检索结果-内蒙古大学图书馆

Characterization of a smart pH-cleavable PEG polymer towards the development of dual pH-sensitive liposomes

INTERNATIONAL JOURNAL OF PHARMACEUTICS 2018年第1期548卷 288-296页

作者： Kanamala, Manju Palmer, Brian D. Wilson, William R. Wu, Zimei Univ Auckland Fac Med & Hlth Sci Sch Pharm Auckland 1142 New Zealand Univ Auckland Fac Med & Hlth Sci Auckland Canc Soc Res Ctr Auckland 1142 New Zealand

To facilitate the development of PEG-cleavable pH-sensitive liposomes (CL-pPSL), this study aimed to fully characterize a new pH-sensitive polymer, PEG(B)-Hz-CHEMS. Polyethylene glycol (PEG) functionalised with 4-carboxybenzaldehyde (PEG(B)) was linked to cholesteryl hemisuccinate (CHEMS) via an acid labile hydrazide-hydrazone hybrid bond (-CO-NH-N=CH-) to form PEG(B)-Hz-CHEMS. The polymer was post-inserted into DOPE/CHEMS liposomes to form CL-pPSL. A validated stability-indicating HPLC-UV method was developed with the aid of multiple linear regression for the mobile phase. The assay was used to evaluate the pH-sensitivity, pathways of cleavage of the polymer and the PEGylation degree of CL-pPSL. The pH-sensitivity of CL-pPSL was compared with conventional PEGylated pH-sensitive (pPSL) using a calcein leakage assay. At 37 degrees C, PEG(B)-Hz-CHEMS was relatively stable at pH 7.4 with a half-life of 24 h. In comparison, at pH 5.5 and pH 6.5 PEG detachment within 1 h was determined as 80%, and 50%, respectively. PEG detachment of the polymer was through simultaneous cleavage of the hydrazine (CO-N) and hydrazone (N=C) bonds, depending on pH, thus the polymer is more pH-sensitive than those with a hydrazine bond only. The grafting densities of PEG(B)-HzCHEMS on CL-pPSL were optimised to achieve a PEG density of 1.7% (mol). The unilamellar CL-pPSL (123 nm) were shown to be sable at least for 3 months at 4 degrees C and have enhanced pH-sensitivity compared with pPSL in the calcein leakage assay. Therefore, the smart cleavable PEG polymer is promising in liposome formulation to overcome the PEG dilemma.

关键词： Cleavable PEG Stability-indicating HPLC method Hydrazide-hydrazone multiple linear regression model PEG detachment pathway Dual pH-sensitive liposomes

来源：评论

学校读者我要写书评

暂无评论

Evaluation of Contribution of PV Array and Inverter Configurations to Rooftop PV System Energy Yield Using Machine Learning Techniques

引用

ENERGIES 2019年第16期12卷 3158页

作者： Ngoc Thien Le Benjapolakul, Watit Chulalongkorn Univ Fac Engn Dept Elect Engn Bangkok 10330 Thailand Univ Architecture Ho Chi Minh City Dept Urban Engn Ho Chi Minh City 72407 Vietnam

Rooftop photovoltaics (PV) systems are attracting residential customers due to their renewable energy contribution to houses and to green cities. However, customers also need a comprehensive understanding of system design configuration and the related energy return from the system in order to support their PV investment. In this study, the rooftop PV systems from many high-volume installed PV systems countries and regions were collected to evaluate the lifetime energy yield of these systems based on machine learning techniques. Then, we obtained an association between the lifetime energy yield and technical configuration details of PV such as rated solar panel power, number of panels, rated inverter power, and number of inverters. Our findings reveal that the variability of PV lifetime energy is partly explained by the difference in PV system configuration. Indeed, our machine learning model can explain approximately confidence interval: 29-38%) of the variant energy efficiency of the PV system, given the configuration and components of the PV system. Our study has contributed useful knowledge to support the planning and design of a rooftop PV system such as PV financial modeling and PV investment decision.

关键词： lifetime energy yield bootstrap confidence interval multiple linear regression model

来源：评论

学校读者我要写书评

暂无评论

The Relative Importance of Spatial Scale Variables for Explaning Macroinvertebrate Richness in Different Aquatic Ecological Function Regions

引用

WATER 2019年第8期11卷 1550页

作者： Zhang, Yuan Jia, Xiaobo Lin, Jianing Qian, Chang Gao, Xin Ding, Sen Chinese Res Inst Environm Sci State Key Lab Environm Criteria & Risk Assessment Beijing 100012 Peoples R China Chinese Res Inst Environm Sci Lab Riverine Ecol Conservat & Technol Beijing 100012 Peoples R China

