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Estimation of free core nutation parameters and availability of computing options
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作者 weiwei yang Xiaoming Cui +2 位作者 Jianqiao Xu Qingchao Liu Ming Qin 《Geodesy and Geodynamics》 EI CSCD 2024年第1期61-74,共14页
The Earth’s Free Core Nutation(FCN) causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance effects.High-precision superconducting gravimeter(SG) and very long baseline interfe... The Earth’s Free Core Nutation(FCN) causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance effects.High-precision superconducting gravimeter(SG) and very long baseline interferometry(VLBI) provide good observation techniques for detecting the FCN parameters.However,some choices in data processing and solution procedures increase the uncertainty of the FCN parameters.In this study,we analyzed the differences and the effectiveness of weight function and ocean tide corrections in the FCN parameter detection using synthetic data,SG data from thirty-one stations,and the 10 celestial pole offset(CPO) series.The results show that significant discrepancies are caused by different computing options for a single SG station.The stacking method,which results in a variation of0.24-5 sidereal days(SDs) in the FCN period(T) and 10^(3)-10^(4) in the quality factor(Q) due to the selection of the weighting function and the ocean tide model(OTM),can effectively suppress this influence.The statistical analysis results of synthetic data shows that although different weight choices,while adjusting the proportion of diurnal tidal waves involved,do not significantly improve the accuracy of fitted FCN parameters from gravity observations.The study evaluated a series of OTMs using the loading correction efficiency.The fitting of FCN parameters can be improved by selecting the mean of appropriate OTMs based on the evaluation results.Through the estimation of the FCN parameters based on the forced nutation,it was found that the weight function P_(1) is more suitable than others,and different CPO series(after 2009) resulted in a difference of 0.4 SDs in the T and of 103 in the Q.We estimated the FCN parameters for SG(T=430.4±1.5 SDs and Q=1.52×10^(4)±2.5×10^(3)) and for VLBI(T=429.8±0.7 SDs,Q=1.88×10^(4)±2.1×10^(3)). 展开更多
关键词 Free core nutation Superconducting gravimeter Very long baseline interferometry Weight function Ocean tide model
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Covert Communication with a Spectrum Sharing Relay in the Finite Blocklength Regime 被引量:5
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作者 Ruiqian Ma weiwei yang +2 位作者 Hui Shi Xingbo Lu Jue Liu 《China Communications》 SCIE CSCD 2023年第4期195-211,共17页
In this paper,we investigate the feasibility and performance of the covert communication with a spectrum sharing relay in the finite blocklength regime.Specifically,the relay opportunistically forwards the source'... In this paper,we investigate the feasibility and performance of the covert communication with a spectrum sharing relay in the finite blocklength regime.Specifically,the relay opportunistically forwards the source's messages to the primary receiver or conveys the covert messages to its own receiver via the sharing spectrum,while the warden attempts to detect the transmission.First,we derive a lower bound on the covertness constraint,and the analytical expressions of both the primary average effective covert throughput(AECT)and sum AECT are presented by considering the overall decoding error performance.Then,we formulate two optimization problems to maximize the primary and sum AECT respectively by optimizing the blocklength and the transmit power at the source and the relay.Our examinations show that there exists an optimal blocklength to maximize the primary and sum AECT.Besides,it is revealed that,to maximize the primary AECT,the optimal transmit power of each hop increases as its channel quality deteriorates.Furthermore,in the optimization for maximizing the sum AECT,the optimal transmit power at the source equals to zero when the channel quality from relay to the secondary receiver is not weaker than that from relay to the primary receiver. 展开更多
关键词 covert communication finite blocklength RELAY spectrum sharing
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Improved Plasmonic Hot‑Electron Capture in Au Nanoparticle/Polymeric Carbon Nitride by Pt Single Atoms for Broad‑Spectrum Photocatalytic H_(2)Evolution 被引量:4
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作者 Manyi Gao Fenyang Tian +3 位作者 Xin Zhang Zhaoyu Chen weiwei yang Yongsheng Yu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第8期423-435,共13页
