock-breaking mechanisms and optimize the cutter arrangement for the Stinger PDC cutter.展开更多
The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by mi...The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by micromechanics. These are also used in the micromechanical damage modeling. Further, these properties are used as an indicator of the excellence of product by manufacturers. In the present study the axial tensile modulus, ultimate strength and failure strain of single fibres are determined for carbon and glass fibres. ASTM D3379-75 standard is followed and a number of fibers are tested for statistical analysis. The axial tensile moduli measured are 246.7 GPa and 93.3 GPa, respectively and strength are 3031.6 MPa and 2035.9 MPa, respectively for carbon and glass fibres. Further, the respective axial tensile failure strains are 0.0137 and 0.0224. The error in the measurement of axial modulus is below 8% while for axial tensile strength is below 1%.展开更多
A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transf...A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.展开更多
The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-...The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian '. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.展开更多
The application of polyimide( PI) fibers in the field of composite materials has been limited because of their smooth surface and chemical inertness. In order to overcome these problems,oxygen plasma was used to modif...The application of polyimide( PI) fibers in the field of composite materials has been limited because of their smooth surface and chemical inertness. In order to overcome these problems,oxygen plasma was used to modify the surface of fibers. The single fiber fragmentation test( SFFT) was used to characterize the interfacial adhesion performance of PI fiber as a simple and accurate analysis method. It was found that the interfacial shear strength between the fiber and resin after oxygen plasma modification was increased by 54% compared to the untreated fiber. Meanwhile, the surface micromorphology,chemical composition, wettability of fibers and the interface morphology at the fiber fracture were analyzed by field emission scanning electron microscope( FESEM), X-ray photoelectron spectroscopy( XPS),contact angle measurement and polarizing microscope,respectively. All of these results demonstrated that the single fiber fragmentation test for analyzing the interfacial adhesion of PI fibers was effective.展开更多
By using swap test,a quantum private comparison(QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed.The semi-honest third party(TP) is required to help two participants perform th...By using swap test,a quantum private comparison(QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed.The semi-honest third party(TP) is required to help two participants perform the comparison.She can record intermediate results and do some calculations in the whole process of the protocol execution,but she cannot conspire with any of participants.In the process of comparison,the TP cannot get two participants’ private information except the comparison results.According to the security analysis,the proposed protocol can resist both outsider attacks and participants’ attacks.Compared with the existing QPC protocols,the proposed one does not require any entanglement swapping technology,but it can compare two participants’ qubits by performing swap test,which is easier to implement with current technology.Meanwhile,the proposed protocol can compare secret integers.It encodes secret integers into the amplitude of quantum state rather than transfer them as binary representations,and the encoded quantum state is compared by performing the swap test.Additionally,the proposed QPC protocol is extended to the QPC of arbitrary single qubit states by using multi-qubit swap test.展开更多
Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an...Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an optical system with objective lens, prism, microscope tube and charge coupled device (CCD). A thin ZnS film doped with Ag ions is used as a luminescent material. Generation efficiency and transmission efficiency of photons in the ZnS(Ag) film created by irradiated Cl ions are calculated. A single Cl ion optical microscopic image is observed by high quantum efficiency CCD. The resolution of a single Cl ion given in this IPEM system is 6μm. Several factors influencing the resolution are discussed. A silicon diode is used to collect the electrical signals caused by the incident ions. Effective and accidental coincidence of optical images and electronic signals are illustrated. A two-dimensional map of single event effect is drawn out according to the data of effective coincidence.展开更多
Natural space presents a complicated radiation environment containing various energetic particle types at different flux level and the flux of the particles is not constant modulating by solar activities[1]. On the ot...Natural space presents a complicated radiation environment containing various energetic particle types at different flux level and the flux of the particles is not constant modulating by solar activities[1]. On the other hand, the heavy ion flux applied in ground based single event test was commonly set at a fixed value. Refs. [2] and [3] both pointed out that the single event test result of harden device may exhibit flux dependency. It is necessary to fully study the ion flux dependency on single event effect.展开更多
