检索结果-南通市图书馆

Miura origami based reconfigurable polarization converter for multifunctional control of electromagnetic waves

Photonics Research 2024年第3期12卷 581-586页

作者： ZHIBIAO ZHU YONGFENG LI ZHE QIN lixin jiang WENJIE WANG HONGYA CHEN JIAFU WANG YONGQIANG PANG SHAOBO QU Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices Air Force Engineering UniversityXi’an 710051China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China

Polarization is one of the basic characteristics of electromagnetic(EM)waves,and its flexible control is very important in many practical *** present,most of the multifunction polarization metasurfaces are electrically tunable based on PIN and varactor diodes,which are easy to operate and have strong real-time ***,there are still some problems in them,such as few degrees of freedom of planar structure control,complex circuit,bulky sample,and high *** view of these shortcomings,this paper proposes a Miura origami based reconfigurable polarization conversion metasurface for multifunctional control of EM *** interaction between the electric dipoles is changed by adjusting the folding angleθ,thereby tuning the operating frequency of the polarization conversion and the polarization state of the reflected *** mechanical control method brings more degrees of freedom to manipulate EM *** the processed sample is with lightweight and low *** verify the performance of the proposed origami polarization converter,a Miura origami structure loaded with metal split rings is designed and *** operating frequency of the structure can be tuned in different folding *** addition,by controlling the folding angleθ,linear-to-linear and linear-to-circular polarization converters can be realized at different folding *** proposed Miura origami polarization conversion metasurface provides a new idea for reconfigurable linear polarization conversion and multifunctional devices.

关键词： polarization reconfigurable tuning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于随机森林的地震灾害直接经济损失评估研究——以中国西部地区为例

引用

中国地震 2024年第2期40卷 355-367页

作者：刘金平姜立新杨天青刘钦中国地震局地震预测研究所北京100036 中国地震台网中心北京100045

为快速评估地震直接经济损失,针对我国西部地区,尝试采用随机森林机器学习回归算法,以1993—2017年震害数据为基础,结合各年份经济数据与抗震设计数据,经特征选择与参数优化后,进行模型的训练与测试。实验结果表明,在减少模型输入特征... 详细信息

为快速评估地震直接经济损失,针对我国西部地区,尝试采用随机森林机器学习回归算法,以1993—2017年震害数据为基础,结合各年份经济数据与抗震设计数据,经特征选择与参数优化后,进行模型的训练与测试。实验结果表明,在减少模型输入特征的情况下,优化后的随机森林模型可得到更优的评估结果。通过删除含有缺失特征样本的数据预处理方法,评估模型的决定系数R2达到0.86,优于中值补齐缺失特征数据预处理下的评估模型,更适用于地震直接经济损失的评估。实例验证表明该模型评估结果与实际经济损失有较好的一致性,可为抗震救灾提供决策支持。

关键词：地震直接经济损失随机森林特征选择超参数优化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

地震应急信息汇聚与发布平台构建

引用

中国地震 2024年第1期40卷 242-250页

作者：刘钦姜立新李继赓董翔杨天青中国地震台网中心北京100045

针对震后灾情获取缓慢且碎片化、决策支持不到位、灾情服务缺位等问题,探讨了地震应急信息汇聚与发布平台的设计与构建,运用大数据、云计算技术,汇聚破裂过程、快速评估、辅助决策等各类地震应急产出,实现了各类地震应急信息的自动汇集... 详细信息

针对震后灾情获取缓慢且碎片化、决策支持不到位、灾情服务缺位等问题,探讨了地震应急信息汇聚与发布平台的设计与构建,运用大数据、云计算技术,汇聚破裂过程、快速评估、辅助决策等各类地震应急产出,实现了各类地震应急信息的自动汇集、全流程模型计算、综合展示等功能,在地震灾情决策支持及地震应急信息服务中发挥了重要作用。

