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Microstrip Patch Antenna with an Inverted T-Type Notch in the Partial Ground for Breast Cancer Detections
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作者 Nure Alam Chowdhury Lulu Wang +2 位作者 Md Shazzadul Islam Linxia Gu Mehmet Kaya 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1301-1322,共22页
This study designs a microstrip patch antenna with an inverted T-type notch in the partial ground to detect tumorcells inside the human breast.The size of the current antenna is small enough(18mm×21mm×1.6mm)... This study designs a microstrip patch antenna with an inverted T-type notch in the partial ground to detect tumorcells inside the human breast.The size of the current antenna is small enough(18mm×21mm×1.6mm)todistribute around the breast phantom.The operating frequency has been observed from6–14GHzwith a minimumreturn loss of−61.18 dB and themaximumgain of current proposed antenna is 5.8 dBiwhich is flexiblewith respectto the size of antenna.After the distribution of eight antennas around the breast phantom,the return loss curveswere observed in the presence and absence of tumor cells inside the breast phantom,and these observations showa sharp difference between the presence and absence of tumor cells.The simulated results show that this proposedantenna is suitable for early detection of cancerous cells inside the breast. 展开更多
关键词 Antenna microwave wideband cancer breast phantom tumor detection
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Targeted anti-cancer therapy: Co-delivery of VEGF siRNA and Phenethyl isothiocyanate (PEITC) via cRGD-modified lipid nanoparticles for enhanced anti-angiogenic efficacy
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作者 Bao Li Haoran Niu +10 位作者 Xiaoyun Zhao Xiaoyu Huang Yu Ding Ke Dang Tianzhi Yang Yongfeng Chen Jizhuang Ma Xiaohong Liu Keda Zhang Huichao Xie Pingtian Ding 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2024年第2期170-187,共18页
Anti-tumor angiogenesis therapy, targeting the suppression of blood vessel growth in tumors, presents a potent approach in the battle against cancer. Traditional therapies have primarily concentrated on single-target ... Anti-tumor angiogenesis therapy, targeting the suppression of blood vessel growth in tumors, presents a potent approach in the battle against cancer. Traditional therapies have primarily concentrated on single-target techniques, with a specific emphasis on targeting the vascular endothelial growth factor, but have not reached ideal therapeutic efficacy. In response to this issue, our study introduced a novel nanoparticle system known as CS-siRNA/PEITC&L-cRGD NPs. These chitosan-based nanoparticles have been recognized for their excellent biocompatibility and ability to deliver genes. To enhance their targeted delivery capability, they were combined with a cyclic RGD peptide (cRGD). Targeted co-delivery of gene and chemotherapeutic agents was achieved through the use of a negatively charged lipid shell and cRGD, which possesses high affinity for integrin αvβ3 overexpressed in tumor cells and neovasculature. In this multifaceted approach, co-delivery of VEGF siRNA and phenethyl isothiocyanate (PEITC) was employed to target both tumor vascular endothelial cells and tumor cells simultaneously. The co-delivery of VEGF siRNA and PEITC could achieve precise silencing of VEGF, inhibit the accumulation of HIF-1α under hypoxic conditions, and induce apoptosis in tumor cells. In summary, we have successfully developed a nanoparticle delivery platform that utilizes a dual mechanism of action of anti-tumor angiogenesis and pro-tumor apoptosis, which provides a robust and potent strategy for the delivery of anti-cancer therapeutics. 展开更多
关键词 ANTI-ANGIOGENESIS Tumor apoptosis Nanoparticles VEGF siRNA Hypoxia inducible factor(HIF)-1 protein Phenethyl isothi ocyanate(PEITC)
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Performance analysis of single-focus phase singularity based on elliptical reflective annulus quadrangle-element coded spiral zone plates
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作者 臧华平 王宝珍 +7 位作者 郑程龙 魏来 范全平 王少义 杨祖华 周维民 曹磊峰 郭海中 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期441-448,共8页
Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we pr... Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition. 展开更多
关键词 optical vortex single-focus spiral zone plate topological charges
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Electricity Carbon Quota Trading Scheme based on Certificateless Signature and Blockchain
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作者 Xiaodong Yang Runze Diao +2 位作者 Tao Liu Haoqi Wen Caifen Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1695-1712,共18页