In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal-oxide-semiconductor (MOS) devices irradiated by pulsed laser beams. Transient sig...In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal-oxide-semiconductor (MOS) devices irradiated by pulsed laser beams. Transient signal characteristics of a 0.18-p.m single MOS device, such as SET pulse width, pulse maximum, and collected charge, are measured and an- alyzed at wafer level. We analyze in detail the influences of supply voltage and pulse energy on the SET characteristics of the device under test (DUT). The dependences of SET characteristics on drain-induced barrier lowering (DIBL) and the parasitic bipolar junction transistor (PBJT) are also discussed. These results provide a guide for radiation-hardened deep sub-micrometer PDSOI technology for space electronics applications.展开更多
[Objective]The paper was to study optimum chemical agents and control periods against rice false smut( Ustilaginoidea virens) in single cropping middle-late rice. [Method]Taking chemical agents( triadimefon,armure,Jin...[Objective]The paper was to study optimum chemical agents and control periods against rice false smut( Ustilaginoidea virens) in single cropping middle-late rice. [Method]Taking chemical agents( triadimefon,armure,Jinggangmycin) as main treatments and spraying periods( within 7 d before initial heading stage,within 7 d before initial heading stage + initial heading stage,initial heading stage) as assisted treatments,the field efficacy trial and optimum control period of U. virens in single cropping middle-late rice were studied using Huanghuazhan and Jinnongsimiao as experimental materials in 2013. [Result] Three chemical agents,triadimefon,armure,Jinggangmycin,extremely reduced diseased panicle rate and disease index of U. virens,but there was no significant difference among three chemical agents. Spraying period did not have significant impact on diseased panicle rate and disease index of U. virens,whereas spraying within7 d before initial heading stage and during initial heading stage had relatively good control effect. Yield increased significantly after application of three chemical agents,and armure led to greater increase. The reason for yield increase was that seed setting rate was significantly increased,and the number of filled grains per panicle was significantly increased. Although spraying period influenced yield,the difference was not significant. [Conclusion] Triadimefon,armure and Jinggangmycin had good control effects against U. virens in single cropping middle-late rice,of which armure had better control effects. Spraying chemical agents increased seed setting rate,and further increased the number of filled grains per panicle and yield. Spraying within 7 d before initial heading stage and during initial heading stage had relatively better control effect against U. virens.展开更多
A frequency domain method for estimating wind-induced fluctuating internal pressure of structure with single windward opening is presented in this paper and wind tunnel tests were carried out to verify the theory. The...A frequency domain method for estimating wind-induced fluctuating internal pressure of structure with single windward opening is presented in this paper and wind tunnel tests were carried out to verify the theory. The nonlinear differential equation of internal pressure dynamics and iteration algorithm were applied to calculate fluctuating internal pressure and time domain analysis was used to verify the accuracy of the proposed method. A simplified estimation method is also provided and its scope of application is clarified. The mechanism of internal pressure fluctuation is obtained by using the proposed method in the frequency domain and a new equivalent opening ratio is defined to evaluate internal pressure fluctuation. A series of low-rise building models with various openings and internal volumes were designed for wind tunnel tests with results agreeing well with analytical results. It is shown that the proposed frequency domain method based on Gaussian distribution of internal pressure fluctuations can be applied to predict the RMS internal pressure coefficient with adequate accuracy for any opening dimensions, while the simplified method can only be used for structure with single dominant opening. Helmholtz resonance is likely to occur when the equivalent opening ratio is adequately high, and controlling individual opening dimension is an effective strategy for avoiding Helmholtz resonance in engineering.展开更多
