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Evolution simulation of lightning discharge based on a magnetohydrodynamics method

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Plasma Science and Technology 2018年第7期20卷 86-97页

作者： Fusheng WANG Xiangteng ma han chEN Yao ZhANG School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi＇an 710129People＇ s Republic of China

In order to solve the load problem for aircraft lightning strikes, lightning channel evolution is simulated under the key physical parameters for aircraft lightning current component c. A numerical model of the discharge channel is established, based on magnetohydrodynamics （MhD） and performed by FLUENT software. With the aid of user-defined functions and a user- defined scalar, the Lorentz force, Joule heating and material parameters of an air thermal plasma are added. A three-dimensional lightning arc channel is simulated and the arc evolution in space is obtained. The results show that the temperature distribution of the lightning channel is symmetrical and that the hottest region occurs at the center of the lightning channel. The distributions of potential and current density are obtained, showing that the difference in electric potential or energy between two points tends to make the arc channel develop downwards. The arc channel comes into expansion on the anode surface due to stagnation of the thermal plasma and there exists impingement on the copper plate when the arc channel comes into contact with the anode plate.

关键词： lightning channel thermal plasma magneto hydro Dynamics (MhD) evolution simulation

A New Free-Standing Aqueous Zinc-Ion capacitor Based on MnO2–cNTs cathode and MXene Anode

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Nano-Micro Letters 2019年第4期11卷 227-238页

作者： Siliang Wang Qiang Wang Wei Zeng Min Wang Limin Ruan Yanan ma Key Laboratory of Intelligent computing and Signal Processing Ministry of EducationAnhui UniversityNo.3 Feixi RoadHefei 230039Anhui ProvincePeople’s Republic of China National Engineering Research center for Agro-Ecological Big Data Analysis and Application School of Electronics and Information EngineeringAnhui UniversityNo.111 Jiulong RoadHefei 230601Anhui ProvincePeople’s Republic of China School of Sciences Hubei University of Automotive TechnologyNo.167 Checheng West RoadShiyan 442002Hubei ProvincePeople’s Republic of China

Restricted by their energy storage mechanism,current energy storage devices have certain drawbacks,such as low power density for batteries and low energy density for ***,the nearest ion capacitors,such as lithium-ion and sodium-ion capacitors containing battery-type and capacitor-type electrodes,may allow achieving both high energy and power *** the inspiration,a new zinc-ion capacitor(ZIc)has been designed and realized by assembling the free-standing manganese dioxide-carbon nanotubes(MnO2-cNTs)battery-type cathode and MXene(Ti3c2Tx)capacitortype anode in an aqueous *** ZIc can avoid the insecurity issues that frequently occurred in lithium-ion and sodium-ion capacitors in organic *** expected,the ZIc in an aqueous liquid electrolyte exhibits excellent electrochemical performance(based on the total weight of cathode and anode),such as a high specific capacitance of 115.1 F g?1(1 mV s?1),high energy density of 98.6 Wh kg?1(77.5 W kg?1),high power density of 2480.6 W kg?1(29.7 Wh kg?1),and high capacitance retention of^83.6%of its initial capacitance(15,000 cycles).Even in an aqueous gel electrolyte,the ZIc also exhibits excellent *** work provides an essential strategy for designing next-generation high-performance energy storage devices.

关键词： Energy storage Zinc-ion capacitor Battery-type and capacitor-type electrodes MXene Electrochemical performance

characteristics and distributions of humic acids in two soil profiles of the southwest china Karst area

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Acta Geochimica 2016年第1期35卷 85-94页

