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

基于扇形枝节加载谐振器的超宽带滤波器

电子科技大学学报 2019年第1期48卷 22-25页

作者：刘家州马宁邓希达延波中国电子科技集团公司电子科学研究院北京石景山区100041 北京空间飞行器总体设计部北京海淀区100094 电子科技大学电子科学与工程学院成都611731

该文提出了一种基于新型扇形枝节加载谐振器的改进上阻带特性的小型化超宽带带通滤波器。该新型多模谐振器由一根高阻微带线上连接三对扇形分流枝节组成。适当调节扇形枝节的尺寸,扇形枝节加载谐振器的谐振频率可以粗略的放置在超宽带... 详细信息

该文提出了一种基于新型扇形枝节加载谐振器的改进上阻带特性的小型化超宽带带通滤波器。该新型多模谐振器由一根高阻微带线上连接三对扇形分流枝节组成。适当调节扇形枝节的尺寸,扇形枝节加载谐振器的谐振频率可以粗略的放置在超宽带频段内(3.1～10.6gHz)。为了加强耦合度,在滤波器的输入和输出端使用了交指型耦合馈线。此外还给出了该滤波器的设计方法和步骤。最后,给出了滤波器的设计和拓扑结构。测量结果和全波仿真结果有很好地一致性。

关键词：带通滤波器小型化扇形枝节加载谐振器超宽带

基于Word2Vec的情感词典自动构建与优化

在线全文

学校读者我要写书评

暂无评论

计算机科学 2017年第1期44卷 42-47,74页

作者：杨小平张中夏王良张永俊马奇凤吴佳楠张悦中国人民大学信息学院北京100872

情感词典的构建是文本挖掘领域中重要的基础性工作。近几年,情感词典的极性标注从二元褒贬标注向多元情绪标注发展,词典的领域特性也日趋明显。但是情感类别的手工标注不但费时费力,而且情感强度难以得到准确量化,同时对领域性的过分关... 详细信息

情感词典的构建是文本挖掘领域中重要的基础性工作。近几年,情感词典的极性标注从二元褒贬标注向多元情绪标注发展,词典的领域特性也日趋明显。但是情感类别的手工标注不但费时费力,而且情感强度难以得到准确量化,同时对领域性的过分关注也大大限制了情感词典的适用性[1]。通过神经网络语言模型对大规模中文语料进行统计训练,并在此基础上提出了基于转换约束集的多维情感词典自动构建方法;然后研究了基于词分布密度的感情色彩消歧方法,对兼具褒贬意味词语的感情极性进行区分和识别,并分别计算两种感情色彩下的情感类别与强度;最后提出基于多个语义资源的全局优化方案,得到包含10种情绪标注的多维汉语情感词典SentiRuc。实验证实该词典1)在类别标注检验、强度标注检验、情感消歧效果及情感分类任务中均具有良好的效果,其中的情感强度检验证实该词典具有极强的情感语义描述力。

关键词：情感分析多元情感分类神经网络语言模型情感消歧情感强度优化框架

Increased expression of matrix metalloproteinase-9 associated with gastric ulcer recurrence

在线全文

学校读者我要写书评

暂无评论

World Journal of gastroenterology 2013年第28期19卷 4590-4595页

作者： Sen-Lin Li Jing-Run Zhao xiao-Yan Ren jia-Ping Xie Qing-Zhu ma QiuHua Rong Department of gastroenterology Liaocheng People's Hospital Central Laboratory Liaocheng People's Hospital

AIM: To compare matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in gastric ulcer (gU) and chronic superficial gastritis (CSg). METHODS: This study enrolled 63 patients with gU and 25 patients with CSg. During upper gastroduodenal endoscopy, we took samples of gastric mucosa from the antrum and ulcer site from patients with gU, and samples of antral mucosa from patients with CSg. Mucosal biopsy tissues were cultured for 24 h, and the culture supernatant was measured for levels of MMP-9 and TIMP-1. After receiving eradication therapy for Helicobacter pylori (H. pylori ) and 8 wk proton-pump inhibitor therapy for gU, follow-up endoscopy examination was performed after 6 mo and whenever severe symptoms occurred. RESULTS: Levels of MMP-9 and TIMP-1 at the ulcer site or in the antrum were significantly higher in gU than CSg patients. MMP-9 levels at the ulcer site were significantly higher than in the antrum in gU patients, and had a significantly positive correlation with TIMP-1. MMP-9 levels were significantly higher in H. pylori -positive than H. pylori -negative gU and CSg patients. Levels of MMP-9 or TIMP-1 at the ulcer site were associated with the histological severity of activity and inflammation. About 57 gU patients were followed up, and seven had gU recurrence. H. pyloriinfection and MMP-9 levels were risk factors for the recurrence of gU adjusted for age and sex by multiple logistic regression analysis. CONCLUSION: MMP-9 may perform an important function in gastric ulcer formation and recurrence.

