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合束方式提高准分子激光输出脉冲能量稳定性

红外与激光工程 2024年第1期53卷 127-135页

作者：刘墨林刘嘉仪王怡哲喻学昊方晓东游利兵深圳技术大学新材料与新能源学院广东深圳518118 深圳盛方科技有限公司广东深圳518173

为了获得稳定性更好、能量更大的准分子激光输出脉冲,对合束方式提高输出脉冲能量稳定性的可行性进行了理论推导、模拟实验以及合束实验研究。从理论推导得知,当激光输出脉冲能量符合正态分布时,多台激光器合束可以降低输出能量相对标... 详细信息

为了获得稳定性更好、能量更大的准分子激光输出脉冲,对合束方式提高输出脉冲能量稳定性的可行性进行了理论推导、模拟实验以及合束实验研究。从理论推导得知,当激光输出脉冲能量符合正态分布时,多台激光器合束可以降低输出能量相对标准差。对三台输出脉冲能量分布特性符合正态分布的准分子激光器进行合束模拟实验研究,每台输出脉冲能量平均值约为153 mJ,脉冲能量相对标准差约为1%。两台准分子激光器合束时得到输出脉冲能量平均值为305 mJ、能量相对标准差为0.7%的准分子激光脉冲。三台准分子激光器合束时可以得到输出能量平均值为458 mJ、能量相对标准差为0.6%的准分子激光脉冲。使用两台准分子激光器进行三次实际合束实验,其中两台准分子激光器三次合束分别输出能量平均值约为355、350、330 mJ,相对标准差为1.3%、1.2%、1.4%的激光脉冲;三次合束后分别得到能量平均值为687、694、646 mJ,相对标准差为0.86%、0.79%、0.83%的激光脉冲。模拟实验以及合束实验都表明,合束后的能量相对标准差均小于单台能量相对标准差,即合束提高准分子输出脉冲的稳定性。因此,当单台准分子激光输出脉冲能量符合正态分布且平均能量相当时,多台合束可以有效提高激光输出脉冲的能量稳定性。

关键词：准分子激光脉冲能量稳定性相对标准差

白屈菜红碱介孔二氧化硅纳米粒缓释片的制备及体外释药考察

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中国医院药学杂志 2024年第2期44卷 159-165页

作者：周敬郑宝玉李阳杰方晓东郑州工业应用技术学院药学与化学工程学院河南郑州451150 河南大学药学院河南开封475004

目的:制备白屈菜红碱介孔二氧化硅纳米粒缓释片(CHE-MSNs-SRTs),并进行体外释药考察。方法:溶剂挥发法制备CHE-MSNs,测定包封率、载药量、粒径、Zeta电位,扫描电镜观察微观形态,X射线粉末衍射法分析晶型。羟丙基甲基纤维素为骨架材料制... 详细信息

目的:制备白屈菜红碱介孔二氧化硅纳米粒缓释片(CHE-MSNs-SRTs),并进行体外释药考察。方法:溶剂挥发法制备CHE-MSNs,测定包封率、载药量、粒径、Zeta电位,扫描电镜观察微观形态,X射线粉末衍射法分析晶型。羟丙基甲基纤维素为骨架材料制备CHE-MSNs-SRTs。单因素考察结合Box-Behnken响应面法优化CHE-MSNs-SRTs处方,对释药模型和释药机理进行探讨。结果:CHE-MSNs平均包封率为(93.58±1.17)%,载药量为(23.15±0.72)%,粒径为(223.7±9.24)nm,Zeta电位为(0.74±0.06)mV,纳米粒呈球形或类球形,白屈菜红碱以无定型状态存在于CHE-MSNs中。CHE-MSNsSRTs最佳处方为:HPMC 4K和HPMC 15K比例为1.9∶1,缓释材料用量为17.8 mg/片,PEG用量为10.6 mg/片,缓释特征明显,12 h累积释放度为93.68%。体外释药符合Higuchi模型,释药机制为扩散和骨架溶蚀并存。结论:CHE-MSNs-SRTs工艺重复性良好,体外释药缓释特征明显。

