Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Current...Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Currently,symmetry-protected QBIC resonance is often achieved by breaking the geometric symmetry,but few cases are achieved by breaking the material symmetry.This paper proposes a dielectric compound grating to achieve a high Q factor and high-reflection symmetry-protectede QBIC resonance based on material asymmetry.Theoretical calculations show that the symmetry-protected QBIC resonance achieved by material asymmetry can significantly increase the GH shift up to-980 times the resonance wavelength,and the maximum GH shift is located at the reflection peak with unity reflectance.This paper provides a theoretical basis for designing and fabricating high-performance GH shift tunable metasurfaces/dielectric gratings in the future.展开更多
In a cloud manufacturing environment with abundant functionally equivalent cloud services,users naturally desire the highest-quality service(s).Thus,a comprehensive measurement of quality of service(QoS)is needed.Opti...In a cloud manufacturing environment with abundant functionally equivalent cloud services,users naturally desire the highest-quality service(s).Thus,a comprehensive measurement of quality of service(QoS)is needed.Opti-mizing the plethora of cloud services has thus become a top priority.Cloud ser-vice optimization is negatively affected by untrusted QoS data,which are inevitably provided by some users.To resolve these problems,this paper proposes a QoS-aware cloud service optimization model and establishes QoS-information awareness and quantification mechanisms.Untrusted data are assessed by an information correction method.The weights discovered by the variable precision Rough Set,which mined the evaluation indicators from historical data,providing a comprehensive performance ranking of service quality.The manufacturing cloud service optimization algorithm thus provides a quantitative reference for service selection.In experimental simulations,this method recommended the optimal services that met users’needs,and effectively reduced the impact of dis-honest users on the selection results.展开更多
Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pum...Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.展开更多
A simple, reliable and rapid isocratic liquid chromatography(LC)-mass spectrometric detection(MS) coupled with electrospray ionization(ESI) method for simultaneous separation and determination of calycosin-7-O-β-D-gl...A simple, reliable and rapid isocratic liquid chromatography(LC)-mass spectrometric detection(MS) coupled with electrospray ionization(ESI) method for simultaneous separation and determination of calycosin-7-O-β-D-glucoside, ononin, calycosin and formonometin in Astragali Radix was developed. After the samples were extracted with ethanol, the optimum separation conditions for these analytes were achieved using water and acetonitrile(70:30, v/v) containing 0.2%(v/v) acetic acid as a mobile phase and a 2.0 mm×150 mm Hypersil-Keystone C18 column. Selective ion monitoring(SIM) mode and [M+H]+ ions at m/z 447, 431, 285 and 269 were used for quantitative analysis of four main active components above mentioned. The calibration curves were linear in the range of 0.4-175.0 μg/mL for calycosin-7-O-β-D-glucoside, 0.2-146.0 μg/m L for ononin, 0.4-210.0 μg/mL for calycosin and 0.5-217.0 μg/mL for formonetion, respectively. The limits of quantification(LOQ) and detection(LOD) were 0.4 μg/mL and 0.08 μg/m L for calycosin-7-O-β-D-glucoside, 0.2 μg/mL and 0.06 μg/m L for ononin, 0.4 μg/mL and 0.1 μg/mL for calycosin, 0.5 μg/m L and 0.1 μg/m L formonetion, respectively. The standard recoveries were in the range of 96.5%-104.7%. The developed method has successfully been used for the determination of four main flavonoids in Astragali Radix from various sources and can be used for identification, differentiation and quality evaluation of Astragali Radix.展开更多
As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorptio...As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.展开更多
In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improv...In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improved scheme with no Share Distribution Center (SDC). This paper shows that Bao, et al.’s scheme suffers from the proxy relationship inversion attack and forgery attack, and pro- poses an improvement of Bao, et al.’s scheme.展开更多
A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC- MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active meta- bolite, 5-methy...A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC- MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active meta- bolite, 5-methyltetrahydrofolic acid (5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% (v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring (MRM) mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.展开更多