In this paper,the nature and origin of single event effects(SEE) are studied by injecting laser pulses into different circuit blocks,combining with analysis to map pulse width modulators circuitry in the microchip die...In this paper,the nature and origin of single event effects(SEE) are studied by injecting laser pulses into different circuit blocks,combining with analysis to map pulse width modulators circuitry in the microchip die.A time-domain error-identification method is used in the temporal characteristic analysis of SEE.SEE signatures of different injection times are compared.More serious SEE are observed when the laser shot occurs on a rising edge of the device output for blocks of the error amplifier,current sense comparator,and T and SR latches.展开更多
In recent decades,designers have increasingly focused on the stability of assemblies in composite materials over time,particularly when used in structural applications.The use of structural adhesives allows for realis...In recent decades,designers have increasingly focused on the stability of assemblies in composite materials over time,particularly when used in structural applications.The use of structural adhesives allows for realising assemblies without mechanical fasteners.In fact,bonding is an assembly technique that prevent corrosion,ensures uniform stresses in the joint,and grows the specific resistance of the assembly.The knowledge of the behaviour of bonded joint is necessary to ensure the reliability of this technique over time,especially in aggressive environments.The aim of this wo rk consists in investigating the combined effect of hydrothermal ageing and temperature test on the lap shear strength of single lap joints realised in CFRP.The results showed a higher influence of the ageing on paste adhesive compared to film adhesive.However,the ageing,combined with the operating temperature,played a fundamental role on the shear strength of the bonded joints.展开更多
A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place so...A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place soils.Firstly,the liquefaction potential of the soil at the project site is analysed according to the code of seismic design.Then the in-situ single point impact tests are performed on the liquefiable soil.Settlement of crater,excess pore pressure,ground heave and lateral deformation under DC impact are measured and analyzed.Subsequently, the standard penetration test(SPT)and cone penetration test(CPT)are used for investigating the compaction effectiveness.At last,the improvement effect of DC is discussed according to the technical specification of dynamic consolidation to ground treatment.The investigation results indicate that the DC technique is an effective way for remediating liquefiable soil in highway engineering practice.展开更多
Recently, it is predicted that the fossil fuels will be sufficient for a few decades at the present extraction rates. So, the performance studies of the internal combustion engines play an important role to achieve th...Recently, it is predicted that the fossil fuels will be sufficient for a few decades at the present extraction rates. So, the performance studies of the internal combustion engines play an important role to achieve the best operating point at different weather temperatures. In the present study, the effects of the inlet air temperatures on the engine performance characteristics were studied at different cooling loads. Several experiments were carried out on a single cylinder diesel engine (SCDI). The performance characteristics of SCDI included: brake power, specific fuel consumption, brake thermal efficiency and exhaust emissions (carbon dioxide, CO2, carbon monoxide CO, and hydrocarbon HC). The findings show that the inlet air temperature and cooling conditions have appreciable effect on the performance characteristics of the SCDI especially at low cooling rate. It can be concluded that the high cooling rate leads to the enhancement in the brake thermal efficiency, the b.s.f.c, and the emitted COz, CO, and HC. On the other hand the high cooling rate leads to the decrease in the volumetric efficiency. So, a compromising between the inlet air temperature and the cooling rate should be recommended for the engine best performance.展开更多
Introduction: The COVID-19 pandemic has resulted in a reconsideration of our traditional teaching modalities and develop newer, dynamic methods. Both high and low fidelity bronchoscopy simulators are costly. The objec...Introduction: The COVID-19 pandemic has resulted in a reconsideration of our traditional teaching modalities and develop newer, dynamic methods. Both high and low fidelity bronchoscopy simulators are costly. The objective was to assess whether a combination of a low-cost bio-simulator made of recyclable materials (ALFIE<sup>TM</sup> Airway Low Fidelity including EBUS (endobronchial ultrasound)) and single use flexible bronchoscopy (SUFB) has the capability of differentiating novices from experts and the ability to train novices in bronchoscopy. Materials and Methods: Trainees were evaluated individually before and after training using a modified validated Bronchoscopy Skills and Tasks Assessment Tool (B-STAT) and SUFB. Results: 18 trainees were included (14 residents and 4 fellows). Pre-training assessment of scope handling differentiated novices from experienced bronchoscopists (p = 0.0025, 95% confidence intervals (CI) 3.12 - 12.17). Training of novices was associated with an improvement in scope handling and sampling (p = 0.0001, 95% CI 4.73 - 10.27). Conclusion: ALFIE<sup>TM</sup> and SUFB have the potential to create a low-cost platform to teach bronchoscopy remotely.展开更多
