检索结果-南通市图书馆

CCS Chemistry 2024年第3期6卷 663-671页

作者： Zhen Yuan Xianghua Jiang Liangji Chen Junjie Chen Lu Li yisi Yang Yunbin Li Fahui Xiang Shengchang Xiang Banglin Chen Zhangjing Zhang Fujian Key Laboratory of Polymer Materials College of Chemistry and Materials ScienceFujian Normal UniversityFuzhou 350007

Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains ***,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···π*** activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray ***-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.

关键词： hydrogen-bonded organic framework flexible-robust sticked-layer D-Aπ···πinteraction in situ powder X-ray diffraction C_(2)H_(2)/CO_(2)separation

Phase-dependent lithium-alloying reactions for lithium-metal batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 1-2页

作者： shu Lin Kezhen Qi College of Pharmacy Dali UniversityDali 671000China

With the increasing demand for higher energy lithium-ion batteries (LIBs), it is imperative to develop high-capacity electrode materials [1–4]. Due to the unique electrochemical Li-alloying reactions, Li-alloys offer high theoretical capacity, especially lithiumrich phase alloys, which exceeds the theoretical capacity of graphite anodes [5–7]. Phase-transition, which significantly influences lithium alloy reactions, determines high voltage hysteresis,low Coulombic efficiency (CE), and short cycling life [8,9].

关键词： alloying alloys cycling

Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2024年第1期45卷 152-159页

作者： Yu-Fa Luo shu-Qiang Li School of Life and Environmental Sciences Shaoxing UniversityShaoxingZhejiang 312000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

We examined the global biogeography of the Scytodes thoracica group of spitting spiders based on 23 years of sampling at the species level(61 species in the thoracica group and 84 species of Scytodes)using DNA data from six *** results indicated that the thoracica group initially dispersed from Southeast Asia to East Africa between 46.5 and 33.0 million years ago,and dispersal events intensified between Southeast/South Asia and East/South Africa from the early to late *** timing of these events indicates that Asian-African faunal exchange of the thoracica group was driven by the Indian monsoon,and the pattern of dispersal suggests that colonialization took root when the Indian monsoon shifted from a North-South direction to an East-West direction from the middle Eocene.

关键词： Geological event Climate change Ballooning organism Faunal exchange Species distribution

Two-component dimers of ultracold atoms with center-of-mass-momentum dependent interactions

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 153-157页

作者： Yaru Liu shu Yang Peng Zhang Department of Physics Renmin University of ChinaBeijing 100872China Graduate School of China Academy of Engineering Physics Beijing 100193China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

In a previous paper[***.A95,060701(R)(2017)],we demonstrated that a new type of two-body interaction,which depends on the center of mass(CoM)momentum,can be realized for ultracold atoms via laser-modulated magnetic Feshbach resonance(MFR).Further studies(e.g.L He et al,***.120,045302(2018))show that various interesting phenomena,such as Fulde–Ferrell superfluids,can be induced by scattering between ultracold atoms with this *** this work we investigate the shallow bound states of two ultracold atoms with this type of *** show that when the magnetic field B is below the MFR point B0,two shallow bound states can appear in this ***,a'two-component dimer'or a dimer with pseudo-spin 1/2 can be formed by two ***,the dispersion curve of the dimer may have either single or double minimums in the CoM momentum *** latter case can be explained as a result from significant pseudo-spin-orbital coupling(SOC)*** results show that the ultracold gases with CoM momentum dependent interaction may be a candidate for quantum simulations with ultracold two-component molecules,especially the molecule gases with SOC.

关键词： center-of-mass-momentum dependent interaction Raman-laser modulated MFR two-component dimer

Low-Brightness Object Recognition Based on Deep Learning

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第5期79卷 1757-1773页

作者： shu-Yin Chiang Ting-Yu Lin Department of Information and Telecommunications Engineering Ming Chuan UniversityTaoyuan City333Taiwan

This research focuses on addressing the challenges associated with image detection in low-light environments,particularly by applying artificial intelligence techniques to machine vision and object recognition *** primary goal is to tackle issues related to recognizing objects with low brightness *** this study,the Intel RealSense Lidar Camera L515 is used to simultaneously capture color information and 16-bit depth information *** detection scenarios are categorized into normal brightness and low brightness *** the system determines a normal brightness environment,normal brightness images are recognized using deep learning *** low-brightness situations,three methods are proposed for *** first method is the SegmentationwithDepth image(SD)methodwhich involves segmenting the depth image,creating amask from the segmented depth image,mapping the obtained mask onto the true color(RGB)image to obtain a backgroundreduced RGB image,and recognizing the segmented *** second method is theHDVmethod(hue,depth,value)which combines RGB images converted to HSV images(hue,saturation,value)with depth images D to form HDV images for *** third method is the HSD(hue,saturation,depth)method which similarly combines RGB images converted to HSV images with depth images D to form HSD images for *** experimental results,in normal brightness environments,the average recognition rate obtained using image recognition methods is 91%.For low-brightness environments,using the SD method with original images for training and segmented images for recognition achieves an average recognition rate of over 82%.TheHDVmethod achieves an average recognition rate of over 70%,while the HSD method achieves an average recognition rate of over 84%.The HSD method allows for a quick and convenient low-light object recognition *** research outcome can be applied to nighttime surveillance systems or nighttime road safety systems