The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have ...The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have been proved to be troublesome and less intuitive. Analytical solutions based on loss-less tube model and average friction tube model are found respectively by using fluid net theory, and they fit the experimental results well. The research work shows that: Fluid net theory can be used to solve the analytical solution of filling and exhausting processes of pneumatic system, and the result of loss-less tube model is close to that of average friction model, so loss-less tube model is recommended since it is simpler, and the difference between filling time and exhausting time is determined by initial and final pressures, the volume of container and the section area of tube, and has nothing to do with the length of the tube.展开更多
A previous study by our group found that inhibition of nischarin promotes neurite outgrowth and neuronal regeneration in Neuro-2 a cells and primary cortical neurons.In recent years,more and more studies have shown th...A previous study by our group found that inhibition of nischarin promotes neurite outgrowth and neuronal regeneration in Neuro-2 a cells and primary cortical neurons.In recent years,more and more studies have shown that nanomaterials have good prospects in treatment of spinal cord injury.We proposed that small interfering RNA targeting nischarin(Nis-si RNA) delivered by polyethyleneimine-alginate(PEIALG) nanoparticles promoted motor function recovery in rats with spinal cord injury.Direct microinjection of 5 μL PEI-ALG/Nis-si RNA into the spinal cord lesion area of spinal cord injury rats was performed.From day 7 after surgery,Basso,Beattie and Bresnahan score was significantly higher in rats from the PEI-ALG/Nis-si RNA group compared with the spinal cord injury group and PEI-ALG/Control-si RNA group.On day 21 after injection,hematoxylin-eosin staining showed that the necrotic area was reduced in the PEI-ALG/Nis-si RNA group.Immunohistochemistry and western blot assay results confirmed successful inhibition of nischarin expression and increased protein expression of growth-associated protein-43 in the PEI-ALG/Nis-si RNA group.These findings suggest that a complex of PEI-ALG nanoparticles and Nis-si RNA effectively suppresses nischarin expression,induces expression of growth-associated protein-43,and accelerates motor function recovery after spinal cord injury.展开更多
A new group signature with one time secret key is proposed. The main merits are that it only needs the trusted center issuing the partial secret key one time for each group member; and that the group member can genera...A new group signature with one time secret key is proposed. The main merits are that it only needs the trusted center issuing the partial secret key one time for each group member; and that the group member can generate his different secret key each time when he wants to sign a message. The group public key is constant and the size of the signature is independent of the number of group members. The total computation cost of signature and verification requires only 8 modular exponentiations.展开更多
The rotating speed fluctuation for turbomachinery is a common problem, which will cause severe destruction for equipments and basis when the fluctuation is very strong. In this paper,in order to study the transient re...The rotating speed fluctuation for turbomachinery is a common problem, which will cause severe destruction for equipments and basis when the fluctuation is very strong. In this paper,in order to study the transient response characteristics of a radial vane pump subjected to slight( 5%) and strong( 20%)fluctuating rotational speeds, the variation characteristics of the external hydraulic performances are numerically predicted by means of computational fluid dynamics( CFD) technology. The results manifest that the responses of head and flow rate are different relative to the fluctuating characteristics of rotational speed. The response of the former is very satisfied in synchronism,while that of the latter is hysteretic. Meanwhile,it is found that the variation tendencies of the static pressures at the inlet and outlet of the pump are completely opposite, while the response characteristics of the dynamic pressures at the inlet and outlet are nearly identical.Subsequently,in order to further reveal the transient behavior during the instantaneous operating periods,two non-dimensional parameters are employed to deeply analyze it. The result shows that the variation tendencies of these two parameters are also approximately opposite.Moreover,the quasi-steady assumption is not able to be used to accurately assess the transient flow during transient operating periods. The comparison results show that the transient behavior does not show obvious distinctions between slight and strong fluctuating rotating speeds.展开更多
