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

健康素养预测模型的构建与改进

江苏预防医学 2024年第3期35卷 283-287页

作者：蔡婷卓琳苗春霞汪秀英卓朗徐州市疾病预防控制中心江苏徐州221006 北京大学人民医院内分泌科徐州医科大学卫生政策与健康管理研究中心徐州市中心医院肾脏内科徐州医科大学公共卫生学院

目的构建健康素养预测模型,为快速筛检低健康素养水平人群提供参考。方法2020年,采用多阶段随机整群抽样方法,抽取苏北X市15~69岁居民为调查对象,采用国家健康素养调查问卷开展调查,建立logistic回归模型和决策树模型,以实际调查结果为... 详细信息

目的构建健康素养预测模型,为快速筛检低健康素养水平人群提供参考。方法2020年,采用多阶段随机整群抽样方法,抽取苏北X市15~69岁居民为调查对象,采用国家健康素养调查问卷开展调查,建立logistic回归模型和决策树模型,以实际调查结果为金标准,比较两种模型预测效果,并通过增加预测变量方法构建新的logistic回归健康素养预测模型。结果共纳入1933名调查对象,不具备健康素养1580人,占81.74%。logistic回归分析结果显示,年龄、文化程度、职业和吸烟情况是居民健康素养水平的影响因素(P值均<0.05)。建立的logistic回归模型AUC为0.79(95%CI:0.77~0.81),构建的决策树模型AUC为0.78(95%CI:0.75~0.80)。以健康素养是否具备分别与56道问题知晓情况进行统计学比较,将问题按照各题χ^(2)值由大到小排列,纳入问卷中前6道题目(C09、C05、D01、C08、C12、C10)构建新的logistic回归预测模型:Logit(P)=ln[P/(1-P)]=-3.104+0.325[年龄(25~34)]-0.149[年龄(35~44)]-0.857[年龄(45~54)]+0.367[年龄(55~64)]-2.748[年龄(65~69)]+2.531[文化程度(小学及以下)]+1.597[文化程度(初中)]+0.303[文化程度(高中/职高/中专)]+1.444[题目C05(错误)]+1.744[题目C08(错误)]+1.621[题目C09(错误)]+2.025[题目C10(错误)]+1.806[题目C12(错误)]+1.958[题目D01(错误)],该预测模型灵敏度为85.90%,特异度为90.04%,AUC为0.95(95%CI:0.94~0.96)。在约登指数取最大值为0.76时,logit(P)对应P值为0.831,即预测概率超过0.831,可判定为不具备健康素养。结论利用改进的健康素养预测模型中的切点值,可在现场调查时快速鉴别出不具备健康素养人群。

关键词：健康素养预测模型 logistic模型决策树模型

Spatial analysis of carbon storage density of mid-subtropical forests using geostatistics： a case study in Jiangle County, southeast China

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2018年第1期37卷 90-101页

作者： zhuo lin lin Chao Chengzhen Wu Wei Hong Tao Hong Xisheng Hu College of Forestry Fujian Agriculture and Forestry University Fuzhou Fujian Province China Fujian Institute of Scientific and Technological Information Fuzhou 350001 Fujian ProvinceChina Institute of Applied Ecology Chinese Academy of ScienceKey Laboratory of Forest Ecology and ManagementShenyang Liaoning Province China University of Chinese Academy of Science Beijing China Department of Ecology and Resource Engineering Wuyi UniversityNanping 354300 Fujian Province China College of Transportation and Civil Engineering Fujian Agriculture and Forestry University FuzhouFujian Province China

