检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

侵彻爆炸作用下钢纤维混凝土结构的破坏模式

爆炸与冲击 2024年第1期44卷 149-161页

作者：杨石刚罗泽许继恒方秦杨亚徐国琳汤俊杰陆军工程大学国防工程学院江苏南京210094

基于大口径发射平台进行了155 mm杀伤爆破榴弹毁伤钢纤维混凝土结构的试验,得到了打击不同位置时结构的破坏情况;结合LS-DYNA数值模拟,分析了不同打击位置和不同命中速度下钢纤维混凝土结构的毁伤效应,讨论了侵彻与爆炸联合作用下钢纤... 详细信息

基于大口径发射平台进行了155 mm杀伤爆破榴弹毁伤钢纤维混凝土结构的试验,得到了打击不同位置时结构的破坏情况;结合LS-DYNA数值模拟,分析了不同打击位置和不同命中速度下钢纤维混凝土结构的毁伤效应,讨论了侵彻与爆炸联合作用下钢纤维混凝土结构的损伤过程和破坏模式。结果表明:钢纤维混凝土结构在155 mm榴弹作用下,配置钢筋的顶板和侧墙发生较轻的爆炸成坑破坏,无配筋的前墙发生严重的爆炸震塌破坏。SPG(smooth particle Galerkin method)-结构化ALE(arbitrary Lagrange-Euler)(S-ALE)流固耦合算法能够有效预测钢筋混凝土结构在侵彻和爆炸共同作用下的损伤发展过程和破坏模式。大口径弹体侵彻有限边界靶的加速度时程曲线特征为突增骤减单峰值形式,弹体速度呈现先快速降低后缓慢减小的特征;靶标在基于侵彻损伤的爆炸作用下,主要破坏模式为混凝土块大量崩塌和裂缝的生长,且随着侵彻速度的增加,爆炸造成的毁伤由局部破坏向结构整体破坏发展;混凝土破碎区内,垂直于弹体的钢筋在侵彻作用下达到屈服,板顶和板底的钢筋在爆炸后达到屈服。

关键词：钢纤维混凝土结构侵彻爆炸破坏模式

中长波Cr^(2+)/Fe^(2+)∶CdSe激光晶体生长及元件制备

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

人工晶体学报 2024年第4期53卷 551-553页

作者：黄昌保胡倩倩朱志成李亚毛长宇徐俊杰吴海信倪友保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合肥230031 中国科学技术大学合肥230026

本文采用自主研发的双温区真空石墨加热单晶炉,通过钼坩埚密封布里奇曼法成功生长出了Cr^(2+)∶CdSe晶体和Fe^(2+)∶CdSe晶体,晶体尺寸达Φ51 mm×110 mm。Cr^(2+)∶CdSe晶体和Fe^(2+)∶CdSe晶体分别在1400~2400 nm和2500~5200 nm波段... 详细信息

本文采用自主研发的双温区真空石墨加热单晶炉,通过钼坩埚密封布里奇曼法成功生长出了Cr^(2+)∶CdSe晶体和Fe^(2+)∶CdSe晶体,晶体尺寸达Φ51 mm×110 mm。Cr^(2+)∶CdSe晶体和Fe^(2+)∶CdSe晶体分别在1400~2400 nm和2500~5200 nm波段存在明显的吸收,同时,Cr^(2+)∶CdSe晶体和Fe^(2+)∶CdSe晶体在7~15μm波段透过率均接近CdSe晶体透过极限(~70%),换算吸收系数约为0.005 cm^(-1)。采用钼坩埚密封布里奇曼法制备的Cr^(2+)/Fe^(2+)∶CdSe晶体具有过渡金属离子掺杂浓度可控、掺杂均匀、晶体品质高等优点,可同时作为中波红外激光晶体和长波红外非线性光学晶体材料。