关键词：白屈菜红碱介孔二氧化硅纳米粒缓释片

载芒果苷的氨基修饰介孔二氧化硅纳米粒的制备及口服药动学评价

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中草药 2024年第8期55卷 2542-2552页

作者：杨丽萍王海军李伟宏王风云方晓东河南应用技术职业学院河南郑州450042 新乡医学院河南新乡453000 河南大学河南开封475001

目的优化芒果苷的氨基修饰介孔二氧化硅纳米粒(mangiferin-amino-modified mesoporous silica nanoparticles,MF-NH_(2)-MSNs)处方,并进行口服药动学评价。方法采用溶剂挥发法制备MF-NH_(2)-MSNs。单因素考察结合Box-Behnken设计-效应面法筛选MF-NH_(2)-MSNs处方,测定包封率、载药量、粒径、多分散指数(polydispersity index,PDI)和ζ电位。X粉末衍射法分析芒果苷在MF-NH_(2)-MSNs粉末中的存在状态,考察MF-NH_(2)-MSNs在模拟胃肠液中的释药行为,并拟合体外释药模型。SD大鼠ig给予MF-NH_(2)-MSNs粉末后采血,测定血药浓度,考察口服药动学行为并计算主要药动学参数。结果MF-NH_(2)-MSNs最佳处方为NH_(2)-MSNs与芒果苷比例1.7∶1,芒果苷质量浓度为0.54 mg/m L,搅拌时间为11.28 h。MF-NH_(2)-MSNs包封率为(92.34±1.04)%,载药量为(33.76±0.17)%,平均粒径为(204.18±8.66)nm,PDI值为0.120±0.014,ζ电位为(11.47±0.81)mV。芒果苷在MF-NH_(2)-MSNs粉末中以无定型状态存在,在模拟胃肠液中体外释药具有缓释特征,释药过程符合Weibull模型:lnln[1/(1-M_(t)/M_(∞))]=1.0320 lnt-1.625。口服药动学显示,MF-NH_(2)-MSNs半衰期(t_(1/2))增加至(4.19±0.87)h,血药浓度(C_(max))增加至(1506.77±404.80)ng/mL,相对口服生物利用度提高至4.02倍。结论MF-NH_(2)-MSNs增加了芒果苷累积释放度,显著促进口服吸收。

关键词：芒果苷介孔二氧化硅纳米粒 Box-Behnken设计-效应面法缓释特征 Weibull模型口服药动学

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深紫外飞秒脉冲准分子激光放大同步特性研究

量子电子学报 2024年第2期41卷 278-288页

作者：范军杨礼昭游利兵戎丹丹王宏伟寸超方晓东中国科学院合肥物质科学研究院安徽光学精密机械研究所安徽省光子器件与材料重点实验室安徽合肥230031 中国科学技术大学安徽合肥230026 深圳技术大学新材料与新能源学院广东深圳518118 深圳盛方科技有限公司广东深圳518173

为了获得大能量的深紫外超短脉冲,将深紫外飞秒种子光通过ArF准分子放大器进行放大。通过对种子光信号和准分子放大器的荧光信号进行测量,在不同环境下,针对种子光信号与放大器放电信号之间的延时对脉冲单程放大特性的影响进行了研究。... 详细信息

为了获得大能量的深紫外超短脉冲,将深紫外飞秒种子光通过ArF准分子放大器进行放大。通过对种子光信号和准分子放大器的荧光信号进行测量,在不同环境下,针对种子光信号与放大器放电信号之间的延时对脉冲单程放大特性的影响进行了研究。研究结果表明,放大系统实现了种子光与准分子放大器的低抖动精确同步,空气和氮气环境下脉冲能量最高分别为197.2μJ和312.6μJ,且氮气环境下脉冲展宽较空气平均降低99.2 fs。相较于空气环境,氮气环境可有效降低深紫外超短脉冲的能量衰减与脉冲展宽,且同步抖动对放大特性影响较小。

关键词：激光技术同步特性准分子放大深紫外飞秒激光

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N, O-doped carbon foam as metal-free electrocatalyst for efficient hydrogen production from seawater

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Nano Research 2022年第10期15卷 8922-8927页

作者： Qian Liu Shengjun Sun Longcheng Zhang Yongsong Luo Qin Yang Kai Dong xiaodong fang Dongdong Zheng Abdulmohsen Ali Alshehri Xuping Sun Institute for Advanced Study Chengdu UniversityChengdu 610106China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Chemistry Department Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinan 250014China

Seawater electrolysis is the most promising technology for large scale hydrogen production due to the abundance and low cost of seawater in ***,compared with the traditional freshwater electrolysis,the issues of electrode poisoning and corrosion will occur during the seawater electrolysis process,and active and stable electrocatalysts for the hydrogen evolution reaction(HER)are thus highly *** this work,N,O-doped carbon foam in-situ derived from commercial melamine foam is proposed as a high-active metal-free HER electrocatalyst for seawater *** acidic seawater,our catalyst shows high hydrogen generation performance with small overpotential of 161 mV at 10 mA·cm^(−2),a low Tafel slop of 97.5 mV·dec^(−1),and outstanding stability.

