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dispersion grating;frequency modulation-to-amplitude modulation conversion;high-power laser facility;inertial confinement fusion;phase modulation

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high power laser Science and Engineering 2024年第1期12卷 84-98页

作者： Yujia Zhang Wei Fan Jiangfeng Wang Xiaochao Wang Xinghua Lu Dajie Huang Shouying Xu Yanli Zhang Mingying Sun Zhaoyang Jiao Shenlei Zhou Xiuqing Jiang key laboratory of high power laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina

Frequency modulation(FM)-to-amplitude modulation(AM) conversion is an important factor that affects the time±power curve of inertial confinement fusion(ICF) high-power laser facilities. This conversion can impact uniform compression and increase the risk of damage to optics. However, the dispersive grating used in the smoothing by spectral dispersion technology will introduce a temporal delay and can spatially smooth the target. The combined effect of the dispersive grating and the focusing lens is equivalent to a Gaussian low-pass filter, which is equivalent to 8 GHz bandwidth and can reduce the intensity modulation on the target to below 5% with 0.3 nm @ 3 GHz + 20 GHz spectrum phase modulation. The results play an important role in the testing and evaluating of the FM-to-AM on the final optics and the target, which is beneficial for comprehensively evaluating the load capacity of the facility and isentropic compression experiment for ICF.

关键词： dispersion grating frequency modulation-to-amplitude modulation conversion high-power laser facility inertial confinement fusion phase modulation

Influence of Nd^(3+) concentration on mid-infrared emission in PbF_(2) crystal co-doped with Ho^(3+) and Nd^(3+) ions

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Journal of Rare Earths 2024年第3期42卷 479-487,I0002页

作者： Yan Chen Juncheng Tan Peixiong Zhang Weibi Zheng Lin Li Lianhan Zhang Zhen Li Yin Hang Zhenqiang Chen Department of Optoelectronic Engineering Jinan UniversityGuangzhou510632China Guangdong Provincial Engineering Research Centerof Crystal and laser Technology.Guangzhou 510632China Research Center of laser Crystal Key Laboratory of High Power Laser MaterialsShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai201800China

A promising series of Ho_(y)Nd_(x)Pb_((1-x-y))F_2(x = 0, 0.01, 0.02, 0.03, 0.04;y = 0.02) crystals was grown by the Bridgman method. The influence of the Nd^(3+)ions concentration on mid-infrared(~2.0, ~2.9 and ~3.9 μm)fluorescence emissions of Ho^(3+)ions in the PbF_(2) crystal excited by 808 nm laser diode was investigated in this work. The energy transfer mechanism between Nd^(3+)ions and Ho~(3+)ions under different concentrations of the Nd^(3+)ions was systematically analyzed. The results show that the Nd^(3+)ions have good sensitization and deactivation effect on the Ho^(3+)ions to stimulate the mid-infrared fluorescence emissions. The experimental analysis proves that the sensitization efficiency of the Nd^(3+)ions is relatively stable at around 93.45% with varying Nd^(3+)-doping concentrations. Concentration dependence studies indicate that the concentration of the Nd^(3+)ions has significant influence on mid-infrared emissions.When the doping concentration of the Nd^(3+)ions is up to 2.0 at%, the intensity of ~2.0, ~2.9 and ~3.9 μm emissions all reach the maximum. The output characteristics of a 3.9 μm laser are simulated, and it is found that with the increase of the Nd^(3+)-doping concentration, the peak power, pulse width, and peak energy all meet the trend of first increasing and then decreasing, and Ho_(0.02)Nd_(0.02)Pb_(0.96)F_(2) crystal displays the best performance. All the results show that the Nd^(3+)/Ho^(3+)co-doped PbF_(2) crystals might act as a useful optical medium for mid-infrared laser applications.

关键词： Crystal growth Mid-infrared PbF_(2) Rare earth ions

Intermediate phase-assisted growth of CsPbBr3 for high performance of carbon-based perovskite solar cells

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Rare Metals 2024年第5期43卷 2222-2229页

作者： Bo-Yan Liu He-Ming Yang Yu-Dong Zuo Zhi-Hao Tao Jun-Chun Li Ya-Jing Chang Guo-Qing Tong Yang Jiang School of materials Science and Engineering Hefei University of Technology State key laboratory of Pulsed power laser Technology National University of Defense Technology

CsPbBr3inorganic perovskites have been regarded as the promising materials in the field of photovoltaics because of the high tolerance against environment The high energy barrier of phase transition from lead bromide （PbBr2） to CsPbBr3perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr3solar cells.Herein,an intermediate phase-assisted growth of CsPbBr3perovskite was proposed by introducing tetraphenylphosphonium bromide （TPPB） as additive.The TPPB is expected to react with PbBr2in organic solvent to form an intermediate phase of[TPPB·DMF]·PbBr2,which not only effectively improves the crystallinity of PbBr2crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr3perovskite films with large grain size and high crystallinity In combination with carbon electrode,the CsPbBr3solar cells yield a champion device performance of 9.57%in comparison of pristine CsPbBr3solar cells showing a low efficiency of 8.17%.Furthermore,the intermediate phaseassisted growth of CsPbBr3-based solar cells displays an outstanding storage over 720 h.