作者： Liangang ma Baohua Xiao Xinyue Di Weilin huang Shijie Wang State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of SciencesGuiyang 550002 China University of chinese Academy of Sciences Beijing 100049China Department of Environmental Sciences Rutgers UniversityNew Brunswick NJ 08901 USA

characteristics and distributions of humic acid(hA) and soil organic matter(SOM) in a yellow soil profile and a limestone soil profile of the southwest china Karst area were systematically investigated to reveal their evolutions in different soils of the study area. The results showed that characteristics and distribution of SOM along the two soil profiles were notably different. Total organic carbon(TOc) contents of soil samples decreased just slightly along the limestone soil profile but sharply along the yellow soil profile. TOcs of the limestone soils were significantly higher than those of the corresponding yellow soils, and c/N ratios of SOMs showed a similar variation trend to that of TOcs, indicating that SOM can be better conserved in the limestone soil than in the yellow soil. The soil humic acids were exhaustively extracted and further fractionated according to their apparent molecular weights using ultrafiltration techniques to explore underlying conservation mechanisms. The result showed that c/N ratios of hAs from different limestone soil layers were relatively stable and that large molecular hA fractions predominated the bulk hA of the top soil, indicating that hA in the limestone profile was protected while bio and chemical degradations were retarded. combined with organic elements contents and mineral contents of two soils, weconcluded that high calcium contents in limestone soils may play a key role in SOM conservation by forming complexation compounds with hAs or/and enclosing SOMs with hypergene cacO_3 precipitation.

关键词： Soil Soil organic matter humic acid characteristics Distribution Southwest china Karst area

Building up 1-D, 2-D, and 3-D Polyiodide Frameworks by Finely Tuning the Size of Aryls on Ar-S-TTF in the charge-Transfer （cT） complexes of Ar-S-TTFs and Iodine

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chinese Journal of chemistry 2018年第9期36卷 845-850页

作者： Longfei ma haili Peng Xiaofeng Lu Lei Liu Xiangfeng Shao State Key Laboratory of Applied Organic chemistry Lanzhou University Lanzhou Gansu 730000 China

The arylthio-substituted tetrathiafuivalenes （Ar-S-TTFs） are electron donors having three reversible states, neutral, cation radical, and dica- tion. The charge-transfer （cT） between Ar-S-TTFs （TTF1--TTF3） and iodine （12） is reported herein. TTF1--TTF3 show the cT with 12 in the ch2c12 solution, but they are not completely converted into cation radical state. In cT complexes of TTF1--TTF3 with 12, the charged states of Ar-S-TTFs are distinct from those in solution. TTF1 is at cation radical state, and TTF2--TTF3 are oxidized to dication. The iodine components in complexes show various structures including 1-D chain of V-shaped （Is）-, and 2-D and 3-D iodine networks composed of 12 and （13）^- .

关键词： polyiodide tetrathiafulvalene charge-transfer complex crystal engineering halogen bond

金属离子配位组装制备负载高效氯氟氰菊酯的壳聚糖纳米颗粒及其对豌豆蚜虫的生物活性

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农药 2024年第1期63卷 13-17页

作者：王崇琳马成立郝立健刘尚可薛超彬山东农业大学植物保护学院山东泰安271018 泰安市农业技术推广中心山东泰安271502 平阴县农业农村局济南250400

[目的]目前纳米农药复杂的制备工艺阻碍了其推广,亟需低能耗、低成本、简便的方法获得载药纳米颗粒,进而提高农药利用率。[方法]采用金属离子配位组装法,利用天然可降解、安全环保的壳聚糖材料制备了2.5%高效氯氟氰菊酯纳米颗粒,通过测... 详细信息

[目的]目前纳米农药复杂的制备工艺阻碍了其推广,亟需低能耗、低成本、简便的方法获得载药纳米颗粒,进而提高农药利用率。[方法]采用金属离子配位组装法,利用天然可降解、安全环保的壳聚糖材料制备了2.5%高效氯氟氰菊酯纳米颗粒,通过测定其释放性能和对豌豆蚜虫的室内生物活性来评估其应用效果。[结果]负载高效氯氟氰菊酯的纳米颗粒为球形,包封率为92.06%,平均粒径(D_(50))为202.83 nm。高效氯氟氰菊酯被纳米颗粒负载后提高了其热稳定性。在释放液中,2 h时纳米载药颗粒的累积释放率为59.25%。在48 h时负载高效氯氟氰菊酯的纳米颗粒对豌豆蚜虫的Lc_(50)值为0.004 mg/L,高于乳油的0.006 mg/L和微米载药颗粒的0.01 mg/L。[结论]实验结果可为开发对叶部害虫具有优异防治效果的纳米制剂提供依据。

