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Coupling of an Individual-Based Model of Anchovy with Lower Trophic Level and Hydrodynamic Models 被引量:2
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作者 WANG Yuheng WEI Hao Michio J. Kishi 《Journal of Ocean University of China》 SCIE CAS 2013年第1期45-52,共8页
Anchovy (Engraulis japonicus), a small pelagic fish and food of other economic fishes, is a key species in the Yellow Sea ecosystem. Understanding the mechanisms of its recruitment and biomass variation is important f... Anchovy (Engraulis japonicus), a small pelagic fish and food of other economic fishes, is a key species in the Yellow Sea ecosystem. Understanding the mechanisms of its recruitment and biomass variation is important for the prediction and management of fishery resources. Coupled with a hydrodynamic model (POM) and a lower trophic level ecosystem model (NEMURO), an individual-based model of anchovy is developed to study the influence of physical environment on anchovy's biomass variation. Seasonal variations of circulation, water temperature and mix-layer depth from POM are used as external forcing for NEMURO and the anchovy model. Biomasses of large zooplankton and predatory zooplankton which anchovy feeds on are output from NEMURO and are controlled by the consumption of anchovy on them. Survival fitness theory related to temperature and food is used to determine the swimming action of anchovy in the model. The simulation results agree well with observations and elucidate the influence of temperature in over-wintering migration and food in feeding migration. 展开更多
关键词 流体动力学模型 基于模型 营养水平 凤尾鱼 生态系统模型 耦合 生物质能 浮游动物
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Individualized music for dementia:Evolution and application of evidence-based protocol 被引量:3
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作者 Linda A Gerdner 《World Journal of Psychiatry》 SCIE 2012年第2期26-32,共7页
The theory-based intervention of individualized music has been evaluated clinically and empirically leading to advancement and refinement of an evidence-based protocol, currently in its 5th edition. An expanded versio... The theory-based intervention of individualized music has been evaluated clinically and empirically leading to advancement and refinement of an evidence-based protocol, currently in its 5th edition. An expanded version of the protocol was written for professional health care providers with a consumer version tailored for family caregivers. The underlying mid-range theory is presented along with a seminal study that was followed by further research in the United States, Canada, Great Britain, France, Sweden, Norway, Japan and Taiwan. Key studies are summarized. Given its efficacy when implemented by research staff, studies have advanced to testing the intervention under real-life conditions when implemented and evaluated by trained nursing assistants in long-term care facilities and visiting family members. In addition, one study evaluated the implementation of music by family members in the home setting. Initial research focused on agitation as the dependent variable with subsequent research indicating a more holistic response such as positive affect, expressed satisfaction, and meaningful interaction with others. The article advances by describing on-line programs designed to train health care professionals in the assessment, implementation and evaluation of individualized music. In addition, Gerdner has written a story for apicture book intended for children and their families(in press). The story models principles of individualized music to elicit positive memories, reduce anxiety and agitation, and promote communication. The article concludes with implications for future research. 展开更多
关键词 individualized MUSIC DEMENTIA Alzheimer’s disease AGITATION EVIDENCE-based PROTOCOL
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An Individual-Based Modeling Approach to Investigate Sympatric Speciation via Specialized Resource Usage
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作者 Maryam Karim Pour Sara Bandehbahman +1 位作者 Robin Gras Melania E. Cristescu 《Open Journal of Ecology》 2017年第3期222-269,共48页
An individual-based model, EcoSim, was employed to investigate if specialized resource use could promote sympatric speciation. Prey individuals in the original version of EcoSim were supplied with a single primary foo... An individual-based model, EcoSim, was employed to investigate if specialized resource use could promote sympatric speciation. Prey individuals in the original version of EcoSim were supplied with a single primary food resource. A dual resource version with different food resources (Food 1 and Food 2) was also developed to create favorable conditions for the emergence of specialized food consumption among prey individuals. The single resource version was used as the control to determine the impact of the presence of multiple food resources