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

自适应初始光子收集半径的卡方渐进光子映射

计算机工程与设计 2024年第8期45卷 2433-2441页

作者：贺怀清元林刘浩翰惠康华中国民航大学计算机科学与技术学院天津300300

卡方渐进光子映射(chi-squared progressive photon mapping, CPPM)使用K近邻法(K nearest neighbor, KNN)为命中点确定初始半径,导致图像中光照均匀区域的噪点及明暗交界区域和焦散区域的模糊。针对此问题,提出一种计算光子映射初始半... 详细信息

卡方渐进光子映射(chi-squared progressive photon mapping, CPPM)使用K近邻法(K nearest neighbor, KNN)为命中点确定初始半径,导致图像中光照均匀区域的噪点及明暗交界区域和焦散区域的模糊。针对此问题,提出一种计算光子映射初始半径的算法,自适应地为各命中点确定初始半径:为CPPM算法增加预处理环节,根据对光子分布的均匀程度的检验及对高频区域的筛选为命中点设置初始半径,以保证光照均匀区域的命中点保持在大半径上,光照变化区域的命中点半径快速下降。实验结果表明,改进算法减少了光子映射算法的方差和偏差,提高了渲染效果。

关键词：渐进光子映射 K近邻法卡方检验自适应初始半径焦散光子分布

基于模糊补偿的塔式起重机自适应模糊滑模控制

在线全文

学校读者我要写书评

暂无评论

科学技术与工程 2024年第2期24卷 639-648页

作者：赵志杰柴琳刘惠康孙家骏武汉科技大学信息科学与工程学院武汉430081

塔式起重机在工作时,负载会产生摆动,且系统具有欠驱动性、非线性和强耦合性的特征,定位与消摆控制难度大。大多数现有控制方法未考虑系统的摩擦项或者考虑系统摩擦项时由固定公式计算得出,而工程实际应用中摩擦项易受到工作环境的影响... 详细信息

塔式起重机在工作时,负载会产生摆动,且系统具有欠驱动性、非线性和强耦合性的特征,定位与消摆控制难度大。大多数现有控制方法未考虑系统的摩擦项或者考虑系统摩擦项时由固定公式计算得出,而工程实际应用中摩擦项易受到工作环境的影响,引起控制效果的降低。为解决上述问题,提出了一种基于模糊补偿的自适应模糊滑模控制器。首先,通过对原有的系统动力学模型进行改造,构造出新的动力学模型,解决了系统由于欠驱动特性导致控制律难以设计的问题。随后采用模糊逼近的方式对系统的摩擦项进行逼近,解决了不确定性的工作环境对摩擦项的影响。其次在此基础上与滑模控制理论相结合设计控制器,并经严格的稳定性分析,证明了系统是渐进稳定的。最后,经仿真和实验结果验证了所提方法的有效性。

关键词：欠驱动系统塔式起重机定位和消摆模糊逼近滑模控制

提高儿科护理人员风险防范意识的管理办法分析

在线全文

学校读者我要写书评

暂无评论

中国卫生产业 2024年第8期21卷 67-70页

作者：杨超蒋双云康慧永州市第三人民医院儿保康复科湖南永州425000

目的分析增强儿科护理人员风险防范意识的重要性。方法选取2023年1—12月永州市第三人民医院儿保康复科24名护理人员作为研究对象,2023年1—7月进行常规管理,2023年8—12月落实风险防范意识管理,分别计入对照组、观察组。对比分析两个... 详细信息

目的分析增强儿科护理人员风险防范意识的重要性。方法选取2023年1—12月永州市第三人民医院儿保康复科24名护理人员作为研究对象,2023年1—7月进行常规管理,2023年8—12月落实风险防范意识管理,分别计入对照组、观察组。对比分析两个阶段儿科护理人员护理工作开展质量评分、风险事件及满意度。结果观察组护理人员护理质量评分明显高于对照组,差异有统计学意义(P均<0.05)。观察组管理满意度为100.00%(24/24),高于对照组的75.00%(18/24),差异有统计学意义(χ^(2)=6.857,P<0.05)。结论增强儿科护理人员风险防范意识可提升护理人员护理质量,减少风险事件的发生率,提高其管理满意度。

关键词：儿科护理护理人员风险防范意识管理措施管理效果

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

238m深古河槽帷幕灌浆试验结果分析

吉林水利 2024年第4期 69-74页

作者：王健郝永志惠康新疆水利水电勘测设计研究院有限责任公司新疆乌鲁木齐830000

古河道两岸基岩出露,河道内沉积了深厚的砂卵砾石层,在托其里萨依河岸边呈直立的陡坎状,上部为第四系上更新统Q3砂卵砾石层,青灰色,厚34~40m;下部岩性为巨厚层的Q_(2)砂卵砾石层,泥质半胶结,呈土黄~棕黄色,厚度50~295m,底部岩性为下元... 详细信息