ABSTRACT Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a“holy grail”for researchers,but is still a challenging issue.Herein,b... ABSTRACT Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a“holy grail”for researchers,but is still a challenging issue.Herein,based on the common polymeric carbon nitride(PCN),a hybrid co-catalysts system comprising plasmonic Au nanoparticles(NPs)and atomically dispersed Pt single atoms(PtSAs)with different functions was constructed to address this challenge.For the dual co-catalysts decorated PCN(PtSAs–Au_(2.5)/PCN),the PCN is photoexcited to generate electrons under UV and short-wavelength visible light,and the synergetic Au NPs and PtSAs not only accelerate charge separation and transfer though Schottky junctions and metal-support bond but also act as the co-catalysts for H_(2) evolution.Furthermore,the Au NPs absorb long-wavelength visible light owing to its localized surface plasmon resonance,and the adjacent PtSAs trap the plasmonic hot-electrons for H_(2) evolution via direct electron transfer effect.Consequently,the PtSAs–Au_(2.5)/PCN exhibits excellent broad-spectrum photocatalytic H_(2) evolution activity with the H_(2) evolution rate of 8.8 mmol g^(−1) h^(−1) at 420 nm and 264μmol g^(−1) h^(−1) at 550 nm,much higher than that of Au_(2.5)/PCN and PtSAs–PCN,respectively.This work provides a new strategy to design broad-spectrum photocatalysts for energy conversion reaction. 展开更多
关键词 Polymeric carbon nitride Au nanoparticles Pt single atoms Photocatalytic H2 evolution Broad-spectrum photocatalysts
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Multi-Antenna Jammer Assisted Covert Communications in Data Collected IoT with NOMA 被引量:2
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作者 Liwei Tao weiwei yang +3 位作者 Xingbo Lu Ruiqian Ma Ling yang Yi Song 《China Communications》 SCIE CSCD 2023年第5期217-231,共15页
In this paper,we investigate covert communications in data collected IoT with NOMA,where the paired sensor nodes S_(m) and S_(n) transmit covert messages to a legitimate receiver(Bob)in the presence of a Warden(Willie... In this paper,we investigate covert communications in data collected IoT with NOMA,where the paired sensor nodes S_(m) and S_(n) transmit covert messages to a legitimate receiver(Bob)in the presence of a Warden(Willie).To confuse the detection at Willie,an extra multi-antenna friendly jammer(Jammer)has been employed to transmit artificial noise(AN)with random power.Based on the CSI of Willie is available or not at Jammer,three AN transmission schemes,including null-space artificial noise(NAN),transmit antenna selection(TAS),and zeroforcing beamforming(ZFB),are proposed.Furthermore,the closed-form expressions of expected minimum detection error probability(EMDEP)and joint connection outage probability(JCOP)are derived to measure covertness and reliability,respectively.Finally,the maximum effective covert rate(ECR)is obtained with a given covertness constraint.The numerical results show that ZFB scheme has the best maximum ECR in the case of the number of antennas satisfies N>2,and the same maximum ECR can be achieved in ZFB and NAN schemes with N=2.Moreover,TAS scheme also can improve the maximum ECR compared with the benchmark scheme(i.e.,signal-antenna jammer).In addition,a proper NOMA node pairing can further improve the maximum ECR. 展开更多
关键词 IOT covert communications NOMA node pairing multi-antenna jammer
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Secure Transmission in Cognitive Radio Networks Using Full-Duplex Technique with Outdated CSI 被引量:1
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作者 Zhihui Shang Tao Zhang +2 位作者 Guojie Hu Yueming Cai weiwei yang 《China Communications》 SCIE CSCD 2023年第1期230-245,共16页
This paper investigates the effects of the outdated channel state information(CSI)on the secrecy performance of an underlay spectrum sharing cognitive radio networks(CRNs),where the secondary user(SU)source node(Alice... This paper investigates the effects of the outdated channel state information(CSI)on the secrecy performance of an underlay spectrum sharing cognitive radio networks(CRNs),where the secondary user(SU)source node(Alice)aims to transmit the trusted messages to the full-duplex(FD)aided SU receiver(Bob)with the assistance of cooperative relay(Relay).Considering the impact of feedback delay,outdated CSI will aggravate the system performance.To tackle such challenge,the collaborative zero-forcing beamforming(ZFB)scheme of FD technique is further introduced to implement jamming so as to confuse the eavesdropping and improve the security performance of the system.Under such setup,the exact and asymptotic expressions of the secrecy outage probability(SOP)under the outdated CSI case are derived,respectively.The results reveal that i)the outdated CSI of the SU transmission channel will decrease the diversity gain from min(NANR,NRNB)to NRwith NA,NRand NBbeing the number of antennas of Alice,Relay and Bob,respectively,ii)the introduction of FD technique can improve coding gain and enhance system performance. 展开更多
