检索结果-南通市图书馆

An Advanced Approach for Improving the Prediction Accuracy of Natural Gas Price

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2021年第2期118卷 303-322页

作者： Quanjia Zuo Fanyi Meng Yang Bai school of Economics and Management Nanjing University of Science and TechnologyNanjingChina school of Business Nanjing Normal UniversityNanjingChina

As one of the most important commodity futures,the price forecasting of natural gas futures is of great signifi-cance for hedging and risk *** paper mainly focuses on natural gas futures pricing which considers *** order to study this issue,we propose a modified approach called six-factor model,in which the influence of seasonalfluctuations are eliminated in every random *** Monte Carlo method,wefirst assess and comparative analyze thefitting ability of three-factor model and six-factor model for the out of sample *** is found that six-factor model has better performance than three-factor model and natural gas futures prices is strongly influenced by winter *** then apply the proposed model to predict the price of natural gas futures in the year *** is found that natural gas prices have a weak upward trend in the coming year and are relatively volatile in winter.

关键词： Natural gas futures price forecasting six-factor model Monte Carlo method seasonality

Chemical vapor deposited diamond with versatile grades:from gemstone to quantum electronics

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

Frontiers of Materials Science 2022年第1期16卷 17-54页

作者： Yuting ZHENG Chengming LI Jinlong LIU Junjun WEI Xiaotong ZHANG Haitao YE Xiaoping OUYANG Institute for Advanced Materials and technology(IAMT) State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Shunde graduate school University of Science and Technology BeijingFoshan 528399China school of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China school of Engineering University of LeicesterLeicester LE17RHUK school of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China

Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various ***,the application-related“grade”concept associated with materials choice and design was gradually formulated,of which the availability and the performance are optimally *** this review,the explicit diversity of CVD diamond and the clarification of typical grades for applications,i.e.,from resplendent gem-grade to promising quantum-grade,were systematically summarized and discussed,according to the crystal quality and main consideration of ubiquitous nitrogen impurity content as well as major *** of those,from quantum-grade with near-ideal crystal to electronic-grade having extremely low imperfections and then to optical,thermal as well as mechanical-grade needing controlled flaws and allowable impurities,would competently fulfill the multi-field application prospects with appropriate choice in terms of cost and ***,wide range defects and impurities in the gem-grade diamond(only indicating single crystal),which are detrimental for technology applications,endows CVD crystals with fancy colors to challenge their natural counterparts.

关键词： CVD diamond synthesis and characterization quality and impurity grading application

A systematic scheme for monitoring waterbird populations at Shengjin Lake,China:methodology and preliminary results

在线全文

学校读者我要写书评

暂无评论

Chinese Birds 2011年第1期02卷 1-17页

作者：曹垒 Mark BARTER 赵美娟孟浩贤张永中国科学技术大学生命学院合肥230026 Resource Ecology Group Wageningen University

Changes in the areas and quality of wetland habitat makes it imperative to monitor trends in the number of wintering waterbirds and their distribution in the Yangtze River floodplain, the most important waterbird region in eastern China, so that effective science-based action can be taken to ensure the survival and future recovery of the waterbirds of the region. However, obtaining accurate data on the number of waterbirds and distribution, which can be confidently compared across years and sites, is complicated by a number of factors which can affect count quality. It is essential to employ a survey methodology which maximizes count accuracy and precision and minimizes the bias inherent in counting waterbirds;failure to achieve these goals will lead to incorrect results and analytical problems. Recently we developed a systematic waterbird survey methodology which was tested, with promising results, in the winters of 2008/2009 and 2009/2010 at Shengjin Lake, an important wetland in the Yangtze River floodplain. The methodology involves dividing the lake into discrete survey areas, each containing a number of subareas, with clear boundaries, which were surveyed separately. Data, which included information on counts, distributions, the environment and disturbance, were collected in a standardized manner to maximize precision and minimize bias. We use the results from the surveys of the first two winters to provide examples of how the data can be employed to provide detailed information on the number of waterbirds, their distributions and habitat usage. Finally, we discuss the importance of wider application of the methodology throughout the Yangtze River floodplain to underpin a much needed floodplain-wide waterbird monitoring program.