古河道两岸基岩出露,河道内沉积了深厚的砂卵砾石层,在托其里萨依河岸边呈直立的陡坎状,上部为第四系上更新统Q3砂卵砾石层,青灰色,厚34~40m;下部岩性为巨厚层的Q_(2)砂卵砾石层,泥质半胶结,呈土黄~棕黄色,厚度50~295m,底部岩性为下元古界蚀变辉绿岩。古河道最底部低于正常蓄水位,最深283m,蓄水后主要位于Q_(2)泥质半胶结的砂卵砾石层,该层存在渗漏的可能。用“孔口封闭灌浆法”进行生产性灌浆试验,取得了一定的成效。经帷幕灌浆处理后受灌地层渗透系数较灌前3.73×10^(-3)cm/s(中等透水地层)、1.0×10^(-2)cm/s(强透水地层)有较明显地减小,表明该地层经帷幕灌浆处理后,地层的防渗性能得到了较大幅度的提升,帷幕灌浆试验取得了一定的成效。

关键词：古河槽砂卵砾石层帷幕灌浆

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

中国老年婚姻状况及其变动特点研究

山东女子学院学报 2024年第3期 108-119页

作者：杨慧康陈友华南京大学社会学院江苏南京210023

婚姻在老年生活中扮演着至关重要的作用。利用我国人口普查、人口变动抽样调查与其他相关老年婚姻状况数据进行分析,可得出以下研究结论:婚姻是我国老年人亲密关系中最普遍和最重要的选择;近30年来,老年婚姻状况变动呈现出“一高一低两... 详细信息

婚姻在老年生活中扮演着至关重要的作用。利用我国人口普查、人口变动抽样调查与其他相关老年婚姻状况数据进行分析,可得出以下研究结论:婚姻是我国老年人亲密关系中最普遍和最重要的选择;近30年来,老年婚姻状况变动呈现出“一高一低两波动”趋势;老年婚姻状况内部并非“铁板一块”,存在性别、年龄、受教育程度、城乡和地区上的异质性。老年婚姻状况的影响不仅限于自身,也与其他事关老年福祉的情境息息相关。据此,提出适时建立完善老年婚姻家庭政策、关注与改善老年婚姻弱势群体福祉、营造老年婚姻友好型社会等政策主张。

关键词：老年婚姻第七次人口普查丧偶养老

Kinetics of hot metal desulfurization using CaO-SiO2-Al2O3-Na2O-TiO2 slag

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2019年第10期26卷 1041-1051页

作者： kang-hui Zhang Yan-ling Zhang Tuo Wu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Kinetics of hot metal desulfurization were studied using CaO-SiO2-Al2O3-Na2O-TiO2 slag in the range of 1400-1500℃on a laboratory *** results of kinetic experiments indicate that the desulfurization rate increases as the temperature,Al2O3 content,Na2O content,and TiO2 content increase and basicity increases from 1.01 to 1.75,but decreases when basicity increases from 1.75 to *** melting effect of slag is promoted as the temperature,Na2O content,and TiO2 content increase and Al2O3 content increases from 12.13 to 17.17 mass%,but worsened as basicity increases and Al2O3 content increases from 17.17 to 22.27 mass%.A kinetic model of hot metal desulfurization has been developed to calculate the mass transfer coefficient and the mass transfer resistance of sulfur in *** mass transfer coefficient of sulfur increases as the temperature,Al2O3 content,Na2O content,and TiO2 content increase and basicity *** mass transfer coefficients of sulfur were in the range of(5.02-23.78)×10^-7 m s^-*** activation energy was estimated to be 464.06 kJ mo1^-1 at the temperature from 1400 to 1450℃and 176.35 kJ mol-1 at the temperature from 1450 to 1500℃.The sulfur distribution at the slag-metal interface was observed using a mineral liberation *** result shows that the mass transfer of sulfur in slag is the controlling step at high temperature during the desulfurization process.

关键词： Hot metal desulfurization Kinetics Model Liquid area Kinetic parameter

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

纵列双桨无人机的气动仿真分析

液压与气动 2024年第1期48卷 63-71页

作者：贺登俊康会峰刘颖刘泽辉宣佳林黄新春北华航天工业学院河北省跨气水介质飞行器重点实验室河北廊坊065000 西北工业大学动力与能源学院陕西西安710072

为解决纵列双桨无人机的桨叶重叠部分的气动干扰导致的旋翼效率减少问题,基于计算流体力学(CFD)方法对纵列双桨无人机的气动特性进行了仿真分析,包括不同攻角、两桨叶相对位置变化以及整流罩气动外型优化。结果表明:在不同攻角下,无人... 详细信息