关键词 cognitive radio network physical layer security full-duplex multiple antennas relay secrecy outage probability outdated CSI
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Sulfur vacancies-induced“Electron Bridge”in Ni_(4)Mo/Sv-Zn_(x)Cd_(1-x)S regulates electron transfer for efficient H_(2)-releasing photocatalysis 被引量:1
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作者 Xin Zhang Manyi Gao +3 位作者 Longyu Qiu Jie Sheng weiwei yang Yongsheng Yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期64-71,共8页
Despite the existence of plentiful photocatalyst heterojunctions,their separation efficiency and charge flow precision remain low on account of lacking interfacial modulation.Herein,through a defect-induced heterojunc... Despite the existence of plentiful photocatalyst heterojunctions,their separation efficiency and charge flow precision remain low on account of lacking interfacial modulation.Herein,through a defect-induced heterojunction constructing strategy,Ni4Mo alloys were in-situ grown on the unsaturated coordinated sulfur atoms of sulfur vacancies-rich ZCS(Sv-ZCS)via interfacial Ni-S covalent bonds.The experimental and theoretical results reveal that these unsaturated sulfur atoms induced by sulfur vacancies vastly facilitate to anchor more Ni-Mo nanoparticles and form abundant Ni-S covalent bonds,meanwhile,these sulfur vacancies could form dual internal electric field(IEF)and work with Ni-S covalent bonds as“Electron Bridge”to further accelerate photoelectrons transfer,as well as promote the activation of water molecules and the desorption of hydrogen proton.Accordingly,the optimized Ni_(4)Mo/Sv-ZCS composite achieves an improved photocatalytic hydrogen evolution(PHE)rate of 94.69 mmol h^(-1)g^(-1)without an evident decrease after 6 cycles of photocatalytic tests,which is 21.2 and 1.94 times higher than those of Pt/ZCS and Ni_(4)Mo/ZCS,respectively.This tactic opens a new way for optimizing Zn_(x)Cd_(1-x)S-based heterojunctions by constructing sulfur vacancies and covalent bonds as“Electron Bridge”to enhance the activity of PHE. 展开更多
关键词 Ni_(4)Mo Sulfur vacancies-rich Zn_(x)Cd_(1-x)S Electron Bridge Photocatalytic hydrogen evolution
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GrapevineXL reliably predicts multi-annual dynamics of vine water status, berry growth, and sugar accumulation in vineyards
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作者 weiwei yang Junqi Zhu +2 位作者 Cornelis van Leeuwen Zhanwu Dai Gregory AGambetta 《Horticulture Research》 SCIE CSCD 2023年第6期56-69,共14页
Climate and water availability greatly affect each season’s grape yield and quality.Using models to accurately predict environment impacts on fruit productivity and quality is a huge challenge.We calibrated and valid... Climate and water availability greatly affect each season’s grape yield and quality.Using models to accurately predict environment impacts on fruit productivity and quality is a huge challenge.We calibrated and validated the functional-structural model,GrapevineXL,with a data set including grapevine seasonal midday stem water potential(�xylem),berry dry weight(DW),fresh weight(FW),and sugar concentration per volume([Sugar])for a wine grape cultivar(Vitis vinifera cv.Cabernet Franc)in field conditions over 13 years in Bordeaux,France.Our results showed that the model could make a fair prediction of seasonal�xylem and good-to-excellent predictions of berry DW,FW,[Sugar]and leaf gas exchange responses to predawn and midday leaf water potentials under diverse environmental conditions with 14 key parameters.By running virtual experiments to mimic climate change,an advanced veraison(i.e.the onset of ripening)of 14 and 28 days led to significant decreases of berry FW by 2.70%and 3.22%,clear increases of berry[Sugar]by 2.90%and 4.29%,and shortened ripening duration in 8 out of 13 simulated years,respectively.Moreover,the impact of the advanced veraison varied with seasonal patterns of climate and soil water availability.Overall,the results showed that the GrapevineXL model can predict plant water use and berry growth in field conditions and could serve as a valuable tool for designing sustainable vineyard management strategies to cope with climate change. 展开更多
关键词 SUGAR CULTIVAR SUGAR
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具有优异甲醇耐受性的Rh掺杂Pd Cu有序金属间化合物纳米粒子增强氧还原电催化 被引量:5
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作者 李蒙刚 夏仲泓 +7 位作者 黄雅荣 陶璐 晁玉广 尹坤 杨文秀 杨微微 于永生 郭少军 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第9期139-146,共8页
由于阴极催化剂有限的活性和耐久性以及甲醇渗透到阴极所导致的催化剂中毒问题,直接甲醇燃料电池(DMFCs)仍面临严峻的挑战。本文报道了一类新型的具有有序金属间结构的Rh掺杂PdCu纳米颗粒用于提高阴极氧还原反应(ORR)的活性、耐久性和... 由于阴极催化剂有限的活性和耐久性以及甲醇渗透到阴极所导致的催化剂中毒问题,直接甲醇燃料电池(DMFCs)仍面临严峻的挑战。本文报道了一类新型的具有有序金属间结构的Rh掺杂PdCu纳米颗粒用于提高阴极氧还原反应(ORR)的活性、耐久性和甲醇耐受性。通过结合Rh原子掺杂以及有序金属间结构两者的优点,在碱性条件下,Rh掺杂Pd Cu金属间化合物催化剂在0.9 V电位下对氧还原质量活性相比商业Pt/C提高7.4倍。这种独特的结构还使其表现出出色的ORR耐久性,在连续20000个循环后的半波电位和质量活性几乎不变。此外,在苛刻的中毒环境下,仍可以保持Rh掺杂PdCu金属间化合物电催化剂高的氧还原催化活性。 展开更多