关键词：中远红外激光非线性光学晶体激光晶体过渡金属掺杂 CdSe晶体晶体生长布里奇曼法

基于蓝莓花青素的新鲜度指示膜制备及性能研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

食品与发酵工业 2024年第15期50卷 97-103页

作者：陈赛艳刘红林汤俊炀赵正禾冀俊杰四川农业大学食品学院四川雅安625014 山东技师学院文化创意学院山东济南250200

为提升pH指示膜的综合性能,以微晶纤维素(micro-crystalline cellulose,MCC)、马铃薯淀粉(potato starch,PS)、聚乙烯醇(polyvinyl alcohol,PVA)为原料,蓝莓花青素(blueberry anthocya.ins,BA)为指示剂,采用流延法制备指示膜,对指示膜的性能进行分析。结果表明,当BA、MCC、PS和PVA的质量比为0.3:0.2:3:0.3时,微晶纤维素提高了薄膜的拉伸强度(1.59 MPa至2.16 MPa)、断裂伸长率(35.83%至38.24%)、杨氏模量(8.25 GPa至25.65 GPa),降低了薄膜的含水率(34.85%至33.23%)和吸水率(122.97%至110.36%)。蓝莓花青素提高了薄膜的机械性能、阻隔性能,降低了耐水性,且与膜中各基质融合良好,指示膜结构均匀、致密。拉伸强度和杨氏模量分别升至2.19 MPa和37.12 GPa;透水率、含水率和吸水率分别降至1.45×10^(-12) g·cm/(cm^(2)·s·Pa)、30.7%和87.52%。蓝莓花青素还赋予薄膜pH敏感性。在不同pH环境中,指示膜与花青素的颜色变化趋势一致,色差可视;同时环境稳定性佳,在不同温度和光照条件下,指示膜的颜色稳定超过14 d(ΔE≤2)。研究结果可为蓝莓花青素指示膜的制备提供参考。

关键词：指示膜蓝莓花青素微晶纤维素马铃薯淀粉聚乙烯醇

Glutamate and GABAA receptor crosstalk mediates homeostatic regulation of neuronal excitation in the mammalian brain

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2022年第11期7卷 4156-4173页

作者： ya.Wen Zhifang Dong Jun Liu Peter Axerio-Cilies Yehong Du junjie Li Long Chen Lu Zhang Lidong Liu Jie Lu Ning Zhou Dong Chuan Wu Yu Tian Wang DM Centre for Brain Health and Department of Medicine Vancouver Coastal Health Research InstituteUniversity of British ColumbiaVancouverBCV6T 2B5Canada Pediatric Research Institute Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren’s Hospital of Chongqing Medical UniversityChongqing400014P.R.China iHuman Institue ShanghaiTech UniversityShanghaiP.R.China

Maintaining a proper balance between the glutamate receptor-mediated neuronal excitation and the A type of GABA receptor(GABAAR)mediated inhibition is essential for brain functioning;and its imbalance contributes to the pathogenesis of many brain disorders including neurodegenerative diseases and mental *** we identify a novel glutamate-GABAAR interaction mediated by a direct glutamate binding of the *** HEK293 cells overexpressing recombinant GABAARs,glutamate and its analog ligands,while producing no current on their own,potentiate GABA-evoked *** potentiation is mediated by a direct binding at a novel glutamate binding pocket located at theα+/β−subunit interface of the ***,the potentiation does not require the presence of aγsubunit,and in fact,the presence ofγsubunit significantly reduces the potency of the glutamate *** addition,the glutamate-mediated allosteric potentiation occurs on native GABAARs in rat neurons maintained in culture,as evidenced by the potentiation of GABAAR-mediated inhibitory postsynaptic currents and tonic *** importantly,we found that genetic impairment of this glutamate potentiation in knock-in mice resulted in phenotypes of increased neuronal excitability,including decreased thresholds to noxious stimuli and increased seizure *** results demonstrate a novel cross-talk between excitatory transmitter glutamate and inhibitory *** a rapid and short feedback loop between the two principal excitatory and inhibitory neurotransmission systems may play a critical homeostatic role in fine-tuning the excitation-inhibition balance(E/I balance),thereby maintaining neuronal excitability in the mammalian brain under both physiological and pathological conditions.

关键词： excitation thereby maintained

^(137)Cs tracing of the spatial patterns in soil redistribution,organic carbon and total nitrogen in the southeastern Tibetan Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2023年第1期11卷 86-96页

作者： Zhengan Su Lijuan Wang Yihan Liu Bin Fu Jjianhui Zhang Zuo Wu Tao Zhou junjie Wang Key Laboratory of Mountain Environment Evolution and Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041PR China University of Chinese Academy of Science Beijing100049PR China College of Geography and Resources Science Sichuan Normal UniversityChengdu610101PR China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa'an625014.PR China

