检索结果-南通市图书馆

reference evapotranspiration concentration and its relationship with precipitation concentration at southern and northern slopes of Tianshan Mountains, China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2019年第6期16卷 1381-1395页

作者： HUANG Fa-rong YANG Tao LI Qian LI Si-si LI Lan-hai Suwannee ADSAVAKULCHAI State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Ili station for Watershed Ecosystem Research Chinese Academy of SciencesXinyuan 835800China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China School of Engineering University of the Thai Chamber of CommerceBangkok 10400Thailand

The investigation of concentration characteristics of reference evapotranspiration(ETref) is important for water resources management. The concentration index(CI), concentration degree(CD) and concentration period(CP) are used to investigate the concentration characteristics of ETref and the relationship between ETref concentration and precipitation concentration at sub-monthly timescale based on the daily climatic variables from 1966 to 2015 in 27 meteorological stations at the southern and northern slopes of Tianshan Mountains in China. It was found that the CI of ETref is about 0.40 and less concentrated than precipitation in the study area. At the southern slope, the maximum ETref appears in late June and is earlier than the maximum precipitation(early July), ETref distributes more equally than precipitation, and the CI, CD and CP of these two variables do not show significant change based on the Mann–Kendall test. At the northern slope, both the maximum ETref and precipitation appear in early July, and ETref is more dispersed than precipitation. During the study period, the maximum ETref at the northern slope tends to appear earlier due to the impacts of wind speed, relative humidity, sunshine duration, and air temperature. ETref concentration does not match the precipitation concentration in the study area, particularly at the southern slope. The mismatch between ETref and precipitation concentration within a year reveals the water resources pressure on environmental, social and economic sustainability in the study area.

关键词： Concentration reference evapotranspiration Precipitation Trend analysis Tianshan Mountains

reference Section Method for Mixed State Geometric Phase in Nonunitary Evolution

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2015年第7期64卷 29-33页

作者：杜光乐李田军 State Key Laboratory of Theoretical Physics and Kavli Institute for Theoretical Physics China (KITPC) Institute of Theoretical Physics Chinese Academy of Sciences

We propose the reference section method to obtain a geometric phase for the mixed states in nonunitary evolution. The reference connection on density operator space is defined. That the parallel transport method and r... 详细信息

关键词： geometric phase reference section mixed states non

Model reference adaptive control with smooth switching scheme for piecewise linear systems and its application in turbofan engine control

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2019年第7期34卷 1615-1623页

作者： SUN Penghui WANG Xi YANG Bei ZENG Detang School of Energy and Power Engineering Beijing University of Aeronautics and AstronauticsBeijing100191China School of Aircraft Engineering Nanchang Hangkong UniversityNanchang330063China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China

A model reference adaptive control(MRAC)with smooth switching scheme was proposed for piecewise linear systems,and the method was utilized in turbofan engine control to avoid the discontinuity of control *** this scheme,each sub-region of the operating envelope had its own MRAC controller,and smooth indicator function based smooth switching scheme was introduced to switch multiple controllers smoothly at the boundary of adjacent *** Lyapunov stability analysis indicated that the proposed smooth switching scheme can guarantee the convergence of the closed-loop system during the controllers *** tracking error system was converted into a switched system to analyze the global stability of the closed-loop *** advantage of the method was that the chattering of system output and instability caused by asynchronous switching can be *** simulation illustrates the effectiveness of the proposed control scheme in comparison with the existing MRAC controller with gain scheduling for turbofan engine.

关键词： model reference adaptive control turbofan engine smooth switching Lyapunov function dwell time Lyapunov stability

reference genes for quantitative RT-PCR data in gastric tissues and cell lines

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第41期19卷 7121-7128页

作者： Fernanda Wisnieski Danielle Queiroz Calcagno Mariana Ferreira Leal Leonardo Caires dos Santos Carolina de Oliveira Gigek Elizabeth Suchi Chen Thaís Brilhante Pontes Paulo Pimentel Assumpo Mnica Barauna de Assumpo Smia Demachki Rommel Rodríguez Burbano Marília de Arruda Cardoso Smith Disciplina de Genética Departamento de Morfologia e GenéticaUniversidade Federal de So PauloSo Paulo 04023900Brazil Departamento de Ortopedia e Traumatologia Universidade Federal de So PauloSo Paulo 04038031Brazil Núcleo de Pesquisa em Oncologia Hospital Joo de Barros BarretoUniversidade Federal do ParáBelém 60673000Brazil Laboratório de Citogenética Humana Instituto de Ciências BiológicasUniversidade Federal do ParáBelém 66075110Brazil

