检索结果-南通市图书馆

科技金融政策的绿色发展效应评价--基于科技和金融结合试点的准自然实验

在线全文

学校读者我要写书评

暂无评论

科技管理研究 2024年第3期44卷 56-66页

作者：刘潭徐璋勇宋甜甜西北大学经济管理学院陕西西安710127

将科技和金融结合试点视为一项准自然试验,运用多期双重差分模型评估科技金融政策的绿色发展效应。研究发现,科技金融政策能够显著提升试点城市绿色发展水平,并且政策效果随时间推移呈“先增加、后减小”的动态特征。另外,对于等级较高... 详细信息

将科技和金融结合试点视为一项准自然试验,运用多期双重差分模型评估科技金融政策的绿色发展效应。研究发现,科技金融政策能够显著提升试点城市绿色发展水平,并且政策效果随时间推移呈“先增加、后减小”的动态特征。另外,对于等级较高城市和东部城市,科技金融政策对绿色发展的驱动效应更强。机制分析表明,产业升级、技术创新、政府支持是科技金融政策促进绿色发展的主要路径,其中技术创新的中介效应最为有效。结论启示应进一步完善科技金融政策实施细则,结合各地区情况补充差异化的绿色发展任务。

关键词：科技金融政策评估绿色发展多期双重差分模型

吉兰-巴雷综合征患者外周血记忆性T细胞和记忆性B细胞亚群的变化及其临床意义

在线全文

学校读者我要写书评

暂无评论

中国现代医生 2024年第6期62卷 54-57,66页

作者：刘坛黄小雨张勇湖州市第一人民医院神经内科浙江湖州313000 徐州医科大学附属医院神经内科江苏徐州2210001

目的探讨吉兰-巴雷综合征(Guillain-Barrésyndrome,GBS)患者外周血记忆性T细胞和记忆性B细胞亚群的变化及其临床意义。方法选取2018年6月至2020年12月于徐州医科大学附属医院神经内科住院的16例GBS患者作为研究组,并选取同期16名来院... 详细信息

目的探讨吉兰-巴雷综合征(Guillain-Barrésyndrome,GBS)患者外周血记忆性T细胞和记忆性B细胞亚群的变化及其临床意义。方法选取2018年6月至2020年12月于徐州医科大学附属医院神经内科住院的16例GBS患者作为研究组,并选取同期16名来院的健康体检者作为对照组。流式细胞术检测两组入选者的外周血T细胞亚群,包括CD4^(+)初始T细胞(naive T cells,TN)、CD4^(+)中央记忆性T细胞(central memory T cells,TCM)、CD4^(+)效应记忆性T细胞(effector memory T cells,TEM)和CD4^(+)终末分化效应记忆性T细胞(terminally differentiated effector memory T cells,TEMRA)及记忆性B细胞、浆母细胞的占比并分析其临床价值。结果与对照组相比,研究组患者的CD4^(+)TN及CD8^(+)TN均明显下降(P0.05)。与对照组相比,研究组记忆性B细胞比例明显升高(P0.05)。GBS患者外周血CD4^(+)TEM及CD8^(+)TEM占比与Hughes残疾评分、脑脊液蛋白、脑脊液免疫球蛋白G及记忆性B细胞占比均呈正相关(P<0.05)。结论GBS患者存在记忆性T细胞和记忆性B细胞亚群免疫紊乱,CD4^(+)TEM细胞、CD8^(+)TEM细胞及记忆性B细胞占比升高,这很可能是GBS发病过程中重要的外周免疫机制。

关键词：吉兰-巴雷综合征效应记忆性T细胞记忆性B细胞

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

分离式插刀开模撞击噪声消除研究

模具工业 2024年第1期50卷 60-65页

作者：刘探胡建全杨玉贵四川成飞集成科技股份有限公司四川成都610091

探讨了冲压生产中分离式插刀结构斜楔开模时频发的撞击噪音问题,并结合冲模的调试过程,分析了撞击噪声的产生机理,根本原因是施加到滑块的压料力传递到斜楔驱动面后因不平衡而发生插刀卡滞并延迟回退,导致插刀瞬间释放而与上模驱动面发... 详细信息