The carbon tradingmarket can promote“carbon peaking”and“carbon neutrality”at low cost,but carbon emission quotas face attacks such as data forgery,tampering,counterfeiting,and replay in the electricity trading mar... The carbon tradingmarket can promote“carbon peaking”and“carbon neutrality”at low cost,but carbon emission quotas face attacks such as data forgery,tampering,counterfeiting,and replay in the electricity trading market.Certificateless signatures are a new cryptographic technology that can address traditional cryptography’s general essential certificate requirements and avoid the problem of crucial escrowbased on identity cryptography.However,most certificateless signatures still suffer fromvarious security flaws.We present a secure and efficient certificateless signing scheme by examining the security of existing certificateless signature schemes.To ensure the integrity and verifiability of electricity carbon quota trading,we propose an electricity carbon quota trading scheme based on a certificateless signature and blockchain.Our scheme utilizes certificateless signatures to ensure the validity and nonrepudiation of transactions and adopts blockchain technology to achieve immutability and traceability in electricity carbon quota transactions.In addition,validating electricity carbon quota transactions does not require time-consuming bilinear pairing operations.The results of the analysis indicate that our scheme meets existential unforgeability under adaptive selective message attacks,offers conditional identity privacy protection,resists replay attacks,and demonstrates high computing and communication performance. 展开更多
关键词 Electricity carbon trading certificateless signature blockchain forgery attack carbon quota
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Model of self-generated magnetic field generation from relativistic laser interaction with solid targets
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作者 严睿 邹德滨 +9 位作者 赵娜 杨晓虎 蒋祥瑞 胡理想 徐新荣 周泓宇 余同普 卓红斌 邵福球 银燕 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期511-517,共7页
Generation of self-generated annular magnetic fields at the rear side of a solid target driven by relativistic laser pulse is investigated by using theoretical analysis and particle-in-cell simulations.The spatial str... Generation of self-generated annular magnetic fields at the rear side of a solid target driven by relativistic laser pulse is investigated by using theoretical analysis and particle-in-cell simulations.The spatial strength distribution of magnetic fields can be accurately predicted by calculating the net flow caused by the superposition of source flow and return flow of hot electrons.The theoretical model established shows good agreement with the simulation results,indicating that the magnetic-field strength scales positively to the temperature of hot electrons.This provides us a way to improve the magnetic-field generation by using a micro-structured plasma grating in front of the solid target.Compared with that for a common flat target,hot electrons can be effectively heated with the well-designed grating size,leading to a stronger magnetic field.The spatial distribution of magnetic fields can be modulated by optimizing the grating period and height as well as the incident angle of the laser pulse. 展开更多
关键词 self-generated magnetic field laser solid-target interaction micro-structured plasma grating
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Comparison study on measurement of rail weld joint between inertial reference method and multi-point chord reference method
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作者 Yifan Shi Yuan Wang +1 位作者 Xiaozhou Liu Ping Wang 《Railway Sciences》 2024年第1期69-83,共15页
Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint ... Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint with a5-m wavelength range, leaving a significant knowledge gap in this field.Design/methodology/approach – In this study, the authors used the well-established inertial referencemethod (IR-method), and the state-of-the-art multi-point chord reference method (MCR-method). Two methodshave been applied in different types of rail straightness measurement trollies, respectively. These instrumentswere tested in a high-speed rail section within a certain region of China. The test results were ultimatelyvalidated through using traditional straightedge and feeler gauge methods as reference data to evaluate the railweld joint straightness within the 5-m wavelength range.Findings – The research reveals that IR-method and MCR-method produce reasonably similar measurementresults for wavelengths below 1 m. However, MCR-method outperforms IR-method in terms of accuracy forwavelengths exceeding 3 m. Furthermore, it was observed that IR-method, while operating at a slower speed,carries the risk of derailing and is incapable of detecting rail weld joints and low joints within the track.Originality/value – The research compare two methods’ measurement effects in a longer wavelength rangeand demonstrate the superiority of MCR-method. 展开更多
