检索结果-南通市图书馆

Study of Zero-Inflated Regression Models in a Large-Scale Population Survey of Sub-Health Status and Its Influencing Factors

引用

Chinese Medical Sciences Journal 2017年第4期32卷 218-225页

作者： Tao Xu guangjin zhu Shaomei Han Department of Epidemiology and Statistics Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & School of Basic Medicine Peking Union Medical College Beijing 100005 China Department of physiopathology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & School of Basic Medicine Peking Union Medical College Beijing 100005 China

Objective Sub-health status has progressively gained more attention from both medical professionals and the publics. Treating the number of sub-health symptoms as count data rather than dichotomous data helps to completely and accurately analyze findings in sub-healthy population. This study aims to compare the goodness of fit for count outcome models to identify the optimum model for sub-health study.Methods The sample of the study derived from a large-scale population survey on physiological and psychological constants from 2007 to 2011 in 4 provinces and 2 autonomous regions in China. We constructed four count outcome models using SAS: Poisson model, negative binomial (NB) model, zero-inflated Poisson (ZIP) model and zero-inflated negative binomial (ZINB) model. The number of sub-health symptoms was used as the main outcome measure. The alpha dispersion parameter and O test were used to identify over-dispersed data, and Vuong test was used to evaluate the excessive zero count. The goodness of fit of regression models were determined by predictive probability curves and statistics of likelihood ratio test.Results Of all 78 307 respondents, 38.53% reported no sub-health symptoms. The mean number of sub-health symptoms was 2.98, and the standard deviation was 3.72. The statistic O in over-dispersion test was 720.995 (P<0.001); the estimated alpha was 0.618 (95% CI: 0.600-0.636) comparing ZINB model and ZIP model; Vuong test statistic Z was 45.487. These results indicated over-dispersion of the data and excessive zero counts in this sub-health study. ZINB model had the largest log likelihood (-167 519), the smallest Akaike’s Information Criterion coefficient (335 112) and the smallest Bayesian information criterion coefficient (335455),indicating its best goodness of fit. The predictive probabilities for most counts in ZINB model fitted the observed counts best. The logit section of ZINB model analysis showed that age, sex, occupation, smoking, alcohol drinking, ethnicity and obesity were determinants for presence

关键词： zero-inflated negative binomial regression sub-health population survey

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

金华数字化改革:理论模型、经验成效与问题改进

引用

经济研究导刊 2024年第7期 81-84页

作者：吕光金朱国华上海财经大学浙江学院教育技术中心浙江金华321013 上海财经大学浙江学院马克思主义研究中心浙江金华321013

在数字中国和数字浙江建设的大背景下,金华正在扎实推进数字化改革,并形成了一批具有金华辨识度的标志性成果与最佳应用,真正实现了让政府更有为、社会治理更高效,让群众更有幸福感与获得感。但是在总结数字化改革成效、方法与督查考核... 详细信息

在数字中国和数字浙江建设的大背景下,金华正在扎实推进数字化改革,并形成了一批具有金华辨识度的标志性成果与最佳应用,真正实现了让政府更有为、社会治理更高效,让群众更有幸福感与获得感。但是在总结数字化改革成效、方法与督查考核时,发现存在一些问题,针对这些问题提出推进与深化数字化改革的对策建议,以期为金华及其他地区的数字化改革提供参考和实践借鉴。

关键词：金华数字化改革实践成效问题对策建议

来源：

维普期刊数据库

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

缝合线中有机质来源、流体运移以及地质意义

引用

沉积学报 2024年第2期42卷 661-674页

作者：朱康乐高岗刘诗局王成云程光瑾胡丹丹中国石油大学(北京)地球科学学院北京102249 中国石油大学(北京)油气资源与探测国家重点实验室北京102249 华北油田分公司勘探开发研究院河北任丘062552 玉门油田勘探开发研究院甘肃酒泉735000

【目的】缝合线作为碳酸盐岩的典型结构,其形成对于碳酸盐岩本身有机质的富集和流体运移具有重要的意义。然而,缝合线中有机质的来源和流体运移的机理目前尚未深入研究。【方法】以四川盆地东部大池干构造带含缝合线的碳酸盐岩岩心样品... 详细信息

