检索结果-南通市图书馆

Red soil for sediment capping to control the internal nutrient release under flow conditions

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2016年第6期10卷 63-71页

作者： lei xia Guo Liu Chunmei Chen Meiyan Wen Yangyang Gao State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China Sichuan Provincial Environmental Protection Key Laboratory of Groundwater Pollution Prevention and Resource Security Chengdu University of Technology Chengdu 610059 China

Nitrogen （N） and phosphorus （P） released from the sediment to the surface water is a major source of water quality impairment. Therefore, inhibiting sediment nutrient release seems necessary. In this study, red soil （RS） was employed to control the nutrients released from a black-odorous river sediment under flow conditions. The N and P that were released were effectively controlled by RS capping. Continuous-flow incubations showed that the reduction efficiencies of total N （TN）, ammonium （NH4＋-N）, total P （TP） and soluble reactive P （SRP） of the overlying water by RS capping were 77%, 63%, 77% and 92%, respectively, and nitrification and denitrification occurred concurrently in the RS system. An increase in the water velocity coincided with a decrease in the nutrient release rate as a result of intensive water aeration.

关键词： Sediment Red soil capping Flow conditions Nitrogen Phosphorus

A comparative investigation of NdSrCu_(1-x) Co_x O_(4-δ) and Sm_(1.8) Ce_(0.2) Cu_(1-x) Co_x O_(4-δ) (x:0–0.4) for NO decomposition

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第3期22卷 448-453页

作者： Jiguang Deng lei Zhang Yunsheng xia Hongxing Dai Hong He Laboratory of Catalysis Chemistry and Nanoscience Department of Chemistry and Chemical Engineering College of Environmental and Energy EngineeringBeijing Unversity of Technology Beijing 100124 China.

A series of single-phase T-structured NdSrCu 1-x Co x O 4-δ with oxygen vacancies and T -structured Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ （x： 0–0.4） with oxygen excess were prepared using ultrasound-assisted citric acid complexing method, and characterized by means of techniques such as thermogravimetric analysis and NO temperature-programmed desorption （NO-TPD）. The catalytic activities of these materials were evaluated for the decomposition of NO. It was found that the NdSrCu 1-x Co x O 4-δ catalysts were of oxygen vacancies whereas the Sm 1.8 Ce 0.2 Cu 1？x Co x O 4-δ ones possessed excessive oxygen （i.e., over-stoichiometric oxygen）; with a rise in Co doping level, the oxygen vacancy density of NdSrCu 1-x Co x O 4-δ decreased while the over-stoichiometric oxygen amount of Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ increased. The NO-TPD results revealed that NO could be activated much easier over the oxygen-deficient perovskite-like oxides than over the oxygen-excessive perovskite-like oxides, with the NdSrCuO 3.702 catalyst showing the best efficiency in activating NO molecules. Under the conditions of 1.0% NO/helium, 2800 hr -1 , and 600–900°C, the catalytic activity of NO decomposition followed the order of NdSrCuO 3.702 〉 NdSrCu 0.8 Co 0.2 O 3.736 〉 NdSrCu 0.6 Co 0.4 O 3.789 〉 Sm 1.8 Ce 0.2 Cu 0.6 Co 0.4 O 4.187 〉 Sm 1.8 Ce 0.2 Cu 0.8 Co 0.2 O 4.104 〉 Sm 1.8 Ce 0.2 CuO 4.045 , in concord with the sequence of decreasing oxygen vacancy or oxygen excess density. Based on the results, we concluded that the higher oxygen vacancy density and the stronger Cu 3＋ /Cu 2＋ redox ability of NdSrCu 1-x Co x O 4-δ account for the easier activation of NO and consequently improve the catalytic activity of NO decomposition over the catalysts.

关键词： perovskite-like oxide catalysts NO decomposition oxygen nonstoichiometry Cu^ 3+ /Cu ^2+ Cu^ 2+ /Cu^ +

Wavelet Phase Synchronization of Fractional-Order Chaotic Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第7期29卷 29-31页

作者： CHEN Feng xia lei LI Chun-Guang School of Electronic Engineering University of Electronic Science and Technology of ChinaChengdu 610054 Xi’an Institute of Electromechanical Information Technology Xi’an 710065 Department of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027

Nowadays,fractional-order systems are attracting more and more *** are several ways available for analyzing fractional-order systems,among which wavelet transform is an efficient method for analyzing system dynamics in both time and frequency *** investigate the wavelet phase synchronization employing wavelet transform to explore the phase synchronization behaviors of fractional-order chaotic *** analyze in detail the synchronization behaviors with changes to the coupling strength,the central frequency Ω0,and the time scale of the wavelet.