=In the advancement of single-isocenter multiple target treatment in the LINAC-based SRS or SRT, the target distance to the isocenter and grouping of multiple targets are the highly concerned and debatable topics in t...=In the advancement of single-isocenter multiple target treatment in the LINAC-based SRS or SRT, the target distance to the isocenter and grouping of multiple targets are the highly concerned and debatable topics in the SRS/SRT field at present. Three failure and success cases of local control in our early practices are presented in this study and it indicated that the target distance to the isocenter directly affects the margin and an inappropriate margin increase the risk of local control failure. The GTV expansion margin should be LINAC-specific and institute-specific. Within the physics and dosimetry scope, the AHARA (as high as reasonably achievable) principle is the first time proposed to the radiation oncology field. Radiobiology and tumor response complexity is beyond this study.展开更多
The testing on the bearing strength of single-shear bolt jointed composite laminates structure is done.And the effect of the fixture on the testing results is analyzed. Then a macro-micro multi-scale analytical model ...The testing on the bearing strength of single-shear bolt jointed composite laminates structure is done.And the effect of the fixture on the testing results is analyzed. Then a macro-micro multi-scale analytical model combined with the improved"Generalized Method of Cells( GMC) "is developed,which is used to predict the macro bearing strength and to characterize the micro constitute material failure of the bolt jointed composite laminates structure. Both the contact conditions at the bolt/hole boundary and the contact conditions at the specimen/fixture boundary,progressive damage,and the material properties degradation are all taken account into the analytical model. Thus,the numerical simulation results agree well with the experimental results.Finally,the effect of the fixture on the testing results is characterized. The results show that the incomplete contaction between the fixture and the specimen or the lack of the lateral constraint on the specimen will affect the limited bearing strength and the offset bearing strength of the bolt jointed composite laminates structure. In addition,the lower support rigid of the fixture will affect the rigid of the bolt jointed composite laminates structure.展开更多
In order to study the infl uence of the ground motion spatial eff ect on the seismic response of large span spatial structures with isolation bearings, a single-layer cylindrical latticed shell scale model with a simi...In order to study the infl uence of the ground motion spatial eff ect on the seismic response of large span spatial structures with isolation bearings, a single-layer cylindrical latticed shell scale model with a similarity ratio of 1/10 was constructed. An earthquake simulation shaking table test on the response under multiple-support excitations was performed with the high-position seismic isolation method using high damping rubber (HDR) bearings. Small-amplitude sinusoidal waves and seismic wave records with various spectral characteristics were applied to the model. The dynamic characteristics of the model and the seismic isolation eff ect on it were analyzed at varying apparent wave velocities, namely infi nitely great, 1000 m/s, 500 m/s and 250 m/s. Besides, numerical simulations were carried out by Matlab software. According to the comparison results, the numerical results agreed well with the experimental data. Moreover, the results showed that the latticed shell roof exhibited a translational motion as a rigid body after the installation of the HDR bearings with a much lower natural frequency, higher damping ratio and only 1/2~1/8 of the acceleration response peak values. Meanwhile, the structural responses and the bearing deformations at the output end of the seismic waves were greatly increased under multiple-support excitations.展开更多
The effect of dielectric barrier discharge(DBD)on the interfacial mechanical property of polypropylene fiber reinforced cement is investigated with the aid of single fiber pull out test.The result shows that the DBD t...The effect of dielectric barrier discharge(DBD)on the interfacial mechanical property of polypropylene fiber reinforced cement is investigated with the aid of single fiber pull out test.The result shows that the DBD treatment improved the adhesion between the PP fiber and the surrounding cement matrix considerably without serious aging.Keywords:dielectric barrier discharge,single fiber pull-out test.展开更多
基金supported by the Joint Funds of The National Natural Science Foundation of China(Grant No.U19B6003-05)the National Key Research and Development Program of China(No.2019YFA0708302)+2 种基金the National Science Fund for Distinguished Young Scholars(Grant No.51725404)the Beijing Outstanding Young Scientist Program(Grant No.BJJWZYJH01201911414038)the Strategic Cooperation Technology Projects of CNPC and CUPB(Grant No.ZLZX2020-01).