【目的】缝合线作为碳酸盐岩的典型结构,其形成对于碳酸盐岩本身有机质的富集和流体运移具有重要的意义。然而,缝合线中有机质的来源和流体运移的机理目前尚未深入研究。【方法】以四川盆地东部大池干构造带含缝合线的碳酸盐岩岩心样品为研究对象,分别对岩心中缝合线和基质进行了有机碳、热解(Rock-Eval)、岩石薄片、荧光薄片、全岩X射线衍射、碳氧同位素以及扫描电镜等分析测试。【结果与结论】缝合线中的有机质主要以可溶有机质、焦沥青和沥青的形式赋存,表明缝合线中的有机质主要为运移而来的次生有机质。且缝合线中的次生白云石和黄铁矿发育,且保留了矿物的晶间孔隙和裂缝,为油气的聚集和运移提供了良好的条件。此外,沿缝合线方向存在明显的油气分馏效应,且在缝合线较薄的区域分馏效应越明显。综合分析认为,缝合线与基质接触界面上的强烈胶结作用及其附近次生矿物的形成是造成烃类流体从基质向缝合线运移时分馏效应的原因。当缝合线发育时,缝合线中的有机质会在高演化阶段裂解形成天然气,与其他成因的天然气混合时会影响天然气来源判别;缝合线作为原油的运移通道时,对原油造成的分馏效应也会对原油来源的判别造成一定困扰,因此应该选择合适的生物标志化合物对比参数来分析油源关系,同时原油性质的空间变化规律也应该被考虑。

关键词：碳酸盐岩缝合线有机质沥青黄铁矿

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

High efficient development of green kinetic hydrate inhibitors via combined molecular dynamic simulation and experimental test approach

引用

Green Chemical Engineering 2022年第1期3卷 34-43页

作者： Liwei Cheng Jinlong Cui Jia Li Ran zhu Bei Liu Shuai Ban guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China

The development of environmental friendly low dose hydrate inhibitors like kinetic hydrate inhibitors(KHIs)is of great significance for the flow assurance in oil&gas production and transportation.In this work,a combined molecular dynamic simulation and experimental verification approach was adopted to increase the efficiency of KHIs development.The inhibition effect of a series of copolymers(N-vinylpyrrolidone and N-acrylate)on hydrate growth was studied by using both molecular dynamics simulation and experimental approaches.The simulation results demonstrated that introduction of hydrophobic ester and butyl group in PVP is beneficial for the inhibition.The length of the alkyl chain of ester group played an important role in improving inhibition performance.PVP-A,the one being introduced butyl ester group into PVP gets the best inhibition effect.In addition,inhibitors can restrict methane bubbles to re-dissolve into the liquid phase,thereby inhibiting the growth of methane hydrate.Increasing the interaction between KHIs and methane can also improve the inhibitory effect of KHIs.The experimental results confirm the reliability of the molecular dynamics simulation.

关键词： Hydrate Molecular dynamics Hydrate inhibition Kinetic hydrate inhibitors

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

高温煤气化水离子交换除硬技术研究

引用

当代化工 2024年第2期53卷 288-293页

作者：朱光锦王鹏王雪清刘娅郭宏山中石化(大连)石油化工研究院有限公司工业废水无害化与资源化国家工程研究中心辽宁大连116045

为解决传统煤气化水加药沉淀法除硬处理深度不足、动设备结垢、加药量大、成本高、能量损失大等问题,采用离子交换法对高温煤气化水除硬,考察不同种类离子交换树脂对高温煤气化水的除硬效果。结果表明:T42型离子交换树脂除硬效果最佳,... 详细信息

为解决传统煤气化水加药沉淀法除硬处理深度不足、动设备结垢、加药量大、成本高、能量损失大等问题,采用离子交换法对高温煤气化水除硬,考察不同种类离子交换树脂对高温煤气化水的除硬效果。结果表明:T42型离子交换树脂除硬效果最佳,再生条件温和;固定床吸附实验表明,高温煤气化水经树脂除硬后,硬度去除率可达99%以上,穿透点可达110 BV以上,树脂经6次吸附-再生循环后除硬性能无明显下降。

关键词：煤气化水除硬吸附离子交换树脂

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

Oxygen and hydrogen peroxide self-supplying magnetic nanoenzymes for cancer therapy through magneto-mechanical force,force-induced reactive oxygen species,chemodynamic effects,and cytotoxicity of Ca^(2+) ions

引用

Nano Research 2023年第5期16卷 7134-7147页

作者： Jie Liu Wenxuan Yang Yuqiao Huang Ji Li Chunjiao zhu guangjin Pu Bo Wang Xin Gui Maoquan Chu Research Center for Translational Medicine at Shanghai East Hospital School of Life Sciences and TechnologyTongji UniversityShanghai 200092China Institute of Biophysics Chinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China