The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage material.However,the slow kinetics and poor cycling stability severely restrict its practical applications.In this work,a ...The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage material.However,the slow kinetics and poor cycling stability severely restrict its practical applications.In this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the Li-Mg-B-H composite.The milled 2LiH+MgB_(2)composites were initially hydrogenated to obtain the 2LiBH_(4)+MgH_(2)composites.The 2LiBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2LiBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and LiBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2LiBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th cycle.Nb_(2)C keeps stable in the composite and acts as an efficient catalyst for the Li-Mg-B-H composite.It is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the Li-Mg-B-H composite.This work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the Li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.展开更多
Heterovalent doped(K_(0.48-0.07)xNa_(0.52-0.43)xBi_(0.5)x)(Nb_(0.95-0.95x)Sb_(0.05-0.05x)Zrx)O_(3)ceramics were fabricated using conventional solid-state reaction.Then,the phase structures,dielectric,ferroelectric,and...Heterovalent doped(K_(0.48-0.07)xNa_(0.52-0.43)xBi_(0.5)x)(Nb_(0.95-0.95x)Sb_(0.05-0.05x)Zrx)O_(3)ceramics were fabricated using conventional solid-state reaction.Then,the phase structures,dielectric,ferroelectric,and electricstrain properties were investigated.The compositions were tuned to be located at polymorphic phase boundary with increasing heterovalent Bi3t and Zr4t doping levels.A large strain of 0.19%was obtained at relatively low electric fields of 30 kV/cm in the composition of x=0.04.The normalized large-signal d33*values were approximately 633 pm/V under a low driving electric field of 30 kV/cm,which were comparable or larger than the values reported for other lead-free families.The large strains obtained can be attributed to the formation of nanodomains and high-density domain walls,which were confirmed by the observations of domain morphology using transmission electron microscopy(TEM)technique.Excellent temperature stability of the strain properties of the x=0.04 sample could be ascribed to the sluggish behaviour for the local structural heterogeneity in heterovalent-ion doped KNN ceramic.Theoretical simulations revealed that the Zr^(4t)produce the local stress at the BO6 octahedra and Bi3t could yield off-centering of AO12 ployhedron due to the nature of Bi 6s lone pair electrons,which induced lattice expansion and local distortions in the sample.The local displacements are strongly anisotropic in heterovalent-ion doped system.It is believed that random local fields exist in these compositions owing to the eixstence of charge distribution.Such heterovalent doping of Bi^(3t)and Zr^(4t)could destory simultaneously the orthorhombic symmetry and the short-range ferroelecctric order,leading to the formation of complex nanodomains and local structral hetergenenity.Heterovalent doping may,therefore,offer a new avenve to design novel K0.5Na0.5NbO3(KNN)-based materials for their mutifunctional applications.展开更多
BaFe10Al2O19 /poly(m-toluidine)(BFA/PMT) composites were synthesized by in-situ polymerization of m-toluidine in the presence of BaFe10Al2O19 particles.The structure,composition and morphology of the obtained samples ...BaFe10Al2O19 /poly(m-toluidine)(BFA/PMT) composites were synthesized by in-situ polymerization of m-toluidine in the presence of BaFe10Al2O19 particles.The structure,composition and morphology of the obtained samples were characterized by using XRD,FT-IR,UV-visible spectroscopy,SEM and TEM techniques.Their electrical conductivity,magnetic property and microwave absorbing property were measured by the four-probe meter,the vibrating sample magnetometer and the vector network analyzer,respectively.The results indicated that BFA particles were coated effectively by PMT polymer and some interactions between PMT and BFA particles existing in the composites.The conductivity of BFA/PMT composite is smaller than that of pure polymers and its saturation magnetization is a little smaller than that of pure BFA.The influence of the constitution and film thickness of absorbent on its microwave absorbing property is evident.The microwave absorbing properties of the BFA/PMT composites are better than those of pure BFA and PMT.When optimizing the mass rate of BFA/PMT to 0.3,the absorbent with 2 mm film thickness has the minimum reflection loss of 28.26 dB at approximate 14.24 GHz,and the maximum available bandwidth of 8.8 GHz,respectively.The results show that these composites can be used as advancing absorption and shielding materials due to their favorable microwave absorbing property.展开更多