The mid-subtropical forest is one of the biggest sections of subtropical forest in China and plays a vital role in mitigating climate change by sequestering *** have examined carbon storage density(CSD) distribution in temperate forests. However, our knowledge of CSD in subtropical forests is limited. In this study, Jiangle County was selected as a study case to explore geographic variation in CSD. A spatial heterogeneity analysis by semivariogram revealed that CSD varied at less than the mesoscale(approximately 2000–3000 m). CSD distribution mapped using Kriging regression revealed an increasing trend in CSD from west to east of the study *** spatial autocorrelation analysis indicated that CSD was clustered at the village level(at 5% significance).Some areas with local spatial autocorrelation were detected by Anselin Local Moran's I and Getis-Ord G*. A geographically weighted regression model showed different impacts on the different areas for each determinant. Generally, diameter at breast height, tree height, and stand density had positive correlation with CSD in Jiangle County, but varied substantially in magnitude by *** contrast, coefficients of elevation and slope ranged from negative to positive. Based on these results, we propose certain measures to increase forest carbon storage,including increasing forested area, improving the quality of the current forests, and promoting reasonable forest management decisions and harvesting strategies. The established CSD model emphasizes the important role of midsubtropical forest in carbon sequestration and provides useful information for quantifying mid-subtropical forest carbon storage.

关键词： Carbon storage density Geostatistics Mid-subtropical forests Spatial autocorrelation Spatial heterogeneity

STRUCTURE PARAMETERS DESIGN AND PERFORMANCE TEST OF FUEL INJECTION SYSTEM

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2006年第3期19卷 407-411页

作者： WU Changshui YU Jinxia YANG lin zhuo Bin Institute of Automotive Electronic Technology Shanghai Jiaotong University Shanghai 200030 China

Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.

关键词： High pressure common rail fuel injection system Structure parameters design Variance analysis

APPLICATION OF CIRCUIT SIMULATION IN HARDWARE DESIGN FOR ELECTRONIC CONTROL HIGH PRESSURE COMMON-RAIL FUEL SYSTEM OF DIESEL ENGINE

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2005年第4期18卷 613-616页

作者： Tan Wenchun Yu Shitao Yang lin zhuo Bin Institute of Automotive Electronic Technology Shanghai Jiaotong University Shanghai 200030 China

By means of circuit simulation, hardware of electronic control unit （ECU） of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance （VR） sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.

关键词： Diesel engine Electronic control unit (ECU) Circuit simulation.

中西医结合治疗冠心病合并高血压的疗效及对心功能的影响观察

在线全文

学校读者我要写书评

暂无评论

中国现代药物应用 2024年第7期18卷 137-140页

作者：戴晓河卓辉林戴剑福建省南安市洪濑中心卫生院内科 362331 福建医科大学附属泉州第一医院心血管内科 362000 福建省泉州市光前医院急诊科 362321

目的探讨中西医结合治疗冠心病合并高血压的疗效及对心功能的影响。方法92例冠心病合并高血压患者,随机分为对照组和观察组,每组46例。对照组使用常规西医治疗,观察组在此基础上使用中医治疗。对比两组的临床疗效、血压[收缩压(SBP)、... 详细信息

目的探讨中西医结合治疗冠心病合并高血压的疗效及对心功能的影响。方法92例冠心病合并高血压患者,随机分为对照组和观察组,每组46例。对照组使用常规西医治疗,观察组在此基础上使用中医治疗。对比两组的临床疗效、血压[收缩压(SBP)、舒张压(DBP)]及心绞痛指标(心绞痛发作次数、持续时间)、心功能指标[左室射血分数(LVEF)、左室舒张末期内径(LVEDd)、左室收缩末期内径(LVESd)、脑钠肽(BNP)]、血清因子[C反应蛋白(CRP)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、内皮素-1(ET-1)]。结果观察组治疗总有效率为95.65%,明显高于对照组的76.09%(P<0.05)。观察组治疗后SBP(123.87±7.75)mm Hg(1 mm Hg=0.133 kPa)、DBP(78.73±5.49)mm Hg、心绞痛发作次数(1.87±0.64)次/周低于对照组的(135.58±9.16)mm Hg、(86.85±6.14)mm Hg、(2.93±0.82)次/周,心绞痛发作持续时间(3.39±0.73)min/次短于对照组的(5.47±1.18)min/次(P<0.05)。观察组治疗后LVEF(52.37±4.42)%高于对照组的(47.84±4.58)%,LVEDd(45.69±3.90)mm、LVESd(50.16±4.13)mm小于对照组的(50.82±4.23)、(55.97±4.29)mm,BNP(306.39±56.84)ng/L低于对照组的(484.67±68.26)ng/L(P<0.05)。观察组治疗后CRP(6.20±1.08)mg/L、IL-6(14.42±2.13)ng/L、TNF-α(10.38±2.05)μg/L、ET-1(41.63±5.74)ng/L均低于对照组的(12.35±2.46)mg/L、(19.07±3.32)ng/L、(14.34±2.67)μg/L、(52.12±6.81)ng/L(P<0.05)。结论中西医结合治疗冠心病合并高血压的疗效显著,能提高对血压及心绞痛的控制效果,改善心功能,抑制炎症反应,保护血管内皮,抑制病情进展。