关键词：应急响应灾情汇集信息服务

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

支持盐碱地综合改造利用的实践和思考

引用

农业发展与金融 2024年第4期 66-69页

作者：王思阳姚程蒋立鑫农发行黑龙江省分行

习近平总书记在二十届中央财经委员会第二次会议上对“加强耕地保护和盐碱地综合改造利用问题”作出深刻阐释和战略部署,为新时代新征程加强耕地保护和盐碱地综合改造利用提供了科学指引。本文基于农发行信贷支持黑龙江省大庆市大同区... 详细信息

习近平总书记在二十届中央财经委员会第二次会议上对“加强耕地保护和盐碱地综合改造利用问题”作出深刻阐释和战略部署,为新时代新征程加强耕地保护和盐碱地综合改造利用提供了科学指引。本文基于农发行信贷支持黑龙江省大庆市大同区盐碱地综合治理项目的主要做法,分析当前政策性金融支持盐碱地综合改造利用存在的困难和问题,并从优化顶层设计、创新信贷模式、建立长效机制等方面提出相关政策建议。

关键词：政策性金融盐碱地治理信贷模式创新

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CT VIRTUAL ENDOSCOPY IN ASSESSING OSSICULAR CHAIN DISRUPTION CSUSED BY TEMPORAL BONE FRACTURE AND EAR TRAUMA

引用

Journal of Otology 2013年第2期8卷 104-111页

作者： jiang lixin Xiao Zhiwen Department of 0torhinolaryngology Head and Neck Surgery The First Affiliated Hospital of Jinan University 510632

Objective To explore the value of computed tomography virtual endoscopy(VE) in assessing ossicular chain disruption in temporal bone fracture and ear trauma with intact tympanum. Methods High resolution spiral computerized tomography(CT) was completed in 35 cases of temporal bone fracture and 5 cases of tympanum trauma, all with intact or healed tympanum. Three-dimensional reconstruction was completed using a virtual endoscopy software. Audiological tests were conducted in all patients and evaluation of facial nerve injury in patients with facial paralysis. Patients with mild conductive deafness, ossicular chain subluxation on VE, and no facial paralysis were treated conservatively for 4-12 weeks with repeated hearing evaluation; those with facial paralysis underwent surgery if no recovery after 4- 8 weeks of conservative treatment. Patients with moderate to severe conductive hearing loss or mixed hearing loss, incus long process fracture or dislocation on VE and facial paralysis, underwent ossicular chain reconstruction and facial nerve decompression after conservative treatment for 4-8 weeks, or exploratory tympanotomy only if no facial paralysis. VE, audiological tests and facial nerve function tests were repeated in 3-6 months after surgery. Results Of the 6 cases with mild conductive hearing loss, ossicular chain subluxation and no facial paralysis, 3recovered to normal hearing spontaneously and 3 showed no significant improvement, after 4-12 weeks of conservative treatment. After conservative treatment for 4-8 weeks, 3 of the 12 cases with mild conductive deafness, ossicular chain dislocation on VE and facial paralysis recovered to normal hearing and HouseBrackmann(HB) grade I facial function from HB grade II,4 showed facial function recovery to HB grade I(n=2) or II(n=2) from HB grade III but no hearing recovery, and 5 gained no recovery and went on to receive exploratory tympanotomy and facial nerve decompression. The 11 cases with moderate to severe conduct

关键词： temporal bone fracture ear trauma virtual CT endoscopy(VE) computerized tomography(CT) ossicular chain disruption

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

漓江上游水沙对降水、土地利用变化的响应

引用

桂林理工大学学报 2024年第1期44卷 115-122页

作者：方荣杰黄卉张帅普代俊峰蒋立新许景璇桂林理工大学广西环境污染控制理论与技术重点实验室广西桂林541006 桂林理工大学岩溶地区水污染控制与用水安全保障协同创新中心广西桂林541006 桂林水文中心广西桂林541001

为了探究漓江流域上游水沙对气候和土地利用变化的响应特征,基于气温、降水量、径流量、输沙量,结合土地利用数据和归一化植被指数(NDVI)数据,应用Mann-Kendall检验法、双累积曲线法分析漓江上游水文气象要素变化趋势,利用累积量斜率变... 详细信息