探讨了冲压生产中分离式插刀结构斜楔开模时频发的撞击噪音问题,并结合冲模的调试过程,分析了撞击噪声的产生机理,根本原因是施加到滑块的压料力传递到斜楔驱动面后因不平衡而发生插刀卡滞并延迟回退,导致插刀瞬间释放而与上模驱动面发生碰撞冲击,提出通过改良模具结构和作用行程关系来消除撞击噪声。

关键词：斜楔插刀撞击噪声压料力

维普期刊数据库博看期刊

Observation of Coulomb blockade and ballistic tunneling in graphene single electron transistor

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第1期55卷 7-10页

作者： tan ZhenBing liu GuangTong LU Li YANG ChangLi Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

A square graphene single electron transistor （SET） was defined with two side gates, and its transport was studied at low temperature at T = 2 K. At zero magnetic field, Coulomb blockade oscillations were clearly observed near the Dirac point of this device. At high magnetic field, in the quantum Hall regime, we observed ballistic tunneling of the carders through the graphene SET, contrary to the Coulomb blockades observed while approaching the vicinity of the Dirac point.

关键词： graphene single electron transistor Coulomb blockade tunneling quantum Hall state

A Novel Extremum Seeking Control to Enhance Convergence and Robustness in the Presence of Nonlinear Dynamic Sensors

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 3-21页

作者： liu Hengchang tan Ying OETOMO Denny School of Electrical Mechanical and Infrastructure EngineeringThe University of MelbourneParkville VIC 3010Australia

This paper focuses on optimizing an unknown cost function through extremum seeking(ES)control in the presence of a slow nonlinear dynamic sensor responsible for measuring the *** contrast to traditional perturbation-based ES control,which often suffers from sluggish convergence,the proposed method eliminates the time-scale separation between sensor dynamics and ES control by using the relative degree of the nonlinear sensor *** improve the convergence rate,the authors incorporate high-frequency dither signals and a *** enhance the robustness with the existence of rapid disturbances,an off-the-shelf linear high-gain differentiator is *** first result demonstrates that,for any desired convergence rate,with properly tuned parameters for the proposed ES algorithm,the input of the cost function can converge to an arbitrarily small neighborhood of the optimal solution,starting from any initial condition within any given compact ***,the second result shows the robustness of the proposed ES control in the presence of sufficiently fast,zero-mean periodic *** results substantiate these theoretical findings.

关键词： Averaging extremum seeking optimization singular perturbation time-scale separation

Artificial Neural Network Modeling of Microstructure During C-Mn and HSLA Plate Rolling

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2009年第2期16卷 80-83页

作者： tan Wen liu Zhen-yu WU Di WANG Guo-dong The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

An artificial neural network （ANN） model for predicting transformed mierostrueture in conventional rolling process and therrnomechanical controlled process （TMCP） is proposed. The model uses austenite grain size and retained strain, which can be calculated by using microstructure evolution models, together with a measured cooling rate and chemical compositions as inputs and the ferrite grain size and ferrite fraction as outputs. The predicted re- suits show that the model can predict the transformed microstructure which is in good agreement with the measured one, and it is better than the empirical equations. Also, the effect of the alloying elements on transformed products has been analyzed by using the model. The tendency is the same as that in the reported articles. The model can be used further for the optimization of processing parameters, mierostructure and properties in TMCP.

关键词： artificial neural network TMCP microstructure ferrite grain size

Functional Characterization and Crystal Structure of the Type Ei Peptidyl Carrier Protein ColAia in Collismydns Biosynthesis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第9期38卷 963-969页

作者： Xueyang Ma Guiyang Wang tan liu Changbiao Chi Zhongyi Zhang Donghui Yang Wen liu Ming Ma State Key Laboratory of Natural and Biomimetic Drugs Department of Natural MedicinesSchool of Pharmaceutical SciencesPeking University38 Xueyuan RoadHaidian DistrictBeijing 100191China State Key Laboratory of Bioorganic and Natural Products Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of Sciences345 Lingling RoadShanghai 200032China