关键词： gastric ulcer matrix metalloproteinase-9 Tissue inhibitor of metalloproteinase-1 Helicobacter pylori

Effects of changing the control ovarian stimulation protocol in patients without a transplantable embryo in the previous in vitro fertilization/intracytoplasmic sperm injection cycle

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

Reproductive and Developmental Medicine 2023年第4期7卷 218-223页

作者： Shan-jia Yi Yi-Hua Yang Yin Bi Zhong-Hong Zeng Xi Wang Mu-Jun Li Wen-Hong ma guangxi Reproductive Medical Center The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021China Reproductive Medicine Center Affiliated Hospital of Guilin Medical UniversityGuilin 541001China Reproductive Medicine Center Liuzhou Maternity and Child Healthcare Hospital Liuzhou 545001China

Objective:Some patients fail to obtain an embryo for transplantation during previousin vitro fertilization(IVF)or intracytoplasmic sperm injection(ICSI)cycles,and require multiple reproductive *** study aimed to evaluate whether changing the control ovarian stimulation(COS)protocol during the subsequent stimulation cycle could improve laboratory and clinical outcomes in these ***:Patients without a transplantable embryo(TE)in the previous IVF/ICSI cycles were recruited during their second *** were classified into two groups according to their first cycle protocol:group A,patients treated with a gonadotropinreleasing hormone agonist(gnRH-a),and group B,patients treated with a gonadotropin-releasing hormone antagonist(gnRH-ant).The study group included patients whose stimulation protocols were changed,whereas the control group consisted of patients who used the same stimulation protocol in the second *** then compared the numbers of oocytes collected(OC)and TE,the incidence of non-TE,the pregnancy rate(PR),and the live birth rate(LBR).Results:In group A,the numbers of OC and TE were significantly lower(6.0±4.7vs.9.4±6.4,2.3±2.2vs.4.5±3.8,Pgroup compared with those in the control *** group B,the numbers of OC and TE were higher(7.0±5.5vs.4.0±4.3,3.5±3.4vs.1.8±2.1,Pgnificant increase in the incidence of non-TE(adjusted odds ratio(AOR)=2.12,95%CI:1.04–4.69)of the study group in group A but not in group *** significant differences in the PR or LBR were found between the study and control groups in either group A or ***:Changing the COS protocol from gnRH-ant to gnRH-a or continuing the gnRH-a protocol can improve laboratory outcomes in patients with no TE in the previous IVF/ICSI cycle.

关键词： gnRH agonist gnRH antagonist Transplantable embryo Pregnancy rate Live birth rate

Diagnosis of Kaposi sarcoma by a modified fine needle aspiration method combing cell block in Chinese patients with human immunodeficiency virus/acquired immunodeficiency syndrome

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2020年第23期133卷 2894-2896页

作者： Lei Sun Liang Zhang Kun Yang jia-Min Chen xiang-Mei Chen man Li Xin-gang Zhou Zhi-Yuan ma Li-Ming Qi Peng Wang Department of Pathology Beijing Ditan HospitalCaptial Medical UniversityBeijing 100015China

To the Editor:Kaposi’s sarcoma(KS),a low-grade vascular tumor,is one of the most common neoplasms reported in patients with acquired immunodeficiency syndrome(AIDS).Based on epidemiological and clinical characteristics,four types of KS have been reported:classic KS,endemic KS(in equatorial Africa),AIDS-associated KS(AIDS-KS),and iatrogenic ***,the presentation of KS can be variable with dark or brown macules,plaques,or nodules that may bleed or,ulcerate on the skin and mucous ***,the lymph nodes and some visceral organs can also be involved in more advanced stages of the disease.

关键词： Kaposi immunodeficiency needle neoplasms organs

人MxA基因启动子-88／-123位多态性荧光PCR检测方法的建立及临床应用

在线全文

学校读者我要写书评

暂无评论

中华传染病杂志 2008年第10期26卷 580-584页

作者：于洁马为民龙霞陈丽嘉黄君美房家智彭雁忠北京大学深圳医院中心实验室深圳518036 北京大学深圳医院感染性疾病科深圳518036

目的建立一套快速、灵敏和特异的人抗黏液蛋白A（MxA）基因启动子中干扰素刺激应答元件-88／-123位多态性检测体系，为合理应用IFN—α治疗慢性乙型肝炎提供分子生物学检测手段。方法对经IFN—α治疗的患者进行HBVDNA、HBV基因分型及Mx... 详细信息