关键词： carbon foam hydrogen evolution reaction seawater electrolysis electrocatalyst

Assessment of Crop Yield in China Simulated by Thirteen Global Gridded Crop Models

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Advances in Atmospheric Sciences 2024年第3期41卷 420-434页

作者： Dezhen YIN fang LI Yaqiong LU xiaodong ZENG Zhongda LIN Yanqing ZHOU International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China

Global gridded crop models(GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. China is a major grain producing country, but thus far only a few studies have assessed the performance of GGCMs in China, and these studies mainly focused on the average and interannual variability of national and regional yields. Here, a systematic national-and provincial-scale evaluation of the simulations by13 GGCMs [12 from the GGCM Intercomparison(GGCMI) project, phase 1, and CLM5-crop] of the yields of four crops(wheat, maize, rice, and soybean) in China during 1980–2009 was carried out through comparison with crop yield statistics collected from the National Bureau of Statistics of China. Results showed that GGCMI models generally underestimate the national yield of rice but overestimate it for the other three crops, while CLM5-crop can reproduce the national yields of wheat, maize, and rice well. Most GGCMs struggle to simulate the spatial patterns of crop yields. In terms of temporal variability, GGCMI models generally fail to capture the observed significant increases, but some can skillfully simulate the interannual variability. Conversely, CLM5-crop can represent the increases in wheat, maize, and rice, but works less well in simulating the interannual variability. At least one model can skillfully reproduce the temporal variability of yields in the top-10 producing provinces in China, albeit with a few exceptions. This study, for the first time, provides a complete picture of GGCM performance in China, which is important for GGCM development and understanding the reliability and uncertainty of national-and provincial-scale crop yield prediction in China.

关键词： global gridded crop model historical crop yield China multi-model evaluation

Heteroatom tuning in agarose derived carbon aerogel for enhanced potassium ion multiple energy storage

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Carbon Energy 2024年第3期6卷 239-254页

作者： Kaijun Xie Xin Liu Haolin Li Long fang Kai Xia Dongjiang Yang Yihui Zou xiaodong Zhang State Key Laboratory of Bio-fibers and Eco-textiles Shandong Collaborative Innovation Center of Marine Biobased Fibers and Ecological TextilesInstitute of Marine Biobased MaterialsCollege of Chemistry and Chemical EngineeringCollege of Environmental Science and EngineeringQingdao UniversityQingdaoChina

The incorporation of heteroatoms into carbon aerogels(CAs)can lead to structural distortions and changes in active sites due to their smaller size and electronegativity compared to pure ***,the evolution of the electronic structure from single-atom doping to heteroatom codoping in CAs has not yet been thoroughly investigated,and the impact of codoping on potassium ion(K+)storage and diffusion pathways as electrode material remains *** this study,experimental and theoretical simulations were conducted to demonstrate that heteroatom codoping,composed of multiple heteroatoms(O/N/B)with different properties,has the potential to improve the electrical properties and stability of CAs compared to single-atom *** states near the Fermi level have revealed that doping with O/N/B generates a greater number of active centers on adjacent carbon atoms than doping with O and O/N *** a result of synergy with enhanced wetting ability(contact angle of 9.26°)derived from amino groups and hierarchical porous structure,ON-CA has the most optimized adsorption capacity(−1.62 eV)and diffusion barrier(0.12 eV)of K^(+).The optimal pathway of K^(+)in ON-CA is along the carbon ring with N or O *** K^(+)storage material for supercapacitors and ion batteries,it shows an outstanding specific capacity and capacitance,electrochemical stability,and rate ***,the assembled symmetrical K^(+)supercapacitor demonstrates an energy density of 51.8 Wh kg^(−1),an ultrahigh power density of 443Wkg^(−1),and outstanding cycling stability(maintaining 83.3%after 10,000 cycles in 1M KPF6 organic electrolyte).This research provides valuable insights into the design of highperformance potassium ion storage materials.

