期刊文献+
共找到18篇文章
< 1 >
每页显示 20 50 100
GP‐FMLNet:A feature matrix learning network enhanced by glyph and phonetic information for Chinese sentiment analysis
1
作者 Jing Li Dezheng Zhang +2 位作者 Yonghong Xie Aziguli Wulamu Yao Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第4期960-972,共13页
Sentiment analysis is a fine‐grained analysis task that aims to identify the sentiment polarity of a specified sentence.Existing methods in Chinese sentiment analysis tasks only consider sentiment features from a sin... Sentiment analysis is a fine‐grained analysis task that aims to identify the sentiment polarity of a specified sentence.Existing methods in Chinese sentiment analysis tasks only consider sentiment features from a single pole and scale and thus cannot fully exploit and utilise sentiment feature information,making their performance less than ideal.To resolve the problem,the authors propose a new method,GP‐FMLNet,that integrates both glyph and phonetic information and design a novel feature matrix learning process for phonetic features with which to model words that have the same pinyin information but different glyph information.Our method solves the problem of misspelling words influencing sentiment polarity prediction results.Specifically,the authors iteratively mine character,glyph,and pinyin features from the input comments sentences.Then,the authors use soft attention and matrix compound modules to model the phonetic features,which empowers their model to keep on zeroing in on the dynamic‐setting words in various positions and to dispense with the impacts of the deceptive‐setting ones.Ex-periments on six public datasets prove that the proposed model fully utilises the glyph and phonetic information and improves on the performance of existing Chinese senti-ment analysis algorithms. 展开更多
关键词 aspect‐level sentiment analysis deep learning feature extraction glyph and phonetic feature matrix compound learning
下载PDF
Determination of Harmful Elements and Analysis of Pollution Level in Lysimachia christinae
2
作者 Li WAN Ya GUO +2 位作者 Qin XIANG Qi XIAO Wenwu YANG 《Medicinal Plant》 CAS 2022年第5期31-33,共3页
[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass... [Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae. 展开更多
关键词 Lysimachia christinae Heavy metals elements Harmful elements ICP-MS Microwave digestion Single factor index method Comprehensive index method Pollution level analysis Quality control
下载PDF
Analysis of the Phenotype and the Restriction Enzyme Mapping Level of Mutations Induced by the New Mutagen Glycidyl Methacrylate 被引量:5
3
作者 XIE DA-YING GAO HUI-LAN +4 位作者 ZUO JIN ZHANG WEI LI ZHONG-SHENG YANG HUI-FANG FANG FU-DE 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1990年第2期146-155,共10页
Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction... Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc. 展开更多
关键词 analysis of the Phenotype and the Restriction Enzyme Mapping level of Mutations Induced by the New Mutagen Glycidyl Methacrylate
下载PDF
Predicting urbanization level by main element analysis and multiple linear regression---taking Xiantao district in Hubei Province as an example
4
作者 Li BingyiDepartment of Urban Planning & Architecture, Wuhan Urban Construction Institute,Wuhan 430074, CHINA 《Journal of Geographical Sciences》 SCIE CSCD 1998年第1期90-91,93-94,共4页
In this paper we firstly select main factors relating to urbanization level of Xiantao District in Hubei Province by main element, then, make model of urbanization level by analysis of multiple liner regression, and l... In this paper we firstly select main factors relating to urbanization level of Xiantao District in Hubei Province by main element, then, make model of urbanization level by analysis of multiple liner regression, and lastly predict its urbanization level 展开更多
关键词 urbanization level main element analysis multiple linear regression Xiantao Hubei PROVINCE
下载PDF
