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Influence of zeolite and cement additions on mechanical behavior of sandy soil

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第5期8卷 746-752页

作者： Hossein Mola-Abasi issa Shooshpasha Geotechnical Department Babol University of Technology

It is well known that the cemented sand is one of economic and environmental topics in soil stabilization. In this instance, a blend of sand, cement and other materials such as fiber, glass, nanoparticle and zeolite can be commercially available and effectively used in soil stabilization in road construction. However, the influence and effectiveness of zeolite on the properties of cemented sand systems have not been completely explored. In this study, based on an experimental program, the effects of zeolite on the characteristics of cemented sands are investigated. Stabilizing agent includes Portland cement of type II and zeolite. Results show the improvements of unconfined compressive strength （UCS） and failure properties of cemented sand when the cement is replaced by zeolite at an optimum proportion of 30% after 28 days. The rate of strength improvement is approximately between 20% and 78%. The efficiency of using zeolite increases with the increases in cement amount and porosity. Finally, a power function of void-cement ratio and zeolite content is demonstrated to be an appropriate method to assess UCS of zeolite-cemented mixtures.

关键词： ZeoliteCemented sand StrengthUnconfined compressive strength (UCS) Void-cement ratio

A highly sensitive DNA-AIEgen-based ＂turn-on＂ fluorescence chemosensor for amplification analysis of Hg^2+ ions in real samples and living cells

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Science China Chemistry 2017年第5期60卷 663-669页

作者： Xiaowen ou Xiaoding Lou Fan Xia Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica School of Chemistry and Chemical Engineering Huazhong University of Science and Technology Wuhan 430074 China Shenzhen Institute of Huazhong University of Science and Technology Shenzhen 518000 China

Functional nucleic acids(FNAs)-based biosensors have shown great potential in heavy metal ions detection due to their low-cost and easy to operate merits. However, in most FNAs based fluorescence probes, the ingenious designs of double-labeled(fluorophore and quencher group) DNA sequence, not only bring the annoyance of organic synthesis, but also restrict its use as a robust biosensor in practical duties. In this paper, we design a simple AIEgens functional nucleic acids(AFNAs) probe which consists of only fluorogen but no quencher group. With the help of duplex-specific nuclease(DSN) enzyme based target recycling, high fluorescence signal and superior sensitivity towards Hg^(2+) are achieved. This robust assay allows for sensitive and selective detection of Hg^(2+) in real water samples and mapping of intracellular Hg^(2+), without double-labeling of oligonucleotide with a dye-quencher pair, nor the multiple assay steps.

关键词： functional nucleic acids AIEgen Hg2+ detection real samples living cells

Study on the local time asymmetry of the Earth's ring currents based on multiple low-Earth-orbit satellite magnetic observations

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Science China(Technological Sciences) 2024年第11期67卷 3354-3364页

作者： ou JiaMing JIANG Yi YAN Qing State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 999078China Macao Institute of Space Technology and Application Macao 999078China Zhuhai MUST Science and Technology Research Institute Macao University of Science and TechnologyZhuhai 519085China

The azimuthal morphology of Earth's ring currents has consistently shown asymmetry during extreme space weather events at low latitudes,particularly during geomagnetic storms.A dawn-dusk pattern has been detected during the storm main phase through near-Earth and in-situ magnetic *** asymmetry is believed to arise from asymmetric solar windmagnetosphere coupling and is linked to the closure of the ring *** evidence has confirmed the existence of asymmetric ring currents during quiet times and the storm recovery *** phenomenon may be closely related to the evolution of ring currents,including plasma injection and decay *** this study,the local time asymmetry of the ring current is estimated using data from low-Earth-orbit Swarm and Macao Science Satellite-1(MSS-1)*** harmonics models are developed to quantify the magnetic field of ring currents through external Gauss coefficients during both quiet periods and the storm recovery *** features of dawn-dusk asymmetry are observed in various cases in different months.(1)The maximum difference in magnetic value across local time ranges from 3 to 10 nT,showing relative invariance compared with various Sym-H levels.(2)Stronger magnetic signals are detected at the premidnight sector during quiet times and at the afternoon sector during the storm recovery phase.(3)Magnetic perturbations remain at a lower level during the postmidnight and morning *** the pattern of local time asymmetry differs between quiet times and the recovery phase,dawn-dusk asymmetry remains the most pronounced feature,affecting the trapping and loss of charged particles in the inner *** Swarm and MSS-1 magnetic observations can enable convenient monitoring of the detailed azimuthal local time effects of the ring current at various disturbance levels in the future.