目的建立一套快速、灵敏和特异的人抗黏液蛋白A（MxA）基因启动子中干扰素刺激应答元件-88／-123位多态性检测体系，为合理应用IFN—α治疗慢性乙型肝炎提供分子生物学检测手段。方法对经IFN—α治疗的患者进行HBVDNA、HBV基因分型及MxA基因启动子中干扰素刺激应答元件-88／-123位多态性位点检测，确定基因多态性与IFN—α治疗效果之间的关系。通过各种条件优化实验，建立MxA基因启动子中干扰素刺激应答元件-88／-123位多态性荧光PCR检测体系，并通过与DNA序列分析法检测结果的对比，验证荧光PCR检测体系的灵敏性及特异性，从而对该体系的临床适用性进行初步评估。采用卡方检验计算P值、回归分析法计算对比率和95％可信区间。结果MxA基因启动子干扰素刺激应答元件中-88位为g／T杂合型和-123位为C／A杂合型者皆为IFN—α敏感型，-88位为g／g纯合型和-123位为C／C纯合型者为IFN—α不敏感型。与DNA序列分析的金标准相比，荧光PCR检测的符合率为99．65％。结论荧光PCR检测体系，可灵敏、快捷地检测患者MxA基因多态性位点。

关键词：蛋白质类抗病毒药操纵子多态现象遗传干扰素α-2b

在线全文

学校读者我要写书评

暂无评论

在非黏性流体域中微悬臂梁振动的建模与仿真

东北大学学报（自然科学版） 2018年第9期39卷 1272-1276页

作者：马树军玄航孙嘉蔚杨磊东北大学机械工程与自动化学院辽宁沈阳110819

借用欧拉-伯努利梁理论推导并计算出微悬臂梁在真空中的共振频率,根据非黏性理论经典模型分别计算出微悬臂梁在不同密度的流体中的共振频率.然后在有限元软件ANSYS(16.0)仿真环境下,采用solid45-fluid30和shell63-fluid30两种单元组合... 详细信息

借用欧拉-伯努利梁理论推导并计算出微悬臂梁在真空中的共振频率,根据非黏性理论经典模型分别计算出微悬臂梁在不同密度的流体中的共振频率.然后在有限元软件ANSYS(16.0)仿真环境下,采用solid45-fluid30和shell63-fluid30两种单元组合建立微悬臂梁在流体域中的三维模型并进行模态分析.最后将仿真结果与相关研究者已发表的实验与理论数据进行对比,在此基础上通过实验来验证新型有限元模型的正确性.通过有限元和实验的方法进一步验证了非黏性流体的密度是影响微悬臂梁共振频率变化的主要因素.

关键词：非黏性流体 ANSYS 模态分析共振频率动态特性

Low temperature fabrication for high-performance semitransparent CsPbI_(2)Br perovskite solar cells

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第3期33卷 1425-1429页

作者： xiaogang Yang Jiejia Han Wei Ruan Yanqiang Hu Zhengyan He xiangrui jia Shufang Zhang Dehua Wang College of Environment and Safety Engineering Qingdao University of Science&TechnologyQingdao 266042China School of Physics and Photoelectronic Engineering Ludong UniversityYantai 264025China College of materials Science and Engineering Nanjing University of Science&TechnologyNanjing 210094China College of Chemistry and Chemical Engineer Nantong UniversityNantong 226001China

All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI_(2)Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI_(2)Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (gABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI_(2)Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI_(2)Br to the semitransparent solar cells.

关键词： CsPbI_(2)Br perovskite γ-Aminobutyric acid Stability Low-temperature fabrication Semitransparent solar cells

电谐振器和磁谐振器构成的左手材料的实验验证

在线全文

学校读者我要写书评

暂无评论

物理学报 2010年第3期59卷 1847-1850页

作者：王甲富屈绍波徐卓夏颂张介秋马华杨一鸣吴翔空军工程大学理学院西安710051 西安交通大学电子陶瓷与器件教育部重点实验室西安710049

加工、制作和测试了由电谐振器和磁谐振器构成的左手材料.首先分别测试了电谐振器、磁谐振器各自的传输频谱,得到各自的负参数区域,然后测试了由电谐振器和磁谐振器构成的左手材料的传输频谱,并提取了其等效介电常数和磁导率.实验结果表... 详细信息

加工、制作和测试了由电谐振器和磁谐振器构成的左手材料.首先分别测试了电谐振器、磁谐振器各自的传输频谱,得到各自的负参数区域,然后测试了由电谐振器和磁谐振器构成的左手材料的传输频谱,并提取了其等效介电常数和磁导率.实验结果表明,在电谐振器和磁谐振器各自传输禁带的重合区域,出现了一个通带,在该通带内,等效介电常数和磁导率同时为负,验证了材料的左手特性.

关键词：左手材料电谐振器磁谐振器