AIM:To evaluate the suitability of reference genes in gastric tissue samples and cell ***:The suitability of genes ACTB,B2M,GAPDH,RPL29,and 18S rRNA was assessed in21 matched pairs of neoplastic and adjacent nonneoplastic gastric tissues from patients with gastric adenocarcinoma,27 normal gastric tissues from patients without cancer,and 4 cell lines using reverse transcription quantitative real-time polymerase chain reaction(RT-qPCR).The ranking of the best single and combination of reference genes was determined by NormFinder,geNorm,BestKeeper,and *** addition,GenEx software was used to determine the optimal number of reference *** validate the results,the mRNA expression of a target gene,DNMT1,was quantified using the different reference gene combinations suggested by the various software packages for ***:ACTB was the best reference gene for all gastric tissues,cell lines and all gastric tissues plus cell ***+B2M or ACTB+B2M was the best combination of reference genes for all the gastric *** the other hand,ACTB+B2M was the best combination for all the cell lines tested and was also the best combination for analyses involving all the gastric tissues plus cell *** to the GenEx software,2 or 3 genes were the optimal number of references genes for all the gastric *** relative quantification of DNMT1 showed similar patterns when normalized by each combination of reference *** level of expression of DNMT1 in neoplastic,adjacent non-neoplastic and normal gastric tissues did not differ when these samples were normalized using GAPDH+B2M(P=0.32),ACTB+B2M(P=0.61),or GAPDH+B2M+ACTB(P=0.44).CONCLUSION:GAPDH+B2M or ACTB+B2M is the best combination of reference gene for all the gastric tissues,and ACTB+B2M is the best combination for the cell lines tested.

关键词： Gastric cancer reference gene Normalization Gene expression Quantitative real-time polymerase chain reaction

Feasibility study on determining the conventional true value of gamma-ray air kerma in a minitype reference radiation

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

Nuclear Science and Techniques 2017年第6期28卷 133-139页

作者： Yi-Xin Liu Biao Wei Yang Xu Meng He Ren-Hong Zhuo De-Zhi Wen Da-Jie Ding Ben-Jiang Mao Key Laboratory of Optoelectronics Technology and System Ministry of EducationChongqing University Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics

A minitype reference radiation(MRR) with dimensions of only 1 m × 1 m × 1 m has been developed for the in situ calibration of photon *** present work conducts a feasibility study on determining the conventional true value of gamma-ray air kerma at the point of test in the *** to its smaller dimensions,the scattered gamma-rays in the MRR are expected to induce a non-negligible interference with the radiation field compared with conditions in the standard reference radiation stipulated by ISO4037-1 or GB/T12162.1.A gamma-ray spectrometer was employed to obtain the spectra of scattered gamma-rays within the MRR,and the feature components of the spectra were extracted by principal component analysis to characterize the interference of a dosimeter probe in the radiation field.A prediction model of the CAK at the point of test was built by least squares support vector machine based on the feature component data obtained from nine sample dosimeters under five different dose *** mean prediction error of the CAK prediction model was within ±4.5%,and the maximum prediction error was about ±10%.

关键词： Air kerma reference radiation Calibration Principal component analysis Support vector machine

reference ranges and age-related changes of peripheral blood lymphocyte subsets in Chinese healthy adults

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2009年第7期52卷 643-650页

作者： JIAO Yang1,QIU ZhiFeng1,XIE Jing1,LI DongJing2 & LI TaiSheng1 1 Department of Infectious Disease,Peking Union Medical College Hospital,Peking Union Medical College & Chinese Academy of Medical Sciences,Beijing,China 2 Department of Special Care Unit,Peking Union Medical College Hospital,Peking Union Medical College & Chinese Academy of Medical Sciences,Beijing,China Department of Infectious Disease Peking Union Medical College Hospital Peking Union Medical College & Chinese Academy of Medical Sciences Beijing China Department of Special Care Unit Peking Union Medical College Hospital Peking Union Medical College & Chinese Academy of Medical Sciences Beijing China