关键词： CsPbBr 3 Perovskite solar cells Carbon electrode Hole transport layer free Intermediate phase

Efficient single-pixel imaging encrypted transmission based on 3D Arnold transformation

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Chinese Physics B 2024年第3期33卷 378-386页

作者：梁振宇王朝瑾王阳阳高皓琪朱东涛许颢砾杨星 State key laboratory of Pulsed power laser Technology National University of Defense TechnologyHefei 230001China Advanced laser Technology laboratory of Anhui Province Hefei 230001China

Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public channels will easily draw the attention of eavesdroppers.Here,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key transmission.This encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel detection.Then the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange mechanism.Compared with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling rules.Additionally,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images.

关键词： single-pixel imaging 3D Arnold transformation elliptic curve encryption image encryption

Insulation Design Rule for a Spacer in SF_(6)/N_(2)-filled DC Gas Insulated Apparatus

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CSEE Journal of power and Energy Systems 2024年第2期10卷 727-735页

作者： Hongyang Zhou Guoming Ma Meng Zhang Cong Wang Youping Tu Chengrong Li State key laboratory of Alternate Electrical power System with Renewable Energy Sources and the Beijing key laboratory of high Voltage and EMC North China Electric Power UniversityBeijing 102206China

A recurring challenge of a DC SF_(6)/N_(2)-filled GIS/GIL apparatus is the charge accumulation at DC stress.The conventional design rules and knowledge of AC spacers may not be applicable for this new type of apparatus.A novel design rule is proposed considering the effect of accumulated charge on the threshold of electric field strength being resistant to the superposed voltage.A surface charge accumulation simulation model is introduced,and the key parameters in the simulation model are measured.In addition,an experimental platform for a 100 kV spacer flashover test is established.Spacer flashover tests under superimposed voltage with opposing polarities are carried out,and the withstanding voltage of the spacer is obtained.Finally,based on the proposed model,the threshold of the surface electric field strength(tangential component)on the DC spacer in SF_(6)/N_(2) mixed gases is discussed.For a reliable insulation design of a DC GIS/GIL apparatus filled with 0.7 MPa SF_(6)/N_(2),the threshold of surface electric field strength on the DC spacer is 12 kV/mm.The insulation design rule can be referenced in the design of a high-voltage DC SF_(6)/N_(2)-filled GIS/GIL apparatus.

关键词： Charge accumulation DC spacer flashover voltage SF_(6)/N_(2) threshold of surface electric field strength

Generation and regulation of electromagnetic pulses generated by femtosecond lasers interacting with multitargets

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Nuclear Science and Techniques 2024年第1期35卷 96-107页

作者： Ya-Dong Xia De-Feng Kong Qiang-You He Zhen Guo Dong-Jun Zhang Tong Yang Hao Cheng Yu-Ze Li Yang Yan Xiao Liang Ping Zhu Xing-Long Xie Jian-Qiang Zhu Ting-Shuai Li Chen Lin Wen-Jun Ma Xue-Qing Yan State key laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Beijing laser Acceleration Innovation Center Beijing 101407China Institute of Guangdong laser Plasma Technology Guangzhou 510540China National laboratory on high power laser and Physics Shanghai Institute of Optics and FineChinese Academy of SciencesShanghai 201800China School of materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Ultrashort and powerful laser interactions with a target generate intense wideband electromagnetic pulses(EMPs).In this study,we report EMPs generated by the interactions between petawatt(30 fs,1.4×10^(20) W/cm^(2))femtosecond(fs)lasers with metal flat,plastic flat,and plastic nanowire-array(NWA)targets.Detailed analyses are conducted on the EMPs in terms of their spatial distribution,time and frequency domains,radiation energy,and protection.The results indicate that EMPs from metal targets exhibit larger amplitudes at varying angles than those generated by other types of targets and are enhanced significantly for NWA targets.Using a plastic target holder and increasing the laser focal spot can significantly decrease the radiation energy of the EMPs.Moreover,the composite shielding materials indicate an effective shielding effect against EMPs.The simulation results show that the NWA targets exert a collimating effect on thermal electrons,which directly affects the distribution of EMPs.This study provides guidance for regulating EMPs by controlling the laser focal spot,target parameters,and target rod material and is beneficial for electromagnetic-shielding design.

