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Dual-Fields Rotational Total Skin Electron Therapy: Investigation and Implementation
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作者 M. Ming Xu Iris Rusu Richard P. Garza 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2024年第1期1-15,共15页
Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and M... Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and Materials: The DFR-TSET combined the Stanford 6-field and McGill rotational methods. Dual 6 MeV electron beams in high dose total skin electron mode were used for DFR-TSET on a commercial linac. Beam profiles and dosimetric properties were measured using solid phantoms. The dose rate at expanded source-to-surface distance (SSD) was a combination of static rate and rotational rate. In vivo dosimetry of patient skin was performed on patients’ skin using film, metal oxide semiconductor field-effect transistors (MOSFET), and optically stimulated luminescent dosimeters (OSLD). Results: Dual field rotational total skin electron therapy exhibited good (≤±10%) uniformity in the beam profiles in the vertical direction at an extended SSD of 332 cm with a gantry angulation of ±20˚ deviated from the horizontal direction. In-vivo measurements confirmed acceptable uniformity of the patients’ total body surfaces and revealed anatomically self-blocked or shielded areas where underdosing occurred. Conclusions: The clinical implementation of DFR-TSET effectively utilizes the special mode on a linac. This technique provides short beam-on times, uniform dose distribution, large treatment field, and reduced dose of x-ray contamination to the patients. In-vivo measurements indicate satisfactory delivery and dose uniformity of the prescribed dose. Electron boost fields are recommended at normal SSDs to address underdosed areas. 展开更多
关键词 Total Skin Electron Therapy Stanford 6 field McGill rotation Therapy In-Vivo Dosimetry
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Characteristics of electromagnetic vector field generated from rock fracturing 被引量:1
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作者 Menghan Wei Dazhao Song +3 位作者 Xueqiu He Quan Lou Liming Qiu Zhenlei Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第2期457-466,共10页
Rock fracturing is often accompanied by electromagnetic phenomenon.As a vector field,in addition to the intensity that is widely concerned,the generated electromagnetic field also has obvious direction-ality.To this e... Rock fracturing is often accompanied by electromagnetic phenomenon.As a vector field,in addition to the intensity that is widely concerned,the generated electromagnetic field also has obvious direction-ality.To this end,a set of electromagnetic antennas capable of simultaneous three-axis measurement is used to monitor the electromagnetic vector field generated from rock fracturing based on Brazilian tests.The signal amplitude on each axis can represent the magnitude of actual magnetic flux density component on the three axes.The intensity and directional characteristics of electromagnetic signals received at different positions are studied using vector synthesis.The directionality of electromagnetic radiation measured using a three-axis electromagnetic antenna shows that the direction of the magnetic flux intensity generated by rock fracturing tends to be parallel to the crack surface,and the measured signal intensity is greater in a direction closer to the crack surface. 展开更多
关键词 Electromagnetic radiation DIRECTIONALITY vector field Rock fracturing
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Conservative Vector Fields and the Intersect Rule
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作者 Daniel A. Jaffa 《Journal of Applied Mathematics and Physics》 2023年第10期2888-2903,共16页
This paper covers the concept of a conservative vector field, and its application in vector physics and Newtonian mechanics. Conservative vector fields are defined as the gradient of a scalar-valued potential function... This paper covers the concept of a conservative vector field, and its application in vector physics and Newtonian mechanics. Conservative vector fields are defined as the gradient of a scalar-valued potential function. Gradient fields are irrotational, as in the curl in all conservative vector fields is zero, by Clairaut’s Theorem. Additionally, line integrals in conservative vector fields are path-independent, and line integrals over closed paths are always equal to zero, properties proved by the Gradient Theorem of multivariable calculus. Gradient fields represent conservative forces, and the associated potential function is analogous to potential energy associated with said conservative forces. The Intersect Rule provides a new, unique shortcut for determining if a vector field is conservative and deriving potential functions, by treating the indefinite integral as a set of infinitely many functions which satisfy the integral. 展开更多
关键词 vector Physics vector Calculus Multivariable Calculus Gradient fields vector fields Conservative vector fields Newtonian Mechanics
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Hybrid gradient vector fields for path-following guidance
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作者 Yi-yang Zhao Zhen Yang +4 位作者 Wei-ren Kong Hai-yin Piao Ji-chuan Huang Xiao-feng Lv De-yun Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期165-182,共18页