Analysis on Serum Trace Element Levels of Echinococciasis Patients in Garze Tibetan Autonomous Prefecture in Sichuan,China,2011
5
作者 LI Jun Jian LI Wei +8 位作者 XU Guang Rong XU Ke Jun YE Ping QUAN Yu NING Rong Bing GAO Hai Jun HE Qian Jun ZHOU Ying WU Wei Ping 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第9期683-686,共4页
In Garze Tibetan autonomous prefecture inSichuan province, China, 41 echinococciasis patientswho had received surgical treatment were recruitedin the study, and 82 health persons who had livedin Garze for at least 10 ... In Garze Tibetan autonomous prefecture inSichuan province, China, 41 echinococciasis patientswho had received surgical treatment were recruitedin the study, and 82 health persons who had livedin Garze for at least 10 years were selected ascontrols. The serum levels of Zn, Se and Cu of thecases and controls were detected. The resultsshowed that most echinococciasis cases weredistributed in Shiqu county (17.1%, 7/41), and only1 case was distributed in Yajiang county (2.4%). Themale to female ratio of the cases was 1:1.56. Theechinococciasis patients were mainly aged 30-39years (36.59%, 15/41). And, the cases aged 20-49years accounted for 68.29% (28/41). Comparedwith health controls, the serum levels of Zn and Seof the cases significantly declined. However, theserum level of Cu of the cases had no significantlychange. It was confirmed that the serum levels ofZn and Se were interrelated with the prevalence ofechinococciasis. 展开更多
关键词 analysis on Serum Trace Element levels of Echinococciasis Patients in Garze Tibetan Autonomous Prefecture in Sichuan China 2011
下载PDF
Aspect Level Songs Rating Based Upon Reviews in English
6
作者 Muhammad Aasim Qureshi Muhammad Asif +4 位作者 Saira Anwar Umar Shaukat Atta-ur-Rahman Muhammad Adnan Khan Amir Mosavi 《Computers, Materials & Continua》 SCIE EI 2023年第2期2589-2605,共17页
With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after ... With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after the use of the item.The enormous increase in these reviews has raised the need for an automated system to analyze these reviews to rate these items.Sentiment Analysis(SA)is a technique that performs such decision analysis.This research targets the ranking and rating through sentiment analysis of these reviews,on different aspects.As a case study,Songs are opted to design and test the decision model.Different aspects of songs namely music,lyrics,song,voice and video are picked.For the reason,reviews of 20 songs are scraped from YouTube,pre-processed and formed a dataset.Different machine learning algorithms—Naïve Bayes(NB),Gradient Boost Tree,Logistic Regression LR,K-Nearest Neighbors(KNN)and Artificial Neural Network(ANN)are applied.ANN performed the best with 74.99%accuracy.Results are validated using K-Fold. 展开更多
关键词 Machine learning natural language processing songs reviews:sentiment analysis songs rating aspect level sentiment analysis reviews analysis text classification MUSIC
下载PDF
Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data
7
作者 Vladimir Kaftan Boris Komitov Sergey Lebedev 《Geodesy and Geodynamics》 2018年第6期449-455,共7页
Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are present... Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are presented. Spectra of the indicated processes were investigated and their approximation models were also built. Previously assumed statistical relationships between space-geophysical processes and Caspian Sea level(CSL) changes were confirmed. A close connection was revealed between the low-frequency models of the solar and geomagnetic activity parameters and the CSL changes. Predictions extending into the next decades showed a high probability of an increase in the CSL and a decrease of the compared space-geophysical parameters. 展开更多
关键词 CSL analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data LOD SSN
下载PDF