关键词： Earth's ring currents local time asymmetry SHA model Macao Science Satellite-1

Role of ERCP in the era of laparoscopic cholecystectomy for the evaluation of choledocholithiasis in sickle cell anemia

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World Journal of Gastroenterology 2011年第14期17卷 1844-1847页

作者： Hussain issa Arabia Ahmed H Al-Salem Department of Internal Medicine King Fahad Specialist HospitalDammamQatif 31911Saudi Department of Pediatric Surgery Maternity and Children HospitalDammamQatif 31911Saudi Arabia

AIM:To evaluate the role of endoscopic retrograde cholangiopancreatography (ERCP) for choledocholithiasis in patients with sickle cell anemia (SCA) in the era of laparoscopic cholecystectomy (LC). METHODS:Two hundred and twenty four patients (144 male,80 female; mean age,22.4 years; range,5-70 years) with SCA underwent ERCP as part of their evaluation for cholestatic jaundice (CJ). The indications for ERCP were:CJ only in 97,CJ and dilated bile ducts on ultrasound in 103,and CJ and common bile duct (CBD) stones on ultrasound in 42. RESULTS:In total,CBD stones were found in 88 (39.3%) patients and there was evidence of recent stone passage in 16. Fifteen were post-LC patients. These had endoscopic sphincterotomy and stone extraction. The remaining 73 had endoscopic sphincterotomy and stone extraction followed by LC without an intraoperative ***:In patients with SCA and cholelithiasis,ERCP is valuable whether preoperative or postoperative,and in none was there a need to perform intraoperative cholangiography. Sequential endoscopic sphincterotomy and stone extraction followed by LC is beneficial in these patients. Endoscopic sphincterotomy may also prove to be useful in these patients as it may prevent the future development of biliary sludge and bile duct stones.

关键词： Sickle cell anemia Cholelithiasis Choledocholithiasis Laparoscopic cholecystectomy Cholangiography Endoscopic retrograde cholangiopancreatography

Sickle cell cholangiopathy:An endoscopic retrograde cholangiopancreatography evaluation

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World Journal of Gastroenterology 2009年第42期15卷 5316-5320页

作者： Hussain issa Ali Al-Haddad Ahmed Al-Salem Department of Internal Medicine Division of GastroenterologyKing Fahad Specialist HospitalDammam 31444Saudi Arabia Department of Internal Medicine Qatif Central HospitalQatif 31911Saudi Arabia Department of Pediatric Surgery Maternity and Children HospitalDammamQatif 31911Saudi Arabia

AIM:To evaluate the role of endoscopic retrograde cholangiopancreatography(ERCP) in patients with sickle cell disease(SCD) .METHODS:Two hundred and twenty four SCD patients with cholestatic jaundice(CJ) had *** indications for ERCP were based on clinical and biochemical evidence of CJ and ultrasound ***:Two hundred and forty ERCPs were *** indications for ERCP were:CJ only in 79,CJ and dilated bile ducts without stones in 103,and CJ and bile duct stones in *** those with CJ only,ERCP was normal in 42(53.2%) ,and 13(16.5%) had dilated bile ducts without an obstructive *** the remaining 22,there were bile duct stones with or without *** those with CJ,dilated bile ducts and no stones,ERCP was normal in 17(16.5%) ,and 28(27.2%) had dilated bile ducts without an obstructive *** the remaining 58,there were bile ducts stones with or without *** those with CJ and bile duct stones,ERCP was normal in two(4.8%) ,and 14(33.3%) had dilated bile ducts without an obstructive *** the remaining 26,there were bile duct stones with or without ***:Considering the high frequency of biliary sludge and bile duct stones in SCD,endoscopic sphincterotomy might prove helpful in these patients.

关键词： Sickle cell disease Hepatobiliary Cholestsatic jaundice Sickle cell hepatopathy Sickle cell cholangiopathy Endoscopic retrograde cholangiopancreatography

Soft Decision Based Gaussian-Laplacian Combination Model for Noisy Speech Enhancement

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Chinese Journal of Electronics 2018年第4期27卷 827-834页

作者： ou Shifeng SONG Peng GAO Ying School of Science and Technology for Opto-electronic Information Yantai University School of Computer and Control Engineering Yantai University

One of the key issues of noisy speech enhancement technique is to achieve appropriate statistical distributions to model the clean speech and noise signals accurately. Most of the existing algorithms try to employ a sole model assumption in transform domain, which, however, has been proven to being contrary with the fact. To address this problem, the statistical properties of clean speech as well as several noise signals are analyzed using actual data in Discrete cosine transform(DCT) domain, and the study indicates the statistic of clean speech DCT coefficients tending to fall somewhere in between the Gaussian and Laplacian distribution. Based on the results,a novel speech enhancement algorithm is proposed using Gaussian-Laplacian combination model, whose core is employing a linear combination of Gaussian and Laplacian distribution to model the statistic of clean speech DCT coefficients. The corresponding weights of either distribution to the combination model are adaptively adjusted in terms of the probability of each hypothesis, which is estimated based on a soft decision technique by using Bayesian theorem. Through a number of objective and subjective tests,we compare the performance of the proposed algorithm with other recent model based approaches and have found that our algorithm is superior to the related approaches at all testing environments.