Guidance path-planning and following are two core technologies used for controlling un-manned aerial vehicles(UAVs)in both military and civilian applications.However,only a few approaches treat both the technologies s... Guidance path-planning and following are two core technologies used for controlling un-manned aerial vehicles(UAVs)in both military and civilian applications.However,only a few approaches treat both the technologies simultaneously.In this study,an innovative hybrid gradient vector fields for path-following guidance(HGVFs-PFG)algorithm is proposed to control fixed-wing UAVs to follow a generated guidance path and oriented target curves in three-dimensional space,which can be any combination of straight lines,arcs,and helixes as motion primitives.The algorithm aids the creation of vector fields(VFs)for these motion primitives as well as the design of an effective switching strategy to ensure that only one VF is activated at any time to ensure that the complex paths are followed completely.The strategies designed in earlier studies have flaws that prevent the UAV from following arcs that make its turning angle too large.The proposed switching strategy solves this problem by introducing the concept of the virtual way-points.Finally,the performance of the HGVFs-PFG algorithm is verified using a reducedorder autopilot and four representative simulation scenarios.The simulation considers the constraints of the aircraft,and its results indicate that the algorithm performs well in following both lateral and longitudinal control,particularly for curved paths.In general,the proposed technical method is practical and competitive. 展开更多
关键词 Unmanned aerial vehicle(UAV) Path-following guidance(PFG) Hybrid gradient vector field(HGVF) Switching strategy
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Rotating magnetic field inhibits Aβ protein aggregation and alleviates cognitive impairment in Alzheimer’s disease mice
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作者 Ruo-Wen Guo Wen-Jing Xie +5 位作者 Biao Yu Chao Song Xin-Miao Ji Xin-Yu Wang Mei Zhang Xin Zhang 《Zoological Research》 SCIE CSCD 2024年第4期924-936,共13页
Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation... Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment. 展开更多
关键词 lzheimer’s disease Rotating magnetic field Amyloid-β Cognitive function Alzheimer’s disease animal models
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On the Rotation of a Vector Field in a Four-Dimensional Space
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作者 Leonardo Simal Moreira 《Applied Mathematics》 2014年第1期128-136,共9页
Recently I published a paper in the journal ALAMT (Advances in Linear Algebra & Matrix Theory) and explored the possibility of obtaining products of vectors in dimensions higher than three [1]. In continuation to ... Recently I published a paper in the journal ALAMT (Advances in Linear Algebra & Matrix Theory) and explored the possibility of obtaining products of vectors in dimensions higher than three [1]. In continuation to this work, it is proposed to develop, through dimensional analogy, a vector field with notation and properties analogous to the curl, in this case applied to the space IR4. One can see how the similarities are obvious in relation to the algebraic properties and the geometric structures, if the rotations are compared in spaces of three and four dimensions. 展开更多
关键词 Products of vectorS Dimensional ANALOGY vector fieldS CURL rotationS CURL by ANALOGY
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Utilizing Iso-Value Field Curves in Lieu of Magnetic Field Lines Amid Infinite and Parallel Electrical Wires
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作者 Geoffroy Auvert 《Open Journal of Applied Sciences》 2024年第1期70-84,共15页
Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This impo... Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel. 展开更多
关键词 Specific field Value Parallel Electrical Wires Magnetic field vector field around Parallel Wires Topographic Level Map
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The Unified Field
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作者 Joseph H. (Cass) Forrington 《Journal of Modern Physics》 2024年第7期1010-1035,共26页
This is a Unified Field description based on the holographic Time Dilation Cosmology, TDC, model, which is an eternal continuum evolving forward in the forward direction of time, at the speed of light, c, at an invari... This is a Unified Field description based on the holographic Time Dilation Cosmology, TDC, model, which is an eternal continuum evolving forward in the forward direction of time, at the speed of light, c, at an invariant 1 s/s rate of time. This is the Fundamental Direction of Evolution, FDE. There is also an evolution down time dilation gradients, the Gravitational Direction of Evolution, GDE. These evolutions are gravity, which is the evolutionary force in time. Gravitational velocities are compensation for the difference in the rate of time, dRt, in a dilation field, and the dRtis equal to the compensatory velocity’s percentage of c, and is a measure of the force in time inducing the velocity. In applied force induced velocities, the dRt is a measure of the resistance in time to the induced velocity, which might be called “anti-gravity” or “negative gravity”. The two effects keep the continuum uniformly evolving forward at c. It is demonstrated that gravity is already a part of the electromagnetic field equations in way of the dRt element contained in the TDC velocity formula. Einstein’s energy formula is defined as a velocity formula and a modified version is used for charged elementary particle solutions. A time dilation-based derivation of the Lorentz force ties gravity directly to the electromagnetic field proving the unified field of gravity and the EMF. It is noted how we could possibly create gravity drives. This is followed by a discussion of black holes, proving supermassive objects, like massive black hole singularities, are impossible, and that black holes are massless Magnetospheric Eternally Collapsing Objects (MECOs) that are vortices in spacetime. . 展开更多