关键词： Low-brightness depth image image segmentation image recognition HDV HSD

Energy-Function Based Pilot Protection Scheme for Hybrid UHVDC Transmission Applying Improved Hausdorff Distance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 891-902页

作者： Zijiang Wang Youping Fan Ben Shang Yinbiao shu School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Institute of Next Generation Power Systems&International Standards Wuhan UniversityWuhan 430072China CSEE IEEE

A hybrid UHVDC transmission system applying LCC as the rectifier and MMC as the inverter combines the advantages of both converter types,which makes this protection scheme more complicated.A new pilot protection scheme for a three-terminal hybrid DC transmission system applying energy functions is *** energy function for LCC is applied to MMC to derive the energy level of the hybrid ***,an improved Hausdorff distance(IHD)algorithm is proposed to detect the difference in energy levels between the normal and fault *** abrupt change in energy level is characterized by IHD change *** points at which the IHD change rate exceeds the threshold at converter stations are applied to determine the fault line and to estimate the fault *** proposed protection scheme is then verified by a simulation model of the Wudongde±800 kV three-terminal hybrid UHVDC transmission *** appropriate sampling frequency is selected for a real-time calculation,and the threshold is selected considering the effect of *** show the proposed scheme can identify and trip fault lines quickly and effectively,even for a 600Ωgrounding *** waveshape similarity algorithms are compared and *** with existing protection schemes,the proposed scheme transmits less data to improve communication speed and reliability.

关键词： Energy function Hausdorff distance pilot protection UHVDC transmission

Evolution of inclusions in vacuum induction melting of superalloys containing 70%return material

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 Iron and Steel Research International 2024年第3期31卷 719-728页

作者： Jin-guo Gao shu-lei Yang shu-feng Yang Jing-she Li Wei Liu Meng-jing Zhao An-ren Wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Metallurgical and Building Materials Business Department China International Engineering Consulting CorporationBeijing 100048China

The variation law of inclusions type and size in the vacuum induction melting process and ingot of Ni-based superalloy containing 70%return material was studied by industrial test sampling,and the mechanism of inclusions formation was analyzed with thermodynamic *** results show that there are mainly two types of composite inclusions in the vacuum induction melting of Ni-based superalloys,which are nitride-and oxide-based composite inclusions,like Al_(2)O_(3)-SiO_(2)-Cr_(2)O_(3),TiN-(Mo,Nb)C,*** type and proportion of inclusions from the center to the edge of the vacuum induction ingot did not change *** number density of inclusions from the center to the edge of the ingot varied less,and the size of inclusions became smaller from the center to the *** addition,thermodynamic calculations show that oxides(M_(2)O_(3))are present in the liquid phase and mainly contain Al,Ti,Cr,Fe and O *** nitride consists mainly of Ti and N and contains small amounts of Cr,C,Nb,and Mo *** is consistent with the results of industrial *** the temperature decreases,the precipitation phases such as M_(2)O_(3),MN,γ,MC,δ,γ'andμphases are gradually precipitated,where oxides and nitrides are present in the liquid *** contents of O and N elements are the main influencing factors for the inclusions content and precipitation temperature;when the nitrogen content is reduced to below 0.0015%,it can make MN precipitate below the liquid-phase line.

关键词： Ni-based superalloy Vacuum induction melting Return material Inclusion Thermodynamic

A Semiparametric Additive-multiplicative Rates Model for the Weighted Composite Endpoint of Recurrent and Terminal Events

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第4期40卷 985-999页

作者： Yi DENG Qiang XIONG shu Wei LI School of Economics and Statistics Guangzhou UniversityGuangzhou 510006P.R.China

Recurrent event data are commonly encountered in many scientific fields,including biomedical studies,clinical trials and epidemiological surveys,and many statistical methods have been proposed for their *** this paper,we consider to use a weighted composite endpoint of recurrent and terminal events,which is weighted by the severity of each event,to assess the overall effects of covariates on the two types of events.A flexible additive-multiplicative model incorporating both multiplicative and additive effects on the rate function is proposed to analyze such weighted composite event process,and more importantly,the dependence structure among the recurrent and terminal events is left *** the estimation,we construct the unbiased estimating equations by virtue of the inverse probability weighting technique,and the resulting estimators are shown to be consistent and asymptotically normal under some mild regularity *** evaluate the finite-sample performance of the proposed method via simulation studies and apply the proposed method to a set of real data arising from a bladder cancer study.