文摘The Stinger PDC cutter has high rock-breaking efficiency and excellent impact and wear resistance, which can significantly increase the rate of penetration (ROP) and extend PDC bit life for drilling hard and abrasive formation. The knowledge of force response and mechanical specific energy (MSE) for the Stinger PDC cutter is of great importance for improving the cutter's performance and optimizing the hybrid PDC bit design. In this paper, 87 single cutter tests were conducted on the granite. A new method for precisely obtaining the rock broken volume was proposed. The influences of cutting depth, cutting angle, and cutting speed on cutting force and MSE were analyzed. Besides, a phenomenological cutting force model of the Stinger PDC cutter was established by regression of experimental data. Moreover, the surface topography and fracture morphology of the cutting groove and large size cuttings were measured by a 3D profilometer and a scanning electron microscope (SEM). Finally, the rock-breaking mechanism of the Stinger PDC cutter was illustrated. The results indicated that the cutting depth has the greatest influence on the cutting force and MSE, while the cutting speed has no obvious effects, especially at low cutting speeds. As the increase of cutting depth, the cutting force increases linearly, and MSE reduces with a quadratic polynomial relationship. When the cutting angle raises from 10° to 30°, the cutting force increases linearly, and the MSE firstly decreases and then increases. The optimal cutting angle for breaking rock is approximately 20°. The Stinger PDC cutter breaks granite mainly by high concentrated point loading and tensile failure, which can observably improve the rock breaking efficiency. The key findings of this work will help to reveal the rock-breaking mechanisms and optimize the cutter arrangement for the Stinger PDC cutter.
文摘The mechanical and damage properties of single fibres used in fibrous composite have gained tremendous importance in recent years. These properties are used in determination of effective properties of composites by micromechanics. These are also used in the micromechanical damage modeling. Further, these properties are used as an indicator of the excellence of product by manufacturers. In the present study the axial tensile modulus, ultimate strength and failure strain of single fibres are determined for carbon and glass fibres. ASTM D3379-75 standard is followed and a number of fibers are tested for statistical analysis. The axial tensile moduli measured are 246.7 GPa and 93.3 GPa, respectively and strength are 3031.6 MPa and 2035.9 MPa, respectively for carbon and glass fibres. Further, the respective axial tensile failure strains are 0.0137 and 0.0224. The error in the measurement of axial modulus is below 8% while for axial tensile strength is below 1%.
基金Supported by the Key Laboratory of Microsatellites,Chinese Academy of Sciences
文摘A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.
基金The project supported by the National Meg-Science Enineering Project of Chinese Government
文摘The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian '. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.
基金National Key R&D Program of China(No.2016YFB0303300)National Natural Science Foundation of China(No.11472077)Fundamental Research Funds for the Central Universities,China(No.2232018G-06)
文摘The application of polyimide( PI) fibers in the field of composite materials has been limited because of their smooth surface and chemical inertness. In order to overcome these problems,oxygen plasma was used to modify the surface of fibers. The single fiber fragmentation test( SFFT) was used to characterize the interfacial adhesion performance of PI fiber as a simple and accurate analysis method. It was found that the interfacial shear strength between the fiber and resin after oxygen plasma modification was increased by 54% compared to the untreated fiber. Meanwhile, the surface micromorphology,chemical composition, wettability of fibers and the interface morphology at the fiber fracture were analyzed by field emission scanning electron microscope( FESEM), X-ray photoelectron spectroscopy( XPS),contact angle measurement and polarizing microscope,respectively. All of these results demonstrated that the single fiber fragmentation test for analyzing the interfacial adhesion of PI fibers was effective.
基金Project supported by the National Natural Science Foundation of China(Grant No.62076042)the Key Research and Development Project of Sichuan Province,China(Grant Nos.2020YFG0307 and 2021YFSY0012)+2 种基金the Key Research and Development Project of Chengdu Municipality,China(Grant No.2019-YF05-02028-GX)the Innovation Team of Quantum Security Communication of Sichuan Province,China(Grant No.17TD0009)the Academic and Technical Leaders Training Funding Support Projects of Sichuan Province,China(Grant No.2016120080102643)。
文摘By using swap test,a quantum private comparison(QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed.The semi-honest third party(TP) is required to help two participants perform the comparison.She can record intermediate results and do some calculations in the whole process of the protocol execution,but she cannot conspire with any of participants.In the process of comparison,the TP cannot get two participants’ private information except the comparison results.According to the security analysis,the proposed protocol can resist both outsider attacks and participants’ attacks.Compared with the existing QPC protocols,the proposed one does not require any entanglement swapping technology,but it can compare two participants’ qubits by performing swap test,which is easier to implement with current technology.Meanwhile,the proposed protocol can compare secret integers.It encodes secret integers into the amplitude of quantum state rather than transfer them as binary representations,and the encoded quantum state is compared by performing the swap test.Additionally,the proposed QPC protocol is extended to the QPC of arbitrary single qubit states by using multi-qubit swap test.