关键词 Unified field GRAVITY Anti-Gravity Astrophysics Einstein General Relativity Special Relativity Galactic rotation Velocities Time Dilation SPACETIME Space Time Spacetime Continuum Quantum Continuum MECO Black Hole Event Horizon Timelike Spacelike Lightlike
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VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS
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作者 周建伟 《苏州大学学报(自然科学版)》 CAS 1991年第2期131-139,共9页
Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the... Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E. 展开更多
关键词 向量丛 KILLING向量场 PONTRYAGIN数 RIEMANN流形
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Left Ventricular Systolic Intraventricular Flow Field Assessment in Hyperthyroidism Patients Using Vector Flow Mapping 被引量:9
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作者 周滨瑜 王静 +2 位作者 谢明星 刘曼薇 吕清 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2015年第4期574-578,共5页
Summary: Intraventricular hydrodynamics is considered an important component of cardiac function assessment. Vector flow mapping (VFM) is a novel flow visualization method to describe cardiac pathophysiological con... Summary: Intraventricular hydrodynamics is considered an important component of cardiac function assessment. Vector flow mapping (VFM) is a novel flow visualization method to describe cardiac pathophysiological condition. This study examined use of new VFM and flow field for assessment of left ventricular (LV) systolic hemodynamics in patients with simple hyperthyroidism (HT). Thirty-seven simple HT patients were enrolled as HT group, and 38 gender- and age-matched healthy volunteers as control group. VFM model was used to analyze LV flow field at LV apical long-axis view. The follow- ing flow parameters were measured, including peak systolic velocity (Vs), peak systolic flow (Fs), total systolic negative flow (SQ) in LV basal, middle and apical level, velocity gradient from the apex to the aortic valve (AV), and velocity according to half distance (V1/2). The velocity vector in the LV cavity, stream line and vortex distribution in the two groups were observed. The results showed that there were no significant differences in the conventional parameters such as left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and left atrium diameter (LAD) between HT group and control group (P〉0.05). Compared with the control group, a brighter flow and more vortexes were detected in HT group. Non-uniform distribution occurred in the LV flow field, and the stream lines were discontinuous in HT group. The values of Vs and Fs in three levels, SQ in middle and basal levels, AV and V1/2 were higher in HT group than in control group (P〈0.01). AV was positively correlated with serum free thyroxin (FT4) (r=0.48, P〈0.01). Stepwise multiple regression analysis showed that LVEDD, FT4, and body surface area (BSA) were the influence factors of △V. The unstable left ventricular sys- tolic hydrodynamics increased in a compensatory manner in simple PIT patients. The present study in- dicated that VFM may be used for early detection of abnormal ventricle contraction in clinical settings. 展开更多
关键词 HYPERTHYROIDISM vector flow mapping left ventricle HYDRODYNAMICS flow field
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Average vector field methods for the coupled Schrdinger KdV equations 被引量:3
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作者 张弘 宋松和 +1 位作者 陈绪栋 周炜恩 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期242-250,共9页
The energy preserving average vector field (AVF) method is applied to the coupled Schr6dinger-KdV equations. Two energy preserving schemes are constructed by using Fourier pseudospectral method in space direction di... The energy preserving average vector field (AVF) method is applied to the coupled Schr6dinger-KdV equations. Two energy preserving schemes are constructed by using Fourier pseudospectral method in space direction discretization. In order to accelerate our simulation, the split-step technique is used. The numerical experiments show that the non-splitting scheme and splitting scheme are both effective, and have excellent long time numerical behavior. The comparisons show that the splitting scheme is faster than the non-splitting scheme, but it is not as good as the non-splitting scheme in preserving the invariants. 展开更多
关键词 coupled Schrodinger-KdV equations average vector field method splitting method Fourier pseu-dospectral method
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An efficient compressed domain moving object segmentation algorithm based on motion vector field 被引量:4
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作者 刘志 沈礼权 张兆杨 《Journal of Shanghai University(English Edition)》 CAS 2008年第3期221-227,共7页
