检索结果-南通市图书馆

THE LINEAR CORRELATIONS BETWEEN ELECTRONIC TRANSITION ENERGY AND HAMMETT CONSTANTS FOR THE SUBSTITUTED PORPHYRIN-LIKE MACROCYCLE

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1993年第3期4卷 243-246页

作者： shi Ming DONG Duo yuan WANG Institute of Photographic Chemistry,Academia Sinica,Beijing 100101

The properties of absorption spectra are presented and the linear correlations of Hammett constants with the 0-0 transition energy(E_(o,o))of S_←S_o, and the ratios of oscillator strength(f/f)are used to probe the interactions betwee π-electron of aromatic maerocycles or metal ion of complexes with the sub- stituents on β-position of benzene ring for porphyrin-like maerocyclic compounds.

关键词： TXP Cd CI THE LINEAR CORRELATIONS BETWEEN ELECTRONIC TRANSITION ENERGY AND HAMMETT CONSTANTS FOR THE SUBSTITUTED PORPHYRIN-LIKE MACROCYCLE

在线全文

学校读者我要写书评

暂无评论

基于多源数据回归分析的糖料蔗产量估计

节水灌溉 2020年第6期 24-28页

作者：黄凯查元源史良胜广西壮族自治区水利科学研究院南宁530023 武汉大学武汉430072

糖料蔗生产已成为广西经济的主要来源,其种植面积达到全国60%以上。然而,广西糖料蔗区大多分布于山丘坡地,下垫面非均质性和管理非均匀性造成了甘蔗产量具有较强的空间变异性。利用模型估计产量需要大量的观测数据,且运行成本较高。利... 详细信息

糖料蔗生产已成为广西经济的主要来源,其种植面积达到全国60%以上。然而,广西糖料蔗区大多分布于山丘坡地,下垫面非均质性和管理非均匀性造成了甘蔗产量具有较强的空间变异性。利用模型估计产量需要大量的观测数据,且运行成本较高。利用无人机等可以较为方便地得到甘蔗不同时期叶面积指数和株高等信息,地面的传感器也可以采集不同深度的土壤含水率。分析了广西崇左60个试验小区2016年采集的叶面积指数、株高、土壤水数据和糖料蔗产量的相关性,发现相比于地面的叶面积指数观测和土壤水分观测,利用无人机平台所提取的株高观测更有利于糖料蔗的产量估计;叶面积指数观测在伸长中期阶段,数据价值最大,而株高观测则在伸长末期与产量的相关性最高;播种后1-2个月根系区土壤水分对甘蔗最终产量的形成起到了至关重要的作用。采用多源数据回归分析的方法对甘蔗产量进行估计,相关性R^2=0.87,是一种较为便捷的甘蔗产量估计方法。

关键词：糖料蔗产量估计土壤含水率株高叶面积指数

在线全文

学校读者我要写书评

暂无评论

链式微腔的低损耗光传输特性

西安电子科技大学学报 2017年第6期44卷 99-102页

作者：史文轩袁斌上海交通大学电子信息与电气工程学院上海200240

针对微腔的光子聚焦独特性质,研究微腔光子聚焦光束的耦合特性及光子传输效率,提出了一种新型链式微腔的光传输方法,分析了球形微腔的光子聚焦强度、位置与入射波长的关系,得到了平面波入射到链式球形微腔的光强分布及传输特性.仿真结... 详细信息

针对微腔的光子聚焦独特性质,研究微腔光子聚焦光束的耦合特性及光子传输效率,提出了一种新型链式微腔的光传输方法,分析了球形微腔的光子聚焦强度、位置与入射波长的关系,得到了平面波入射到链式球形微腔的光强分布及传输特性.仿真结果和分析表明,微腔的光子聚焦效应及光场的后向放大效应使链式微腔具有高聚焦波束和低损耗特性,可以应用于低损耗光波导的设计;在亚波长空间分辨率的光学微探针、微创激光手术、光镊等方面也具有实际的应用价值.

关键词：光子聚焦链式微腔光传输

Optical topologicallattices of Bloch-type skyrmion and meron topologies

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2022年第4期10卷 947-957页

作者： Qiang Zhang Zhenwei Xie Peng shi Hui Yang Hairong He Luping Du Xiaocong yuan Nanophotonics Research Center Shenzhen Key Laboratory of Micro-Scale Optical Information Technology&Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China

Optical skyrmions, quasiparticles that are characterized by the topologically nontrivial vectorial textures of optical parameters such as the electromagnetic field, Stokes parameters, and spin angular momentum, have aroused great attention recently. New dimensions for optical information processing, transfer, and storage have become possible, and developing multiple schemes for manipulating the topological states of skyrmions, thus, is *** we propose an approach toward achieving dynamic modulation of skyrmions via changing the field symmetry and adding chirality. We demonstrate that field symmetry governs the skyrmionic transformation between skyrmions and merons, whereas material chirality modulates the twist degree of fields and spins and takes control of the Néel-type–Bloch-type skyrmionic transition. Remarkably, the enantioselective twist of skyrmions and merons results from the longitudinal spin arising from the chirality-induced splitting of the hyperboloid in the momentum space. Our investigation, therefore, acts to enrich the portfolio of optical quasiparticles. The chiral route to topological state transitions will deepen our understanding of light–matter interaction and pave the way for chiral sensing, optical tweezers, and topological phase transitions in quantum matter.