on the occurrence of sympatric speciation. Each unit of Food 2 contained a higher amount of energy than Food 1, and Food 1 was more accessible than Food 2. Initially, prey individuals mostly fed on Food 1. How-ever, after the emergence of food specialization, the consumption rate of Food 2 signifi-cantly exceeded the consumption rate of Food 1;although prey individuals more frequently encountered Food 1. While sympatric speciation was observed in the dual resource version runs, we could not identify any sympatric species in the single resource version runs. Machine learning techniques were also employed to identify the most influential initial conditions leading to sympatric speciation. According to the obtained results, in most lineages sympatric speciation occurred at the beginning of the food specialization pro-cess. When the lineage had a high special diversity, the lineage needed two different criteria to diverge sympatrically: possessing high genetic diversity and a large population size. In support of previous findings, this study demonstrated that the most accurate determination of initial conditions leading to sympatric speciation can be obtained from lineages that are at the beginning of the divergence process. In conclusion, this study indicated that divergent foraging behavior could potentially lead to the sympatric emergence of new species in the absence of geographic isolation. 展开更多
关键词 individual-based Models Disruptive Selection DIVERGENT FEEDING Behavior Modeling SYMPATRIC SPECIATION
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The RFI Fast Mitigation Algorithm Based on Block LMS Filter
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作者 Han Wu Hai-Long Zhang +4 位作者 Ya-Zhou Zhang Jie Wang Xu Du Ting Zhang Xin-Chen Ye 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期265-272,共8页
The radio telescope possesses high sensitivity and strong signal collection capabilities.While receiving celestial radiation signals,it also captures Radio Frequency Interferences(RFIs)introduced by human activities.R... The radio telescope possesses high sensitivity and strong signal collection capabilities.While receiving celestial radiation signals,it also captures Radio Frequency Interferences(RFIs)introduced by human activities.RFI,as signals originating from sources other than the astronomical targets,significantly impacts the quality of astronomical data.This paper presents an RFI fast mitigation algorithm based on block Least Mean Square(LMS)algorithm.It enhances the traditional adaptive LMS filter by grouping L adjacent time-sampled points into one block and applying the same filter coefficients for filtering within each block.This transformation reduces multiplication calculations and enhances algorithm efficiency by leveraging the time-domain convolution theorem.The algorithm is tested using baseband data from the Parkes 64 m radio telescope's pulsar observations and simulated data.The results confirm the algorithm's effectiveness,as the pulsar profile after RFI mitigation closely matches the original pulsar profile. 展开更多
关键词 methods:data analysis techniques:interferometric (stars:)pulsars:individual(J0437-4715)
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A 330-500 GHz Zero-Biased Broadband Tripler Based on Terahertz Monolithic Integrated Circuits 被引量:2
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作者 任田昊 张勇 +4 位作者 延波 徐锐敏 杨成樾 周静涛 金智 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第2期31-34,共4页
A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteri... A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteristic test shows that the output i dB compression point is about -8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated. 展开更多
关键词 InP InGaAs A 330-500 GHz Zero-Biased Broadband Tripler based on Terahertz Monolithic Integrated Circuits dBm SBD
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Constraints on individual supermassive binary black holes using observations of PSR J1909-3744 被引量:1
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作者 Yi Feng Di Li +1 位作者 Yan-Rong Li Jian-Min Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第12期257-268,共12页
We perform a search for gravitational waves(GWs) from several supermassive binary black hole(SMBBH) candidates(NGC 5548, Mrk 231, OJ 287, PG 1302–102, NGC 4151, Ark 120 and 3C 66B) in long-term timing observations of... We perform a search for gravitational waves(GWs) from several supermassive binary black hole(SMBBH) candidates(NGC 5548, Mrk 231, OJ 287, PG 1302–102, NGC 4151, Ark 120 and 3C 66B) in long-term timing observations of the pulsar PSR J1909-3744 obtained using the Parkes radio telescope.No statistically significant signals were found. We constrain the chirp masses of those SMBBH candidates and find the chirp mass of NGC 5548 and 3C 66B to be less than 2.4 × 10^9 M⊙ and 2.5 × 10^9 M⊙(with 95% confidence), respectively. Our upper limits remain a factor of 3 to 370 above the likely chirp masses for these candidates as estimated from other approaches. The observations processed here provide upper limits on the GW strain amplitude that improve upon the results from the first Parkes Pulsar Timing Array data release by a factor of 2 to 7. We investigate how information about the orbital parameters can help to improve the search sensitivity for individual SMBBH systems. Finally, we show that these limits are insensitive to uncertainties in the Solar System ephemeris model. 展开更多