Tissue level microstructure and mechanical properties of the femoral head in the proximal femur of fracture patients 被引量:5
8
作者 Linwei Lü Guangwei Meng +3 位作者 He Gong Dong Zhu Jiazi Gao Yubo Fan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第2期259-267,共9页
This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and... This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation(Tb.Sp),trabecular thickness(Tb.Th),specific bone surface(BS/B V),bone volume fraction(BV/TV),structural model index(SMI),and degree of anisotropy(DA) were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young's modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters(P〈0.05).Young's moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly. 展开更多
关键词 Femoral head Trabecular bone Morphological parameters Micro-finite element analysis Apparent level Tissue level
下载PDF
Relationship between lipidslevelsand right ventricular volume overload in congestive heart failure 被引量:3
9
作者 Ying CHEN Xiao-Mei HE +11 位作者 Hong MENG Qing-Zhen ZHAO Yu-Zhi ZHEN Li TIAN Le WANG Li-Shuang JI Guo-Ping MA Yu TIAN Gang LIU Zhen-Guo JI Kun-Shen LIU Chao LIU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2014年第3期192-199,共8页
BackgroundThe relationship between lipids and coronary artery disease has been well established. However, this is not the case between lipids and heart failure. Ironically, high lipid levels are associated with better... BackgroundThe relationship between lipids and coronary artery disease has been well established. However, this is not the case between lipids and heart failure. Ironically, high lipid levels are associated with better outcomes in heart failure, but the mechan-isms underlying the phenomenon are not fully understood. This study was performed to test the hypothesis that reduced intestinal lipid absorption due to venous congestion may lead to low lipid levels.MethodsWe collected data of clinical characteristics, echocardio-graph, and lipid profile in 442 unselected patients with congestive heart failure. Correlations between lipid levels[including total cho-lesterol(TCL), high-density lipoprotein cholesterol(HDL-C), low-density lipoprotein cholesterol(LDL-C), and triglycerides(TG)]and right ventricle end diastolic diameter (RVEDD), left ventricle end diastolic diameter (LVEDD), right atrium diameter (RA), left atrium diameter (LA), or left ventricle ejection fraction (LVEF) were analyzed using Pearson correlation and partial correlation. RVEDD, LVEDD, RA, and LA were indexed to the body surface area.ResultsThere was a significantly inverse correlation between TCL le-vels and RVEDD (r=-0.34,P〈0.001) and RA (r=-0.36,P〈0.001). Other lipids such as LDL-C, HDL-C, and TG had asimilar inverse correlation with RVEDD and RA. All these correlations remained unchanged after adjusting for age, gender, smoking status, physical activity levels, comorbidities, and medication use.ConclusionsLipid levels were inversely correlated to RVEDD in patients with congestive heart failure; however, because this was an observational study, further investigation is needed to verify our results as wellas identify a causal relationship, if any. 展开更多
关键词 Lipid levels Heart failure Right ventricle Volume overload Correlation analysis
下载PDF
Assessment of Flue Gas Reinjecting Operating Strategy in Performance of CCHP System using Energy Level Difference Analysis 被引量:1
10
作者 WANG Zefeng HAN Wei LI Yimin 《Journal of Thermal Science》 SCIE EI CAS CSCD 2023年第1期125-134,共10页