关键词： agarose carbon aerogels O/N/B codoping potassium-ion battery potassium-ion supercapacitor

The impact of the Rural Minimum Living Standard Guarantee(Rural Dibao)Program on child nutrition outcomes

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Journal of Integrative Agriculture 2024年第2期23卷 444-456页

作者： Dian Chen Xiangming fang Yu Chen xiaodong Zheng Zhuo Chen Rodney B.W.Smith Academy of Global Food Economics and Policy China Agricultural UniversityBeijing 100083China School of Public Health Georgia State UniversityAtlanta 30303USA School of Economics Zhejiang Gongshang UniversityHangzhou 310018China College of Public Health University of GeorgiaAthens 30602USA Department of Applied Economics University of MinnesotaSaint Paul 55108USA

The Rural Minimum Living Standard Guarantee(Rural Dibao)is an important unconditional cash transfer program to alleviate poverty in rural *** the importance of children’s nutrition in breaking poverty cycles,little is known about the impact of Rural Dibao on child nutrition *** China Family Panel Studies(CFPS),this paper examines the effects of Rural Dibao on child nutrition outcomes and investigates potential pathways and heterogeneous *** exploit propensity score matching and difference-in-differences techniques to evaluate the effects of the Rural Dibao program on child nutrition *** results suggest that Rural Dibao significantly impacts the nutrition outcomes of children up to 15 years of ***,our results suggest that Rural Dibao improves child height-to-age z-scores by 1.05 standard deviations and lowers the probability of stunting by 11.9 percentage *** analyses suggest that increased protein intake is the main pathway through which Rural Dibao participation contributes to better nutrition *** also find that the effect of the program is more pronounced among girls,children who are non-left-behind or live with highly educated mothers,and those from low-income families and poor *** findings suggest that Rural Dibao participation helps improve child nutrition outcomes through improving diet quality.

关键词： Rural Minimum Living Standard Guarantee nutrition height-to-age z-scores stunting rural China

Efficient photocatalytic biomass-alcohol conversion with simultaneous hydrogen evolution over ultrathin 2D NiS/Ni-CdS photocatalyst

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Chinese Chemical Letters 2024年第7期35卷 422-427页

作者： Zongyi Huang Cheng Guo Quanxing Zheng Hongliang Lu Pengfei Ma Zhengzhong fang Pengfei Sun xiaodong Yi Zhou Chen State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China College of Materials Key Laboratory of High Performance Ceramic Fibers(Xiamen University)Ministry of EducationXiamen UniversityXiamen 361005China Technology Center China Tobacco Fujian Industrial Co.Ltd.Xiamen 361021 China

The photocatalytic conversion of biomass into high-value chemicals,coupled with simultaneous hydrogen(H_(2))evolution,leveraging the electrons and holes generated by solar energy,holds great promise for addressing energy *** this study,we constructed a dual functional photocatalytic system formed by NiS loaded on Ni doped two-dimensional(2D)CdS nanosheet(NiS/Ni-CdSNS)heterostructure for visible-light-driven H_(2)evolution and ethanol oxidation to ***,the 2D NiS/NiCdSNS exhibited significant activity and selectivity in both photocatalytic H_(2)evolution and ethanol oxidation,achieving yields of 7.98 mmol g^(-1)h^(-1)for H_(2)and 7.33 mmol g^(-1)h^(-1)for *** heterogeneous interface of the composite facilitated efficient charge separation,while NiS provided abundant sites for proton reduction,thereby promoting the overall dual-functional photocatalytic *** functional theory calculations further reveal that both Ni doping and NiS loading can reduce the reaction energy barrier of ethanol oxidation of free radicals,and NiS/Ni-CdSNS composite materials exhibit stronger ethanol C-H activation ability to generate key intermediate·CH(OH)CH_(3)on the *** work serves as a valuable guide for the rational design of efficient dual functional photocatalytic systems that combine H_(2)evolution with the selective conversion of organic compounds into high-value chemicals.

关键词： Photocatalysis Biomass-alcohol oxidation H_(2)evolution Dual-functional catalysis