关键词： synchronization Synchronization fractional

An AIEgens and exonuclease Ⅲ aided quadratic amplification assay for detecting and cellular imaging of telomerase activity

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

Science Bulletin 2017年第14期62卷 997-1003页

作者： Xuehong Min lei xia Yuan Zhuang Xudong Wang Jie Du xiaojin Zhang xiaoding Lou Fan xia Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica School of Chemistry and Chemical Engineering Huazhong University of Science and Technology College of Materials and Chemistry Engineering Hainan University Faculty of Material Science and Chemistry China University of Geosciences Shenzhen Institute of Huazhong University of Science & Technology

Monitoring telomerase activity with high sensitive and reliable is of great importance to cancer analysis. In this paper, we report a sensitive and facile method to detect telomerase activity using AIEgens mod- ified probe （TPE-Py-DNA） as a fluorescence reporter and exonuclease llI （Exo lIl） as a signal amplifier. With the aid of telomerase, repeat units （TrAGGG）n are extended from the end of template substrate oligonucleotides （TS primer） that form duplex DNAs with TPE-Py-DNA. Then, Exo llI catalyzes the diges- tion of duplex DNAs, liberating elongation product and releasing hydrophobic TPE-Py. The released hydrophobic TPE-Py aggregate together and produce a telomerase-activity-related fluorescence signal. The liberated product hybridizes with another TPE-Py-DNA probe, starting the second cycle. Finally, we obtain the target-to-signal amplification ratio of 1 ：N2. This strategy exhibits good performance for detecting clinical urine samples （distinguishing 15 cancer patients＇ samples from 8 healthy ones） and checking intracellular telomerase activity （differentiating cell lines including HeLa, MDA-MB-231, MCF-7, A375, HLF and MRC-5 from the cells pretreated with telomerase-related drug）, which shows its potential in clinical diagnosis as well as therapeutic monitoring of cancer.

关键词： Quadratic amplification AIEgens Telomerase Urine samples Exonuclease Ill Cell imaging

Privacy-Preserving Deep Learning on Big Data in Cloud

在线全文

学校读者我要写书评

暂无评论

China Communications 2023年第11期20卷 176-186页

作者： Yongkai Fan Wanyu Zhang Jianrong Bai xia lei Kuanching Li State Key Laboratory of Media Convergence and Communication Communication University of ChinaBeijing 100024China Industrial and Commercial Bank of China Zhuhai Branch Zhuhai 519000China Dept.of Computer Science and Information Engineering Providence UniversityTaichung 43301China

In the analysis of big data,deep learn-ing is a crucial *** data analysis tasks are typically carried out on the cloud since it offers strong computer capabilities and storage ***-ertheless,there is a contradiction between the open nature of the cloud and the demand that data own-ers maintain their *** use cloud resources for privacy-preserving data training,a viable method must be found.A privacy-preserving deep learning model(PPDLM)is suggested in this research to ad-dress this preserving *** preserve data privacy,we first encrypted the data using homomorphic en-cryption(HE)***,the deep learn-ing algorithm’s activation function—the sigmoid func-tion—uses the least-squares method to process non-addition and non-multiplication operations that are not allowed by ***,experimental re-sults show that PPDLM has a significant effect on the protection of data privacy *** with Non-Privacy Preserving Deep Learning Model(NPPDLM),PPDLM has higher computational effi-ciency.

关键词： big data cloud computing deep learning homomorphic encryption privacy-preserving

A feedback control method for phase signal demodulation in fber-optic hydrophones

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 515-528页

作者： Zhiqiang LIU lei xia Qiangfeng LYU Bin WU Ronghua HUAN Zhilong HUANG Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou 310000China Huanjiang Laboratory Zhuji 311899Zhejiang ProvinceChina Advanced Technology Research Institute Zhejiang UniversityHangzhou 310000China

In the realm of acoustic signal detection,the identification of weak signals,particularly in the presence of negative signal-to-noise ratios,poses a significant *** challenge is further heightened when signals are acquired through fiber-optic hydrophones,as these signals often lack physical significance and resist clear systematic *** processing methods,e.g.,low-pass filter(LPF),require a thorough understanding of the effective signal bandwidth for noise reduction,and may introduce undesirable time *** paper introduces an innovative feedback control method with dual Kalman filters for the demodulation of phase signals with noises in fiber-optic hydrophones.A mathematical model of the closed-loop system is established to guide the design of the feedback control,aiming to achieve a balance with the input phase *** dual Kalman filters are instrumental in mitigating the effects of signal noise,observation noise,and control execution noise,thereby enabling precise estimation for the input phase *** effectiveness of this feedback control method is demonstrated through examples,showcasing the restoration of low-noise signals,negative signal-to-noise ratio signals,and multi-frequency *** research contributes to the technical advancement of high-performance devices,including fiber-optic hydrophones and phase-locked amplifiers.