Background Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Platelet activation may play an important role in pathologic progress in lung cancer. In this study, we aimed to clar...Background Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Platelet activation may play an important role in pathologic progress in lung cancer. In this study, we aimed to clarify the influence of activated platelets on lung cancer generation and growth, and the relationship among these functional and ultrastructural chanqes of platelets and the severity of pathoeenetic condition in these Datients with NSCLC.Methods One hundred and thirty-six cases of patients with pathologically confirmed NSCLC were included in this study. Fifty-four healthy people were enrolled as controls. The change of ultra microstructure and activity of blood platelets were observed under the transmission and scanning electron microscope. Simultaneous determination of plasma granule membrane protein 140 (GMP-140) was made.Results Transmission electron microscopy showed remarkable changes of ultra microstructure of platelets in patients with NSCLC, including swelling, increase of α-granules, vesicles, and glycogenosome. Scanning electron microscopy showed many more surface processes and wrinkles on platelets in patients with NSCLC. The reference plasma levels of GMP-140 of healthy controls were (18.2±2.7) μg/L. The plasma levels of GMP-140 in patients with NSCLC were (47.8±12.3) μg/L, which were much higher than those of the controls. There was a medium positive correlation between plasma levels of GMP-140 and amount of α-granules (r=0.514, P 〈0.01) and a high positive correlation between plasma levels of GMP-140 and area of platelet (r=0.84, P 〈0.01) in patients with NSCLC. The Kaplan-Meier survival curve analysis showed significant shift to the left in patients with NSCLC whose a-granules per platelet were 19 or more compared to those 18 or less (Log rank statistic, X^2= 17.38, P〈0.01).Conclusions There are significant activated changes of ultra microstructure and increased activity of blood platelets in patients with NSCLC. These activated platelets may play an important role in the generation and growth of lung cancer. These changes can be used as a diagnostic index of severity, progression, and prognosis of NSCLC.展开更多
Secret sharing schemes are multi-party protocols related to key establishment. They also facilitate distributed trust or shared control for critical activities (e.g., signing corporate cheques and opening bank vaults)...Secret sharing schemes are multi-party protocols related to key establishment. They also facilitate distributed trust or shared control for critical activities (e.g., signing corporate cheques and opening bank vaults), by gating the critical action on cooperation from t(t ∈Z+) of n(n ∈Z+) users. A (t, n) threshold scheme (t < n) is a method by which a trusted party computes secret shares Γi(1 i n) from an initial secret Γ0 and securely distributes Γi to user. Any t or more users who pool their shares may easily recover Γ0, but any group knowing only t-1 or fewer shares may not. By the ElGamal public key cryptophytes and the Schnorr's signature scheme, this paper proposes a new (t,n) threshold signature scheme with (k,m) (k,m ∈Z+) threshold verification based on the multivariate linear polynomial.展开更多
Let T=T(p,q,α) be the number of solutions of the congruence x~α≡1 (rood p^nq~θ).Let A and B be sets of primes satisfying x_1<p≤x_2 and y_1<q≤y_2,respectively.A mean value estimation of (?)∑_(p∈A)∑_(q∈B...Let T=T(p,q,α) be the number of solutions of the congruence x~α≡1 (rood p^nq~θ).Let A and B be sets of primes satisfying x_1<p≤x_2 and y_1<q≤y_2,respectively.A mean value estimation of (?)∑_(p∈A)∑_(q∈B) logT (p,q,α) is given.展开更多
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ23F040001)the National Natural Science Foundation of China(Grant No.12204446)+1 种基金the Public Welfare Technology Research Project of Zhejiang Province(Grant No.LGC22E050006)the Quzhou Science and Technology Project of China(Grant No.2022K104).