The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,wind erosion,tillage erosion,freeze-thaw erosion and overgrazing under global climate changes and intensive human *** variations in soil erosion in terraced farmland(TL),sloping farmland(SL)and grassland(GL)were determined by the^(137)Cs tracing method and compared with spatial variations in soil organic carbon(SOC)and total nitrogen(total N).The^(137)Cs concentration in the GL was higher in the 0-0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions,while the^(137)Cs concentration in the soil layer of the SL was generally uniform in the 0-0.18 m soil layer due to tillage-induced ***^(137)Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion,respectively,while the highest^(137)Cs inventories appeared at the middle slope posi-tions due to soil accumulation under relatively flat landform *** the GL,the^(137)Cs data showed that higher soil erosion rates appeared at the summit due to freeze-thaw erosion and steep slope gradients and at the toe slope position due to wind erosion,gully erosion,freeze-thaw erosion and ***^(137)Cs inventory generally increased from upper to lower slope positions within each terrace(except the lowest terrace).The^(137)Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe ***,tillage erosion played an important role in the soil loss at the summit slope positions of each terrace,while water erosion dominantly transported soil from the upper terrace to

关键词： Southeastern Tibetanplateau ^(137)Cs SOC Total N Soil erosion

Epi-Brassinolide Positively Affects Chlorophyll Content and Dark-Reaction Enzymes of Maize Seedlings

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2021年第5期90卷 1465-1476页

作者： Yuanfen Gao Tinglan Jiang Yin Xiang Xuewu He Zhen Zhang Shengjuan Wen junjie Zhang College of Life Sciences Sichuan Agricultural UniversityYa’an625014China

Brassinosteroids participate in many physiological processes in plants;however,their regulatory roles on the activities of the enzymes involved in dark phase of photosynthesis remains *** this study,detached leaves and protoplasts of maize seedlings were treated with epi-brassinolide(EBR)and brassinazole followed by the determination of the contents of chlorophyll(a+b)and soluble sugars,and the activity of dark reaction enzymes and the expression of the relevant *** results showed that chlorophyll(a+b)content increased by 7.4%under 0.1μM EBR treatment for 48 h;furthermore,chlorophyll(a+b)content increased by 34%in detached leaves that were continuously soaked in *** addition,the transcription levels of glyceraldehyde3-phosphate dehydrogenase subunit A(GAPA),cytoplasmic FBPase(cyFBPase),ribulose-1,5-bisphosphate carboxylase small subunit(rbcS),phosphoenolpyruvate carboxylase(PEPC),fructose-1,6-bisphosphatase(FBPase),Rubisco activaseβsubunit(RCAβ),ribulose-l,5-bisphosphate carboxylase large subunit(rbcL),and glutathione reductase(GR)were 96.8%,48.4%,79.3%,41%,85.6%,133.3%,68.8%,and 119.8%higher,respectively,in 0.1μM EBR than in the control *** activity of RCA and Rubisco and soluble sugar content increased by 53.4%,28.7%,and 35.4%under 0.1μM *** inhibits the expression of these ***,the transcription level,protein content,and activity of some dark-reaction enzymes cannot be increased at the same time under EBR *** results indicate that the effect of EBR on dark-reaction is mainly in transcription level.

关键词： Zea mays epi-brassinolide brassinazole rbcL RCA PEPC soluble sugar

一种无重叠频带的自适应非对称并联图示均衡器校正方法

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

电子与信息学报 2022年第5期44卷 1734-1742页

作者：李亚杨俊杰冯奇秦先清广东技术师范大学电子与信息学院广州510665 广州市车厘子电子科技有限公司广州510805

针对车载音响的声场校正精度低、效率低的问题,该文提出一种无重叠频带的自适应非对称并联图示均衡器校正方法。在车载音响声场动态变化情况下,该方法考虑了有效均衡范围和自适应增益,而不是经典方法中的固定均衡范围和人工给定的增益... 详细信息

针对车载音响的声场校正精度低、效率低的问题,该文提出一种无重叠频带的自适应非对称并联图示均衡器校正方法。在车载音响声场动态变化情况下,该方法考虑了有效均衡范围和自适应增益,而不是经典方法中的固定均衡范围和人工给定的增益。通过对实测数据进行实验分析,所提方法比经典方法所用均衡滤波器个数平均减少大约20%,拟合目标增益更准确,校正后频谱曲线更平坦。