关键词 Rail weld joint Inertial reference method Short-wavelength irregularities Multi-point chord reference method 5-m wavelength range
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A deep convolutional neural network for diabetic retinopathy detection via mining local and long-range dependence
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作者 Xiaoling Luo Wei Wang +4 位作者 Yong Xu Zhihui Lai Xiaopeng Jin Bob Zhang David Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第1期153-166,共14页
Diabetic retinopathy(DR),the main cause of irreversible blindness,is one of the most common complications of diabetes.At present,deep convolutional neural networks have achieved promising performance in automatic DR d... Diabetic retinopathy(DR),the main cause of irreversible blindness,is one of the most common complications of diabetes.At present,deep convolutional neural networks have achieved promising performance in automatic DR detection tasks.The convolution operation of methods is a local cross-correlation operation,whose receptive field de-termines the size of the local neighbourhood for processing.However,for retinal fundus photographs,there is not only the local information but also long-distance dependence between the lesion features(e.g.hemorrhages and exudates)scattered throughout the whole image.The proposed method incorporates correlations between long-range patches into the deep learning framework to improve DR detection.Patch-wise re-lationships are used to enhance the local patch features since lesions of DR usually appear as plaques.The Long-Range unit in the proposed network with a residual structure can be flexibly embedded into other trained networks.Extensive experimental results demon-strate that the proposed approach can achieve higher accuracy than existing state-of-the-art models on Messidor and EyePACS datasets. 展开更多
关键词 image classification medical image processing pattern recognition
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Isorhamnetin protects porcine oocytes from zearalenone-induced reproductive toxicity through the PI3K/Akt signaling pathway 被引量:1
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作者 Xiaoya Li Jiaxin Duan +6 位作者 Shiyou Wang Jianyong Cheng Huali Chen Zelin Zhang Li Yang Rongmao Hua Qingwang Li 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第3期1054-1067,共14页
Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and... Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and the underlying molecular mechanism of isorhamnetin involvement in ZEA-induced porcine oocyte damage have not been investigated.Methods Oocytes were treated with different concentrations of ZEA(3,5,8 and 10μmol/L)and isorhamnetin(5,10,20 and 30μmol/L)for 44 h at 39℃.ZEA(5μmol/L)and isorhamnetin(10μmol/L)were selected for subsequent studies.Polar body exclusion rate,apoptosis rate and apoptosis related proteins,ROS levels and SOD2 protein,mitochondrial membrane potential and distribution,endoplasmic reticulum distribution and proteins expression,and PI3K,Akt and p-Akt proteins expression of oocytes were detected.In addition,the effect of PI3K antagonist(LY294002)on oocyte nuclear maturation and apoptosis were used to determine the involvement of PI3K/Akt signaling pathway.Results Our findings showed that ZEA exposure damaged oocytes and isorhamnetin therapy restored the developmental capability of porcine oocytes.Isorhamnetin promoted polar body extrusion rate to rescue ZEA-induced meiotic arrest in porcine oocytes.Isorhamnetin alleviated ZEA-induced oxidative stress by stimulating SOD2 protein expression and inhibiting ROS production.Moreover,isorhamnetin enhanced normal mitochondrial distribution and mitochondrial membrane potential to prevent mitochondrial dysfunction induced by ZEA.Changing the expression of endoplasmic reticulum stress-related marker proteins(CHOP,GRP78)and the distribution rate of normal endoplasmic reticulum showed that isorhamnetin relieved ZEA-caused endoplasmic reticulum stress.Mechanistically,isorhamnetin decreased Bax/Bcl-2 protein expression and inhibited ZEA-induced apoptosis through PI3K/Akt signaling pathway.Conclusions Collectively,these results suggest that isorhamnetin protects oocytes from ZEA-caused damage through PI3K/Akt signaling pathway,which enhances meiotic maturation and mitochondrial function,and inhibits early apoptosis,oxidative stress and endoplasmic reticulum stress in porcine oocytes.Our study provides a new strategy for solving the reproductive toxicity induced by ZEA and treating woman infertility. 展开更多
关键词 Apoptosis ISORHAMNETIN OOCYTE Oxidative stress PORCINE ZEARALENONE
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Nonlinear branched flow of intense laser light in randomly uneven media 被引量:1