文摘Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Currently,symmetry-protected QBIC resonance is often achieved by breaking the geometric symmetry,but few cases are achieved by breaking the material symmetry.This paper proposes a dielectric compound grating to achieve a high Q factor and high-reflection symmetry-protectede QBIC resonance based on material asymmetry.Theoretical calculations show that the symmetry-protected QBIC resonance achieved by material asymmetry can significantly increase the GH shift up to-980 times the resonance wavelength,and the maximum GH shift is located at the reflection peak with unity reflectance.This paper provides a theoretical basis for designing and fabricating high-performance GH shift tunable metasurfaces/dielectric gratings in the future.
基金supported by the National Natural Science Foundation,China (Grant No:61602413,Jianwei Zheng,https://www.nsfc.gov.cn)the Natural Science Foundation of Zhejiang Province (Grant No:LY15E050007,Wenlong Ma,http://zjnsf.kjt.zj.gov.cn/portal/index.html).
文摘In a cloud manufacturing environment with abundant functionally equivalent cloud services,users naturally desire the highest-quality service(s).Thus,a comprehensive measurement of quality of service(QoS)is needed.Opti-mizing the plethora of cloud services has thus become a top priority.Cloud ser-vice optimization is negatively affected by untrusted QoS data,which are inevitably provided by some users.To resolve these problems,this paper proposes a QoS-aware cloud service optimization model and establishes QoS-information awareness and quantification mechanisms.Untrusted data are assessed by an information correction method.The weights discovered by the variable precision Rough Set,which mined the evaluation indicators from historical data,providing a comprehensive performance ranking of service quality.The manufacturing cloud service optimization algorithm thus provides a quantitative reference for service selection.In experimental simulations,this method recommended the optimal services that met users’needs,and effectively reduced the impact of dis-honest users on the selection results.
文摘Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.
基金Project(21472110)supported by the National Natural Science Foundation of ChinaProject(LY15B050008)supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(2013Y003)supported by Quzhou Technology Projects,China
文摘A simple, reliable and rapid isocratic liquid chromatography(LC)-mass spectrometric detection(MS) coupled with electrospray ionization(ESI) method for simultaneous separation and determination of calycosin-7-O-β-D-glucoside, ononin, calycosin and formonometin in Astragali Radix was developed. After the samples were extracted with ethanol, the optimum separation conditions for these analytes were achieved using water and acetonitrile(70:30, v/v) containing 0.2%(v/v) acetic acid as a mobile phase and a 2.0 mm×150 mm Hypersil-Keystone C18 column. Selective ion monitoring(SIM) mode and [M+H]+ ions at m/z 447, 431, 285 and 269 were used for quantitative analysis of four main active components above mentioned. The calibration curves were linear in the range of 0.4-175.0 μg/mL for calycosin-7-O-β-D-glucoside, 0.2-146.0 μg/m L for ononin, 0.4-210.0 μg/mL for calycosin and 0.5-217.0 μg/mL for formonetion, respectively. The limits of quantification(LOQ) and detection(LOD) were 0.4 μg/mL and 0.08 μg/m L for calycosin-7-O-β-D-glucoside, 0.2 μg/mL and 0.06 μg/m L for ononin, 0.4 μg/mL and 0.1 μg/mL for calycosin, 0.5 μg/m L and 0.1 μg/m L formonetion, respectively. The standard recoveries were in the range of 96.5%-104.7%. The developed method has successfully been used for the determination of four main flavonoids in Astragali Radix from various sources and can be used for identification, differentiation and quality evaluation of Astragali Radix.
文摘As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.
基金Supported by the National Natural Science Foundation of China (No.10671051)the Natural Science Foundation of Zhejiang Province (No.Y105067).
文摘In 2005, Bao, et al. [Appl. Math. and Comput., vol.169, No.2, 2005] showed that Tzeng, et al.’s nonrepudiable threshold multi-proxy multi-signature scheme with shared verification was insecure, and proposed an improved scheme with no Share Distribution Center (SDC). This paper shows that Bao, et al.’s scheme suffers from the proxy relationship inversion attack and forgery attack, and pro- poses an improvement of Bao, et al.’s scheme.