A proper operating strategy is helpful to improve the off-design performance of combined cooling,heating and power(CCHP)systems,providing high efficiency and low emission.The energy level difference graphic analysis m... A proper operating strategy is helpful to improve the off-design performance of combined cooling,heating and power(CCHP)systems,providing high efficiency and low emission.The energy level difference graphic analysis method is used to identify energy level as well as exergy destruction of the part-load process.This method illustrates the energy efficiency upgrading mechanism of the flue gas reinjecting(FGR)operating strategy.It is referenced to a reducing turbine inlet temperature(TIT)operating strategy.By comparison,the FGR operating strategy leads to a 2.62%exergy distribution reduction in a gas turbine at an 85%load level due to the decrease of the energy level difference.When the output power is reduced further,the FGR operating strategy is supplanted by the TIT operating strategy with the limit of compressor inlet temperature.However,the opposite results of exergy distribution are presented in the exhaust-heat recovery devices.A heat-driven refrigeration and power cycle is introduced in a typical CCHP system as a solution.Moreover,the results suggest that the operational flexibility of the CCHP system is improved by enlarging the ratio of cooling to electricity. 展开更多
关键词 CCHP systems off-design performance energy level difference analysis operating strategies
原文传递
TopicBubbler:An interactive visual analytics system for cross-level fine-grained exploration of social media data
11
作者 Jielin Feng Kehao Wu Siming Chen 《Visual Informatics》 EI 2023年第4期41-56,共16页
How to explore fine-grained but meaningful information from the massive amount of social media data is critical but challenging.To address this challenge,we propose the TopicBubbler,a visual analytics system that supp... How to explore fine-grained but meaningful information from the massive amount of social media data is critical but challenging.To address this challenge,we propose the TopicBubbler,a visual analytics system that supports the cross-level fine-grained exploration of social media data.To achieve the goal of cross-level fine-grained exploration,we propose a new workflow.Under the procedure of the workflow,we construct the fine-grained exploration view through the design of bubble-based word clouds.Each bubble contains two rings that can display information through different levels,and recommends six keywords computed by different algorithms.The view supports users collecting information at different levels and to perform fine-grained selection and exploration across different levels based on keyword recommendations.To enable the users to explore the temporal information and the hierarchical structure,we also construct the Temporal View and Hierarchical View,which satisfy users to view the cross-level dynamic trends and the overview hierarchical structure.In addition,we use the storyline metaphor to enable users to consolidate the fragmented information extracted across levels and topics and ultimately present it as a complete story.Case studies from real-world data confirm the capability of the TopicBubbler from different perspectives,including event mining across levels and topics,and fine-grained mining of specific topics to capture events hidden beneath the surface. 展开更多
关键词 Cross level analysis Fine grained exploration Topic analysis Social media
原文传递
基于SysML扩展的系统安全性分析与评估方法
12
作者 吴超 杨雨婷 +2 位作者 付修锋 陈旭 杨波 《计算机应用研究》 CSCD 北大核心 2020年第S02期216-220,213,共6页
软件系统的复杂度越来越高给系统安全性分析工作带来了巨大挑战。基于SysML扩展的系统安全性分析与评能估力;方然法后对结Sy合sMALR P块-4定75义4/视47图61(b的loc系k统de级fin功itio能n危dia害gr分am析,(BFDHDA))进过行程pr分ofi析le... 软件系统的复杂度越来越高给系统安全性分析工作带来了巨大挑战。基于SysML扩展的系统安全性分析与评能估力;方然法后对结Sy合sMALR P块-4定75义4/视47图61(b的loc系k统de级fin功itio能n危dia害gr分am析,(BFDHDA))进过行程pr分ofi析le系弱统扩失展效,使状其况、具失备效描影述响系和统失安效全等性级失,效计的算系统安全性评估结果。最后,该算法在某雷达系统开展实验验证,结果表明,该算法可在设计早期发现系统可能存在的失效状态,提高系统安全性。 展开更多
关键词 SYSML system level functional hazard analysis(FHA) profile弱扩展 安全性分析 安全性评估
下载PDF
Testability Analysis at Switch Level for CMOS Circuits
13
作者 沈理 《Journal of Computer Science & Technology》 SCIE EI CSCD 1990年第2期197-202,共6页
In this paper we propose a controllability and observability measure at switch level for CMOS circuits based on the cost analysis approach.The complexity of the algorithm is nearly linear.