The use of magneto-mechanical force to kill cancer cells has attracted significant attention in recent years.However,many reports have focused on in vitro experiments with a single treatment.Herein,CaO_(2)-coated Fe_(3)O_(4)core–shell magnetic nanoenzymes(Fe_(3)O_(4)/CaO_(2))are developed for low frequency vibrating magnetic field(VMF)-induced multimodal cancer therapy.Fe_(3)O_(4)/CaO_(2)are shown to efficiently generate O_(2),H_(2)O_(2),·OH through hydrolysis of CaO_(2)and a CaO_(2)-strengthened Fenton reaction,killing laryngeal carcinoma cells and inhibiting mouse tumor growth(chemodynamic therapy(CDT)).Both Fe_(3)O_(4)and Fe_(3)O_(4)/CaO_(2)triggered by a VMF are shown to damage the cytoskeleton of cancer cells through magneto-mechanical force(maxima:223 piconewtons or larger by Fe_(3)O_(4)/CaO_(2)aggregations)and induce the generation of intracellular reactive oxygen species(ROS),the VMF-triggered Fe_(3)O_(4)/CaO_(2)is shown to generate additional intracellular ROS.Upon exposure to a VMF,the cell killing efficiency and tumor growth inhibition were further significantly improved by Fe_(3)O_(4)/CaO_(2)through CDT,magnetomechanical force,force-induced ROS,the cytotoxicity of Ca^(2+)ions.In addition,the Fe_(3)O_(4)/CaO_(2)nanoenzymes and VMFinduced treatment are shown to be safe for mice.The results of this study open the door for treating solid tumors without inducing multidrug resistance through the combination of CDT and force.

关键词： CaO_(2)-coated Fe_(3)O_(4)nanoenzymes magneto-mechanical force reactive oxygen species chemodynamic effect cancer therapy

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

Synthesis and evaluation of poly(N-vinyl caprolactam)-co-tert-butyl acrylate as kinetic hydrate inhibitor

引用

Chinese Journal of Chemical Engineering 2022年第10期50卷 317-325页

作者： Xing Huang Ran zhu Liwei Cheng Yijian zhu Peng Xiao Xiaohui Wang Bei Liu Changyu Sun Weixin Pang Qingping Li guangjin Chen Xinjing Xu Jinfeng Ji State Key Laboratory of Natural Gas Hydrates/College of Chemical Engineering and Environment China University of PetroleumBeijing 102249China State Key Laboratory of Natural Gas Hydrate CNOOCBeijing 100010China College of Chemistry and Chemical Engineering Neijiang Normal UniversityNeijiang 641100China Faculty of Engineering China University of GeosciencesWuhan 430074China Hainan Longpan Oilfield Technology Co. LtdHainan 571900China

Low dosage kinetic hydrate inhibitors(KHIs)are a kind of alternative chemical additives to high dosage thermodynamic inhibitors for preventing gas hydrate formation in oil&gas production wells and transportation pipelines.In this paper,a new KHI,poly(N-vinyl caprolactam)-co-tert-butyl acrylate(PVCapco-TBA),was successfully synthesized with N-vinyl caprolactam(NVCap)and tert-butyl acrylate.The kinetic inhibition performances of PVCap-co-TBA on the formations of both structureⅠmethane hydrate and structureⅡnatural gas hydrate were investigated by measuring the onset times of hydrate formation under different conditions and compared with commercial KHIs such as PVP,PVCap and inhibex 501.The results indicated that PVCap-co-TBA outperformed these widely applied inhibitors for both structureⅠand structureⅡhydrates.At the same dosage of KHI,the maximum tolerable degree of subcooling under which the onset time of hydrate formation exceeded 24 hours for structureⅠhydrate was much lower than that for structureⅡhydrate.The inhibition strength increased with the increasing dosage of PVCap-co-TBA;The maximum tolerable degree of subcooling for the natural gas hydrate is more than10 K when the dosage was higher than 0.5%(mass)while it achieved 12 K when that dosage rose to0.75%(mass).Additionally,we found polypropylene glycol could be used as synergist at the dosage of 1.0%(mass)or so,under which the kinetic inhibition performance of PVCap-co-TBA could be improved significantly.All evaluation results demonstrated that PVCap-co-TBA was a very promising KHI and a competitive alternative to the existing commercial KHIs.