文摘A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC- MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active meta- bolite, 5-methyltetrahydrofolic acid (5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% (v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring (MRM) mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.
基金This project is supported by National Natural Science Foundation of China(No.50575209).
文摘The filling and exhausting processes in a pneumatic system are involved with many factors, and numerical solutions of many partial differential equations are always adapted in the study of those processes, which have been proved to be troublesome and less intuitive. Analytical solutions based on loss-less tube model and average friction tube model are found respectively by using fluid net theory, and they fit the experimental results well. The research work shows that: Fluid net theory can be used to solve the analytical solution of filling and exhausting processes of pneumatic system, and the result of loss-less tube model is close to that of average friction model, so loss-less tube model is recommended since it is simpler, and the difference between filling time and exhausting time is determined by initial and final pressures, the volume of container and the section area of tube, and has nothing to do with the length of the tube.
基金supported by the Natural Science Foundation of Zhejiang Province of China,No.LY15H250001 and LY14H090002the National Natural Science Foundation of China,No.81000535 and 81402872+1 种基金the Medical Science and Technology Project Foundation of Zhejiang Province of China,No.2014KYA166the Science and Technology Innovation Talents Development Plan Foundation for High School Students in Zhejiang Province of China,No.2014R401186
文摘A previous study by our group found that inhibition of nischarin promotes neurite outgrowth and neuronal regeneration in Neuro-2 a cells and primary cortical neurons.In recent years,more and more studies have shown that nanomaterials have good prospects in treatment of spinal cord injury.We proposed that small interfering RNA targeting nischarin(Nis-si RNA) delivered by polyethyleneimine-alginate(PEIALG) nanoparticles promoted motor function recovery in rats with spinal cord injury.Direct microinjection of 5 μL PEI-ALG/Nis-si RNA into the spinal cord lesion area of spinal cord injury rats was performed.From day 7 after surgery,Basso,Beattie and Bresnahan score was significantly higher in rats from the PEI-ALG/Nis-si RNA group compared with the spinal cord injury group and PEI-ALG/Control-si RNA group.On day 21 after injection,hematoxylin-eosin staining showed that the necrotic area was reduced in the PEI-ALG/Nis-si RNA group.Immunohistochemistry and western blot assay results confirmed successful inhibition of nischarin expression and increased protein expression of growth-associated protein-43 in the PEI-ALG/Nis-si RNA group.These findings suggest that a complex of PEI-ALG nanoparticles and Nis-si RNA effectively suppresses nischarin expression,induces expression of growth-associated protein-43,and accelerates motor function recovery after spinal cord injury.
基金Project (No. 10271037) supported by the National Natural Sci-ence Foundation of China
文摘A new group signature with one time secret key is proposed. The main merits are that it only needs the trusted center issuing the partial secret key one time for each group member; and that the group member can generate his different secret key each time when he wants to sign a message. The group public key is constant and the size of the signature is independent of the number of group members. The total computation cost of signature and verification requires only 8 modular exponentiations.
基金Zhejiang Provincial Natural Science Foundation of China(No.LY14E090011)Quzhou Science and Technology Development Fund,China(No.20121057)Zhejiang Provincial Science and Technology Project,China(No.2015C31129)
文摘The rotating speed fluctuation for turbomachinery is a common problem, which will cause severe destruction for equipments and basis when the fluctuation is very strong. In this paper,in order to study the transient response characteristics of a radial vane pump subjected to slight( 5%) and strong( 20%)fluctuating rotational speeds, the variation characteristics of the external hydraulic performances are numerically predicted by means of computational fluid dynamics( CFD) technology. The results manifest that the responses of head and flow rate are different relative to the fluctuating characteristics of rotational speed. The response of the former is very satisfied in synchronism,while that of the latter is hysteretic. Meanwhile,it is found that the variation tendencies of the static pressures at the inlet and outlet of the pump are completely opposite, while the response characteristics of the dynamic pressures at the inlet and outlet are nearly identical.Subsequently,in order to further reveal the transient behavior during the instantaneous operating periods,two non-dimensional parameters are employed to deeply analyze it. The result shows that the variation tendencies of these two parameters are also approximately opposite.Moreover,the quasi-steady assumption is not able to be used to accurately assess the transient flow during transient operating periods. The comparison results show that the transient behavior does not show obvious distinctions between slight and strong fluctuating rotating speeds.