关键词：纳米农药农药利用率纳米悬浮剂

Synergic catalytic effect of Ti hydride and Nb nanoparticles for improving hydrogenation and dehydrogenation kinetics of Mg-based nanocomposite

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Progress in Natural Science:materials International 2017年第1期27卷 99-104页

作者： Xiujuan ma Xiubo Xie Peng Liu Li Xu Tong Liu Key Laboratory of Aerospace materials and Performance (Ministry of Education) School of Materials Science and Engineering Beihang University State Grid Smart Grid Research Institute Future Science and Technology City Changping

The Mg-9.3 wt%(Tih;-Tih)-0.7 wt% Nb nanocomposite has been synthesized by hydrogen plasma-metal reaction（hPMR） approach to enhance the hydrogen sorption kinetics of Mg at moderate temperatures by providing nanosizing effect of increasing h "diffusion channels" and adding transition metallic catalysts. The Mg nanoparticles（NPs） were in hexagonal shape range from 50 to 350 nm and the average size of the NPs was 177 nm. The small spherical Tih;, Tih and Nb NPs of about 25 nm uniformly decorated on the surface of the big Mg NPs. The Mg-Tih;-Tih-Nb nanocomposite could quickly absorb 5.6 wt% h;within 5 min at 573 K and 4.5 wt% h;within 5 min at 523 K, whereas the pure Mg prepared by hPMR could only absorb 4 and 1.5 wt% h;at the same temperatures. Tih;, Tih and Nb NPs transformed into Tih;and Nb h during hydrogenation and recovered after dehydrogenation process. The apparent activation energies of the nanocomposite for hydrogenation and dehydrogenation were 45.0 and 50.7 kJ mol;, which are much smaller than those of pure Mg NPs, 123.8 and 127.7 kJ mol;. The improved sorption kinetics of the Mg-based nanocomposite at moderate temperatures and the small activation energy can be interpreted by the nanostructure of Mg and the synergic catalytic effects of Ti hydrides and Nb NPs.

关键词： magnesium Nanocomposite catalytic effect hydrogen storage

Fibrotouch联合血清标志物评估慢性乙型肝炎肝纤维化的价值

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中国卫生标准管理 2024年第14期15卷 14-18页

作者：杨兆辉陈珑斌马龙厦门市第三医院感染科福建厦门361100

目的分析瞬时弹性成像技术(Fibrotouch)评估联合血清标志物在慢性乙型肝炎肝纤维化程度评估中的价值。方法选择厦门市第三医院2019年3月—2021年9月收治的180例慢性乙型肝炎患者作为研究对象。依病理结果分为无纤维化组72例、早期纤维化... 详细信息

目的分析瞬时弹性成像技术(Fibrotouch)评估联合血清标志物在慢性乙型肝炎肝纤维化程度评估中的价值。方法选择厦门市第三医院2019年3月—2021年9月收治的180例慢性乙型肝炎患者作为研究对象。依病理结果分为无纤维化组72例、早期纤维化组68例和进展性纤维化组40例。所有患者均接受Fibrotouch检测肝脏硬度值(liver stiffness measurement,LSM)、血清透明质酸(hyaluronic acid,hA)、黏连蛋白(laminin,LN)、Ⅳ型胶原(collage typeⅣ,cⅣ)和Ⅲ型前胶原(precollagen typeⅢ,PcⅢ)水平。Spearman相关性分析LSM、hA、LN、cⅣ、PcⅢ水平与肝纤维化程度的相关性。受试者工作特征(receiver operating characteristic,ROc)曲线分析上述指标联合检测诊断肝纤维化的价值。结果不同肝纤维程度患者LSM、hA、LN、cⅣ、PcⅢ比较,差异有统计学意义(PhA、LN、cⅣ、PcⅢ均与肝纤维化程度呈正相关,相关系数分别为0.949、0.912、0.898、0.867、0.893(Pc曲线分析显示,LSM、hA、LN、cⅣ、PcⅢ、联合检测肝纤维化曲线下面积(area under curve,AUc)分别为0.790、0.839、0.623、0.863、0.804、0.968,联合检测预测效果最好,且联合检测敏感度高于其他各项单独检测指标(PhA、LN、cⅣ、PcⅢ均与肝纤维化程度呈正相关,上述指标联合检查效果最好,敏感度最高,临床可联合检测上述指标诊断肝纤维化。