关键词 Rh掺杂 有序金属间化合物 纳米颗粒 氧还原 甲醇耐受性
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Boron-doping induced lithophilic transition of graphene for dendrite-free lithium growth 被引量:4
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作者 Wei Liu Pengbo Zhai +8 位作者 Shengjian Qin Jing Xiao Yi Wei weiwei yang Shiqiang Cui Qian Chen Chunqiao Jin Shubin yang Yongji Gong 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第5期463-469,共7页
Li metal,possessing advantages of high theoretical specific capacity and low electrochemical potential,is regarded as the most promising anode material for next-generation batteries.However,despite decades of intensiv... Li metal,possessing advantages of high theoretical specific capacity and low electrochemical potential,is regarded as the most promising anode material for next-generation batteries.However,despite decades of intensive research,its practical application is still hindered by safety hazard and low Coulombic efficiency,which is primarily caused by dendritic Li deposition.To address this issue,restraining dendrite growth at the nucleation stage is deemed as the most effective method.By utilizing the difference of electronegativity between boron atoms and carbon atoms,carbon atoms around boron atoms in boron-doped graphene(BG)turn into lithiophilic sites,which can enhance the adsorption capacity to Li^(+)at the nucleation stage.Consequently,an ultralow overpotential of 10 mV at a current density of 0.5 mA/cm^(2) and a high average Coulombic efficiency of 98.54%over more than 140 cycles with an areal capacity of 2 mAh/cm^(2) at a current density of 1 m A/cm^(2) were achieved.BG-Li|LiFePO_(4) full cells delivered a long lifespan of480 cycles at 0.5 C and excellent rate capability.This work provides a novel method for rational design of dendrite-free Li metal batteries by regulating nucleation process. 展开更多
关键词 Lithium metal anode B-doped graphene Lithophilic transition DFT calculation Uniform Li deposition
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Room-temperature solid phase surface engineering of BiOI sheets stacking g-C_(3)N_(4) boosts photocatalytic reduction of Cr(Ⅵ) 被引量:4
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作者 Xin Zhang weiwei yang +3 位作者 Manyi Gao Hu Liu Kefei Li Yongsheng Yu 《Green Energy & Environment》 SCIE EI CSCD 2022年第1期66-74,共9页
Cr(Ⅵ)-based compounds pollution have attracted global concern due to serious harm to humans and environment.Hence,it is crucial to exploit an effective technique to eliminate Cr(Ⅵ)in water.Herein,we in-situ grown Bi... Cr(Ⅵ)-based compounds pollution have attracted global concern due to serious harm to humans and environment.Hence,it is crucial to exploit an effective technique to eliminate Cr(Ⅵ)in water.Herein,we in-situ grown BiOI on graphitic carbon nitride to prepare the BiOI/g-C_(3)N_(4)(BCN)direct Z-scheme heterojunction by solid phase engineering method at room temperature.Experimental result shown the photocatalytic activity of pure BiOI were obviously enhanced by constructing Z-scheme BCN heterostructure,and BCN-3 heterostructure exhibited the optimal photocatalytic degradation of RhB with 98%yield for 2.5 h and reduction of Cr(Ⅵ)with more than 99%yield for 1.5 h at pH=2.Stability test shows BCN-3 still kept more than 98%reduction efficiency after 6 cycles.In addition,we also studied the reduction mechanism that shown the.O_(2)^(-)radicals essentially helped to reduce the Cr(Ⅵ)in aqueous solution under illumination,verified the direct Z-scheme charge transfer path by X-ray photoelectron spectroscopy(XPS)and the free radical trapping experiment.The work open a new way for rationally designing photocatalyst heterostructure to reduce Cr(Ⅵ)to Cr(Ⅲ). 展开更多
关键词 BiOI/g-C_(3)N_(4) Photocatalytic reduction Solid phase Direct Z-scheme Cr(Ⅵ)reduction
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Photo-thermal CO_(2) reduction with methane on group Ⅷ metals:In situ reduced WO_(3) support for enhanced catalytic activity 被引量:3
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作者 Huimin Liu Xianguang Meng +3 位作者 weiwei yang Guixia Zhao Dehua He Jinhua Ye 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第11期1976-1982,共7页
Photo-thermal CO_(2) reduction with methane(CRM)is beneficial for solar energy harvesting and energy storage.The search for efficient photo-thermal catalysts is of great significance.Here,we reveal that group Ⅷ metal... Photo-thermal CO_(2) reduction with methane(CRM)is beneficial for solar energy harvesting and energy storage.The search for efficient photo-thermal catalysts is of great significance.Here,we reveal that group Ⅷ metal catalysts supported by optical material WO_(3) are more effective for photo-thermal CRM,giving catalytic activities with visible light assistance that are 1.4-2.4 times higher than that achieved under thermal conditions.The activity enhancement(1.4-2.4 times)was comparable to that achieved with plasmonic-Au-promoted catalysts(1.7 times).Characterization results indicated that WO_(3) was partially reduced to WO_(3-x) in situ under the reductive CRM reaction atmosphere,and that WO_(3-x) rather than WO_(3) enhanced the activities with visible light assistance.Our method provides a promising approach for improving the activity of catalysts under light irradiation. 展开更多