Identifying the key drivers of aquatic fauna structuring at multiple spatial scales is critical in reducing biodiversity loss. Macroinvertebrates are the most sensitive indicators of disturbance and they are used as a cost-effective tool for bioassessment at catchment and site scales. The focus of our study was to identify the key drivers from three classes of environmental variables (geophysical landscape, land use, and site habitat) that influence macroinvertebrate richness in different aquatic ecological function regions (AEFRs) of the Liaohe River Basin. We sampled macroinvertebrate assemblages, extracted geophysical and climate variables from geospatial data, and quantified physical and chemical habitats from 407 randomly distributed sites that belong to the three level-I AEFRs. We analyzed our data through multiple linear regression models by using the three classes of predicted variables alone and in combination. The models that were constructed in the first level-I AEFR explained similar amounts of macroinvertebrate richness and had the maximum ability to explain how macroinvertebrate richness distributed (denoted explaining ability;geophysical landscape: R-GL(2) approximate to 60%, land use and site habitat: R-LU(2) and R-SH(2) approximate to 50%, and combined: R-CB(2) approximate to 75%). The explaining abilities for the third level-I AEFR were as follows: R-GL(2) approximate to 11%, R-LU(2) approximate to 14%, R-SH(2) approximate to 25%, and R-CB(2) approximate to 38%. The explaining abilities for the 4th level-I AEFR were as follows: R-GL(2) approximate to 30%, R-LU(2) approximate to 7%, R-SH(2) approximate to 40%, and R-CB(2) approximate to 55%. We conclude that: (1) all of the combined models explained more interaction as compared with the single models;(2) the environmental variables differed among different level-I AEFRs;and, (3) variables in the site habitat scale were the most robust explainers when analyzing the relationship between environmental

关键词： geophysical landscape land use habitat quality aquatic ecological function region (AEFR) anthropogenic disturbances biodiversity macroinvertebrate richness multiple linear regression model variance partitioning

来源：评论

学校读者我要写书评

暂无评论

Research on Estimation Method of Surface Soil Moisture Content Based on Multi-Star Fusion

Research on Estimation Method of Surface Soil Moisture Conte...

引用

第十届中国卫星导航年会

作者： Huasheng Huang Yueji Liang Mingli Yuan Yifan Qiu He Huang Chao Ren College of Geomatics and Geoinformation Guilin University of Technology Research Center of Precise Engineering Surveying Guangxi Key Laboratory of Spatial Information and Geomatics College of Geomatics and Geoinformation Guilin University of Technology

Global Positioning System Interferometric Reflectance(GPS-IR) is a new remote sensing technique, which can be used to estimate soil moisture content near the surface. From the view of multi-satellite fusion, an estimating method of surface soil water content based on multi-satellite fusion is proposed. Firstly, the direct and reflected signals of multiple satellites are separated by low order polynomial fitting, and then the sinusoidal fitting model of the reflected signals is established to obtain the relative delay phase. Secondly, the multiple linear regression inversion model of soil moisture is established, and the input variable set of the model is determined by the correlation coefficient of each satellite. Finally, the advantage of multi-satellite fusion is brought into full play to retrieve soil moisture. The feasibility and effectiveness of single satellite and multiple satellite fusion inversion are compared and analyzed through the monitoring data provided by the Plate Boundary Observation(PBO). The experimental results show that the multiple linear regression model can realize the effective fusion of multiple satellites. Compared with the single satellite, the inversion accuracy is higher and the inversion error is more stable.

关键词： GPS-IR soil moisture multi-satellite fusion multiple linear regression model

来源：评论

学校读者我要写书评

暂无评论

Temperature prediction of molten iron transporting process based on extended Kalman filter 37

Temperature prediction of molten iron transporting process b...

引用

37th Chinese Control Conference (CCC)

作者： Song, Dongying Yang, Yang Northeastern Univ Liaoning Engn Lab Operat Analyt & Optimizat Smart Shenyang Liaoning Peoples R China Northeastern Univ Inst Ind & Syst Engn Shenyang 110819 Peoples R China

ISBN: (纸本)9789881563958

Molten iron transportation is implemented by torpedo cars controlled by computer-based algorithms, and the process is accompanied by high energy loss, thus it forms a molten iron transportation cyber physical energy system (MIT-CPES). This paper interests in temperature prediction of molten iron transporting process (MITP) derived from MIT-CPES. where the temperature measuring devices locates at the physical layer. historical data of temperature of molten iron, information of torpedo car and weather information are abstracted from information layer. To solve the problem. a nonlinear system model is constructed based on heat transfer mechanism, to describe torpedo car transportation from reladling station (RS) to blast furnace (BF) with residual molten iron. The proposed model is more consistent with the actual production. Moreover, a filter model is also formulated based on extended Kalman filter, in order to predict temperature during the molten iron transporting process. The process data used in the filter model are produced by a multiple linear regression model based actual production data. Numerical results show that the proposed method is superior to traditional mechanism model and beneficial to energy-saying measures in molten iron transporting process.