关键词：车载音响图示均衡器无重叠频带自适应校正非对称并联

青藏高原东坡两次暴雨的MCS演变及机理对比分析

在线全文

学校读者我要写书评

暂无评论

暴雨灾害 2024年第5期43卷 509-520页

作者：竹利康岚陈永仁吕俊杰李晓容周学云高原与盆地暴雨旱涝灾害四川省重点实验室成都610072 川东北强天气研究南充市重点实验室南充637000 四川省气象台成都610072 四川省气象灾害防御技术中心成都610072

受MCS长时间影响下的暴雨天气在复杂地形区容易造成山洪等严重灾害,研究其特征及成因有助于更好地认识和防御类似的灾害天气。利用多源气象观测资料对青藏高原东坡复杂地形区2020年8月10—11日(过程1)和2021年8月4—5日(过程2)两次暴雨... 详细信息

受MCS长时间影响下的暴雨天气在复杂地形区容易造成山洪等严重灾害,研究其特征及成因有助于更好地认识和防御类似的灾害天气。利用多源气象观测资料对青藏高原东坡复杂地形区2020年8月10—11日(过程1)和2021年8月4—5日(过程2)两次暴雨过程的降水特征和中尺度对流系统(MCS)演变特征及形成机理进行对比分析,结果表明:(1)两次过程均为弱天气尺度系统影响下的暖区暴雨天气过程,强降水落区均位于罗纯山脉西侧的平坝河谷地带,地形对强降水落区的影响十分明显;相较过程2,过程1降水强度更大、范围更广且降水落区更集中。(2)造成两次暴雨的MCS均在雅安西部的高海拔迎风坡初生,并在罗纯山西侧维持发展,但过程1的MCS尺度和强度更大、维持时间更长。(3)过程1的强降水主要由一尺度更大的对流性(积状云为主)MCS稳定少动造成,过程2则分别为两个相继发展的混合性(积云-层云混合)MCS经过同一地区造成。(4)两次过程中的MCS维持机制不同,过程1的主要机制为罗纯山地形强迫抬升作用下不断形成的深对流单体与原MCS_1A合并,使其长时间维持在罗纯山西侧,形成准静止后向建立型MCS回波带,同时地形对冷池出流的阻挡作用以及对暖湿气流的绕流作用也在一定程度上使得MCS_1A稳定少动。而过程2的MCS维持的主要机制为高海拔迎风坡地形反馈作用。

关键词：青藏高原中尺度对流系统维持机制地形作用冷池

Superconductivity in CuIr_(2-x)Al_(x)Te_(4) telluride chalcogenides

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第3期31卷 538-544页

作者： Dong ya. Lingyong Zeng Yijie Zeng Yishi Lin junjie Yin Meng Wang Yihua Wang Daoxin ya. Huixia Luo School of Materials Science and Engineering State Key Laboratory of Optoelectronic Materials and TechnologiesKey aboratory of Polymer Composite&Functional MaterialsGuangzhou Key Laboratory of Flexible Electronic Materials and Wearable DevicesSun Yat Sen UniversiyGuangzhou 510275China Center for Neuron Science and Technology School of PhysicsSun Ya-Sen UniversityGuangzhou 510275China State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Shanghai Research Center for Quantum Sciences Shanghai 201315China Key Laboratory of Functional Molecular Solids Ministry of EducationCollege of Chenistry and Materials ScienceAnhui Normal UniversityWuhu 241002China College of Science Hangzhou Dianzi UniversityHangzhou 310018China

The relationship between charge-density-wave(CDW) and superconductivity(SC), two vital physical phases in condensed matter physics, has always been the focus of scientists’ research over the past decades. Motivated by this research hotspot, we systematically studied the physical properties of the layered telluride chalcogenide superconductors CuIr_(2-x)Al_(x)Te_(4)(0 ≤x≤ 0.2). Through the resistance and magnetization measurements, we found that the CDW order was destroyed by a small amount of Al doping. Meanwhile, the superconducting transition temperature(T_(c)) kept changing with the change of doping amount and rose towards the maximum value of 2.75 K when x = 0.075. The value of normalized specific heat jump(△C/γT_(c)) for the highest T_(c) sample CuIr_(2-x)Al_(x)Te_(4)was 1.53, which was larger than the BCS value of 1.43 and showed the bulk superconducting nature. In order to clearly show the relationship between SC and CDW states,we propose a phase diagram of T_(c) vs. doping content.

关键词： layered telluride chalcogenide superconductivity charge-density-wave CuIr_(2-x)Al_(x)Te_(4)