关键词 Tungsten oxide Visible light In situ reduction PHOTOCATALYSIS CO_(2) reduction
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Resveratrol inhibits angiotensin II-induced ERK1/2 activation by downregulating quinone reductase 2 in rat vascular smooth muscle cells 被引量:2
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作者 Xiwen Zhang Yao Wang +3 位作者 weiwei yang Xiaofeng Hou Jiangang Zou Kejiang Cao 《The Journal of Biomedical Research》 CAS 2012年第2期103-109,共7页
Our previous studies showed that resveratrol could inhibit the proliferation of vascular smooth muscle cells (VSMCs) and repress mRNA and protein expression of quinone reductase 2 (NQO2). This study further explor... Our previous studies showed that resveratrol could inhibit the proliferation of vascular smooth muscle cells (VSMCs) and repress mRNA and protein expression of quinone reductase 2 (NQO2). This study further explored the potential mechanisms whereby resveratrol inhibits the proliferation of rat VSMCs. Lentiviral vectors that incorporated NQO2 small interfering RNA (siRNA) were constructed and transduced into rat VSMCs. The cell proliferation was detected using the bromodeoxyuridine (BrdU) assay. Cultured rat VSMCs were stimulated with angiotensin II and the level of reactive oxygen species (ROS) was measured using a ROS assay kit. A realtime quantitative PCR was used to detect NQO2 mRNA levels. Extracellular signal-regulated kinase (ERK1/2) and NQO2 protein expression were determined by Western blotting analysis. The inhibitory effect of resveratrol (10 and 50 μmol/L) on the proliferation of rat VSMCs in the NQO2 siRNA group was significantly weaker than that in the normal and scrambled siRNA group (P 〈 0.01). The ROS level in the NQO2 siRNA and resveratrol (50 μmol/L) treatment groups were lower than that in the normal and scrambled siRNA groups (P 〈 0.01 in both). Compared with the normal and scrambled siRNA group, the phosphorylation of ERK1/2 was significantly decreased in the NQO2 siRNA and resveratrol (50 μmol/L) treatment group (P 〈 0.01 in both). In conclusion, high concentration of resveratrol inhibits angiotensin II-induced ERK1/2 phosphorylation and subsequent proliferation by down-regulation of NQO2 in cultured rat VSMCs. 展开更多
关键词 RESVERATROL quinone reductase 2 (NQO2) reactive oxygen species extracellular signal-regulatedkinase (ERK) vascular smooth muscle cells
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Adaptive Secure Transmission for Wireless Powered Communication Networks 被引量:1
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作者 Yong Wang weiwei yang +3 位作者 Tao Zhang Yong Chen Xiaohui Shang Quan Wang 《China Communications》 SCIE CSCD 2021年第3期155-173,共19页
This paper investigates secure transmission in a wireless powered communication network(WPCN)with an energy harvesting(EH)source configured with multiple antennas.In the WPCN,the EH source harvests energy from the rad... This paper investigates secure transmission in a wireless powered communication network(WPCN)with an energy harvesting(EH)source configured with multiple antennas.In the WPCN,the EH source harvests energy from the radio frequency(RF)signals broadcasted by a power beacon(PB),and purely relies on the harvested energy to communicate with the destination in the presence of passive eavesdroppers.It is noteworthy that the RF-EH source is equipped with a finite energy storage to accumulate the harvested energy for the future usage.Moreover,due to energy-constraint and complexitylimitation,the multi-antenna source is only configured with a single RF-chain.To enhance the security for the WPCN,we propose two adaptive transmission schemes,i.e.,energy-aware transmit antenna selection(EATAS)and energy-aware differential spatial modulation(EADSM).According to the energy status and the channel quality,the source adaptively decides whether to transmit confidential information or harvest RF energy.To evaluate the secrecy performance of the proposed schemes,we first study the evolution of the energy storage,and then derive the analytical expressions of connection outage probability(COP),secrecy outage probability(SOP)and efficient secrecy throughput(EST).Numerical results demonstrate that our proposed schemes outperform the existing schemes,i.e.,time-switching based TAS(TS-TAS)Received:May 19,2020 Revised:Sep.13,2020 Editor:Deli Qiao and accumulate-then-transmit(ATT).And,increasing the transmit power of the PB or the capacity of the source’s energy storage is helpful to improve the secrecy performance.Moreover,there exists an optimal transmission rate for each proposed scheme to achieve best secrecy performance. 展开更多