为了探究漓江流域上游水沙对气候和土地利用变化的响应特征,基于气温、降水量、径流量、输沙量,结合土地利用数据和归一化植被指数(NDVI)数据,应用Mann-Kendall检验法、双累积曲线法分析漓江上游水文气象要素变化趋势,利用累积量斜率变化率比较法定量揭示气候因子对上游径流变化的贡献率,结合植被覆盖变化特征探讨土地利用类型变化对河流水沙的影响。结果表明:1965—2019年漓江流域上游气温呈显著增加趋势,降水量、径流量、输沙量未呈现显著增加或减少趋势,同时期NDVI呈上升趋势,但土地利用结构未发生明显变化,仍以林地、耕地为主。漓江上游气温未出现突变点,降水量与径流量于1991年发生突变,1992—2019年漓江上游NDVI平均值显著高于突变前的1981—1991年,耕地面积平均值与林地面积平均值显著低于突变前的1981—1991年;输沙量于2003年发生突变,2004—2019年漓江上游NDVI平均值与建设用地面积平均值显著高于1981—2003年。降水对径流改变的贡献率为56.30%,降水量-径流量关系并未在突变点前后发生改变。降水量对输沙量改变的贡献率为-12.67%,降水量-输沙量关系在突变后发生改变。

关键词：水沙特征气候变化土地利用贡献率漓江

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of the Levenberg-Marquardt Method in Improving Technology of the Seismic Influence Field

引用

Earthquake Research in China 2018年第3期32卷 400-411页

作者： Yang Yanming jiang lixin Wang Zhenxiang Earthquake Agency of Inner Mongolia Autonomous Region Hohhot 010010China China Earthquake Networks Center Beijing 100045China

Attenuation relation of seismic intensity is fitted by using 152 complete isoseismic lines from65 earthquakes which were greater than MS4. 0 from 1940 to 2015 in Inner Mongolia and neighboring regions. Meanwhile,based on the difference of land form and geological structure characteristics,the study area is the divided into eastern,western and *** intensity attenuation relationships are established separately by using the LM( Levenberg-Marquardt) method and elliptic attenuation model. Comparisons are made by using the earthquake affecting field model of North China and computed results. The analytical study shows that the relation obtained represents the features of earthquake damage distribution in the areas well,and has positive meaning to guide loss assessments immediately after a destroyed earthquake.

关键词： Seismic Intensity Earthquake affecting field Inner Mongolia Levenberg-Marquardt Attenuation relationship

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Do nocturnal birds use acoustic and visual cues to avoid predation by bats?

引用

Integrative Zoology 2024年第3期19卷 524-537页

作者： lixin GONG Huan WU Zhiqiang WANG Hui WU jiang FENG Tinglei jiang Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization Northeast Normal UniversityChangchunChina Key Laboratory of Vegetation Ecology of Education Ministry Institute of Grassland ScienceNortheast Normal UniversityChangchunChina College of Life Science Jilin Agricultural UniversityChangchunChina

Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey *** an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal *** prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal ***,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by ***,and presented the birds with individual bats under different light *** results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic *** the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched *** results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid *** work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine *** results provide new insights into the anti-predation behavior of nocturnal animals.

关键词： anti-predation behavior nocturnal animals sensory cues sensory defenses

来源：

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

基于响应面法优化脂质纳米颗粒的配方及表征

引用

中国兽医科学 2024年第10期54卷 1399-1407页

作者：麻玉清柳海云郭伟江丽馨孙世琪王晓强马全英郭慧琛兰州交通大学化学化工学院中国农业科学院兰州兽医研究所兰州大学动物医学与生物安全学院动物疫病防控全国重点实验室兰州交通大学生物与制药工程学院

脂质纳米颗粒是目前最有应用前景的药物载体之一，本研究旨在解决原材料配方对脂质纳米颗粒自组装的影响，优化其配方。首先，以包封率为评价指标，通过单因素试验确定膜材比、脂质浓度和DMG-PEG 2000的含量。其次，采用Box-Benhnken响... 详细信息