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作者 K.Jiang T.W.Huang +7 位作者 C.N.Wu M.Y.Yu H.Zhang S.Z.Wu H.B.Zhuo A.Pukhov C.T.Zhou S.C.Ruan 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2023年第2期25-32,共8页
Branched flow is an interesting phenomenon that can occur in diverse systems.It is usually linear in the sense that the flow does not alter the properties of the medium.Branched flow of light on thin films has recentl... Branched flow is an interesting phenomenon that can occur in diverse systems.It is usually linear in the sense that the flow does not alter the properties of the medium.Branched flow of light on thin films has recently been discovered.It is therefore of interest to know whether nonlinear light branching can also occur.Here,using particle-in-cell simulations,we find that in the case of an intense laser propagating through a randomly uneven medium,cascading local photoionization by the incident laser,together with the response of freed electrons in the strong laser fields,triggers space–time-dependent optical unevenness.The resulting branching pattern depends dramatically on the laser intensity.That is,the branching here is distinct from the existing linear ones.The observed branching properties agree well with theoretical analyses based on the Helmholtz equation.Nonlinear branched propagation of intense lasers potentially opens up a new area for laser–matter interaction and may be relevant to other branching phenomena of a nonlinear nature. 展开更多
关键词 laser INTENSE FLOW
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Relativistic toroidal light solitons in plasma
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作者 程中明 邓达超 +1 位作者 郁明阳 武慧春 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第3期1-5,共5页
In the laser–plasma interaction,relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas.Here,it is shown by threedimensional particle-in-cell simulations t... In the laser–plasma interaction,relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas.Here,it is shown by threedimensional particle-in-cell simulations that relativistic toroidal solitons,composed of intense light self-consistently trapped in toroidal plasma cavities,can be produced by azimuthallypolarized relativistic laser pulses in a near-critical underdense plasma. 展开更多
关键词 azimuthally polarized laser pulse near-critical underdense plasma toroidal solitons relativistic solitons in plasma 3D particle-in-cell simulation self-focusing in plasma
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A Linear Homomorphic Proxy Signature Scheme Based on Blockchain for Internet of Things
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作者 Caifen Wang Bin Wu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第8期1857-1878,共22页
The mushroom growth of IoT has been accompanied by the generation of massive amounts of data.Subject to the limited storage and computing capabilities ofmost IoT devices,a growing number of institutions and organizati... The mushroom growth of IoT has been accompanied by the generation of massive amounts of data.Subject to the limited storage and computing capabilities ofmost IoT devices,a growing number of institutions and organizations outsource their data computing tasks to cloud servers to obtain efficient and accurate computation while avoiding the cost of local data computing.One of the most important challenges facing outsourcing computing is how to ensure the correctness of computation results.Linearly homomorphic proxy signature(LHPS)is a desirable solution to ensure the reliability of outsourcing computing in the case of authorized signing right.Blockchain has the characteristics of tamper-proof and traceability,and is a new technology to solve data security.However,as far as we know,constructions of LHPS have been few and far between.In addition,the existing LHPS scheme does not focus on homomorphic unforgeability and does not use blockchain technology.Herein,we improve the security model of the LHPS scheme,and the usual existential forgery and homomorphic existential forgery of two types of adversaries are considered.Under the new model,we present a blockchain-based LHPS scheme.The security analysis shows that under the adaptive chosen message attack,the unforgeability of the proposed scheme can be reduced to the CDH hard assumption,while achieving the usual and homomorphic existential unforgeability.Moreover,comparedwith the previous LHPS scheme,the performance analysis shows that our scheme has the same key size and comparable computational overhead,but has higher security. 展开更多
关键词 Homomorphic signature proxy signature security model provable security UNFORGEABILITY
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Magic wavelengths for 6s_(1/2)→5d_(3/2,5/2)transitions of Yb~+ions