关键词 black hole physics gravitational waves pulsars:general pulsars:individual(PSR J1909-3744)
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The W UMa binaries USNO-A2.0 1350-17365531,V471 Cas,V479 Lac and V560 Lac:light curve solutions and global parameters based on Gaia distances 被引量:2
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作者 Diana P.Kjurkchieva Velimir A.Popov +1 位作者 Yordanka Eneva Nikola I.Petrov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第1期141-148,共8页
We present photometric observations in Sloan filters g′, i′of the eclipsing W UMa stars USNOA2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram of V471 Cas indicates the presence of ... We present photometric observations in Sloan filters g′, i′of the eclipsing W UMa stars USNOA2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram of V471 Cas indicates the presence of a third body with mass 0.12 M_⊙(a red dwarf) at distance 897 R_⊙. The O-C diagram of V479 Lac reveals a period decrease of d P/dt =-1.69 × 10-6d yr-1. The results of the light curve solutions are:(i) the targets are overcontact binaries with small fill-out factors;(ii) their components are F–K stars, comparable in size, whose temperature differences are below 80 K;(iii) all targets undergo partial eclipses and to limit the possible mass ratios we carried out two-step q-search analysis. The target global parameters(luminosities, radii, masses) were obtained on the basis of their Gaia distances and the results of our light curve solutions. The obtained total mass of V560 Lac turns out to be smaller than the lower mass limit for presently known W UMa binaries of 1.0-1.2 M_⊙, i.e. this target is a peculiar overcontact system. 展开更多
关键词 binaries:close binaries:eclipsing methods:data analysis stars:fundamental PARAMETERS stars:individual(USNO-A2.0 1350-17365531 V471 Cas V479 Lac V560 Lac)
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Study of Type-B QPOs Observed in Black Hole X-Ray Binary Swift J1728.9-3613
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作者 Raj Kumar 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期1-9,共9页
We report the detection of type-B quasi-periodic oscillation(QPO)of the black hole X-ray binary Swift J1728.9-3613 observed by NICER during the 2019 outburst.A type-B QPO was observed for the first two days and it dis... We report the detection of type-B quasi-periodic oscillation(QPO)of the black hole X-ray binary Swift J1728.9-3613 observed by NICER during the 2019 outburst.A type-B QPO was observed for the first two days and it disappeared as flux increased,but again appeared at∼7.70 Hz when flux was dramatically decreased.The source was found in the soft intermediate state during these observations.We further studied the energy dependence of the QPO.We found that QPO was observed only for a higher energy range implying that the origin of QPO is possibly due to the corona emitting higher energy photons by the inverse Compton process.The variation of spectral parameters can be explained with the disk truncation model.The fractional rms was found to be monotonically increased with energy.The phase lag spectrum followed the“U-shaped”curve.The rms and phase lag spectrum are modeled and explained with the single-component Comptonization model vkompthdk. 展开更多
关键词 X-rays binaries-accretion-accretion disks-X-rays individual (Swift J1728.9-3613)
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A Possible γ-Ray Pulsation from PSR J1740-5340B in the Globular Cluster NGC 6397
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作者 Jiao Zheng Pengfei Zhang Li Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期285-291,共7页
Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a ... Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris. 展开更多
关键词 gamma-rays:galaxies (stars:)pulsars:individual(PSR J1740-5340B) (Galaxy:)globular clusters:individual(NGC 6397)
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GRB 200612A:An Ultralong Gamma-Ray Burst Powered by Magnetar Spinning Down
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作者 陈良军 王祥高 +1 位作者 杨德龙 梁恩维 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期190-195,共6页