关键词 NNI ES NODE Testability analysis at Switch level for CMOS Circuits NPI ED EN DOWN DCG CMOS
原文传递
Genetic climatic regionalization of the Balkan Peninsula using cluster analysis 被引量:2
14
作者 Peter NOJAROV 《Journal of Geographical Sciences》 SCIE CSCD 2017年第1期43-61,共19页
Sea Level Pressure(SLP) data for the period 1950–2012 at 61 stations located in or around the Balkan Peninsula was used. The main concept is that intra-annual course of SLP represents the best different air masses ... Sea Level Pressure(SLP) data for the period 1950–2012 at 61 stations located in or around the Balkan Peninsula was used. The main concept is that intra-annual course of SLP represents the best different air masses that are situated over the Balkan Peninsula during the year. The method for differentiation of climatic zones is cluster analysis. A hierarchical clustering technique–average linkage between groups with Pearson correlation for measurement of intervals was employed in the research. The climate of the Balkan Peninsula is transitional between oceanic and continental and also between subtropical and temperate climates. Several major changes in atmospheric circulation over the Balkan Peninsula have happened over the period 1950–2012. There is a serious increase of the influence of the Azores High in the period January–Marchwhich leads to an increase of SLP and enhances oceanic influence. There is an increase of the influence of the north-west extension of the monsoonal low in the period June–September. This leads to more continental climatebut also to more tropical air masses over the Balkan Peninsula. Accordinglythe extent of subtropical climate widens in northern direction. There is an increase of the influence of the Siberian High in the period October–December. This influence covers central and eastern part of the peninsula in October and Novemberand it reaches western parts in December. Thusthe climate becomes more continental. 展开更多
关键词 genetic classification regionalization Balkan Peninsula cluster analysis Sea level Pressure circulation indices
原文传递
Static Frame Model Validation with Small Samples Solution Using Improved Kernel Density Estimation and Confidence Level Method 被引量:5
15
作者 ZHANG Baoqiang CHEN Guoping GUO Qintao 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2012年第6期879-886,共8页
An improved method using kernel density estimation (KDE) and confidence level is presented for model validation with small samples. Decision making is a challenging problem because of input uncertainty and only smal... An improved method using kernel density estimation (KDE) and confidence level is presented for model validation with small samples. Decision making is a challenging problem because of input uncertainty and only small samples can be used due to the high costs of experimental measurements. However, model validation provides more confidence for decision makers when improving prediction accuracy at the same time. The confidence level method is introduced and the optimum sample variance is determined using a new method in kernel density estimation to increase the credibility of model validation. As a numerical example, the static frame model validation challenge problem presented by Sandia National Laboratories has been chosen. The optimum bandwidth is selected in kernel density estimation in order to build the probability model based on the calibration data. The model assessment is achieved using validation and accreditation experimental data respectively based on the probability model. Finally, the target structure prediction is performed using validated model, which are consistent with the results obtained by other researchers. The results demonstrate that the method using the improved confidence level and kernel density estimation is an effective approach to solve the model validation problem with small samples. 展开更多
关键词 model validation small samples uncertainty analysis kernel density estimation confidence level prediction
原文传递
Gravimetric analysis for PM_(2.5) mass concentration based on year-round monitoring at an urban site in Beijing 被引量:5
16
作者 Yanli Wang Wen Yang +3 位作者 Bin Han Wenjie Zhang Mindong Chen Zhipeng Bai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第2期154-160,共7页
Daily PM_(2.5)(particulate matter with an aerodynamic diameter of below 2.5 μm) mass concentrations were measured by gravimetric analysis in Chinese Research Academy of Environmental Sciences(CRAES), in the nor... Daily PM_(2.5)(particulate matter with an aerodynamic diameter of below 2.5 μm) mass concentrations were measured by gravimetric analysis in Chinese Research Academy of Environmental Sciences(CRAES), in the northern part of the Beijing urban area, from December 2013 to April 2015. Two pairs of Teflon(T1/T2) and Quartz(Q1/Q2) samples were obtained, for a total number of 1352 valid filters. Results showed elevated pollution in Beijing,with an annual mean PM_(2.5)mass concentration of 102 μg/m^3. According to the calculated PM_(2.5)mass concentration, 50% of our sampling days were acceptable(PM_(2.5)〈 75 μg/m^3), 30% had slight/medium pollution(75–150 μg/m^3), and 7% had severe