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作者 陈婷 吴磊 +3 位作者 张儒奎 唐永波 蒋军 董晨钟 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期405-412,共8页
The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabiliti... The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabilities of the ground state and low-lying excited states are determined.Then,the magic wavelengths of the magnetic sublevel 6s_(1/2,m=1/2)→5d_(3/2,m=±3/2,±1/2)and 6s_(1/2,m=1/2)→5_(d5/2,m=±5/2,±3/2,±1/2)transitions in the linearly,right-handed,and left-handed polarized light are further determined.The dependence of the magic wavelengths upon the angle between the direction of magnetic field and the direction of laser polarization is analyzed. 展开更多
关键词 matrix elements POLARIZABILITIES magic wavelengths relativistic configuration interaction plus core polarization(RCICP)method
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Overcritical electron acceleration and betatron radiation in the bubble-like structure formed by re-injected electrons in a tailored transverse plasma
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作者 Yuan Zhao Haiyang Lu +1 位作者 Cangtao Zhou Jungao Zhu 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2023年第1期20-27,共8页
We present a novel scheme for dense electron acceleration driven by the laser irradiation of a near-critical-density plasma.The electron reflux effect in a transversely tailored plasma is particularly enhanced in the ... We present a novel scheme for dense electron acceleration driven by the laser irradiation of a near-critical-density plasma.The electron reflux effect in a transversely tailored plasma is particularly enhanced in the area of peak density.We observe a bubble-like distribution of re-injected electrons,which forms a strong quasistatic electromagnetic field that can accelerate electrons longitudinally while also preserving the electron transverse emittance.Simulation results demonstrate that over-dense electrons could be trapped in such an artificial bubble and accelerated to an energy of ~500 MeV.The obtained relativistic electron beam can reach a total charge of up to 0.26 nC and is well collimated with a small divergence of 17 mrad.Moreover,the wavelength of electron oscillation is noticeably reduced due to the shaking of the bubble structure in the laser field.As a result,the energy of the produced photons is substantially increased to the range.This new regime provides a path to generating high-charge electron beams and high-energy-ray sources. 展开更多
关键词 field BUBBLE ACCELERATION
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Proton acceleration from picosecond-laser interaction with a hydrocarbon target
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作者 杨宇晨 黄太武 +2 位作者 蒋轲 郁明阳 周沧涛 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第2期77-85,共9页
As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the lase... As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the laser and hydrocarbon target parameters on proton acceleration with two/threedimensional particle-in-cell simulations.It is found that the resulting two-ion species plasma can generate a multiple peaked charge-separation field that accelerates the protons.In particular,a smaller carbon-to-hydrogen ratio,as well as the thinner and/or lower density of the target,leads to a larger sheath field and thus proton beams with a larger cutoff energy and smoother energy spectrum.These results may be useful in achieving high-flux quasi-monoenergetic proton beams by properly designing the hydrocarbon target. 展开更多
关键词 picosecond laser pulse proton acceleration multiple peaked charge-separation field carbon-to-hydrogen ratio
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Bifunctional PdPt bimetallenes for formate oxidation-boosted water electrolysis
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作者 Xi-Lai Liu Yu-Chuan Jiang +4 位作者 Jiang-Tao Huang Wei Zhong Bin He Pu-Jun Jin Yu Chen 《Carbon Energy》 SCIE EI CAS CSCD 2023年第12期175-186,共12页
Small-molecule electrooxidation-boosted water electrolysis(WE)is an energy-saving method for hydrogen(H2)production.Herein,PdPt bimetallenes(PdPt BMLs)are obtained through the simple galvanic replacement reaction.PdPt... Small-molecule electrooxidation-boosted water electrolysis(WE)is an energy-saving method for hydrogen(H2)production.Herein,PdPt bimetallenes(PdPt BMLs)are obtained through the simple galvanic replacement reaction.PdPt BMLs reveal 2.93-fold enhancement in intrinsic electroactivity and 4.53-fold enhancement in mass electroactivity for the formate oxidation reaction(FOR)with respect to Pd metallenes(Pd MLs)at 0.50 V potential due to the synergistic effect.Meanwhile,the introduction of Pt atoms also considerably increases the electroactivity of PdPt BMLs for hydrogen evolution reaction(HER)with respect to Pd MLs in an alkaline medium,which even exceeds that with the use of commercial Pt nanocrystals.Inspired by the outstanding FOR and HER electroactivity of bifunctional PdPt BMLs,a two-electrode FOR-boosted WE system(FOR-WE)is constructed by using PdPt BMLs as the cathode and the anode.The FOR-WE system only requires an operational voltage of 0.31 V to achieve H2 production,which is 1.48 V lower than that(ca.1.79 V)with the use of the traditional WE system. 展开更多