关键词： Hydrate Kinetics Inhibitor Poly(N-vinyl aprolactam)–co-tert-butyl acrylate Synergist Synthesis

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

气冷搅拌棒流变压铸在高强高导铝合金中的应用

引用

特种铸造及有色合金 2024年第3期44卷 289-293页

作者：祁明凡朱国明康永林王继成张莹李谷南张光金北京科技大学材料科学与工程学院北京100083 珠海市润星泰电器有限公司珠海519099 山东德泰机械制造集团有限公司青岛266599

开发了一种高效、低成本的铝合金均匀凝固控制制备大体积半固态浆料工艺——气冷搅拌棒工艺(Air-cooled stirring rod process,ACSR),将该制浆工艺与压铸机衔接形成多条一体化智能流变压铸生产线进行铝合金大型薄壁件流变压铸高效制备... 详细信息

开发了一种高效、低成本的铝合金均匀凝固控制制备大体积半固态浆料工艺——气冷搅拌棒工艺(Air-cooled stirring rod process,ACSR),将该制浆工艺与压铸机衔接形成多条一体化智能流变压铸生产线进行铝合金大型薄壁件流变压铸高效制备。目前,ACSR工艺可实现在30 s内制备出40 kg固相率为25%~35%的大体积半固态浆料。该流变压铸工艺已在新能源汽车、5G通信等高品质铝合金大型薄壁件的制备领域得到产业化应用,制备的典型产品包括5G通信用散热壳体、滤波器壳体、天线机箱与新能源汽车用三电结构壳体、端盖、ABS系统阀体等。与传统压铸件相比,新工艺制备的铝合金铸件显微组织细小圆整、表面品质好、内部气孔少,且具有更为优异的力学性能和导热系数。

关键词：铝合金均匀凝固控制半固态浆料流变压铸

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

A large-scale experimental study on CO_(2) capture utilizing slurry-based ab-adsorption approach

引用

Chinese Journal of Chemical Engineering 2021年第3期34卷 56-66页

作者： Shuren Yan Peng Xiao Ding zhu Hai Li guangjin Chen Bei Liu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China

The increasing concentration of CO_(2) in atmosphere is deemed the main reason of global warming.Therefore,efficiently capturing CO_(2) from various sources with energy conservation is of great significance.Herein,a series of experiments were carried out to successfully test the slurry-based ab-adsorption method for continuously capturing CO_(2) in the large-scale cycled separation unit with cost-effect taking into account the scale-up criteria.A bubble column(with height 4900 mm and inner diameter 376 mm)and a desorption tank(with volume 310 L)are the essential components of the separation unit.The novel slurry used in this study was formed with zeolitic imidazolate framework-8 and 2-methylimidazole-water solution.The influence of operation conditions was investigated systematically.The results show that increasing sorption pressure and slurry height level,decreasing gas volume flow and sorption temperature are beneficial for separation processes.The volume fraction of CO_(2) in the feed gas was also studied.Although the scale-up effect had been observed and it was found that it exerted a negative effect on CO_(2) capture,depending on experimental conditions,CO_(2) removal efficiency could still reach 85%-95%and the maximum CO_(2) loading in the recycled slurry could be up to0.007 mol·L-1·kPa-1.Furthermore,the slurry-based method could be operated well even under very moderate regeneration conditions(333 K and 0.05 MPa),which means that the novel approach shows greater energy conservation than traditional amine absorption methods.

关键词： CO_(2)capture Zeolitic imidazolate framework-8 Slurry Bubble column Scale-up

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

Differences in Heart Stroke Volume between Han and Korean-Chinese Nationalities and Correlative Factors

引用

Biomedical and Environmental Sciences 2011年第3期24卷 249-254页

作者： PAN YangXing QI BaoShen ZHOU XiaoMei HAN ShaoMei ZHANG Xue ZHANG ZhengGuo zhu guangjin Department of Physiology and Pathophysiology Department of Epidemiology and Statistics Department of Biomedical Engineering Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic Medicine Peking Union Medical College Beijing 100005 China

Objective To compare the differences in stroke volume （SV） and stroke volume index （Sl） between Han and Korean-Chinese and to investigate the correlated risk factors. Methods A total of 1 647 Han and 876 Korean-Chinese aged 10-80 years were investigated. SV, SI, cardiac output, cardiac output index, heart rate （HR）, systemic vascular resistance （SVR）, systemic vascular resistance index （SVRI）, and blood pressure were measured. Results SV/SI values in Korean-Chinese were lower than those in the Han of the same sex and age. Covariance analysis showed that, apart from the effect of sex, age and body mass index （BMI）, the differences in SV and SI between the two cohorts were still significant （P〈O.O01）. Multiple regression analysis revealed that the SV difference between the two ethnicities was affected （in descending order from a strong to weak correlation） by SVR, SVRI, HR, diastolic blood pressure, mean arterial pressure, BMI, and systolic blood pressure, while the SI difference was affected by SVR, SVRI, HR, mean arterial pressure, diastolic and systolic blood pressure, and BMI. Conclusion The Fact that SV and SI in Korean-Chinese are lower than those in Han is related with higher SVR, HR and blood pressure in the Korean-Chinese.

关键词： Heart stroke volume Heart stroke volume index Systemic vascular resistance Bloodpressure Korean-Chinese Han

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：