基金financially supported by the Science and Technology Department of Guangxi Zhuang Autonomous(No.GuiKeAD21238022)the National Natural Science Foundation of China(Nos.52001079,22379030 and 52261038)Quzhou Science and Technology Project(No.2022K103)。
文摘The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage material.However,the slow kinetics and poor cycling stability severely restrict its practical applications.In this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the Li-Mg-B-H composite.The milled 2LiH+MgB_(2)composites were initially hydrogenated to obtain the 2LiBH_(4)+MgH_(2)composites.The 2LiBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2LiBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and LiBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2LiBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th cycle.Nb_(2)C keeps stable in the composite and acts as an efficient catalyst for the Li-Mg-B-H composite.It is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the Li-Mg-B-H composite.This work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the Li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.
基金supported by National Science Foundation of China(NSFC No.52172125),the CSS project(YK2015-0602006),the Natural Science Foundation of Shandong Province of China(Grant No.ZR2018BA028),Quzhou Science and Technology Plan Project(2022K108)and General Research Project of Zhejiang Provincial Department of Education(Y202249978).
文摘Heterovalent doped(K_(0.48-0.07)xNa_(0.52-0.43)xBi_(0.5)x)(Nb_(0.95-0.95x)Sb_(0.05-0.05x)Zrx)O_(3)ceramics were fabricated using conventional solid-state reaction.Then,the phase structures,dielectric,ferroelectric,and electricstrain properties were investigated.The compositions were tuned to be located at polymorphic phase boundary with increasing heterovalent Bi3t and Zr4t doping levels.A large strain of 0.19%was obtained at relatively low electric fields of 30 kV/cm in the composition of x=0.04.The normalized large-signal d33*values were approximately 633 pm/V under a low driving electric field of 30 kV/cm,which were comparable or larger than the values reported for other lead-free families.The large strains obtained can be attributed to the formation of nanodomains and high-density domain walls,which were confirmed by the observations of domain morphology using transmission electron microscopy(TEM)technique.Excellent temperature stability of the strain properties of the x=0.04 sample could be ascribed to the sluggish behaviour for the local structural heterogeneity in heterovalent-ion doped KNN ceramic.Theoretical simulations revealed that the Zr^(4t)produce the local stress at the BO6 octahedra and Bi3t could yield off-centering of AO12 ployhedron due to the nature of Bi 6s lone pair electrons,which induced lattice expansion and local distortions in the sample.The local displacements are strongly anisotropic in heterovalent-ion doped system.It is believed that random local fields exist in these compositions owing to the eixstence of charge distribution.Such heterovalent doping of Bi^(3t)and Zr^(4t)could destory simultaneously the orthorhombic symmetry and the short-range ferroelecctric order,leading to the formation of complex nanodomains and local structral hetergenenity.Heterovalent doping may,therefore,offer a new avenve to design novel K0.5Na0.5NbO3(KNN)-based materials for their mutifunctional applications.