为解决纵列双桨无人机的桨叶重叠部分的气动干扰导致的旋翼效率减少问题,基于计算流体力学(CFD)方法对纵列双桨无人机的气动特性进行了仿真分析,包括不同攻角、两桨叶相对位置变化以及整流罩气动外型优化。结果表明:在不同攻角下,无人机的攻角对升力系数的影响大于阻力系数;无人机两桨叶在纵向距离3420 mm、轴向距离540 mm时旋翼的干扰最小,效率最高。之后进行了无人机整流罩优化,得到了更加理想的气动外型。为纵列双桨无人机的气动设计提供了重要的参考和指导,同时也为无人机的发展和应用提供了有益的实践经验。

关键词：纵列双桨无人机气动特性旋翼效率

Exploring prognostic potential of long noncoding RNAs in colorectal cancer based on a competing endogenous RNA network

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

World Journal of Gastroenterology 2020年第12期26卷 1298-1316页

作者： Zhi-Dong Yang hui kang Department of Laboratory Medicine The First Affiliated Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina

BACKGROUND Colorectal cancer(CRC)is one of the most prevalent tumors ***,long noncoding RNAs(lncRNAs)have been shown to influence tumorigenesis and tumor progression by acting as competing endogenous RNAs(ceRNAs).It is difficult to extract prognostic lncRNAs and useful bioinformation from most ceRNA networks constructed *** To construct a prognostic related ceRNA regulatory network and lncRNA related signature based on risk score in *** RNA transcriptome profile and clinical information of 506 CRC patients were downloaded from the Cancer Genome Atlas database.R packages and Perl program were used for data *** regression analysis was used for prognostic model *** real-time polymerase chain reaction was used to detect the expression of *** A prognostic-related ceRNA network was constructed,including 9 lncRNAs,44 mRNAs,and 30 *** addition,a four-lncRNA model was constructed using multivariate Cox regression analysis,which could be an independent prognostic model in *** risk score for each patient was calculated,and the 506 patients were divided into high and low-risk groups(253 for each group)based on the median risk *** results of the survival analysis showed that patients with a high-risk score had a poor survival ***,the predictive value of the four-lncRNA model was evaluated in *** survival probabilities could be better predicted when combing the risk score and clinical *** Set Enrichment Analysis results verified that a number of cancer-related signaling pathways were enriched with a high-risk score in ***,we validated a novel lncRNA(LINC00488)using quantitative real-time polymerase chain reaction in 22 paired CRC patient tumor tissues compared to adjacent non-tumor *** The four-lncRNA model could give better predictive value for CRC *** understanding of the lncRNA-related ceRNA regulatory mechanism coul

关键词： Colorectal cancer Long noncoding RNA miRNA mRNA Transcription factor Competing endogenous RNA Survival

A clinical study to determine the threshold of bronchodilator response for diagnosing asthma in Chinese children

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

World Journal of Pediatrics 2019年第6期15卷 559-564页

作者： Xiao-hui kang Wan Wang Ling Cao Children's Hospital Affiliated to the Capital Institute of Pediatrics No.2 Ya bao RoadChaoyang DistrictBeijingChina Shanxi Provincial Children's Hospital TaiyuanChina

Background There is few objective,clinically feasible and inexpensive test for diagnosing childhood *** want to find an ideal way to solve *** The control group was 301 non-asthmatic children,and the asthma group was 286 asthmatic *** asthmatic children were divided into three groups according to the severity of their ***-and post-bronchodilator spirometer tests were performed,and the main spirometer parameters were *** bronchodilator response(BDR)[BDR is used to determine the reversibility of airway obstruction by measuring the changes of forced expiratory volume in the first second(FEV1)before and after inhalation of bronchodilators]was then determined,and the optimal threshold of BDR for diagnosing childhood asthma was *** 301 non-asthmatic children and 286 asthmatic children participated in the study,the demographics were *** 1 for pre-bronchodilator of asthmatic children was significantly lower than that of non-asthmatic children(P≤0.01).BDR of non-asthmatic children was 3.30±3.85%.BDR of asthmatic children was 9.45±9.15%.There was no significant difference in BDR for patients with different severities of asthma within the *** had no statistical correlation with gender,age,height,weight in neither non-asthmatic children nor asthmatic *** the receiver-operating characteristic curve,a BDR threshold of≥7.5%offered an optimal balance in asthma diagnosis with a sensitivity rate of 50.7%and specificity rate of 87.7%.Meanwhile,with a BDR threshold of≥12%,the sensitivity rate was 28.7%and the specificity rate was 96.3%.Conclusion A BDR threshold of≥7.5%has more value in childhood asthma diagnosis as compared to≥12%.

关键词： Asthma diagnosis Bronchodilator response Threshold