In this paper an efficient compressed domain moving object segmentation algorithm is proposed, in which the motion vector (MV) field parsed from the compressed video is the only cue used for moving object segmentati... In this paper an efficient compressed domain moving object segmentation algorithm is proposed, in which the motion vector (MV) field parsed from the compressed video is the only cue used for moving object segmentation. First the MV field is temporally and spatially normalized, and then accumulated by an iterative backward projection to enhance salient motions and alleviate noisy MVs. The accumulated MV field is then segmented into motion-homogenous regions using a modified statistical region growing approach. Finally, moving object regions are extracted in turn based on minimization of the joint prediction error using the estimated motion models of two region sets containing the candidate object region and other remaining regions, respectively. Experimental results on several H.264 compressed video sequences demonstrate good segmentation performance. 展开更多
关键词 moving object segmentation compressed domain segmentation motion vector (MV) field
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Effect of Rotation on the Propagation of Waves in Hollow Poroelastic Circular Cylinder with Magnetic Field 被引量:3
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作者 A.M.Farhan 《Computers, Materials & Continua》 SCIE EI 2017年第2期129-156,共28页
Employing Biot’s theory of wave propagation in liquid saturated porous media,the effect of rotation and magnetic field on wave propagation in a hollow poroelastic circular of infinite extent is investigated.An exact ... Employing Biot’s theory of wave propagation in liquid saturated porous media,the effect of rotation and magnetic field on wave propagation in a hollow poroelastic circular of infinite extent is investigated.An exact closed form solution is presented.General frequency equations for propagation of poroelastic cylinder are obtained when the boundaries are stress free.The frequencies are calculated for poroelastic cylinder for different values of magnetic field and rotation.Numerical results are given and illustrated graphically.The results indicate that the effect of rotation,and magnetic field are very pronounced.Such a model would be useful in large-scale parametric studies of mechanical response. 展开更多
关键词 Wave propagation rotation magnetic field poroelastic medium natural frequency.
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Pressure and velocity cross-spectrum of normal modes in low-frequency acoustic vector field of shallow water and its application 被引量:2
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作者 Yun Yu Qing Ling Jiang Xu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第2期241-249,共9页
The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especi... The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range. 展开更多
关键词 low frequency acoustic vector field effective depth complex cross acoustic intensity active component target depth classificatio
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Three-dimensional Holographic Vector of Atomic Interaction Field(3D-HoVAIF) for the QSPR/QSAR of Polychlorinated Naphthalenes 被引量:1
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作者 李正华 陈刚 +3 位作者 陈志涛 夏之宁 程凡圣 陈华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第3期345-352,共8页
Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regressio... Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regression(SMR) technique,the liner relationships between gas-chromatographic relative retention time(RRT),298 K supercooled liquid pressures(logPL),n-octanol/air partition coefficient(logKOA),n-octanol/water partition coefficient(logKOW),aqueous solubilities(logSW),relative in vitro potency values(-logEROD) of PCNs and 3D-HoVAIF descriptors have been established by partial least-square(PLS) regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property(activity) relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models. 展开更多
关键词 polychlorinated naphthalenes three-dimensional holographic vector of atomic interaction field QSPR QSAR
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THE INVARIANT CLOSED CONES OF HOMOGENEOUS VECTOR FIELDS OFDEGREE TWO IN R^3 被引量:1
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作者 梁肇军 《Acta Mathematica Scientia》 SCIE CSCD 2001年第1期29-36,共8页
In this paper, the authors investigate the invariant cones of quadratic homoge- neous polynomial vector fields in three variables. Necessary and sufficient conditions for the existence of non-isolated invariant closed... In this paper, the authors investigate the invariant cones of quadratic homoge- neous polynomial vector fields in three variables. Necessary and sufficient conditions for the existence of non-isolated invariant closed cones are obtained by the algebraic expressions in terms of the coefficients of certain quadratic homogeneous polynomials. 展开更多
关键词 Homogeneous vector field invariant cone
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Effects of Paddy Field Rotation on Diseases,Pests and Weeds of Rice 被引量:1
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作者 Xu Ning Huang Guoqin 《Plant Diseases and Pests》 CAS 2013年第4期20-24,共5页