关键词 physical layer security energy harvesting markov chain transmit antenna selection differential spatial modulation
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Homozygous lethality and heterozygous spotting due to a novel missense mutation in the mouse Kit gene
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作者 Baojin WU Lijing YIN +4 位作者 Xiaoshu YIN weiwei yang Bing CHEN Zhengfeng XUE Peilin WU 《Current Zoology》 SCIE CAS CSCD 北大核心 2009年第6期430-434,共5页
N-ethyl-N-nitrosourea (ENU) mutagenesis in mice can be used to study gene function in vivo and to establish genetic mouse models of human disease. In this study, a white spotted mouse (named Kit^W-1 Bao) was obtai... N-ethyl-N-nitrosourea (ENU) mutagenesis in mice can be used to study gene function in vivo and to establish genetic mouse models of human disease. In this study, a white spotted mouse (named Kit^W-1 Bao) was obtained by ENU-induced mutagenesis. Inheritance testing showed a single-gene dominant mutation and lethality in the Kit^W-1 Bao homozygous mice. The mutation was mapped to Chromosome 5 between markers DSMit356 and DSMit308. The region contains the Kit gene, whose mutations are known to lead to pigmentation defects in mice. Sequence analysis of the Kit cDNA from Kit^W-1 Bao heterozygotes revealed an A to T missense mutation resulting in an amino acid substitution of Asp (D) by Val (V) at amino acid position 849 within a highly conserved tyrosine kinase domain. The combined phenotype displayed by the Kit^W-1 Bao heterozygous and homozygous mutant mice demonstrates the critical function of the highly conserved aspartie acid residue at position 849 in the Kit gene product 展开更多
关键词 White spotting DEATH Mapping Identification KIT
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N,P co-doped porous graphene with high electrochemical properties obtained via the laser induction of cellulose nanofibrils
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作者 Jie Wei weiwei yang +2 位作者 Shuai Jia Jie Wei Ziqiang Shao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第7期31-38,共8页
Cellulose and its derivatives are natural materials with high carbon contents, but it is challenging to convert their carbon into high value-added carbonaceous materials(e.g., graphene). Here, an approach to convert t... Cellulose and its derivatives are natural materials with high carbon contents, but it is challenging to convert their carbon into high value-added carbonaceous materials(e.g., graphene). Here, an approach to convert the carbon in cellulose into N, P co-doped porous graphene(LIG) materials via laser induction is proposed. Cellulose nanofibrils(CNFs), a cellulose derivative with high dispersion uniformity and abundant surface hydroxyl groups, were easily formed on a bulk substrate(thickness ≥5 mm) containing ammonium polyphosphate(APP). Then, a 10.6 μm CO2 laser was used to scribe for 1–5 passes on the CNFs/APP substrate under an ambient environment to produce N, P co-doped porous LIG. Upon increasing the number of laser scribing passes, the IG/IDof LIG first increased and then decreased, reaching a maximum of 1.68 at 4 passes. The good pore structure and low resistance also showed that 4 laser passes were ideal. Besides, the N, P co-doped LIG also showed excellent electrochemical performance, with a specific capacitance of 221.4 FF·g^(-1) and capacitance retention of 89.9%. This method exploits the advantages of nanocellulose and overcomes the difficulties associated with directly compounding cellulosic materials, providing a method for the further development of biomass nanomaterials. 展开更多
关键词 Cellulose nanofibrils Laser induction Porous graphene Multiple lasing Supercapacitor
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Hypoxic/ischemic preconditioning attenuate PKCδ-medi-ated injury in patients and mice with cerebral infarction
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作者 weiwei yang Shengli Xu +1 位作者 Liyong Zhang Zidong Wang 《Journal of Translational Neuroscience》 2021年第3期19-29,共11页