关键词 ELECTROCATALYST formate oxidation reaction hydrogen evolution reaction metallene water electrolysis
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Particle-in-cell simulations of low-β magnetic reconnection driven by laser interaction with a capacitor–coil target
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作者 原晓霞 周沧涛 +3 位作者 张华 李然 平永利 仲佳勇 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期413-420,共8页
The dynamics of low-β magnetic reconnection(MR) driven by laser interaction with a capacitor–coil target are reexamined by simulations in this paper. We compare two cases MR and non-MR(also referred as AP-case and P... The dynamics of low-β magnetic reconnection(MR) driven by laser interaction with a capacitor–coil target are reexamined by simulations in this paper. We compare two cases MR and non-MR(also referred as AP-case and P-case standing for the anti-parallel and parallel magnetic field lines, respectively) to distinguish the different characteristics between them.We find that only in the AP-case the reconnection electric field shows up around the X line and the electron jet is directed toward the X line. The quadruple magnetic fields exist in both cases, however, they distribute in the current sheet area in the AP-case, and out of the squeezing area in the P-case, because electrons are demagnetized in the electron diffusion region in the MR process, which is absent in the P-case. The electron acceleration is dominant by the Fermi-like mechanism before the MR process, and by the reconnection electric field when the MR occurs. A power-law electron energy spectrum with an index of 1.8 is found in the AP-case. This work proves the significant potential of this experimental platform to be applied in the studies of low-β astronomy phenomena. 展开更多
关键词 magnetic reconnection intense laser low-βplasma
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Local wavelength evolution and Landau damping of electrostatic plasma wave driven by an ultra-relativistic electron beam in dense inhomogeneous plasma
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作者 李然 黄太武 +2 位作者 郁明阳 周沧涛 阮双琛 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第7期6-13,共8页
Evolution of an electrostatic plasma wave driven by a low-density ultra-relativistic electron beam in dense inhomogeneous plasma is considered. In particular, the wavelength variation as observed at fixed locations in... Evolution of an electrostatic plasma wave driven by a low-density ultra-relativistic electron beam in dense inhomogeneous plasma is considered. In particular, the wavelength variation as observed at fixed locations in the plasma is analyzed in terms of the wave characteristics. It is shown that for a negative density gradient, the observed local wavelength decreases monotonically with time, but for a positive density gradient, it first increases and then decreases with time, accompanied by reversal of the wave phase. However, in both cases the local wavelength eventually decreases with time since Landau damping becomes significant as the wavelength becomes of the order of the plasma Debye length. Results from particle-in-cell simulations agree well with theoretical analyses of the wavelength variation. 展开更多
关键词 relativistic electron beam transport inhomogeneous plasma energy dissipation
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Performance optimization of scintillator neutron detectors for EMD in CSNS
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作者 蔡小杰 于潜 +5 位作者 黄畅 唐彬 周诗慧 王小胡 岳秀萍 孙志嘉 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期207-213,共7页
Chinese Spallation Neutron Source(CSNS) has successfully produced its first neutron beam in 28th August 2017. It has been running steadily from March, 2018. According to the construction plan, the engineering material... Chinese Spallation Neutron Source(CSNS) has successfully produced its first neutron beam in 28th August 2017. It has been running steadily from March, 2018. According to the construction plan, the engineering materials diffractometer(EMD) will be installed between 2019–2023. This instrument requires the neutron detectors with the cover area near3 m2in two 90° neutron diffraction angle positions, the neutron detecting efficiency is better than 40%@1A, and the spatial resolution is better than 4 mm×200 mm in horizontal and vertical directions respectively. We have developed a onedimensional position-sensitive neutron detector based on the oblique6Li F/Zn