关键词： Spotted Owlet food invertebrates Coleoptera vertebrates

Transcriptome and phytochemical analyses reveal the roles of characteristic metabolites in the taste formation of white tea during the withering process

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第3期21卷 862-877页

作者： ZHOU Cheng-zhe ZHU Chen LI Xiao-zhen CHEN Lan XIE Si-yi CHEN Guang-wu ZHANG Huan LAI Zhong-xiong LIN Yu-ling GUO Yu-qiong College of Horticulture Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China Institute of Horticultural Biotechnology Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China Key Laboratory of Tea Science of Fujian Province/Tea Industry Research Institute Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China

In the postharvest processing of tea leaves,withering is the first indispensable manufacturing process which produces the mellow,umami and sweet taste of white *** this study,we aimed to determine the dynamic changes of the main metabolites and clarify the key differentially expressed genes(DEGs) involved in forming the characteristic taste of white tea during *** analyses revealed that the contents of total catechins and starch decreased continuously,whereas the contents of theaflavin,γ-aminobutyric acid(GABA),maltose,and soluble sugars increased significantly during withering(from 0–48 h).Meanwhile,the elevation of α-amylase(AMY),β-amylase(BAM),total amylase,and glutamate decarboxylase(GAD) activities may be correlated with the accumulation of GABA and *** transcriptome sequencing,we detected 9 707,15 921,17 353,and 17 538 DEGs at 12,24,36,and 48 h of the withering process,respectively,compared with 0 h sample(fresh leaves).The transcript levels of most of the DEGs involved in catechin biosynthesis were significantly inhibited,whereas those involved in catechin oxidation were significantly up-regulated,which could be correlated to a decrease in catechin content and an increase in theaflavin *** DEGs involved in GABA biosynthesis were considerably up-regulated,and the down-regulation of SPMS could reduce the competition for converting spermidine to *** up-regulation of the AMY and BAM genes could trigger starch degradation,resulting in the increase of soluble sugar *** results provide new insights into the importance of the withering process to the characteristic taste of white tea.

关键词： white tea withering transcriptome analysis phytochemical analysis

RNA Methylome Reveals the m^(6)A-mediated Regulation of Flavor Metabolites in Tea Leaves under Solar-withering

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2023年第4期21卷 769-787页

作者： Chen Zhu Shuting Zhang Chengzhe Zhou Caiyun Tian Biying Shi Kai Xu Linjie Huang Yun Sun Yuling Lin Zhongxiong Lai Yuqiong Guo College of Horticulture Fujian Agriculture and Forestry UniversityFuzhou 350002China Institute of Horticultural Biotechnology Fujian Agriculture and Forestry UniversityFuzhou 350002China Tea Industry Research Institute Fujian Agriculture and Forestry UniversityFuzhou 350002China

The epitranscriptomic mark N6-methyladenosine(m^(6)A),which is the predominant internal modification in RNA,is important for plant responses to diverse *** environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea ***,the effects of the m^(6)A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively *** performed an integrated RNA methylome and transcriptome analysis to explore the m^(6)Amediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea(Camellia sinensis)leaves under solar-withering *** changes in global m^(6)A level in tea leaves were mainly controlled by two m^(6)A erasers(CsALKBH4A and CsALKBH4B)during solar-withering *** methylated peak-associated genes following solarwithering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome *** analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid,catechin,and theaflavin contents by triggering alternative splicing-mediated *** findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m^(6)A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions.

关键词： Camellia sinensis RNA methylation Epitranscriptome Secondary metabolite Withering

Sub-pixel extraction of laser stripeand itsapplication in laser plane calibration

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

Journal of Southeast University(English Edition) 2015年第1期31卷 107-112页

作者：陈平张志胜戴敏陈恺东南大学机械工程学院南京211189

For calibrating the laser plane to implement 3D shape measurement, an algorithm for extracting the laser stripe with sub-pixel accuracy is proposed. The proposed algorithm mainly consists of two stages： two-side edge detection and center line extraction. First, the two-side edge of laser stripe is detected using the principal component angle-based progressive probabilistic Hough transform and its width is calculated through the distance between these two edges. Secondly, the center line of laser strip is extracted with 2D Taylor expansion at a sub-pixel level and the laser plane is calibrated with the 3D reconstructed coordinates from the extracted 2D sub-pixel ones. Experimental results demonstrate that the proposed method can not only extract the laser stripe at a high speed, nearly average 78 ms/frame, but also calibrate the coplanar laser stripes at a low error, limited to 0.3 mm. The proposed algorithm can satisfy the system requirement of two-side edge detection and center line extraction, and rapid speed, high precision, as well as strong anti-jamming.