基金Supported by the National Natural Science Foundation of China under Grant No 11690044
文摘Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an optical system with objective lens, prism, microscope tube and charge coupled device (CCD). A thin ZnS film doped with Ag ions is used as a luminescent material. Generation efficiency and transmission efficiency of photons in the ZnS(Ag) film created by irradiated Cl ions are calculated. A single Cl ion optical microscopic image is observed by high quantum efficiency CCD. The resolution of a single Cl ion given in this IPEM system is 6μm. Several factors influencing the resolution are discussed. A silicon diode is used to collect the electrical signals caused by the incident ions. Effective and accidental coincidence of optical images and electronic signals are illustrated. A two-dimensional map of single event effect is drawn out according to the data of effective coincidence.
文摘Natural space presents a complicated radiation environment containing various energetic particle types at different flux level and the flux of the particles is not constant modulating by solar activities[1]. On the other hand, the heavy ion flux applied in ground based single event test was commonly set at a fixed value. Refs. [2] and [3] both pointed out that the single event test result of harden device may exhibit flux dependency. It is necessary to fully study the ion flux dependency on single event effect.
文摘In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal-oxide-semiconductor (MOS) devices irradiated by pulsed laser beams. Transient signal characteristics of a 0.18-p.m single MOS device, such as SET pulse width, pulse maximum, and collected charge, are measured and an- alyzed at wafer level. We analyze in detail the influences of supply voltage and pulse energy on the SET characteristics of the device under test (DUT). The dependences of SET characteristics on drain-induced barrier lowering (DIBL) and the parasitic bipolar junction transistor (PBJT) are also discussed. These results provide a guide for radiation-hardened deep sub-micrometer PDSOI technology for space electronics applications.
基金Supported by National Science and Technology Support Program(2007BAD89B14)Special Fund for Agro-scientific Research in the Public Interest(00803028)+3 种基金Major Technical Research Project of Ministry of Agriculture for Agricultural Structure Adjustment(06-03-07B)Project of Guangdong Provincial Finance Department(YCY[2005]No.11,YCJ[2006]No.187)Agricultural Research Project of Guangdong Provincial Science and Technology Department(2005B20101001)Special Fund for Agro-scientific Research in the Public Interest(201103001)
文摘[Objective]The paper was to study optimum chemical agents and control periods against rice false smut( Ustilaginoidea virens) in single cropping middle-late rice. [Method]Taking chemical agents( triadimefon,armure,Jinggangmycin) as main treatments and spraying periods( within 7 d before initial heading stage,within 7 d before initial heading stage + initial heading stage,initial heading stage) as assisted treatments,the field efficacy trial and optimum control period of U. virens in single cropping middle-late rice were studied using Huanghuazhan and Jinnongsimiao as experimental materials in 2013. [Result] Three chemical agents,triadimefon,armure,Jinggangmycin,extremely reduced diseased panicle rate and disease index of U. virens,but there was no significant difference among three chemical agents. Spraying period did not have significant impact on diseased panicle rate and disease index of U. virens,whereas spraying within7 d before initial heading stage and during initial heading stage had relatively good control effect. Yield increased significantly after application of three chemical agents,and armure led to greater increase. The reason for yield increase was that seed setting rate was significantly increased,and the number of filled grains per panicle was significantly increased. Although spraying period influenced yield,the difference was not significant. [Conclusion] Triadimefon,armure and Jinggangmycin had good control effects against U. virens in single cropping middle-late rice,of which armure had better control effects. Spraying chemical agents increased seed setting rate,and further increased the number of filled grains per panicle and yield. Spraying within 7 d before initial heading stage and during initial heading stage had relatively better control effect against U. virens.