关键词：冠心病高血压中西医结合治疗疗效心功能

肉汤微量稀释法对耐多药结核分枝杆菌敏感性检测的评价

在线全文

学校读者我要写书评

暂无评论

中国感染控制杂志 2024年第7期23卷 840-846页

作者：钟业腾王洁莹陈灼霖许玉妮邱文华裴华海南医学院第二附属医院检验科海南海口570216

目的评价肉汤微量稀释(BMD)法在耐多药结核分枝杆菌(MDR-MTB)敏感性检测中的应用效果。方法采用罗氏比例法和BMD法对海南省108株MDR-MTB及11株非MDR-MTB菌株进行药敏试验,并对两种药敏方法检测结果不一致菌株进行全基因组测序(WGS)。结... 详细信息

目的评价肉汤微量稀释(BMD)法在耐多药结核分枝杆菌(MDR-MTB)敏感性检测中的应用效果。方法采用罗氏比例法和BMD法对海南省108株MDR-MTB及11株非MDR-MTB菌株进行药敏试验,并对两种药敏方法检测结果不一致菌株进行全基因组测序(WGS)。结果罗氏比例法和BMD法药敏结果平均判读时间分别为28.0、8.5 d。罗氏比例法检测异烟肼、利福平、乙胺丁醇、卡那霉素和卷曲霉素的耐药率高于BMD法(均P<0.001);BMD法检测丙硫异烟胺和对氨基水杨酸的耐药率高于罗氏比例法(均P<0.001)。以罗氏比例法药敏结果为金标准,BMD法检测耐药性的灵敏度和特异度分别为50.00%~100%、95.69%~100%,除EMB(87.39%)、INH(94.96%)外,BMD法检测其他药物的耐药性符合率均≥95%。罗氏比例法药敏结果与WGS总符合率为76.19%(32/42),BMD法药敏结果与WGS总符合率为23.81%(10/42),差异具有统计学意义(χ^(2)=23.048,P<0.001)。两种药敏方法检测结果不一致的MTB共34株,罗氏比例法耐药+BMD法敏感的26株MTB中,22株(84.62%)相关耐药基因发生突变;罗氏比例法敏感+BMD法耐药的11株MTB中,5株(45.45%)相关耐药基因发生突变。结论BMD法是一种准确、快速的MDR-MTB敏感性检测方法,但仍需要进一步改进和优化,耐药性与相关耐药基因的突变密切相关。

关键词：耐多药结核分枝杆菌罗氏比例法肉汤微量稀释法最低抑菌浓度药物敏感试验

国产交联透明质酸钠凝胶纠正中重度鼻唇沟皱纹的安全性及有效性

在线全文

学校读者我要写书评

暂无评论

临床和实验医学杂志 2024年第6期23卷 670-672,F0003页

作者：江萌李妍禚风麟徐薇李邻峰首都医科大学附属北京友谊医院皮肤性病科北京100050

目的评价国产注射用交联透明质酸钠凝胶纠正中重度鼻唇沟皱纹(NLF)的安全性和有效性。方法本研究采用多中心、前瞻性、评价者-受试者双盲、随机对照的非劣效试验设计,自2021年4月至2023年4月在首都医科大学附属北京友谊医院、河南科技... 详细信息