GRB 200612A could be classified as an ultralong gamma-ray burst due to its prompt emission lasting up to~1020 s and the true timescale of the central engine activity t_(burst)≥4×10^(4) s.The late X-ray light cur... GRB 200612A could be classified as an ultralong gamma-ray burst due to its prompt emission lasting up to~1020 s and the true timescale of the central engine activity t_(burst)≥4×10^(4) s.The late X-ray light curve with a decay index ofα=7.53 is steeper than the steepest possible decay from an external shock model.We propose that this X-ray afterglow can be driven by dipolar radiation from the magnetar spindown during its early stage,while the magnetar collapsed into the black hole before its spindown,resulting in a very steep decay of the late X-ray light curve.The optical data show that the light curve is still rising after 1.1 ks,suggesting a late onset.We show that GRB 200612A’s optical afterglow light curve is fitted with the forward shock model by Gaussian structured off-axis jet.This is a special case among GRBs,as it may be an ultralong gamma-ray burst powered by a magnetar in an off-axis observation scenario. 展开更多
关键词 (stars:)gamma-ray burst individual(GRB 200612A)-(stars:)gamma-ray burst general-stars MAGNETARS
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Study of Complex Nitrogen and Oxygen-bearing Molecules toward the High-mass Protostar IRAS 18089–1732
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作者 Arijit Manna Sabyasachi Pal +1 位作者 Tapas Baug Sougata Mondal 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期81-93,共13页
The observation of oxygen(O)-and nitrogen(N)-bearing molecules gives an idea about the complex prebiotic chemistry in the interstellar medium.Recent millimeter and submillimeter wavelength observations have shown the ... The observation of oxygen(O)-and nitrogen(N)-bearing molecules gives an idea about the complex prebiotic chemistry in the interstellar medium.Recent millimeter and submillimeter wavelength observations have shown the presence of complex O-and N-bearing molecules in the star formation regions.So,the investigation of those molecules is crucial to understanding the chemical complexity in the star-forming regions.In this article,we present the identification of the rotational emission lines of N-bearing molecules ethyl cyanide(C_(2)H_(5)CN)and cyanoacetylene(HC_(3)N),and O-bearing molecule methyl formate(CH_(3)OCHO)toward high-mass protostar IRAS18089–1732 using the Atacama Compact Array.We also detected the emission lines of both the N-and O-bearing molecule formamide(NH_(2)CHO)in the envelope of IRAS 18089–1732.We have detected the v=0 and 1 state rotational emission lines of CH_(3)OCHO.We also detected the two vibrationally excited states of HC_(3)N(v7=1 and v7=2).The estimated fractional abundances of C_(2)H_(5)CN,HC_(3)N(v7=1),HC_(3)N(v7=2),and NH_(2)CHO toward IRAS 18089–1732 are(1.40±0.5)×10^(-10),(7.5±0.7)×10^(-11),(3.1±0.4)×10^(-11),and(6.25±0.82)×10^(-11)respectively.Similarly,the estimated fractional abundances of CH_(3)OCHO(v=0)and CH_(3)OCHO(v=1)are(1.90±0.9)×10^(-9)and(8.90±0.8)×10^(-10),respectively.We also created the integrated emission maps of the detected molecules,and the observed molecules may have originated from the extended envelope of the protostar.We show that C_(2)H_(5)CNand HC_(3)N are most probably formed via the subsequential hydrogenation of the CH_(2)CHCNand the reaction between C_(2)H_(2)and CN on the grain surface of IRAS 18089–1732.We found that NH_(2)CHO is probably produced due to the reaction between NH_(2)and H_(2)CO in the gas phase.Similarly,CH_(3)OCHO is possibly created via the reaction between radical CH_(3)O and radical HCO on the grain surface of IRAS 18089–1732. 展开更多
关键词 ISM:individual objects(IRA 18089-1732)(except) ISM:abundances ISM:kinematics and dynamics stars:formation ASTROCHEMISTRY
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SELECTING CLUSTER MODEL IN Sn - BASED SOLDER ALLOY DESIGN WITH DV - X_α CALCULATION METHOD
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作者 C. Q. Wang and W. F. Feng National ho. of Advanced welding Technolgy, HIT, Harbin 150001,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第1期84-88,共5页
Applying calculation method in alloy design should be an important tendency due to its characters of inexpensive cost, high efficiency and prediction. DOS calculations of AuSn, AsSn and SbSn Sn- based alloys have ... Applying calculation method in alloy design should be an important tendency due to its characters of inexpensive cost, high efficiency and prediction. DOS calculations of AuSn, AsSn and SbSn Sn- based alloys have been investigated by employing DV - Xa method, in which different cluster models were adopted to calculate electron structure.It is proved that some regulations must be taken into ac- count in order to carry out alloy design calculation successfully,which are described in this paper in detail. 展开更多
关键词 Cluster model Sn - based alloy design DV - X_a calculation method DOS
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Preparation and the Pore Structure of Viscose-based Activated Carbon Fibers Treated with Pretreatment Reagents