关键词： Additive-multiplicative rates model estimating equation recurrent events terminal event weighted composite endpoint

GNSS gyroscopes:determination of angular velocity and acceleration with very high-rate GNSS

在线全文

学校读者我要写书评

暂无评论

Satellite Navigation 2024年第1期5卷 74-90页

作者： Yun Shi Peiliang Xu Yuanming shu Xiaolin Meng School of Geomatics Xi’an University of Science and TechnologyXi’an710054People’s Republic of China Disaster Prevention Research Institute Kyoto UniversityUjiKyoto611-0011Japan College of Marine Geosciences Ocean University of ChinaQingdaoPeople’s Republic of China School of Instrument Science and Engineering Southeast UniversityNanjing210096People’s Republic of China

Although global navigation satellite systems(GNSS)have been routinely applied to determine attitudes,there exists no literature on determining angular velocity and/or angular acceleration from *** by the invention of computerized accelerometers of the correspondence author and following the success of accurately recovering translational velocity and acceleration waveforms from very high-rate GNSS precise positioning by Xu and his collaborators in 2021,we propose the concept of GNSS gyroscopes and reconstruct angular velocity and acceleration from very high-rate GNSS attitudes by applying regularization under the criterion of minimum mean squared *** major results from the experiments can be summarized in the following:(i)angular velocity and acceleration waveforms computed by applying the difference methods to high-rate GNSS attitudes are too noisy and can be physically not meaningful and numerically *** same can be said about inertial measurement unit(IMU)attitudes,if IMU gyros are not of very high accuracy;(ii)regularization is successfully applied to reconstruct the high-rate angular velocity and acceleration waveforms from 50 Hz GNSS attitudes and significantly outperforms the difference methods,validating the proposed concept of GNSS *** comparing the angular velocity and acceleration results by using the difference methods and regularization,we find that the peak values of angular velocity and acceleration by regularization are much smaller by a maximum factor of 1.57 in the angular velocity to a maximum factor of 8662.53 times in the angular acceleration in the case of high-rate GNSS,and by a maximum factor of 1.26 in the angular velocity to a maximum factor of 2819.85 times in the angular acceleration in the case of IMU,respectively;and(iii)the IMU attitudes apparently lead to better regularized angular velocity and acceleration waveforms than the high-rate GNSS attitudes,which can well be explained by the fact that the

关键词： Angular velocity Angular acceleration High-rate GNSS GNSS attitudes GNSS gyroscopes Regularization

CuInS_(2)quantum-dot-modified g-C_(3)N_(4)S-scheme heterojunction photocatalyst for hydrogen production and tetracycline degradation

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 Materials Science & Technology 2024年第5期172卷 145-155页

作者： Jingjing Zhang Yue Zhao Kezhen Qi shu-yuan Liu College of Pharmacy Dali UniversityDali 671000China Department of Pharmacology Shenyang Medical CollegeShenyang 110034China

CuInS_(2)quantum-dot(CIS QD)-modified g-C_(3)N_(4)(CN)catalysts(CIS/CN)were prepared with the aid of an in-situ growth *** as-obtained photocatalysts were explored by measuring their crystallinity,surface morphology,binding energy and light absorption *** photocatalytic efficiency of the pho-tocatalysts was evaluated through photocatalytic water splitting for hydrogen production and tetracycline(TC)antibiotic degradation under the simulated solar light and visible light *** optimized sample(10CIS/CN)showed the best photocatalytic activity:producing 102.4μmol g^(-1)h^(-1)of hydrogen in 1 h,or degrading 52.16%of TC in 120 min,which were respectively 48 or 3.4 times higher than the photocatalytic activity of CN *** enhancement in the efficiency of the composite system was prin-cipally accredited to the enlargement of light absorption,the more effective in charge transfer and the dropping of the charge carrier pair recombination through a formed S-scheme heterojunctional *** work is an effort to adjust CN-based polysulfide QD for speedy *** enriched photo-catalytic activity grants a new sense for adjusting the optical properties of CN.

关键词： CuInS_(2)QDs g-C_(3)N_(4) Photocatalysis Hydrogen production S-scheme heterojunction