关键词： sub-pixel extraction center line extraction laser plane calibration progressive probabilistic Hough transform (PPHT) principal component (PC) angle 2D Taylor expan- sion

Mechanism of the Salvia miltiorrhiza-Codonopsis pilosula drug pair in the treatment of premature ovarian failure based on network pharmacology-molecular docking

在线全文

学校读者我要写书评

暂无评论

Reproductive and Developmental Medicine 2022年第1期6卷 26-33页

作者： Rui-Jun Ni Li Dong Hong-Li Huang Yanq-Qiu Xia Shanghai University of Traditional Chinese Medicine Shanghai 201203China Department of Gynecology Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese MedicineShanghai 200437China

Objective: Premature ovarian failure (POF) is a disease characterized by irregular menstruation and results in infertility which markedly affects the reproductive health of women. TheSalvia miltiorrhiza-Codonopsis pilosula drug pair is effective at treating POF;however, knowledge of the mechanisms ofS. miltiorrhiza-C. pilosula in the treatment of POF is lacking. Thus, we carried out network pharmacology and molecular docking to clarify the mechanisms of this drug ***: The core components and targets ofS. miltiorrhiza-C. pilosula were obtained using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database and UniProt database, and the disease targets related to POF were searched using different tools to obtain the overlapping target genes ofS. miltiorrhiza andC. pilosula. A protein interaction network of the intersection target was constructed using STRING database, and the network of "traditional Chinese medicine-active ingredient-intersection target-disease" and "pathways-targets" was constructed using Cytoscape 3.8.0. The DAVID online tool was also used to determine the gene ontology functions and Kyoto Encyclopedia of Genes and Genomes pathways associated with the intersection target genes. Finally, the binding ability of the drug to the active components and potential targets were predicted using molecular ***: S. miltiorrhizae-C. pilosula had 72 active components, 128 targets, 3,775 POF targets, and 106 common targets. The potential targets were mainly related to the biological processes of DNA-binding transcription factor binding, RNA polymerase II-specific DNA-binding transcription factor binding, transcription factor activity, steroid receptor activity, and hypoxia response. Further, the Kyoto Encyclopedia of Genes and Genomes enrichment pathways included PI3K-Akt signaling pathway, apoptosis, interleukin (IL)-17 signaling pathway, relaxin signaling pathway, and other biological ***

关键词： Salvia miltiorrhiza-Codonopsis pilosula Drug pair Premature ovarian failure Network pharmacology Molecular docking

Experimental investigation on failure process and spatio-temporal evolution of rockburst in granite with a prefabricated circular hole

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2020年第10期27卷 2930-2944页

作者： LIU Chong-yan ZHAO Guang-ming XU Wen-song MENG Xiang-rui HUANG Shun-jie ZHOU Jun WANG Yun-kun State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China school of Mining and Safety Engineering Anhui University of Science and TechnologyHuainan 232001China Department of Civil&Mineral Engineering University of TorontoOntarioM5S 1A4Canada

To study the mechanism of rockburst and its spatio-temporal evolution criterion,a rockburst simulation experiment was performed on granite specimens,each with a prefabricated circular hole,under different lateral *** micro camera,acoustic emission(AE)system,and infrared thermal imager,the AE characteristics and thermal radiation temperature migration were studied during the rockburst ***,the failure mode and damage evolution of the surrounding rock were *** results demonstrate that increasing the lateral load can first increase and then reduce the bearing capacity of the *** this experiment,the hole failure process could be divided into four periods:quiet,particle ejection,stability failure and ***,the AE signals evolved from a calm stage,to have intermittent appearance;then,they were continuous with a sudden increase,and finally increased *** failure of the surrounding rock was mainly tensile failure,while shear failure tended to first increase and then ***,damage to the hole increased gradually during the particle ejection period,whereas damage to the rockburst mainly occurred in the stability failure *** thermal radiation temperature migration exhibited warming in shallow parts,inward expansion,cooling in the shallow parts with free surface heating,inward expansion,a sudden rise in temperature of the rockburst pits,and finally specimen *** initial reinforcement support should fully contribute to surface ***,an appropriate tensile capacity and good energy absorption capacity should be established in support systems for high-stress roadways.

关键词： rockburst acoustic emission spatio-temporal evolution thermal imaging

Effects of cadence on lower extremity joints during cycling at constant power output

在线全文

学校读者我要写书评

暂无评论

Effects of cadence on lower extremity joints during cycling ...