基金Project (No. 50378085) supported by the National Natural ScienceFoundation of China
文摘A frequency domain method for estimating wind-induced fluctuating internal pressure of structure with single windward opening is presented in this paper and wind tunnel tests were carried out to verify the theory. The nonlinear differential equation of internal pressure dynamics and iteration algorithm were applied to calculate fluctuating internal pressure and time domain analysis was used to verify the accuracy of the proposed method. A simplified estimation method is also provided and its scope of application is clarified. The mechanism of internal pressure fluctuation is obtained by using the proposed method in the frequency domain and a new equivalent opening ratio is defined to evaluate internal pressure fluctuation. A series of low-rise building models with various openings and internal volumes were designed for wind tunnel tests with results agreeing well with analytical results. It is shown that the proposed frequency domain method based on Gaussian distribution of internal pressure fluctuations can be applied to predict the RMS internal pressure coefficient with adequate accuracy for any opening dimensions, while the simplified method can only be used for structure with single dominant opening. Helmholtz resonance is likely to occur when the equivalent opening ratio is adequately high, and controlling individual opening dimension is an effective strategy for avoiding Helmholtz resonance in engineering.
基金supported by the National Basic Research Program of China(No.613224)
文摘In this paper,the nature and origin of single event effects(SEE) are studied by injecting laser pulses into different circuit blocks,combining with analysis to map pulse width modulators circuitry in the microchip die.A time-domain error-identification method is used in the temporal characteristic analysis of SEE.SEE signatures of different injection times are compared.More serious SEE are observed when the laser shot occurs on a rising edge of the device output for blocks of the error amplifier,current sense comparator,and T and SR latches.
基金the funding of the Italian M.I.U.R.(Ministry of Instruction,University and Technological Research)。
文摘In recent decades,designers have increasingly focused on the stability of assemblies in composite materials over time,particularly when used in structural applications.The use of structural adhesives allows for realising assemblies without mechanical fasteners.In fact,bonding is an assembly technique that prevent corrosion,ensures uniform stresses in the joint,and grows the specific resistance of the assembly.The knowledge of the behaviour of bonded joint is necessary to ensure the reliability of this technique over time,especially in aggressive environments.The aim of this wo rk consists in investigating the combined effect of hydrothermal ageing and temperature test on the lap shear strength of single lap joints realised in CFRP.The results showed a higher influence of the ageing on paste adhesive compared to film adhesive.However,the ageing,combined with the operating temperature,played a fundamental role on the shear strength of the bonded joints.
基金Supported by the National Youth Science Foundation of China(40802065)the Jiangsu Province Ed-ucation Science Foundation(08KJD580004)the Innovation Research Foundation of Nanjing Institute of Technology(CKJ2011010)
文摘A highway in the floodplain of the Abandoned Yellow River in the north of Jiangsu Province is recently remediated to reduce liquefaction potential using the dynamic compaction(DC)method of densification of in-place soils.Firstly,the liquefaction potential of the soil at the project site is analysed according to the code of seismic design.Then the in-situ single point impact tests are performed on the liquefiable soil.Settlement of crater,excess pore pressure,ground heave and lateral deformation under DC impact are measured and analyzed.Subsequently, the standard penetration test(SPT)and cone penetration test(CPT)are used for investigating the compaction effectiveness.At last,the improvement effect of DC is discussed according to the technical specification of dynamic consolidation to ground treatment.The investigation results indicate that the DC technique is an effective way for remediating liquefiable soil in highway engineering practice.
文摘Recently, it is predicted that the fossil fuels will be sufficient for a few decades at the present extraction rates. So, the performance studies of the internal combustion engines play an important role to achieve the best operating point at different weather temperatures. In the present study, the effects of the inlet air temperatures on the engine performance characteristics were studied at different cooling loads. Several experiments were carried out on a single cylinder diesel engine (SCDI). The performance characteristics of SCDI included: brake power, specific fuel consumption, brake thermal efficiency and exhaust emissions (carbon dioxide, CO2, carbon monoxide CO, and hydrocarbon HC). The findings show that the inlet air temperature and cooling conditions have appreciable effect on the performance characteristics of the SCDI especially at low cooling rate. It can be concluded that the high cooling rate leads to the enhancement in the brake thermal efficiency, the b.s.f.c, and the emitted COz, CO, and HC. On the other hand the high cooling rate leads to the decrease in the volumetric efficiency. So, a compromising between the inlet air temperature and the cooling rate should be recommended for the engine best performance.