关键词： Speech enhancement Soft decision Speech distortion Combination model

Future penetration and impacts of electric vehicles on transport energy consumption and CO_2 emissions in different Chinese tiered cities

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Science China(Technological Sciences) 2018年第10期61卷 1483-1491页

作者： ZHANG Qian ou XunMin ZHANG XiLiang China Automotive Energy Research Center (CAERC) Tsinghua University

This study focuses on the penetration of electric vehicles(EVs) within the private passenger vehicle market in selected Chinese cities categorized into different tiers. It presents an analysis of factors driving the market diffusion of EVs and the reasons for varying results across the investigated cities and provides estimates of related EV impacts on local energy consumption and CO_2 emissions. A nested multinomial model incorporating technological attributes of vehicles, energy prices, charging conditions,and incentive policies was developed for conducting a scenario analyses covering six cities. The results indicated that in a stagnation scenario in which policy support was absent, the market share of electric vehicles would be less than 7% in all six cities under investigation by 2030. In medium growth and rapid growth scenarios, the market share of EVs across the six cities was projected to be within the ranges of 29%–68% and 49%–80%, respectively. The impacts of EVs on gasoline demand depended not just on their cumulative sales but also on the share of electrified vehicle distance, and the CO_2 emission reduction effect was influenced by local EV stocks and the mix of local electricity sources. Battery costs, charging conditions, and energy prices were primary driving factors. Charging conditions and energy prices were key reasons for differences in the penetration curves among cities. These driving factors were further affected by differences in local income levels, housing and parking conditions, and availability of land resources. Subsidies were found to be effective in the short term, whereas in the medium term,tax breaks could serve as the main monetary incentive. In the long term, national policy should focus on technology-related R&D, whereas local policies should focus on the operational phase and be tailored to specific local situations.

关键词： clean vehicles electric vehicle penetration CO2 emissions China

Control of Unknown Chaotic Systems Based on Neural Predictive Control

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Communications in Theoretical Physics 2003年第4X期40卷 439-442页

作者： LIDong-Mei WANGZheng-ou InstituteofSystemsEngineering TianjinUniversityTianjin300072China SchoolofEconomyandManagement HebeiUniversityofScienceandTechnologyShijiazhuang050018China

We introduce the predictive control into the control of chaotic system and propose a neural network control algorithm based on predictive control. The proposed control system stabilizes the chaotic motion in an unknown chaotic system onto the desired target trajectory. The proposed algorithm is simple and its convergence speed is much higher than existing similar algorithms. The control system can control hyperchaos. We analyze the stability of the control system and prove the convergence property of the neural controller. The theoretic derivation and simulations demonstrate the effectiveness of the algorithm.

关键词：神经预控制未知混沌系统控制神经网络非线性动力学控制模型模拟稳定性分析

High-throughput screening of single-atom catalysts confined in monolayer black phosphorus for efficient nitrogen reduction reaction

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Nano Research 2024年第4期17卷 2360-2367页

作者： Xiao-Yan Li Manyi Duan Pengfei ou Department of Electrical and Computer Engineering University of TorontoTorontoOntario M5S 1A4Canada School of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610101China Department of Chemistry Northwestern UniversityEvanstonIL 60208USA

The discovery of metal-nitrogen centers as the active sites for electrolysis has aroused significant interest in utilizing single-atom catalysts for nitrogen reduction reaction(NRR).Properly designed nanostructured catalysts that strongly interact with nitrogen molecules(N_(2))can promote adsorption and activation,thereby resulting in efficient catalysts with high stability,activity,and *** this study,using density functional theory calculations,we selected monolayer black phosphorus(BP)as the substrate and screened a series of single-atom transition metals confined in tri-coordinated and tetra-coordinated active centers(without and with N dopants)to electro-catalyze *** a result,we have identified two promising candidates(Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4)),which exhibit not only low overpotentials of 0.56 and 0.49 V but also high thermodynamic and electrochemical stability,as well as good selectivity towards NRR over the competing hydrogen evolution *** also demonstrate the ability of Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4) to activate and hydrogenate N_(2) by donating electrons and regulating charge *** study not only predicts new BP-based promising catalysts but also provides guidance for the rational design of high-performance NRR electrocatalysts under ambient conditions.

关键词： N_(2) electroreduction reaction single-atom catalysts black phosphorus density functional theory high-throughput calculations