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作者 罗艳 黄永辉 《Journal of China Textile University(English Edition)》 EI CAS 2000年第2期16-18,共3页
The viscose rayon was pretreated with four different pre-treatment reagents respectively, and the preparation ofactivated carbon fibers (ACF) was performed undersame carbonizing and activating conditions. The poresize... The viscose rayon was pretreated with four different pre-treatment reagents respectively, and the preparation ofactivated carbon fibers (ACF) was performed undersame carbonizing and activating conditions. The poresize distribution, the specific surface area, and the porestructure parameter of these viscose - based ACF werestudied by using quartz spring balance BET- weightmethod. The experiment result indicates that the poresize distribution and the pore structure parameter ofACF is varied by using different pretreatment reagents. 展开更多
关键词 PRETREATMENT REAGENT VISCOSE - based ACF PORE size PORE structure specific surface area
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An application of the KNND method for detecting nearby open clusters based on Gaia-DR1
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作者 Xin-Hua Gao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第6期89-94,共6页
This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (〈 100 pc) from the Gaia-DR1 catalog,... This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (〈 100 pc) from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions (the Hyades and Coma Berenices (Coma Ber) open clusters), and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data. 展开更多
关键词 open clusters and associations individual (Hyades Coma Ber) - astrometry- parallaxes- stars distances
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GRAPHICAL COMPUTING METHOD ON FOUR-BAR LINKAGE(1)——Inflexion Circle,Focal Axis,Ball's Point,Centering-point Curve and Circling-point Curve For Four ISPs,Coupler Curves Based on Ball's Points——
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作者 周晋康 《苏州大学学报(工科版)》 CAS 1992年第S2期27-34,共8页
By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we... By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points. 展开更多
关键词 Ball’s POINT centering - POINT CURVE and CIRCLING CURVE four ISPS Coupler curves based on BALLS POINTS
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“账户养老金”的实践问题与制度重构--基于零工经济适应性的视角 被引量:3
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作者 张盈华 《华中科技大学学报(社会科学版)》 北大核心 2023年第4期28-36,共9页
全球养老金领域共有六大类养老金个人账户,分布于公共养老金和私人养老金领域,但对零工劳动者存在制度包容性不足和缺乏可携带性的问题。我国三支柱养老金均有个人账户,但该制度有五项严重“漏损”,难以对零工劳动者形成有效覆盖。近年... 全球养老金领域共有六大类养老金个人账户,分布于公共养老金和私人养老金领域,但对零工劳动者存在制度包容性不足和缺乏可携带性的问题。我国三支柱养老金均有个人账户,但该制度有五项严重“漏损”,难以对零工劳动者形成有效覆盖。近年来,为满足零工经济的劳动权益保障要求,一些国家对养老金个人账户进行改良和创新,形成不少有益实践。本文在这些实践基础上,提出“账户养老金”概念和“3+3”功能的思考,从制度原则、管理主体和账户属性重构养老金个人账户,提出“账户养老金”的实现路径,即覆盖无歧视、责任明晰化、缴费灵活化、功能综合化、福利可携带、管理公共化,以期在改进养老金个人账户对零工经济适应性方面,提供新的研究视角。 展开更多
关键词 账户养老金 零工劳动者 个人账户
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NEW SOLID BASE DERIVED FROM AIPO4-5 SUPPORTED KF
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作者 Jian Hua ZHU Qin Hug XU Hideshi HATTORI(Chemistry Department, Nanjing University.Nanjing 210093,China.)(Centre for Advanced Research of Energy Technology, Hokkaido University,Sapporo 060.Japan) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第7期671-674,共4页
Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the iso... Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the isomerization of butenes at 273K. and the activity increasedwith the pre-treatment temperature up to 923K. 展开更多
关键词 NEW SOLID base DERIVED FROM AIPO4-5 SUPPORTED KF
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Stellar Population Analysis of Galaxies based on Genetic Algorithms
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作者 Abdel-Fattah Attia H. A. Ismail +4 位作者 I. M. Selim A. M. Osman I. A. Isaa M. A. Marie A. A. Shaker 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第4期347-355,共9页
We present a new method for determining the age and relative contribution of different stellar populations in galaxies based on the genetic algorithm.We apply this method to the barred spiral galaxy NGC 3384, using CC... We present a new method for determining the age and relative contribution of different stellar populations in galaxies based on the genetic algorithm.We apply this method to the barred spiral galaxy NGC 3384, using CCD images in U, B, V, R and I bands. This analysis indicates that the galaxy NGC 3384 is mainly inhabited by old stellar population (age 〉 10^9 yr). Some problems were encountered when numerical simulations are used for determining the contribution of different stellar populations in the integrated color of a galaxy. The results show that the proposed genetic algorithm can search efficiently through the very large space of the possible ages. 展开更多
关键词 methods: numerical - galaxies: stellar population - galaxies: individual (NGC 3384).