关键词： topological nontrivial Bloch

遮阴方式和时间对海南雪茄田间小气候、烟叶生长及产质量的影响

在线全文

学校读者我要写书评

暂无评论

中国烟草学报 2024年第5期30卷 62-73页

作者：贺远李龙科高华军耿召良刘春奎郭栋陈国瑀史晓芙伍宗毅贾超峰郑州轻工业大学烟草科学与工程学院烟草行业烟草工业生物技术重点实验室郑州450002 中国烟草总公司海南省公司海口雪茄研究所海口571100

【目的】探讨不同遮阴方式和时间对海南雪茄田间小气候、烟叶生长及产质量的影响。【方法】设全生育期不遮阴(Z1)、移栽后第3周烟株顶部遮阴(Z2)、移栽后第5周烟株顶部遮阴(Z3)、移栽后第3周烟株四周全遮阴(Z4)、移栽后第5周烟株四周全... 详细信息

【目的】探讨不同遮阴方式和时间对海南雪茄田间小气候、烟叶生长及产质量的影响。【方法】设全生育期不遮阴(Z1)、移栽后第3周烟株顶部遮阴(Z2)、移栽后第5周烟株顶部遮阴(Z3)、移栽后第3周烟株四周全遮阴(Z4)、移栽后第5周烟株四周全遮阴(Z5)5个处理,测定雪茄烟田小气候、烟株农艺性状及发酵后烟叶理化指标,并进行感官评价,计算烟叶经济效益。【结果】遮阴处理雪茄烟株高增加、茎围减小,烟叶最大叶长、宽增大,厚度变薄。遮阴处理下冠层光照强度、空气温度、风速下降,空气湿度提高,全遮阴处理对冠层降温增湿、风速减缓效果更明显。Z3发酵后烟叶叶长、叶宽、叶面积和伸长量较好,遮阴处理雪茄烟叶燃烧后灰分灰度值升高,烟叶钾、氯含量上升,烟碱与总氮含量下降;综合感官评价得分以Z3最高,且Z3茄衣产出率、经济效益分别较Z1提高90.23%、12.24%。【结论】移栽后第5周烟株顶部遮阴处理烟叶综合产质量较好,可在海南儋州烟区推广应用。

关键词：雪茄遮阴栽培田间小气候经济效益产质量

Immune Responses and Protective Efficacy Induced by 85B Antigen and Early Secreted Antigenic Target-6 kDa Antigen Fusion Protein Secreted by Recombinant Bacille Calmette-Guérin

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2007年第4期39卷 290-296页

作者： Changhong shi~1* Xiaowu WANG~1 Hai ZHANG~1 Zhikai XU~2 yuan LI~2 Lintian yuan~11 Laboratory Animal Researeh Center,Fourth Military Medical University,Xi’an 710033,China2 Department of Microbiology,Fourth Military Medical University,Xi’an 710033,China Laboratory Animal Research Center Fourth Military Medical UniversityXi'an 710033 China Department of Microbiology Fourth Military Medical UniversityXi'an 710033 China

In an attempt to improve immune responses and protective efficacy,we constructed tworecombinant bacille Calmette-Guérin(rBCG)strains expressing an 85B antigen(Ag85B)and early secretedantigenic target-6 kDa antigen(ESAT6)of M vcobacterium tuberculosis(MTB)fusion *** rBCGstrains have the same protein insertion but in a different order(Ag85B-ESAT6 and ESAT6-Ag85B).Thecultured supernatant of rBCG strains and the sera from the mice immunized with the fusion protein Ag85B-ESAT6 or ESAT6-Ag85B formed a band with a fraction size of 37 kDa,equalivalent to the sum of Ag85B *** weeks after BALB/c mice were immunized with BCG or rBCG,spleen lymphocytes showedsignificant proliferation in response to culture filtrate protein of *** with the BCG group,micevaccinated with rBCG elicited a high level increase of immunoglobulin G antibodies to culture filtrate proteinin the *** γ-interferon levels in the lymphocyte culture medium supernatants increased remarkably inthe rBCG1 group,significantly higher than that of the BCG immunized group(P0.05).