基金supported by the National Nature Science Foundation of China (21071125)the Natural Science Foundation of Zhejiang Province(Y4100022,Y4090636)the Science and Technology Key Project of Zhejiang Province (2010C11053)
文摘BaFe10Al2O19 /poly(m-toluidine)(BFA/PMT) composites were synthesized by in-situ polymerization of m-toluidine in the presence of BaFe10Al2O19 particles.The structure,composition and morphology of the obtained samples were characterized by using XRD,FT-IR,UV-visible spectroscopy,SEM and TEM techniques.Their electrical conductivity,magnetic property and microwave absorbing property were measured by the four-probe meter,the vibrating sample magnetometer and the vector network analyzer,respectively.The results indicated that BFA particles were coated effectively by PMT polymer and some interactions between PMT and BFA particles existing in the composites.The conductivity of BFA/PMT composite is smaller than that of pure polymers and its saturation magnetization is a little smaller than that of pure BFA.The influence of the constitution and film thickness of absorbent on its microwave absorbing property is evident.The microwave absorbing properties of the BFA/PMT composites are better than those of pure BFA and PMT.When optimizing the mass rate of BFA/PMT to 0.3,the absorbent with 2 mm film thickness has the minimum reflection loss of 28.26 dB at approximate 14.24 GHz,and the maximum available bandwidth of 8.8 GHz,respectively.The results show that these composites can be used as advancing absorption and shielding materials due to their favorable microwave absorbing property.
文摘Background Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Platelet activation may play an important role in pathologic progress in lung cancer. In this study, we aimed to clarify the influence of activated platelets on lung cancer generation and growth, and the relationship among these functional and ultrastructural chanqes of platelets and the severity of pathoeenetic condition in these Datients with NSCLC.Methods One hundred and thirty-six cases of patients with pathologically confirmed NSCLC were included in this study. Fifty-four healthy people were enrolled as controls. The change of ultra microstructure and activity of blood platelets were observed under the transmission and scanning electron microscope. Simultaneous determination of plasma granule membrane protein 140 (GMP-140) was made.Results Transmission electron microscopy showed remarkable changes of ultra microstructure of platelets in patients with NSCLC, including swelling, increase of α-granules, vesicles, and glycogenosome. Scanning electron microscopy showed many more surface processes and wrinkles on platelets in patients with NSCLC. The reference plasma levels of GMP-140 of healthy controls were (18.2±2.7) μg/L. The plasma levels of GMP-140 in patients with NSCLC were (47.8±12.3) μg/L, which were much higher than those of the controls. There was a medium positive correlation between plasma levels of GMP-140 and amount of α-granules (r=0.514, P 〈0.01) and a high positive correlation between plasma levels of GMP-140 and area of platelet (r=0.84, P 〈0.01) in patients with NSCLC. The Kaplan-Meier survival curve analysis showed significant shift to the left in patients with NSCLC whose a-granules per platelet were 19 or more compared to those 18 or less (Log rank statistic, X^2= 17.38, P〈0.01).Conclusions There are significant activated changes of ultra microstructure and increased activity of blood platelets in patients with NSCLC. These activated platelets may play an important role in the generation and growth of lung cancer. These changes can be used as a diagnostic index of severity, progression, and prognosis of NSCLC.
基金the National Natural Science Foundation of China (No. 10671051)the Natural Science Foundation of Zhejiang Province (No. Y6110782)the Key Laboratory Foundation of Hangzhou(No. 20100331T11)
文摘Secret sharing schemes are multi-party protocols related to key establishment. They also facilitate distributed trust or shared control for critical activities (e.g., signing corporate cheques and opening bank vaults), by gating the critical action on cooperation from t(t ∈Z+) of n(n ∈Z+) users. A (t, n) threshold scheme (t < n) is a method by which a trusted party computes secret shares Γi(1 i n) from an initial secret Γ0 and securely distributes Γi to user. Any t or more users who pool their shares may easily recover Γ0, but any group knowing only t-1 or fewer shares may not. By the ElGamal public key cryptophytes and the Schnorr's signature scheme, this paper proposes a new (t,n) threshold signature scheme with (k,m) (k,m ∈Z+) threshold verification based on the multivariate linear polynomial.
基金Supported by National Natural Science Foundation of China(No.19971024)Zhejiang Provincial Natural Science Foundation of China(No.199047)
文摘Let T=T(p,q,α) be the number of solutions of the congruence x~α≡1 (rood p^nq~θ).Let A and B be sets of primes satisfying x_1<p≤x_2 and y_1<q≤y_2,respectively.A mean value estimation of (?)∑_(p∈A)∑_(q∈B) logT (p,q,α) is given.