Summary of main observation and conclusion Collismycins(COLs)are antibiotics characterized by a 2,2'-bipyridine(2,2'-BP)core composed of a trisubstituted ring A and an unmodified ring *** 2,2'-BP core,which possesses metal-chelating ability and plays key roles in various biological activities of COLs,is biosynthesized by a nonribosomal peptide synthetase(NRPS)-polyketide synthase(PKS)hybrid *** starter module of the NRPS-PKS hybrid machinery consists of a type II peptidyl carrier protein(PCP)ColA1a and an adenylation protein *** here report the functional characterization of ColAia and ColAlb in vitro,confirming their functions in selection and loading of picolinic acid(PA),instead of normal amino acid substrates,as the origin of ring B in *** 2.1 A crystal structure of ColAia was solved,revealing structural features including the additional helices ala,alb and missing helix a3,which may reflect unique interactions of ColAia with other NRPS-PKS proteins/domains or *** and tertiary structural comparison of ColAia with other PCPs revealed the structural basis for their typical a-helical bundle,providing a better understanding of the structural flexibility of *** results facilitate the starter module engineering for the generation of COL derivatives with ring B modifications in the future.

关键词： conclusion machinery fir

Host–Guest Molecular Recognition at Liquid–Liquid Interfaces

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

Engineering 2021年第5期7卷 603-614页

作者： Beibei Wang Hao Chen tan liu Shaowei Shi Thomas P.Russell Beijing Advanced Innovation Center for Soft Matter Science and Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China Department of Polymer Science and Engineering University of MassachusettsAmherstMA 01003USA Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA

Host–guest molecular recognition at the liquid–liquid interface endows the interface with unique properties,including stimuli-responsiveness and self-regulation,due to the dynamic and reversible nature of non-covalent *** research efforts have been put into the preparation of supramolecular interfacial systems such as films and microcapsules by integrating functional components(e.g.,colloidal particles,polymers)at the interface,providing tremendous opportunities in the areas of encapsulation,delivery vehicles,and biphasic reaction *** this review,we summarize recent progress in supramolecular interfacial systems assembled by host–guest chemistry,and provide an overview of the fabrication process,functions,and promising applications of the resultant constructs.

关键词： Liquid-liquid interface Self-assembly Host-guest chemistry Microcapsules

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

感染性心内膜炎急诊手术经验总结

中国中西医结合急救杂志 2024年第3期31卷 346-349页

作者：陈磊余云生司可刘坦苏州大学附属第一医院心脏大血管外科和苏州大学心血管病研究所江苏苏州215006

目的总结急诊手术治疗感染性心内膜炎(IE)的临床经验。方法回顾性分析2019年1月至2022年8月在苏州大学附属第一医院心脏大血管外科诊治的76例IE患者的临床资料,总结并分享急诊手术治疗IE的经验。结果76例IE患者中男性55例(72.4%),女性21... 详细信息

目的总结急诊手术治疗感染性心内膜炎(IE)的临床经验。方法回顾性分析2019年1月至2022年8月在苏州大学附属第一医院心脏大血管外科诊治的76例IE患者的临床资料,总结并分享急诊手术治疗IE的经验。结果76例IE患者中男性55例(72.4%),女性21例(27.6%),男性和女性比例为2.6∶1;年龄17~76岁,平均(52.1±15.6)岁;血培养阳性率25.0%(19例);治愈57例(75.0%),自动出院8例(10.5%),好转9例(11.8%),术前死亡2例(2.6%)。患者行二尖瓣手术30例(39.5%),主动脉瓣置换手术24例(31.6%),二尖瓣+主动脉瓣手术12例(15.7%);合并先天性心脏病15例(19.7%),风湿性心脏病69例(90.8%);左心系统赘生物66例(93.0%),右心系统4例(5.6%);行急诊手术13例(17.1%),且无死亡病例。结论IE病死率较高,目前有效的治疗方法仍然是外科手术,但手术时机仍有争议。本研究经过多例急诊手术总结经验,认为只要患者情况允许,尽早手术可提高患者的存活率,改善预后。

关键词：心内膜炎症状和体征并发症病原菌