This study was performed to build region-specific reference ranges of peripheral blood lymphocyte subsets for Chinese healthy adults from the young to the elderly and analyze the trends of changes in lymphocyte subsets for evaluating the impact of age on the values.151 healthy adults aged 19-86 were recruited based on the SENIEUR *** sets of reference ranges were finally built applicable for the healthy young(19-44 years),middle-aged(45-64 years) and elder adults(≥65).Comparisons in parameters among the three cohorts showed that a statistically significant increase in CD16CD56+ NK cell was observed between the middle-aged and elder cohorts,whereas for the majority of the parameters,a significant decline was observed between the young and the middle-aged *** results showed that inverse correlations were observed between the age and CD19+ B,CD3+ T,CD3+CD4+ T,CD4+CD45RA+CD62L+ nave T cell and CD4+CD28+/CD4+,while the positive one was identified between the age and the NK *** significant changes of the most of immune parameters provided evidence for ***,T cell activation markers of CD8+CD38+ and CD8+HLA-DR+ showed reverse trends of association with age,which provides a clue for further researches on the mechanisms underlying the paradoxical clinical presentation of the elder patients.

关键词： lymphocyte subsets age reference range immunosenescence

Fixed-time adaptive model reference sliding mode control for an air-to-ground missile

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第5期32卷 1268-1280页

作者： Liang ZHANG Changzhu WEI Rong WU Naigang CUI School of Astronautics Harbin Institute of Technology

This paper addresses the fixed-time adaptive model reference sliding mode control for an air-to-ground missile associated with large speed ranges, mismatched disturbances and un-modeled dynamics. Firstly, a sliding mode surface is developed by the tracking error of the state equation and the model reference state equation with respect to the air-to-ground missile. More specifically,a novel fixed-time adaptive reaching law is presented. Subsequently, the mismatched disturbances and the un-modeled dynamics are treated as the model errors of the state equation. These model errors are estimated by means of a fixed-time disturbance observer, and they are also utilized to compensate the proposed controller. Therefore, the fixed-time controller is obtained by an adaptive reaching law and a fixed-time disturbance observer. Closed-loop stability of the proposed controller is established. Finally, simulation results including Monte Carlo simulations, nonlinear six-DegreeOf-Freedom(6-DOF) simulations and different ranges are presented to demonstrate the efficacy of the proposed control scheme.

关键词： Adaptive controller Air-to-ground missile Fixed-time adaptive reaching law Fixed-time disturbance observer Model reference sliding mode control

An Yb-fiber frequency comb phase-locked to microwave standard and optical reference

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第3期29卷 142-147页

作者： Hui-Bo Wang Hai-Nian Han Zi-Yue Zhang Xiao-Dong Shao Jiang-Feng Zhu Zhi-Yi Wei School of Physics and Optoelectronic Engineering Xidian UniversityXi’an 710071China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China

We present a fully stabilized Yb-fiber frequency comb locked to a microwave standard and an optical reference separately. The carrier-envelope offset frequency is generated by a standard f–2f interferometer with 40 dB signal-tonoise ratio. The offset frequency and the repetition rate are stabilized simultaneously to the radio frequency reference for more than 30 hours, and the fractional Allan deviation of the comb is the same as the microwave standard of 10^(-12) at 1 ***, the comb is locked to an ultra-stable optical reference at 972 nm using an intracavity electro-optic modulator,exhibiting a residual integrated phase noise of 458 mrad(1 Hz–10 MHz) and an in-loop tracking stability of 1.77× 10^(-18) at 1 s, which is significantly raised by six orders comparing to the case locked to the microwave frequency standard.

关键词： Yb-fiber frequency comb low-noise optical reference

Defocus Hyperspectral Image Deblurring with Adaptive reference Image and Scale Map

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2019年第3期34卷 569-580页

作者： De-Wang Li Lin-Jing Lai Hua Huang School of Computer Science and Technology Beijing Institute of TechnologyBeijing 100081China

Defocus blur is one of the primary problems among hyperspectral imaging systems equipped with simple lenses. Most of the previous deblurring methods focus on how to utilize structure information of a single channel, while ignoring the characteristics of hyperspectral images. In this work, we analyze the correlations and differences among spectral channels, and propose a deblurring framework for defocus hyperspectral images. First, we divide the hyperspectral image channels into two sets, and the set with less blur is treated as a group of spectral bases. Then, according to the inherent correlations of spectral channels, a reference image can be derived from the spectral bases to guide the restoration of blurry channels. Finally, considering the disagreement between the reference image and the ground truth, a scale map based on gradient similarity is introduced as a prior in the deblurring framework. The experimental results on public dataset demonstrate that the proposed method outperforms several image deblurring methods in both visual effect and quality metrics.

关键词： hyperspectral image defocus blur deblurring reference image scale map