Objective:cerebral ischemic/hypox-ic preconditioning(I/HPC)is an endogenous strategy in which brief periods of sublethal ischemia/hypoxia render neural tissues resistant to subsequent ischemic/hypoxic damage.This phen... Objective:cerebral ischemic/hypox-ic preconditioning(I/HPC)is an endogenous strategy in which brief periods of sublethal ischemia/hypoxia render neural tissues resistant to subsequent ischemic/hypoxic damage.This phenomenon has been found in the brain,heart,liver,intestine,muscle,kidneys,and lung.How-ever,whether HPC has a protective effect on secondary cerebral ischemic injury or protein kinase Cδ(PKCδ)within ischemic patients and animal models is still un-clear.Methods:using a hypoxic preconditioned mouse model and a middle cerebral artery occlusion mouse mod-el,combined with 2,3,5-triphenyl tetrazolium chloride(TTC)staining,SDS-polyacrylamide gel electrophoresis(SDS-PAGE),and Western blot,we observed changes in infarction size,density,edema ratio,and changes in PKCδand membrane translocation within the ischemic cortex of the middle cerebral artery occlusion(MCAO)mice.Results:HPC can attenuate neurological deficits and cerebral ischemic injuries of mice following MCAO,including decreases in infarct size,edema ratio,densities of infarct area,and neuron loss.In addition,HPC inhib-its PKCδmembrane translocation in the penumbra of the MCAO-induced ischemic cortex.We found that admin-istration of PKCδ-specific inhibitor dV1-1 mimics the neuroprotective effects of HPC,and nonisoform-specif-ic activation of PKC can partially abolish HPC-induced neuroprotection.Ischemic preconditioning decreased the levels of PKCδin the serum of patients with cerebral in-farction and reduced the cerebral nerve damage caused by ischemia.Conclusion:hypoxic/ischemic precondi-tioning attenuates PKCδ-mediated injury in patients and mice.These findings enrich our understanding of the sig-nal transduction mechanism underlying cerebral HPC and provide clues to developing medicine against ischemia/hypoxia-induced cerebral injuries. 展开更多
关键词 hypoxic preconditioning(HPC) middle cerebral artery occlusion(MCAO) protein kinase C(PKC) PENUMBRA NEUROPROTECTION
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Comparison of leaf morphological,anatomical,and photosynthetic responses to drought stress among eight apple rootstocks
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作者 Pengpeng Sun Muhammad Mobeen Tahir +9 位作者 Xian Lu Zhimin Liu Xiaoyun Zhang Xiya Zuo Yun Shao Xiangyun Xiao Na An Chao Wang Dong Zhang weiwei yang 《Fruit Research》 2022年第1期195-207,共13页
The drought resistance of eight commonly used apple rootstocks under natural drought conditions was examined to provide clues for the selection,promotion,and utilization of drought-resistant apple rootstocks.The ultra... The drought resistance of eight commonly used apple rootstocks under natural drought conditions was examined to provide clues for the selection,promotion,and utilization of drought-resistant apple rootstocks.The ultrastructural differences and physiological and biochemical characteristics of the leaves of eight apple rootstocks under drought stress were observed.The index changes were used to rank drought resistance by the membership function method comprehensively.The results showed that the leaf thickness,palisade tissue thickness,sponge tissue thickness,net photosynthetic rate,and chlorophyll content were significantly higher in‘Fupingqiuzi'than those of other rootstocks at various stress conditions.The leaf water content and water use efficiency of'Qingzhen 1'were significantly higher than those of other rootstocks under different stress conditions.The root vigor of‘B.9'was significantly higher than that of other rootstocks.The results of membership function analysis showed that the drought resistance of different rootstocks was in the order:‘Fupingqiuzi'>‘Qingzhen 1'>‘B.9'>‘MM.111'>‘GM256'>‘MM.106'>‘M.26'>‘M.9-Nic29'.‘Fupingqiuzi'had the strongest drought resistance,and‘Qingzhen 1'and‘B.9'were also relatively droughtresistant.These rootstocks can be used as raw materials for drought-resistant apple rootstock breeding and are propagated and utilized in arid areas. 展开更多
关键词 ROOTSTOCKS BREEDING DROUGHT
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Current status and trends of antimicrobial resistance among clinical isolates in China:a retrospective study of CHINET from 2018 to 2022 被引量:4
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作者 weiwei yang Li Ding +7 位作者 Renru Han Dandan Yin Shi Wu yang yang Demei Zhu Yan Guo Fupin Hu on behalf of the China Antimicrobial Surveillance Network(CHINET)Study Group 《One Health Advances》 2023年第1期289-297,共9页
Antimicrobial resistance(AMR)is a pressing issue in China,with antibiotic therapy becoming less effective against bacterial infections.To address this challenge,the China Antimicrobial Surveillance Network(CHINET)was ... Antimicrobial resistance(AMR)is a pressing issue in China,with antibiotic therapy becoming less effective against bacterial infections.To address this challenge,the China Antimicrobial Surveillance Network(CHINET)was established in 2005 to monitor antimicrobial resistance in the country.This study analyzed the CHINET data from teaching hospi-tals and evaluated the trends of AMR in China from 2018 to 2022.A range of 163,636 to 301,917 isolates was obtained per year,with the majority being Gram-negative bacilli(69.0%to 71.8%).The proportion of important multidrug-resistant pathogens remained stable over the years.While the analysis showed diverse AMR profiles for different bac-terial species.Over the five years,generally decreased resistance rates were observed from the majority of the tested species.For example,resistance to ceftriaxone decreased in Escherichia coli and Klebsiella pneumoniae,while resistance to imipenem and meropenem decreased in Pseudomonas aeruginosa.Moreover,resistance to methicillin,gentamicin,fosfomycin,and clindamycin also decreased in clinical Staphylococcus aureus isolates.On the other hand,resistance levels of Acinetobacter baumannii remained stable.Our study provides a comprehensive overview of the AMR profiles of common bacterial species in China and highlights the ongoing efforts to address this challenge. 展开更多