脂质纳米颗粒是目前最有应用前景的药物载体之一，本研究旨在解决原材料配方对脂质纳米颗粒自组装的影响，优化其配方。首先，以包封率为评价指标，通过单因素试验确定膜材比、脂质浓度和DMG-PEG 2000的含量。其次，采用Box-Benhnken响应面分析法优化脂质纳米颗粒制备工艺，并对其进行表征评价。结果表明，通过单因素试验确定的三因素分别是：膜材比、脂质浓度和DMG-PEG 2000含量。三因素的三水平分别为：膜材比选择1∶1、2∶1、3∶1，脂质浓度选择15、20、25 mmol/L,DMG-PEG2000含量选择5%、7%、9%。通过Box-Benhnken响应面分析法得出：当脂质纳米颗粒的膜材比为2∶1，脂质浓度为20 mmol/L,DMG-PEG2000含量为7%时，其脂质纳米颗粒的包封率为（94.8±0.15）%，粒径为（43.77±0.25） nm，聚合物分散指数（polymer dispersity index,PDI）为（0.14±0.04）,Zeta电位为（-0.44±0.15） m V。利用透射电镜观察该脂质纳米颗粒的形态为球形结构、分散均匀。稳定性试验显示4℃放置28 d，脂质纳米颗粒的平均粒径、PDI和包封率无显著变化，说明该脂质纳米颗粒稳定性良好。本研究为制备一种高效的脂质纳米颗粒提供了参考依据。

关键词：脂质纳米颗粒 Box-Benhnken响应面法单因素包封率

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Comparison of lymph node number and prognosis in gastric cancer patients with perigastric lymph nodes retrieved by surgeons and pathologists

引用

Chinese Journal of Cancer Research 2016年第5期28卷 511-518页

作者： lixin jiang Zengwu Yao Yifei Zhang Jinchen Hu Dawei Zhao Huiyuan Zhai Xixun Wang Zhenbin Zhang Dong Wang Gastrointestinal Surgery Ward I Yantai Yuhuangding Hospital the Affiliated Hospital of Qingdao University Yantai 264000 China

Objective： To compare the numbers of positive and total lymph nodes and prognosis in gastric cancer patients whose perigastric lymph node retrieval was performed by surgeons and pathologists. Methods： We conducted a retrospective analysis of clinical and follow-up data from 1,056 patients who underwent gastric cancer D2 radical lymph node resection between January 2008 and December 2010 in the Gastrointestinal Surgery Department of Yantai Yuhuangding Hospital. The follow-up ended in December 2015. Patients were divided into two groups according to the specialty of physicians who performed the postoperative perigastric lymph node retrieval： the surgeon group （475 cases） and the pathologist group （581 cases）. The numbers of positive and total perigastric lymph nodes and the 3- and 5-year survival were compared between gastric cancer patients in the two groups overall and stratified by TNM stage （AJCC 7th Edition）. Results： Overall, the numbers of positive and total lymph nodes were significantly higher in the surgeon group than in the pathologist group （6.53±4.07 vs. 4.09±3.70, P=0.021; 29.64±11.50 vs. 20.71±8.56, P〈0.001）. Further analysis showed that the total number of lymph nodes in stage Ⅰ patients （19.40±9.62 vs. 15.45±8.59, P=0.011） and the numbers of positive and total lymph nodes in stage Ⅱ（1.38±1.08 vs. 0.87±1.55, P=0.031; 25.35±10.80 vs. 16.75±8.56, P〈0.001） and stage Ⅲ patients （8.11±6.91 vs. 6.66±5.12, P=0.026; 32.34±12.55 vs. 25.45±8.31, P〈0.001） were significantly higher in the surgeon group than in the pathologist group. The survival analysis showed that the 3- and 5-year survival of stage Ⅱ and Ⅲ patients was significantly higher in the surgeon group than in the pathologist group （82.0% vs. 73.1%, 69.5% vs. 61.2%, P=0.038; 49.2% vs. 38.9%, 36.3% vs. 28.0%; P=0.045）. Conclusions： Compared with retrieval performed by pathologists, postoperative perigastrie lymph node retrieval performed by surgeons was associated with significant increase in the total l

关键词： Gastric cancer surgeon and pathologist lymph node retrieval prognosis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：