关键词： feedback control method fiber-optic hydrophone acoustic signal detection phase signal

Retrospective and prospective review of the generalized nonlinear strength theory for geomaterials

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1767-1787页

作者： Shunchuan Wu Jiaxin Wang Shihuai Zhang Shigui Huang lei xia Qianping Zhao Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Geohazard Forecast and Geoecological Restoration in Plateau Mountainous Area MNRKunming 650093China Yunnan Key Laboratory of Geohazard Forecast and Geoecological Restoration in Plateau Mountainous Area Kunming 650093China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

Strength theory is the basic theory for calculating and designing the strength of engineering materials in civil,hydraulic,mechanical,aerospace,military,and other engineering ***,the comprehensive study of the generalized nonlinear strength theory(GNST)of geomaterials has significance for the construction of engineering rock *** paper reviews the GNST of geomaterials to demonstrate the research status of nonlinear strength characteristics of geomaterials under complex stress ***,it systematically summarizes the research progress of GNST(classical and empirical criteria).Then,the latest research the authors conducted over the past five years on the GNST is introduced,and a generalized three-dimensional(3D)nonlinear Hoek‒Brown(HB)criterion(NGHB criterion)is proposed for practical *** criterion can be degenerated into the existing three modified HB criteria and has a better prediction *** strength prediction errors for six rocks and two in-situ rock masses are 2.0724%-3.5091%and 1.0144%-3.2321%,***,the development and outlook of the GNST are expounded,and a new topic about the building strength index of rock mass and determining the strength of in-situ engineering rock mass is *** summarization of the GNST provides theoretical traceability and optimization for constructing in-situ engineering rock mass strength.

关键词： rock mechanics rock mass strength strength theory failure criterion Hoek-Brown criterion intermediate principal stress deviatoric plane smoothness and convexity

Dynamic Ring-chain Equilibrium of Nucleophilic Thiol-yne "Click" Polyaddition for Recyclable Poly(dithioacetal)s

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2021年第9期39卷 1146-1154页

作者： Jin-xia lei Qi-Yuan Wang Fu-Sheng Du Zi-Chen Li Beijing National Laboratory for Molecular Sciences(BNLMS) Key Laboratory of Polym.Chem.&Physics of Ministry of EducationDepartment of Polymer Science&EngineeringCollege of Chemistry and Molecular EngineeringCenter for Soft Matter Science and EngineeringPeking UniversityBeijing 100871China

We report a dynamic polymerization system based on the reversible nucleophilic Michael polyaddition of activated alkynes and *** poly(dithioacetal)s(P1-P4)were prepared via the base-catalyzed thiol-yne"click"polyaddition of two dithiols(1,4-butanedithiol(4S)and 1,5-pentanedithiol(5S))and two alkynones(3-butyn-2-one(Y1)and 1-phenyl-2-propyn-1-one(Y2))at high *** systematically investigated the base-catalyzed polymerization of 4S and Y1(for polymer PI)under different conditions,and found that this polymerization was a highly concentration-dependent dynamic system:polymer PI was formed at high concentration,while seven-membered dithioacetal,1-(1,3-dithiepan-2-yl)propan-2-one(C1),was obtained at low *** polymerization of 4S and Y2(for polymer P4)displayed similar polymerization behavior,generating 2-(1,3-dithiepan-2-yl)-1-phenylethanone(C4)at low *** the contrary,polymer P2(from Y1 and 5S)was exclusively obtained with no formation of eight-membered *** polymerizations of Y1 with 1,2-ethanedithiol(2S)and 1,3-dimercaptopropane(3S)only afforded corresponding five-and six-membered dithioacetals,1-(1,3-dithiolan-2-yl)propan-2-one(C2)and 1-(1,3-dithian-2-yl)propan-2-one(C3).This dynamic behavior of PI and P4 was attributed to the concentration-dependent retro-Michael addition reaction between a thiol and a β-sulfido-α,β-unsaturated carbonyl compound catalyzed by ***,polymers P1 and P4 could be depolymerized into Cl and C4 in yields of 58% and 95%,*** ring-opening polymerization of Cl at high concentration could successfully regenerate polymer ***,a new type of closed-loop recyclable poly(dithioacetal)s was developed.

关键词： Poly(dithioacetal)s Nucleophilic thiol-yne"click"polyaddition Chemical recycling Ring-chain equilibrium

A Low-Interference Time-Domain N-Continuous OFDM Scheme

在线全文

学校读者我要写书评

暂无评论

China Communications 2016年第S2期13卷 150-158页

作者： Peng Wei Lilin Dan Yue xiao xia lei Shaoqian Li National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China National Mobile Communications Research Laboratory Southeast University

N-continuous orthogonal frequency division multiplexing(NC-OFDM) is an outstanding method to suppress sidelobe for baseband OFDM signals in future 5G wireless ***,the precoder of NCOFDM usually causes severe interference and high *** alleviate these problems,this paper proposes an improved time-domain N-continuous OFDM(TD-NC-OFDM) by optimizing the smooth signal,which is the linear combination of rectangularly pulsed OFDM basis signals truncated by a smooth ***,we show that the proposed scheme is with lower transceiver complexity and notable performance gain in signal-tointerference-plus-noise ratio(SINR).Lastly,simulation results show that the proposed low-interference TD-NC-OFDM can achieve similar sidelobe suppression performance,with negligible bit-error rate(BER) degradation,compared to conventional NC-OFDM.

关键词： orthogonal frequency division multip-lexing(OFDM) sidelobe suppression N-continuous OFDM(NC-OFDM)