目的评价国产注射用交联透明质酸钠凝胶纠正中重度鼻唇沟皱纹(NLF)的安全性和有效性。方法本研究采用多中心、前瞻性、评价者-受试者双盲、随机对照的非劣效试验设计,自2021年4月至2023年4月在首都医科大学附属北京友谊医院、河南科技大学第一附属医院、沧州市人民医院和应急总医院4个研究中心前瞻性纳入296例中重度NLF患者作为研究对象。按照1∶1比例随机分为国产组和进口组,每组各148例。国产组注射用交联透明质酸钠凝胶,进口组注射用修饰透明质酸钠凝胶。注射后0.5、1、2 h,采用视觉模拟评分法(VAS)评估受试者两侧面部的疼痛情况;比较两组注射后1、3、6、12个月的鼻唇沟皱纹严重程度分级(WSRS)和面部整体美容效果改善分级(GAIS);比较两组受试者不良事件及实验室检查结果。结果注射后0.5、1、2 h,国产组与进口组两侧面部的VAS评分比较,差异均无统计学意义(P>0.05)。国产组注射1、3、6、12个月的WSRS改善率分别为96.62%、89.19%、91.22%、35.14%,进口组分别为97.30%、90.54%、90.54%、29.73%,两组WSRS改善率比较,差异均无统计学意义(P>0.05)。注射后1、3、6、12个月,国产组与进口组的GAIS改善情况比较,差异均无统计学意义(P>0.05)。本次试验无严重不良事件发生且实验室常规检查及生命体征组间均正常。结论国产注射用交联透明质酸钠凝胶在纠正中重度NLF的效果和安全性与进口产品相当。

关键词：鼻唇沟皱纹透明质酸钠凝胶皮肤填充美容

Microstructure and mechanical properties of Fe/NbC composite layer prepared by in-situ reaction

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第4期20卷 356-364页

作者： Le Chen Ji-lin Li Meng-jun Wang Jie Zheng Yao Zhu zhuo-lin Liu Bing-gui Lü School of Materials Science and Engineering Central South UniversityChangsha 410083China School of Materials Science and Engineering Xi'an University of TechnologyXi'an 710048China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China Guangdong Provincial Key Laboratory of Metal Toughening Technology and Application Guangzhou 510650China Guangdong Guangyun New Material Co. Ltd.Yunfu 527527GuangdongChina Yunfu Guangyun Technology R&D Co. Ltd.Yunfu 527527GuangdongChina

NbC ceramic surface-reinforced steel matrix composites were prepared by an in-situ reaction method at different temperatures(1,050℃,1,100℃and 1,150℃)for different times(1 h,2 h and 3 h).The phase constitution,microstructure and fracture morphology of NbC ceramic surface-reinforced steel matrix composites were analyzed by XRD,SEM and EDS,and the effects of the in-situ reaction temperature and time on the mechanical properties were systematically *** results indicate that the NbC reinforcement layer is formed through the reaction between Nb atoms and carbon atoms diffused from the steel matrix to the Nb *** thickness of this reinforcement layer increases as the reaction time ***,an increase in reaction temperature results in a thicker reinforcement layer,although the rate of increase gradually *** relationship among the thickness of the Nb C reinforcement layer,the reaction time and temperature was established by data *** optimal tensile performance is achieved at 1,100℃for 1 h,with a tensile strength of 228 *** is also found that the defects between the reinforcement layer and the steel matrix are related to reaction *** 1,100℃,these defects are *** mostly occurs in the NbC reinforced layer of the composites,and the fracture mode is characterized by typical intergranular brittle fracture.

关键词： in-situ reaction NbC reinforcement layer microstructure mechanical property

Extraction of vanadium from vanadium slag by high pressure oxidative acid leaching

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 21-26页

作者： Guo-quan Zhang Ting-an Zhang Guo-zhi Lü Ying Zhang Yan Liu zhuo-lin Liu Key Laboratory of Ecological Utilization of Multi-Metal Intergrown Ores of the Ministry of Education School of Materials and MetallurgyNortheastern University

To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vana-dium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L^-1, a leaching tem-perature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10：1 mL·g^-1, and oxygen pressure at 0.2 MPa, the leaching rate of vana-dium reaches 97.69%.

关键词： extraction vanadium slag pressure leaching sulfuric acid mineralogy