pollution(〉 250 μg/m^3). Sampling interruption occurred frequently for the Teflon filter group(75%) in severe pollution periods,resulting in important data being missing. Further analysis showed that high PM_(2.5)combined with high relative humidity(RH) gave rise to the interruptions. The seasonal variation of PM_(2.5)was presented, with higher monthly average mass concentrations in winter(peak value in February, 422 μg/m^3), and lower in summer(7 μg/m^3 in June). From May to August, the typical summer period, least severe pollution events were observed, with high precipitation levels accelerating the process of wet deposition to remove PM_(2.5). The case of February presented the most serious pollution, with monthly averaged PM_(2.5)of 181 μg/m^3 and 32% of days with severe pollution. The abundance of PM_(2.5)in winter could be related to increased coal consumption for heating needs. 展开更多
关键词 PM_(2.5) Gravimetric analysis Sampling interruption Pollution level Relative humidity(RH) Seasonal variation
原文传递
Distribution and origin of polycyclic aromatic hydrocarbons in surface sediments from an urban river basin at the Metropolitan Region of Curitiba,Brazil 被引量:4
17
作者 Natalicio Ferreira Leite Patricio Peralta-Zamora Marco Tadeu Grassi 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第6期904-911,共8页
The concentrations of 16 polycyclic aromatic hydrocarbons(PAHs) were determined in surface sediment samples from nine sites located at the Iguau River Basin in the Metropolitan Region of Curitiba,Brazil to evaluate ... The concentrations of 16 polycyclic aromatic hydrocarbons(PAHs) were determined in surface sediment samples from nine sites located at the Iguau River Basin in the Metropolitan Region of Curitiba,Brazil to evaluate their distribution and sources.The total concentration of the PAHs was greater for sediments from highly urbanized areas,while the sediments from the Iraí Environmental Protection Area(Iraí EPA) showed significantly low concentrations.The sediments from the Iguau and Barigui rivers were classified as highly contaminated,while those from the Cercado and Curralinho rivers were classified as moderately contaminated.The predominance of PAHs containing two to four aromatic rings in most of the samples suggested the direct input of raw sewage into the water resources evaluated.Benzo[g,h,i]perylene,dibenzo[a,h]anthracene and indeno[1,2,3-cd]pyrene were predominant in sediments from the areas under the greatest urban and industrial development.The correlation between thermodynamic stability and the kinetics of evolution presented by the isomeric pairs indicated that combustion is the predominant source of PAHs in the sediments because the combustion of fossil fuels affected most of the points evaluated,followed by combustion of biomass and eventually combustion of oil product inputs.In general,the results showed that areas under strong urban influence,as well as the Iraí EPA,receive contributions of PAHs from similar sources. 展开更多
关键词 PAHS trace level analysis fiver sediment isomeric ratio Igua^u River Basin
原文传递
Blockchain applied to the construction supply chain:A case study with threat model 被引量:2
18
作者 Gjorgji SHEMOV Borja GARCIA de SOTO Hoda ALKHZAIMI 《Frontiers of Engineering Management》 2020年第4期564-577,共14页
The construction industry has long faced the challenge of introducing collaborative systems among multiple stakeholders.This challenge creates a high level of rigidity in terms of processing shared information related... The construction industry has long faced the challenge of introducing collaborative systems among multiple stakeholders.This challenge creates a high level of rigidity in terms of processing shared information related to different processes,robust holistic regulations,payment actualizations,and resource utilization across different nodes.The need for a digital platform to crossconnect all stakeholders is necessary.A blockchain-based platform is a prime candidate to improve the industry in general and the construction supply chain(CSC)in particular.In this paper,a literature review is presented to establish the main challenges that CSC faces in terms of its effects on productivity and efficiency.In addition,the effect of applying blockchain platforms on a case study is presented and analyzed from performance and security level.The analysis aims to emphasize that blockchain,as presented in this paper,is a viable solution to the challenges in the CSC regardless of the risks associated with the security and robustness of the flow of information and data protection.Moreover,a threat analysis of applying a blockchain model on the CSC industry is introduced.This model indicates potential attacks and possible countermeasures to prevent the attacks.Future work is needed to expand,quantify,and optimize the threat model and conduct simulations considering proposed countermeasures for the different blockchain attacks outlined in this study. 展开更多
关键词 blockchain taxonomy construction supply chain threat model analysis security level analysis CYBERSECURITY VULNERABILITY smart contract cyber-attack
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部