[ Objective] The paper was to explore ecological effect of paddy field rotation on reducing disease, pests and weeds of rice. [ Method] With long-term continuous cropping rice as control, according to field location e... [ Objective] The paper was to explore ecological effect of paddy field rotation on reducing disease, pests and weeds of rice. [ Method] With long-term continuous cropping rice as control, according to field location experiments for consecutive 14 years, the effects of paddy field rotation on diseases, pests and weeds of rice were studied in details. [ Result] Paddy field rotation in some extent could reduce diseases, pests and weeds of rice. The diseased plant rate and disease in- dex of rice sheath blight in early rice under paddy field rotation treatment were averagely 10% and 0.4% lower than those in continuous cropping treatment, respec- tively. The diseased plant rate and disease index of rice sheath blight in late rice were 17.7% and 13.3% lower than those in treatments with continuous cropping mode, respectively. The diseased plant rate and disease index of rice false smut in both early rice and late rice under rotation treatments were lower than those in treatments with continuous cropping mode. White leaf rate caused by rice leaf roller and dry heart rate caused by striped rice borer under rotation treatments were significantly lower than those under continuous cropping treatment. The growth status of weeds under rotation treatments was weaker than that under continuous cropping treatment. [ Conclusion] The paper has important significance on alleviating diseases, pests and weeds of rice and improvement of ecological environment of farmland, and provides theoretical basis for sustainable development of agriculture. 展开更多
关键词 Long-term location test Paddy field rotation Diseases pests and weeds
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QSAR Study on Some N-[5-(2-Furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-Substituted-5-(2-furanyl)-2-methyl-3H-thieno-[2,3-d]pyrimidin-4-ones Using Three-dimensional Holographic Vector of Atomic Interaction Field 被引量:1
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作者 杨善彬 夏之宁 +4 位作者 梅虎 潘元 杨青林 许罗楠 李志良 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第10期1197-1204,共8页
Study on the quantitative structure-activity relationship (QSAR) of 26 compounds, N-[5-(2-furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-(2-furanyl)-2-methyl-3H-thieno[2... Study on the quantitative structure-activity relationship (QSAR) of 26 compounds, N-[5-(2-furanyl)-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-(2-furanyl)-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field (3D-HoVAIF) was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction. 展开更多
关键词 three-dimenslonal holographic vector of atomic interaction field (3D-HoVAIF) thienopyrimidones quantitative structure-activity relationship (QSAR)
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LIC color texture enhancement algorithm for ocean vector field data based on HSV color mapping and cumulative distribution function 被引量:1
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作者 Hongbo Zheng Qin Shao +4 位作者 Jie Chen Yangyang Shan Xujia Qin Ji Ma Xiaogang Xu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第10期171-180,共10页
Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in text... Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in texture image,a new color texture enhancement algorithm based on the Line Integral Convolution(LIC)for the vector field data is proposed,which combines the HSV color mapping and cumulative distribution function calculation of vector field data.This algorithm can be summarized as follows:firstly,the vector field data is convoluted twice by line integration to get the gray texture image.Secondly,the method of mapping vector data to each component of the HSV color space is established.And then,the vector field data is mapped into HSV color space and converted from HSV to RGB values to get the color image.Thirdly,the cumulative distribution function of the RGB color components of the gray texture image and the color image is constructed to enhance the gray texture and RGB color values.Finally,both the gray texture image and the color image are fused to get the color texture.The experimental results show that the proposed LIC color texture enhancement algorithm is capable of generating a better display of vector field data.Furthermore,the ambiguity of vector direction in the texture images is solved and the direction information of the vector field is expressed more accurately. 展开更多
关键词 ocean vector field visualization texture enhancement color mapping line integral convolution
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EMBEDDING THEOREMS ON CAMPANATO-MORREY SPACES FOR VECTOR FIELDS OF HoRMANDER TYPE 被引量:3
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作者 Guozhen Lu (Wright State University, USA) 《Analysis in Theory and Applications》 1998年第1期69-80,共12页
This paper deals with embedding theorems on Campanato-Marrey spaces formed by degenerate vector fields, which include Honnander and Grushin type of vector fields. These embedding theorems are somewhat different from t... This paper deals with embedding theorems on Campanato-Marrey spaces formed by degenerate vector fields, which include Honnander and Grushin type of vector fields. These embedding theorems are somewhat different from the known Poincare estimates. The main ingredients of the proofs rely on the fractional maximal functions. These results evidently have applications to the regularity of subelliptic PDE. 展开更多
关键词 EMBEDDING THEOREMS ON CAMPANATO-MORREY SPACES FOR vector fieldS OF HoRMANDER TYPE MATH
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