关键词：瞬时弹性成像技术评估血清标志物慢性乙型肝炎肝纤维化程度肝脏硬度值价值评估

Optimization of the resonant frequency servo loop technique in the resonator micro optic gyro

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Journal of Zhejiang University-Science c(computers and Electronics) 2011年第11期12卷 942-950页

作者： Yang REN Zhong-he JIN Yan chEN hui-lian ma Department of Information Science ＆ Electronic Engineering Zhejiang University Hangzhou 310027 China

Proportional integrator (PI) is always adopted in the resonant frequency servo loop in a resonator micro optic gyro (RMOG). The oscillation phenomenon is observed when adjusting the loop gain surpassing a threshold. This phenomenon limits system performance on step response speed and residual error. Based on the experiment system, a simulation model was set up. Further analysis shows that the threshold gain is related to the system loop filter setting and the loop delay. The traditional PI frequency servo loop technique in the RMOG system cannot keep up with the environment's disturbance quickly enough, which leads to a large residual error. A compensating method is proposed to optimize the tracking performance, solve the oscillation problem, and speed up the system response. Simulation and experiment results show that the compensated system is superior in performance. It has less residual error in the stable state and is 10 times quicker than the uncompensated system on the step response.

关键词： Resonator micro optic gyro (RMOG) Resonance frequency servo loop Phase compensating method

手术室人性化管理对卵巢囊肿手术患者术后恢复、心理应激及治疗依从性影响

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中国计划生育学杂志 2024年第7期32卷 1582-1585,1590页

作者：冯磊王慧张梅马翠兰安徽省临泉县人民医院 236400 安徽省阜阳市人民医院

目的:探究手术室人性化管理对卵巢囊肿手术患者术后恢复效果、心理应激、治疗依从性影响。方法:选择2021年10月-2024年3月本院收治的妇科卵巢囊肿手术患者80例,随机数字法分为两组各40例,两组均予以常规护理,观察组加用手术室人性化管理... 详细信息

目的:探究手术室人性化管理对卵巢囊肿手术患者术后恢复效果、心理应激、治疗依从性影响。方法:选择2021年10月-2024年3月本院收治的妇科卵巢囊肿手术患者80例,随机数字法分为两组各40例,两组均予以常规护理,观察组加用手术室人性化管理,护理两个月,对比两组术后康复、心理应激、依从性及并发症发生情况。结果:观察组下床活动时间(16.79±4.12h)、术后住院时间(4.68±0.49d)、导尿管留置时间(8.59±2.27h)、初次排气时间(26.15±5.35h)均短于对照组(25.64±5.49h、5.62±0.79d、13.34±2.84h、35.24±7.35h),出院时汉密尔顿焦虑量表(8.16±2.19分)评分、汉密尔顿抑郁量表(6.35±1.98分)评分、并发症发生率(5.0%)均低于对照组(11.63±2.54分、9.12±2.12分、17.0%),治疗依从性(97.5%)、出院时Morisky服药依从性量表(6.15±1.24分)均高于对照组(82.5%、6.15±1.24分)(均P<0.05)。结论:手术室人性化管理干预对卵巢囊肿手术患者术后恢复、心理应激、治疗依从性及术后并发症减少均有较好效果。

关键词：卵巢囊肿手术手术室人性化管理术后恢复心理应激治疗依从性