关键词： Mycobacterium tuberculosis vaccine Ag85B ESAT6 BCG

Preliminary research on problems of northeastChina's participation in the northeast Asianeconomic cooperation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 1999年第4期9卷 410-414页

作者： yuan kai-guo CHEN Chang-chun(Geography Dept., Xiangtan Normal University, Hunan 411201, China)

According to various factors influencing the economic openness, this paper probestentatively into the way Northeast China complies with and participates in the Northeast Asiancooperation, with perticular attention to the analysis and estimation of the advantageousgeographical condition of the extenal cooperation in Northeast China from the present situation ofdeveloping the external economy and cooperation with the adjacent countries.

关键词： regional economical cooperation, Northeast Asia, Northeast China geographical factors,econonuc openness

Clinical characteristics and risk factors of severe respiratory syncytial virus-associated acute lower respiratory tract infections in hospitalized infants

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2014年第4期10卷 360-364页

作者： Xiao-Bo Zhang Li-Juan Liu Li-Ling Qian Gao-Li Jiang Chuan-kai Wang Pin Jia Peng shi Jin Xu Li-Bo Wang Department of Respiratory Medicine Children's Hospital of Fudan University399 Wanyuan RoadShanghai 201102China

Background:To investigate the clinical characteristics and analyze risk factors for severe respiratory syncytial virus(RSV)infection in hospitalized infants with acute lower respiratory tract infections(ALRIs).Methods:A retrospective review of the medical records of infants with RSV-associated ALRIs between March 1st,2011 and February 29th,2012 was *** were followed up over the phone or by outpatient visit six and twelve months after ***:Among 913 RSV-associated ALRIs infants,288(31.5%)had severe infections,which accounted for 4.2%of hospitalized *** hospital RSV mortality rate was 1.0%.The proportions of cases with tachypnea,apnea,cyanosis,and fine rales were significantly higher in the severe ALRIs group(all P<0.001).Multivariate logistic regression showed that low-birth-weight[1.698(1.028-2.805)],age less than 3 months old[3.385(2.174-5.271)],congenital heart disease[1.667(1.149-2.418)],bronchopulmonary dysplasia[8.505(1.731-41.780)],and airway abnormalities[2.246(1.008-5.005)]were independent risk factors for severe *** incidence of bronchitis,pneumonia and readmission in the severe group was significantly higher than that of the non-severe group during the one-year follow-up(all P<0.001).Conclusions:Younger age,low birth weight and underlying disease are associated with severe RSVassociated ***,severe RSV infections may be associated with a higher frequency of subsequent bronchitis,pneumonia and re-hospitalization in the following year.

关键词： infant respiratory infectious diseases respiratory syncytial virus

Ultimate dielectric scaling of 2D transistors via van der Waals metal integration

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

Nano Research 2022年第2期15卷 1603-1608页

作者： Weiqi Dang Bei Zhao Chang Liu Xiangdong Yang Lingan Kong Zheyi Lu Bo Li Jia Li Hongmei Zhang Wanying Li Shun shi Ziyue Qin Lei Liao Xidong Duan yuan Liu Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics College oj Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Hunan Key Laboratory of Two-Dimensional Materials Department of Applied PhysicsSchool of Physics and ElectronicsHunan UniversityChangsha 410082China Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China

The two-dimensional transition metal dichalcogenides(TMDs)have attracted intense interest as an atomically thin semiconductor channel for the continued transistor ***,with a dangling bond free surface,it has been a key challenge to reliably integrate high-quality gate dielectrics on *** particular,the atomic layer deposition of dielectrics on TMDs typically features highly non-uniform nucleation and produces a highly rough or porous dielectric film with rich pinholes that are prone to further damage during the gate integration *** we report a van der Waals(vdW)integration route towards highly reliable gate metal integration on porous *** physical lamination process employed by the vdW integration avoids the direct deposition of metal electrodes into porous dielectrics to ensure reliable gate integration and produce low gate leakage *** electrical measurements demonstrate the vdW integrated MoS_(2) top gate devices exhibit substantially reduced gate leakage current that is about 3-5 orders of magnitude smaller than that with deposited metal ***,we show the vdW integration process can be used to create high performance top-gated MoS_(2) transistors with ultrathin Al_(2)O_(3) dielectrics down to 1 nm,representing the ultimate dielectric scaling for TMDs *** study demonstrates that vdW integration can enable highly reliable gate integration on relatively low quality dielectrics on TMDs,and opens an interesting pathway to high-performance top-gate transistors using dangling bond free two-dimensional(2D)semiconductors.

关键词： van der Waals(vdW)integration dielectric scaling transfer gate MoS_(2) metal oxide semiconductor field effect transistor(MOSFET)