关键词 CHINET E.COLI K.pneumoniae P.aeruginosa A.baumannii S.aureus Antimicrobial susceptibility testing
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Impaired dNKAP function drives genome instability and tumorigenic growth in Drosophila epithelia
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作者 Ting Guo Chen Miao +11 位作者 Zhonghua Liu Jingwei Duan Yanbin Ma Xiao Zhang weiwei yang Maoguang Xue Qiannan Deng Pengfei Guo Yongmei Xi Xiaohang yang Xun Huang Wanzhong Ge 《Journal of Molecular Cell Biology》 SCIE CAS CSCD 2023年第12期50-64,共15页
Mutations or dysregulated expression of NF-kappaB-activating protein(NKAP)family genes have been found in human cancers.How NKAP family gene mutations promote tumor initiation and progression remains to be determined.... Mutations or dysregulated expression of NF-kappaB-activating protein(NKAP)family genes have been found in human cancers.How NKAP family gene mutations promote tumor initiation and progression remains to be determined.Here,we characterized dNKAP,the Drosophila homolog of NKAP,and showed that impaired dNKAP function causes genome instability and tumorigenic growth in a Drosophila epithelial tumor model.dNKAP-knockdown wing imaginal discs exhibit tumorigenic characteristics,including tissue overgrowth,cell-invasive behavior,abnormal cell polarity,and cell adhesion defects.dNKAP knockdown causes both R-loop accumulation and DNA damage,indicating the disruption of genome integrity.Further analysis showed that dNKAP knockdown induces c-Jun N-terminal kinase(JNK)-dependent apoptosis and causes aberrant cell proliferation in distinct cell populations.Activation of the Notch and JAK/STAT signaling pathways contributes to the tumorigenic growth of dNKAP-knockdown tissues.Furthermore,JNK signaling is essential for dNKAP depletion-mediated cell invasion.Transcriptome analysis of dNKAP-knockdown tissues confirmed the misregulation of signaling pathways involved in promoting tumorigenesis and revealed abnormal regulation of metabolic pathways.dNKAP knockdown and oncogenic Ras,Notch,or Yki mutations show synergies in driving tumorigenesis,further supporting the tumor-suppressive role of dNKAP.In summary,this study demonstrates that dNKAP plays a tumor-suppressive role by preventing genome instability in Drosophila epithelia and thus provides novel insights into the roles of human NKAP family genes in tumor initiation and progression. 展开更多
关键词 Drosophila wing imaginal disc dNKAP genome instability tumorigenic growth
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Unusual local electric field concentration in multilayer ceramic capacitors
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作者 Wentong Du Huarong Zeng +5 位作者 weiwei yang Kunyu Zhao Faqiang Zhang Guorong Li Yongxiang Li Zhifu Liu 《Journal of Materiomics》 SCIE CSCD 2023年第2期403-409,共7页
Local electric-field around multitype pores(dielectric pore,interface pore,electrode pore)in multilayer ceramic capacitors(MLCCs)was investigated using Kelvin probe force microscopy combined with the finite element si... Local electric-field around multitype pores(dielectric pore,interface pore,electrode pore)in multilayer ceramic capacitors(MLCCs)was investigated using Kelvin probe force microscopy combined with the finite element simulation to understand the effect of pores on the electric reliability of MLCCs.Electricfield is found to be concentrated significantly in the vicinity of these pores and the strength of the local electric-field is 1.5e5.0 times of the nominal strength.Unexpectedly,the concentration degree of the pores in the inner electrode is much higher than that in the dielectrics and dielectric-electrode interfaces.Meanwhile,geometry orientations are found to have a remarkable influence on the local electric field strength.The pores act as an insulation degradation precursor via local electric,thermal center,and oxygen vacancies accumulation center.Such unusual local electric field concentration of multitype pores can provide new insights into the understanding of insulation degradation evolution,processing tailoring and design optimization for MLCCs. 展开更多
关键词 Multilayer ceramic capacitors(MLCCs) Kelvin probe force microscopy PORE Local electric field concentration
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