文摘Introduction: The COVID-19 pandemic has resulted in a reconsideration of our traditional teaching modalities and develop newer, dynamic methods. Both high and low fidelity bronchoscopy simulators are costly. The objective was to assess whether a combination of a low-cost bio-simulator made of recyclable materials (ALFIE<sup>TM</sup> Airway Low Fidelity including EBUS (endobronchial ultrasound)) and single use flexible bronchoscopy (SUFB) has the capability of differentiating novices from experts and the ability to train novices in bronchoscopy. Materials and Methods: Trainees were evaluated individually before and after training using a modified validated Bronchoscopy Skills and Tasks Assessment Tool (B-STAT) and SUFB. Results: 18 trainees were included (14 residents and 4 fellows). Pre-training assessment of scope handling differentiated novices from experienced bronchoscopists (p = 0.0025, 95% confidence intervals (CI) 3.12 - 12.17). Training of novices was associated with an improvement in scope handling and sampling (p = 0.0001, 95% CI 4.73 - 10.27). Conclusion: ALFIE<sup>TM</sup> and SUFB have the potential to create a low-cost platform to teach bronchoscopy remotely.
文摘=In the advancement of single-isocenter multiple target treatment in the LINAC-based SRS or SRT, the target distance to the isocenter and grouping of multiple targets are the highly concerned and debatable topics in the SRS/SRT field at present. Three failure and success cases of local control in our early practices are presented in this study and it indicated that the target distance to the isocenter directly affects the margin and an inappropriate margin increase the risk of local control failure. The GTV expansion margin should be LINAC-specific and institute-specific. Within the physics and dosimetry scope, the AHARA (as high as reasonably achievable) principle is the first time proposed to the radiation oncology field. Radiobiology and tumor response complexity is beyond this study.
基金Sponsored by the National Natural Science Foundation of China(Grant No.11272105)the Heilongjiang Province Science Foundation for Youths(Grant No.QC2015003)the Harbin Science and Technology Bureau Young Talent Reserve Project(Grant No.RC2016QN001011,RC2016QN017023)
文摘The testing on the bearing strength of single-shear bolt jointed composite laminates structure is done.And the effect of the fixture on the testing results is analyzed. Then a macro-micro multi-scale analytical model combined with the improved"Generalized Method of Cells( GMC) "is developed,which is used to predict the macro bearing strength and to characterize the micro constitute material failure of the bolt jointed composite laminates structure. Both the contact conditions at the bolt/hole boundary and the contact conditions at the specimen/fixture boundary,progressive damage,and the material properties degradation are all taken account into the analytical model. Thus,the numerical simulation results agree well with the experimental results.Finally,the effect of the fixture on the testing results is characterized. The results show that the incomplete contaction between the fixture and the specimen or the lack of the lateral constraint on the specimen will affect the limited bearing strength and the offset bearing strength of the bolt jointed composite laminates structure. In addition,the lower support rigid of the fixture will affect the rigid of the bolt jointed composite laminates structure.
基金National Natural Science Foundation of China under Grant No.51278008the National Key Research and Development Plan of China under Grant No.2016YFC0701103
文摘In order to study the infl uence of the ground motion spatial eff ect on the seismic response of large span spatial structures with isolation bearings, a single-layer cylindrical latticed shell scale model with a similarity ratio of 1/10 was constructed. An earthquake simulation shaking table test on the response under multiple-support excitations was performed with the high-position seismic isolation method using high damping rubber (HDR) bearings. Small-amplitude sinusoidal waves and seismic wave records with various spectral characteristics were applied to the model. The dynamic characteristics of the model and the seismic isolation eff ect on it were analyzed at varying apparent wave velocities, namely infi nitely great, 1000 m/s, 500 m/s and 250 m/s. Besides, numerical simulations were carried out by Matlab software. According to the comparison results, the numerical results agreed well with the experimental data. Moreover, the results showed that the latticed shell roof exhibited a translational motion as a rigid body after the installation of the HDR bearings with a much lower natural frequency, higher damping ratio and only 1/2~1/8 of the acceleration response peak values. Meanwhile, the structural responses and the bearing deformations at the output end of the seismic waves were greatly increased under multiple-support excitations.
基金This work was aupported by the National Foundation(Cranted number 29874030)
文摘The effect of dielectric barrier discharge(DBD)on the interfacial mechanical property of polypropylene fiber reinforced cement is investigated with the aid of single fiber pull out test.The result shows that the DBD treatment improved the adhesion between the PP fiber and the surrounding cement matrix considerably without serious aging.Keywords:dielectric barrier discharge,single fiber pull-out test.