关键词： Temperature prediction molten iron transporting process extended Kalman filter multiple linear regression model

来源：评论

学校读者我要写书评

暂无评论

Analysis of Onion Marketing: The Case of Kobo District, North Wollo Zone, Amhara National Regional State, Ethiopia

Analysis of Onion Marketing: The Case of Kobo District, Nort...

引用

作者： Maru Zinabie Aragie Haramaya University

学位级别：硕士

The study attempted to examine onion marketing in Kobo District of Amhara National Regional State with specific objectives of analyzing the structure-conduct-performance of onion market, the determinants of onion marketed surplus and the spatial market integration between the district market and other destination markets (Mekele, Dessie and Bahir Dar). Both primary and secondary data were used for this study. Multistage sampling procedure was employed to select sample onion producers while traders were selected on census and purposive way. Primary data for this study were collected from 156 onion producer farmers and 54 onion traders using pre-tested structured questionnaire. Secondary data were collected from the office of district Agriculture and Rural Development, Kobo Girana Valley Development Program office and Central Statistical Agency. Both descriptive and econometric analysis were used in data analysis. In the structure conduct analysis, Concentration ratio of top four firm for onion wholesalers of 50%, shows district level onion wholesale market was concentrated and exhibit oligopolistic market. Onion Price setting in the district was dominated by traders and the total gross margin was higher in channels where the onion marketing channel is relative long due to the inclusion of rural and urban assemblers. The multiple linear regression model result revealed that seven variables land allocated for onion, family labor, experience in onion production, credit use, and education level of household head, frequency of extension visits and cooperative membership significantly and positively affected onion marketed surplus while the distance to the nearest market significantly and negatively affected it. In the analysis of spatial market integration, results of Vector Error Correction model revealed that in Kobo-Mekele, Kobo-Dessie and Kobo-Bahir Dar market pairs, following a shock that creates any disequilibrium between each market pairs, Kobo adjusts by 27.2%, 34

关键词： Market integration Vector error correction model multiple linear regression model

来源：评论

学校读者我要写书评

暂无评论

Effects of land use and topography on spatial variety of soil organic carbon density in a hilly, subtropical catchment of China

引用

SOIL RESEARCH 2017年第2期55卷 134-144页

作者： Liu, Huanyao Zhou, Jiaogen Feng, Qingyu Li, Yuyuan Li, Yong Wu, Jinshui Chinese Acad Sci Changsha Res Stn Agr & Environm Monitoring Inst Subtrop Agr 644Yunda 2nd Rd Changsha 410125 Hunan Peoples R China Univ Chinese Acad Sci Yuquan Rd Beijing 100049 Peoples R China Purdue Univ Agr & Biol Engn 225 South Univ St W Lafayette IN 47907 USA

A good understanding the effects of environmental factors on the spatial variety of soil organic carbon density (SOCD) helps achieve a relatively accurate estimation of the soil organic carbon stock of terrestrial ecosystems. The present study analysed the SOCD of 1033 top soil samples (0-20cm) from the Jinjing catchment located in subtropical China. Spatial variability of SOCD was estimated using a geostatistics method and a geographically weighted regression (GWR) model, and the major environmental factors affecting SOCD were also explored. In the present study, SOCD had a moderate spatial dependence and the best-fitting model was exponential with a nugget-to-sill ratio of 60.72% and a range of 182m. Land use types (woodlands, paddy fields and tea fields) and topography (elevation, slope, topographic wetness index (TWI)) affected the spatial variation of SOCD. Mean SOCD in the paddy fields was higher than in woodland and tea fields (3.50 vs 3.24 and 2.81kgCm(-2) respectively;P<0.05). In addition, SOCD was generally higher in the valleys of paddy fields (with low slope and high TWI) and the hills of woodland (with high elevation and increased slope). GWR generated the spatial distribution of SOCD more accurately than ordinary kriging, inverse distance weighted, multiple linear regression model, and linear mixed-effects model. The results of the present study could enhance our understanding of the effects of land use and topography on SOCD, and improve the accuracy in predicting SOCD by GWR in small catchments of complex land use and topography.