S(Ag) scintillators, wavelength shifting fibers,and Si PMs(silicon photomultipliers) readout. The inhomogeneity of the neutron detection efficiency between each pixel and each detector module, which caused by the inconsistency of the wave-length shifting fibers in collecting scintillation photons, needs to be mitigated before the installation. A performance optimization experiment of the detector modules was carried out on the BL20(beam line 20) of CSNS. Using water sample, the neutron beam with Φ5 mm exit hole was dispersed related evenly into the forward space. According to the neutron counts of each pixel of the detector module, the readout electronics threshold of each pixel is adjusted. Compared with the unadjusted detector module, the inhomogeneity of the detection efficiency for the adjusted one has been improved from 69% to 90%. The test result of the diffraction peak of the standard sample Si showed that the adjusted detector module works well. 展开更多
关键词 scintillator neutron detector silicon photomultipliers wavelength shifting fiber LiF/ZnS scintil-lator detection efficiency inhomogeneity
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Multi‐task framework of precipitation nowcasting
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作者 Zheng Zhang Chuyao Luo +2 位作者 Baoquan Zhang Hao Jiang Bowen Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第4期1350-1363,共14页
Precipitation forecasting plays an important role in disaster warning,agricultural production,and other fields.To solve this issue,some deep learning methods are proposed to forecast future radar echo images and conve... Precipitation forecasting plays an important role in disaster warning,agricultural production,and other fields.To solve this issue,some deep learning methods are proposed to forecast future radar echo images and convert them into rainfall distributions.Prevailing spatiotemporal sequence prediction methods are usually based on a ConvRNN structure that combines a Convolutional Neural Network and Recurrent Neural Network.However,these existing methods ignore the image change prediction,which causes the coherence of the predicted image has deteriorated.Moreover,these approaches mainly focus on complicating model structure to exploit more historical spatiotemporal representations.Nevertheless,they ignore introducing other valuable information to improve predictions.To tackle these two issues,we propose GCMT‐ConvRNN,a multi‐ask framework of ConvRNN.Except for precipitation nowcasting as the main task,it combines the motion field estimation and sub‐regression as auxiliary tasks.In this framework,the motion field estimation task can provide motion information,and the sub‐regression task offers future information.Besides,to reduce the negative transfer between the auxiliary tasks and the main task,we propose a new loss function based on the correlation of gradients in different tasks.The experiments show that all models applied in our framework achieve stable and effective improvement. 展开更多
关键词 deep neural networks motion estimation
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Interfacial engineering of holey platinum nanotubes for formic acid electrooxidation boosted water splitting
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作者 Zi-Xin Ge Yu Ding +6 位作者 Tian-Jiao Wang Feng Shi Pu-Jun Jin Pei Chen Bin He Shi-Bin Yin Yu Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期209-216,I0006,共9页
Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to syn... Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures.In this work,we develop a facile pyrolysis strategy to synthesize the high-quality holey platinum nanotubes(Pt-H-NTs)using nanorods-like Pt^(Ⅱ)-phenanthroline(PT)coordination compound as self-template and self-reduction precursor.Then,an up-bottom strategy is used to further synthesize polyallylamine(PA)modified Pt-H-NTs(Pt-HNTs@PA).PA modification sharply promotes the catalytic activity of Pt-H-NTs for the formic acid electrooxidation reaction(FAEOR)by the direct reaction pathway.Meanwhile,PA modification also elevates the catalytic activity of Pt-H-NTs for the hydrogen evolution reaction(HER)by the proton enrichment at electrolyte/electrode interface.Benefiting from the high catalytic activity of Pt-H-NTs@PA for both FAEOR and HER,a two-electrode FAEOR boosted water electrolysis system is fabricated by using Pt-H-NTs@PA as bifunctio nal electrocatalysts.Such FAEOR boosted water electrolysis system only requires the operational voltage of 0.47 V to achieve the high-purity hydrogen production,showing an energy-saving hydrogen production strategy compared to traditional water electrolysis system. 展开更多
关键词 Holey platinum nanotubes Chemical functionalization Formic acid oxidation reaction Hydrogen evolution reaction Water splitting
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