关键词： Electromagnetic pulses laser plasma interaction Electromagnetic shielding Electron distribution

Plasma potential measurements using an emissive probe made of oxide cathode

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Chinese Physics B 2024年第4期33卷 571-577页

作者：李建泉马海杰陆文琪 Department of Electronic and Communication Engineering North China Electric Power UniversityBaoding 071003China Hebei key laboratory of power Internet of Things Technology North China Electric Power UniversityBaoding 071003China key laboratory of materials Modification by laser Ion and Electron BeamsSchool of PhysicsDalian University of TechnologyDalian 116024China

A novel emissive probe consisting of an oxide cathode coating is developed to achieve a low operating temperature and long service life.The properties of the novel emissive probe are investigated in detail,in comparison with a traditional tungsten emissive probe,including the operating temperature,the electron emission capability and the plasma potential measurement.Studies of the operating temperature and electron emission capability show that the tungsten emissive probe usually works at a temperature of 1800 K-2200 K while the oxide cathode emissive probe can function at about 1200 K-1400 K.In addition,plasma potential measurements using the oxide cathode emissive probe with different techniques have been accomplished in microwave electron cyclotron resonance plasmas with different discharge powers.It is found that a reliable plasma potential can be obtained using the improved inflection point method and the hot probe with zero emission limit method,while the floating point method is invalid for the oxide cathode emissive probe.

关键词： emissive probe oxide cathode plasma potential filament temperature

Removal of pathogenic indicator microorganisms during partial nitrification:the role of free nitrous acid

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 93-102页

作者： Jiaojiao Xu Xiaotian Chen Rui Tang Jingwei Feng Shoujun Yuan Wei Wang Zhen-Hu Hu Anhui Engineering laboratory of Rural Water Environment and Resource School of Civil EngineeringHefei University of TechnologyHefei 230009China Hefei 168 high School Hefei 230025China Shanghai key laboratory of materials Protection and Advanced materials in Electric power Shanghai University of Electric PowerShanghai 200090China

Digested wastewater contains pathogenic microorganisms and high ammonia concentrations,which can pose a potential risk to public health.Effective removal of pathogens and nitrogen is crucial for the post-treatment of digested wastewater.Partial nitrification-anammox is an energy-saving nitrogen removal process.Free nitrous acid(FNA),an intermediate product of partial nitrification,has the potential to inactivate microorganisms.However,the efficiency and mechanisms of FNA-related inactivation in pathogens during partial nitrification remains unclear.In this study,Enterococcus and Escherichia coli(E.coli)were selected to investigate the efficiency and mechanisms of FNA-related inactivation in partial nitrification process.The results revealed that 83%±13%and 59%±27%of E.coli and Enterococcus were removed,respectively,in partial nitrification process at FNA concentrations of 0.023−0.028 mg/L.When the concentration of FNA increased from 0 to 0.5 mg/L,the inactivation efficiencies of E.coli and Enterococcus increased from 0 to 99.9%and 89.9%,respectively.Enterococcus exhibited a higher resistance to FNA attack compared to E.coli.3D-laser scanning microscopy(3D-LSM)and scanning electron microscopy(SEM)revealed that FNA exposure caused the surface collapse of E.coli and Enterococcus,as well as visible pore formation on the surface of E.coli cells.4',6-Diamidino-2-phenylindole dihydrochloride n-hydrate(DAPI)/propidium iodide(PI)and biomolecule leakage confirmed that inactivation of E.coli and Enterococcus occurred due to breakdown of cell walls and cell membranes.These findings indicate that partial nitrification process can be used for the removal of residual pathogenic microorganisms.

关键词： Partial nitrification Free nitrous acid Pathogenic indicator microorganism Inactivation Cell structure

Homogenous coating of Li+ conductive Li5AlO4 on single-crystalline nonstoichiometric Li1.04Ni0.92Al0.04O2 for rechargeable lithium-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 651-659页

作者： Guoyu Ding Shizhou Wang Jinhan Li Ziyan Wu Jiayu Chen Jiayong Du Xinhui Huang Kuiming Liu Yudong Zhang Zhonghan Wu Yiyang Peng Qiancheng Zhao Meng Yu Fangyi Cheng key laboratory of Advanced Energy materials Chemistry(Ministry of Education) Engineering Research Center of High-efficiency Energy Storage(Ministry of Education) College of Chemistry Nankai University State key laboratory of Advanced Chemical power Sources Nankai University Haihe laboratory of Sustainable Chemical Transformations

Cobalt-free,nickel-rich LiNi1-xAlxO2（x ≤ 0.1） is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum segregation strategy to prepare Li5AlO4-coated single-crystalline slightly Li-rich Li1.04Ni0.92Al0.04O2.The symbiotic formation of Li5AlO4from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li5AlO4that permits high Li+conductivity.Benefiting from mitigated undesirable side reactions and phase evolution,the Li5AlO4-coated single-crystalline Li1.04Ni0.92Al0.04O2delivers a high specific capacity of220.2 mA h g-1at 0.1 C and considerable rate capability(182.5 mA h g-1at 10 C).Besides,superior capacity retention of 90.8% is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li1.04Ni0.92Al0.04O2remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li0.98Ni0.97Al0.05O2features intragranular cracks and irreversible lattice distortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced elemental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries.

关键词： Aluminum segregation Cathode materials Molten synthesis Nonstoichiometric oxides Surface coating