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Estimating Individual Tree Diameter and Stem Volume Using Airborne LiDAR in Saga Prefecture, Japan
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作者 Katsumasa Oono Satoshi Tsuyuki 《Open Journal of Forestry》 2018年第2期205-228,共24页
Advancements in airborne LiDAR analysis technology have made it possible to quantify forest resource volumes based on individual trees, and such technology may soon replace field surveys. Unlike individual tree detect... Advancements in airborne LiDAR analysis technology have made it possible to quantify forest resource volumes based on individual trees, and such technology may soon replace field surveys. Unlike individual tree detection or tree height measurements, diameter at breast height (DBH) is difficult to determine directly from measured data and is instead estimated indirectly using the correlation between crown size and DBH. Indicators that represent crown size include crown area, surface area, length, and length ratio, and were utilized with tree height as explanatory variables in ten combinations to determine a regression formula. DBH and tree height calculated from the regression formula were applied to an equation to calculate stem volumes of individual trees. Airborne LiDAR measurements were taken using ALS50-II and ALS60 (Leica) at a density of 4 points/m2. An evaluation of the relationship between the regression formulae and DBH estimates indicated that a combination of crown area, tree height, and crown ratio for Japanese cedar, and a combination of crown area and tree height for Japanese cypress, yielded the highest coefficients of determination. The average error and RMSE were 6.9% and 2.38 cm respectively for Japanese cedar, while the corresponding values for Japanese cypress were 8.35% and 2.51 cm. Once the relationship was extended to the stem volumes of individual trees, the average error was 14.4% and RMSE was 0.10 m3 for Japanese cedar. The corresponding values for Japanese cypress were 18.9% and 0.10 m3. These results demonstrate the potential use of airborne LiDAR as a substitute for field surveys. 展开更多
关键词 Airborne LiDAR Diameter at BREAST HEIGHT individual Treevolume FOREST Resource individual-Tree-based Approach
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Biological Evaluation of New Schiff Bases: Synthesized from 4-Amino-3,5-dimethyl-1,2,4-triazole, Phenathroline and Bipyridine Dicarboxaldehydes
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作者 Md. Shafiqul Islam Mohammad R. Karim +2 位作者 William Boadi Seyi Falekun Aminul H. Mirza 《Advances in Biological Chemistry》 2016年第6期180-192,共13页
Four new Schiff bases with promising anticancer activity have been synthesized from 4-amino-3,5-dimethyl-1,2,4-triazole and di-pyridyl-aldehydes. Structures have been established by various spectroscopic methods. The ... Four new Schiff bases with promising anticancer activity have been synthesized from 4-amino-3,5-dimethyl-1,2,4-triazole and di-pyridyl-aldehydes. Structures have been established by various spectroscopic methods. The compounds were tested in vitro to study their cytotoxicity and anti-oxidative activity in human lung carcinoma (A549), breast carcinoma (BT549), prostate adenocarcinoma (PC3) and mouse preadipocytes (3T3-L1) cells. Compound 1 was found to increase Glutathione (GSH) level slightly in all four cell lines. Compound 4 showed better selectivity and cytotoxicity against both BT549 and A549 cells compared to the anticancer drug tamoxifen. With the exception of compound 4 which reduced GSH levels in A549 and BT549, all other compounds maintained GSH levels in comparison to their respective controls. 展开更多
关键词 [2 2’-Bipyridine]-5 5’-dicarboxaldehyde Schiff bases Anticancer GLUTATHIONE ANTI-BACTERIAL
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