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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Nano Research - Copper nanowires (CuNWs) are becoming an indispensable item for next-generation transparent optical devices due to their excellent conductivity and transparency. In this work,... 相似文献
152.
在对垃圾处理现状进行系统的调查研究的基础上,作者提出了湖北省城镇垃圾处理的合理改革与相应措施. 相似文献
153.
Defense frontier analysis of quantum cryptographic systems 总被引:1,自引:0,他引:1
When a quantum cryptographic system operates in the presence of background noise, security of the key can be recovered by a procedure called key distillation. A key-distillation scheme effective against so-called individual (bitwise-independent) eavesdropping attacks involves sacrifice of some of the data through privacy amplification. We derive the amount of data sacrifice sufficient to defend against individual eavesdropping attacks in both BB84 and B92 protocols and show in what sense the communication becomes secure as a result. We also compare the secrecy capacity of various quantum cryptosystems, taking into account data sacrifice during key distillation, and conclude that the BB84 protocol may offer better performance characteristics than the B92. 相似文献
154.
Generalized spin filters, including several directional filters such as the directional median filter and the directional binary filter, are proposed for removal of the noise of fringe patterns and the extraction of fringe skeletons with the help of fringe-orientation maps (FOM's). The generalized spin filters can filter off noise on fringe patterns and binary fringe patterns efficiently, without distortion of fringe features. A quadrantal angle filter is developed to filter off the FOM. With these new filters, the derivative-sign binary image (DSBI) method for extraction of fringe skeletons is improved considerably. The improved DSBI method can extract high-density skeletons as well as common density skeletons. 相似文献
155.
Summary Catechin binds strongly to both poly(vinylpyrrolidone) and poly(L-proline) in dilute aqueous solution, inducing a collapse of the more flexible poly(vinylpyrrolidone) chains, but forming a microgel with the more extended poly(L-proline) chains. Low concentrations of poly(L-proline) inhibit the discoloration of aqueous solutions of catechin, thereby implicating the ortho hydroxyyl groups in the catechol moiety in the binding process. Modeling shows that the likely binding sites on poly(L-proline) arise from two minor local conformations. These minor conformations are less frequent in poly(-hydroxy-L-proline) than in poly(L-proline), which may explain why catechin interacts more strongly with poly(L-proline) than with poly(-hydroxy-L-proline). 相似文献
156.
T. -C. Sun 《Structural and Multidisciplinary Optimization》1996,11(2):113-119
This paper analyses the design sensitivity of a suspension system with material and geometric nonlinearities for a motorcycle structure. The main procedures include nonlinear structural analysis, formulation of the problem with nonlinear dynamic response, design sensitivity analysis, and optimization. The incremental finite element method is used in structural analysis. The stiffness and damping parameters of the suspension system are considered as design variables. The maximum amplitude of nonlinear transient response at the seat is taken as the objective function during the optimization simulation. A more realistic finite element model for the motorcycle structure with elasto-damping elements of different material models is presented. A comparison is made of the optimum designs with and without geometric nonlinear response and is discussed.Nomenclature A
amplitude of the excitation function
-
a
0,a
1
time integration constants for the Newmark method
-
t+t
C
s
secant viscous damping matrix at timet+t
-
t
C
T
tangent viscous damping matrix at timet
- C
linear part of
t
C
T
-
D
i
0
initial value of thei-th design variable
-
D
i
instanenous value of thei-th design variables
-
t+t
F(t–1)
total internal force vector at the end of iteration (i–1) and timet+t
-
t+t
F
(NL)
(i–1)
nonlinear part of
t+t
F(i–1)
-
f
frequency of the excitation function
-
t+t
K
s
secant stiffness matrix at timet+t
-
t
K
T
tangent stiffness matrix at timet
- K
linear part of
t
K
T
-
effective stiffness matrix at timet
-
L
distance between the wheel centres
- M
constant mass matrix
-
m
T
number of solution time steps
-
NC
number of constraint equations
- Q
nonlinear dynamic equilibrium equation of the structural system
-
t+t
R
external applied load vector at timet+t
-
t
e
active time interval for the excitation function
-
t
U
displacement vector of the finite element assemblage at timet
-
velocity of the finite element assemblage at timet
-
t
Ü
acceleration vector of the finite element assemblage at timet
-
t+t
U
(i)
displacement vector of the finite element assemblage at the end of iterationi and timet+t
-
velocity vector of the finite element assemblage at the end of iterationi and timet+t
-
t+t
Ü(i)
acceleration vector of the finite element assemblage at the end of iterationi and timet+t
- U
(i)
vector of displacement increments from the end of iteration (i–1) to the end of iterationi at timet+t
- V
driving speed of motorcycle
- x
vector of design variable
- ()
quantities of variation
- 0
objective function
-
i
i-th constraint equation 相似文献
157.
利润-CVaR准则下的二级供应链定价与订货策略研究 总被引:1,自引:0,他引:1
传统的定价与订货策略研究多是建立在风险中性的假设之上,近来也有利用风险度量CVaR研究风险厌恶对库存的影响.因此,以期望利润和CVaR的加权平均为目标函数,研究零售商的订货策略,并在此基础上研究上游供应商的定价策略.这样的利润-CVaR目标既反映了决策者追求高利润的愿望,又反映了其对潜在风险的控制. 相似文献
158.
FacetAtlas: multifaceted visualization for rich text corpora 总被引:1,自引:0,他引:1
Cao N Sun J Lin YR Gotz D Liu S Qu H 《IEEE transactions on visualization and computer graphics》2010,16(6):1172-1181
Documents in rich text corpora usually contain multiple facets of information. For example, an article about a specific disease often consists of different facets such as symptom, treatment, cause, diagnosis, prognosis, and prevention. Thus, documents may have different relations based on different facets. Powerful search tools have been developed to help users locate lists of individual documents that are most related to specific keywords. However, there is a lack of effective analysis tools that reveal the multifaceted relations of documents within or cross the document clusters. In this paper, we present FacetAtlas, a multifaceted visualization technique for visually analyzing rich text corpora. FacetAtlas combines search technology with advanced visual analytical tools to convey both global and local patterns simultaneously. We describe several unique aspects of FacetAtlas, including (1) node cliques and multifaceted edges, (2) an optimized density map, and (3) automated opacity pattern enhancement for highlighting visual patterns, (4) interactive context switch between facets. In addition, we demonstrate the power of FacetAtlas through a case study that targets patient education in the health care domain. Our evaluation shows the benefits of this work, especially in support of complex multifaceted data analysis. 相似文献
159.
Yuan X He X Guo H Guo P Kendall W Huang J Zhang Y 《IEEE transactions on visualization and computer graphics》2010,16(6):1413-1420
Over the past few years, large human populations around the world have been affected by an increase in significant seismic activities. For both conducting basic scientific research and for setting critical government policies, it is crucial to be able to explore and understand seismic and geographical information obtained through all scientific instruments. In this work, we present a visual analytics system that enables explorative visualization of seismic data together with satellite-based observational data, and introduce a suite of visual analytical tools. Seismic and satellite data are integrated temporally and spatially. Users can select temporal ;and spatial ranges to zoom in on specific seismic events, as well as to inspect changes both during and after the events. Tools for designing high dimensional transfer functions have been developed to enable efficient and intuitive comprehension of the multi-modal data. Spread-sheet style comparisons are used for data drill-down as well as presentation. Comparisons between distinct seismic events are also provided for characterizing event-wise differences. Our system has been designed for scalability in terms of data size, complexity (i.e. number of modalities), and varying form factors of display environments. 相似文献
160.