关键词： environmental factors geographically weighted regression inverse distance weighted linear mixed-effects model multiple linear regression model ordinary kriging spatial distribution spatial variation

来源：评论

学校读者我要写书评

暂无评论

An empirical model for prediction of household solid waste generation rate - A case study of Dhanbad, India

引用

WASTE MANAGEMENT 2017年 68卷 3-15页

作者： Kumar, Atul Samadder, S. R. Indian Sch Mines Indian Inst Technol Dept Environm Sci & Engn Dhanbad 826004 Bihar India

Accurate prediction of the quantity of household solid waste generation is very much essential for effective management of municipal solid waste (MSW). In actual practice, modelling methods are often found useful for precise prediction of MSW generation rate. In this study, two models have been proposed that established the relationships between the household solid waste generation rate and the socioeconomic parameters, such as household size, total family income, education, occupation and fuel used in the kitchen. multiple linear regression technique was applied to develop the two models, one for the prediction of biodegradable MSW generation rate and the other for non-biodegradable MSW generation rate for individual households of the city Dhanbad, India. The results of the two models showed that the coefficient of determinations (R-2) were 0.782 for biodegradable waste generation rate and 0.676 for non biodegradable waste generation rate using the selected independent variables. The accuracy tests of the developed models showed convincing results, as the predicted values were very close to the observed values. Validation of the developed models with a new set of data indicated a good fit for actual prediction purpose with predicted R-2 values of 0.76 and 0.64 for biodegradable and non-biodegradable MSW generation rate respectively. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Biodegradable waste multiple linear regression model Solid waste generation rate Non-biodegradable waste Prediction SPSS

来源：评论

学校读者我要写书评

暂无评论

Carbonyl compounds at Mount Tai in the North China Plain: Characteristics, sources, and effects on ozone formation

引用

ATMOSPHERIC RESEARCH 2017年第Nov.期196卷 53-61页

作者： Yang, Xue Xue, Likun Yao, Lan Li, Qinyi Wen, Liang Zhu, Yanhong Chen, Tianshu Wang, Xinfeng Yang, Lingxiao Wang, Tao Lee, Shuncheng Chen, Jianmin Wang, Wenxing Shandong Univ Environm Res Inst Jinan 250100 Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hong Kong Hong Kong Peoples R China Shandong Univ Sch Environm Sci & Engn Jinan 250100 Peoples R China Fudan Univ Dept Environm Sci & Engn Fudan Tyndall Ctr Shanghai Key Lab Atmospher Particle Pollut & Prev Shanghai 200433 Peoples R China

Carbonyl compounds, an important category of volatile organic compounds (VOCs), play important roles in ozone (O-3) formation and atmospheric chemistry. To better understand the characteristics and sources of carbonyl compounds and their effects on 03 formation, C-1-C-8 carbonyls were measured at Mount Tai, the highest mountain in the North China Plain (NCP), in summer 2014. Acetone (3.57 +/- 0.55 ppbv), formaldehyde (3.48 +/- 0.98 ppbv) and acetaldehyde (1.27 +/- 0.78 ppbv) are the three most abundant species, comprising as high as 90% of the total observed compounds. Isovaleraldehyde (0.37 +/- 0.17 ppbv) presents another important carbonyl compound despite its high reactivity. Comparison with the observations available in China highlights the serious situation of carbonyls pollution in the NCP region. The sources of carbonyls are dominated by photo oxidation of VOCs during the daytime and regional transport at night. Secondary sources from oxidation of hydrocarbons contribute on average 44% of formaldehyde, 31% of acetone, 85% of acetaldehyde, 78% of benzaldehyde, and 84% of isovaleraldehyde, demonstrating the dominant role of secondary formation in the ambient carbonyl levels. Formaldehyde, acetaldehyde and isovaleraldehyde are the most important contributors to the OH reactivity and O-3 production among the measured carbonyls. This study shows that carbonyl compounds contribute significantly to the photochemical pollution in the NCP region and hence understanding their sources and characteristics is essential for developing the science-based O-3 pollution control strategies.

关键词： Carbonyls Secondary formation Regional transport OH reactivity Ozone formation multiple linear regression model

来源：评论

学校读者我要写书评

暂无评论

Analysis of influential factors on heat accumulation in structural elements of road underpasses

引用

SOLAR ENERGY 2017年第Oct.期155卷 25-34页

作者： Androjic, Ivica Marovic, Ivan Univ Rijeka Fac Civil Engn Rijeka 51000 Croatia Asphalt Design Doo Osijek 31220 Croatia

This study shows the results of field tests on heat accumulation in asphalt surfaces and concrete curbs on two road underpasses in Osijek, Republic of Croatia. The tests were conducted in 9 daytime periods over several months in 2014. The MLR model (multiple linear regression model) was made using measurements from 36 hourly periods and the model was tested in 9 hourly periods chosen at random from the overall data. The conducted research showed that by using the MLR models it was possible to successfully predict heat accumulation in the asphalt surfaces and concrete curbs of the underpasses using varying air temperature and humidity. Finally, a schematic view is shown of critical points in road underpasses in the event of the possible occurrences of slippery road surfaces, freezing road surfaces, plastic deformation of asphalt surfaces and any possible health hazards for pedestrians in the event of great temperature differences between road surfaces. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Temperature Road underpasses multiple linear regression model Asphalt surfaces Concrete curbs

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：