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1.
大坝安全监控指标的制定 总被引:10,自引:3,他引:7
本文论述了大坝安全监控指标的含义、制定安全监控指标的意义、制定安全监控指标的基本原则、制定大坝施工阶段和首次蓄水阶段以及运行阶段安全监控指标的方法。 相似文献
2.
3.
C. L. J. A. Verbraak J. Van Dam A. K. Van Der Vegt 《Polymer Engineering and Science》1985,25(7):431-433
Orientation-induced crystallization of crystallizable polymer melts can occur, under certain conditions, during flow through converging channels. Attempts have been made to achieve this phenomenon in a two-phase system, i.e., during simultaneous extrusion of a continuous concentric core of polypropylene within a polystyrene matrix through a conical duct. On one occasion, using Carlona P SY6100 (MFI = 11.0) with Hostyren N2000-V-01 (MFI = 25.0), a highly oriented polypropylene thread with a modulus of 14.6 GPa and a melting point of 178°C was extruded at a die temperature of approximately 170°C and a pressure lower than 40 MPa. It is, in principle, possible to form highly oriented, fiber-like structures as reinforcing elements in a polymer matrix. 相似文献
4.
Dam H.H. Nordholm S. Cantoni A. de Haan J.M. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2004,51(11):581-586
Multirate adaptive filters have numerous advantages such as low computational load, fast convergence, and parallelism in the adaptation. Drawbacks when using multirate processing are mainly related to aliasing and reconstruction effects. These effects can be minimized by introducing appropriate problem formulation and employing sophisticated optimization techniques. In this paper, we propose a formulation for the design of a filter bank which controls the distortion level for each frequency component directly and minimizes the inband aliasing and the residual aliasing between different subbands. The advantage of this problem formulation is that the distortion level can be weighted for each frequency depending on the particular practical application. A new iterative algorithm is proposed to optimize simultaneously over both the analysis and the synthesis filter banks. This algorithm is shown to have a unique solution for each iteration. For a fixed distortion level, the proposed algorithm yields a significant reduction in both the inband aliasing and the residual aliasing levels compared to existing methods applied to the numerical examples. 相似文献
5.
Welch G. State A. Ilie A. Kok-Lim Low Lastra A. Cairns B. Towles H. Fuchs H. Ruigang Yang Becker S. Russo D. Funaro J. van Dam A. 《Multimedia, IEEE》2005,12(3):22-35
Immersive electronic books (IEBooks) for surgical training will let surgeons explore previous surgical procedures in 3D. The authors describe the techniques and tools for creating a preliminary IEBook, embodying some of the basic concepts. 相似文献
6.
Dam H.H. Cantoni A. Nordholm S. Teo K.L. 《IEEE transactions on circuits and systems. I, Regular papers》2006,53(5):1108-1118
In this paper, we formulate a general design of transversal filter structures with maximum relative passband-to-stopband energy ratio subject to complex frequency response constraints in the passband and the stopband as well as additional constraints such as constraints. These constraints are important for applications where the suppression of noise at certain frequencies are important. Additional constraints are introduced allowing approximately linear phase and constant group delay in the passband. For a given set of basis functions, the design problem can be formulated as a semi-infinite quadratic optimization problem in the filter coefficients, which are the decision variables to be optimized. In this paper, we focus on the design of digital Laguerre filter and digital finite impulse response (FIR) filter structures. A modified bridging algorithm is developed for searching for the optimum pole of the Laguerre filters. Design examples are given to demonstrate the effectiveness of the proposed algorithm. 相似文献
7.
Polyaniline (PAN), poly(o‐bromoaniline) (POBA), and poly(aniline‐co‐o‐bromoaniline) (PABA) were synthesized by oxidative coupling. These polymers are protonated by 10–20% methane sulfonic acid (MSA) and 1M HCl. The new polymer bases have greater solubility than that of PAN in common polar organic solvents; PAN–MSA was observed to be the most thermally stable of these polymers. POBA is associated with residual quinoid diimine units as illustrated in the IR and UV‐vis spectra, after reduction with hydrazine dihydrochloride. Both the doping agents cause a downward shift of the quinoid absorption in the IR spectra. MSA‐ and HCl‐doped PAN and PABA polymers exhibit a coil‐like conformation in DMSO, whereas only MSA‐doped PAN and PABA show an “expanded coil‐like” conformation in m‐cresol with a “free carrier tail” above 800 nm in their electronic spectra. XPS spectra indicated the presence of covalent bromine in the POBA and PABA polymers. Bromine retention was greater in the homopolymer as evidenced by the IR studies after aging at 350°C. Compared to HCl, MSA is found to be a more effective dopant, enhancing the conductivity of the copolymers by 102–103 times in magnitude. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2662–2669, 2002 相似文献
8.
Eugenia Awuah Boadi Samuel Shin Samuel Yeroushalmi Bok-Eum Choi Peijun Li Bidhan C. Bandyopadhyay 《International journal of molecular sciences》2021,22(6)
Proximal tubular (PT) acidosis, which alkalinizes the urinary filtrate, together with Ca2+ supersaturation in PT can induce luminal calcium phosphate (CaP) crystal formation. While such CaP crystals are known to act as a nidus for CaP/calcium oxalate (CaOx) mixed stone formation, the regulation of PT luminal Ca2+ concentration ([Ca2+]) under elevated pH and/or high [Ca2+] conditions are unknown. Since we found that transient receptor potential canonical 3 (TRPC3) knockout (KO; -/-) mice could produce mild hypercalciuria with CaP urine crystals, we alkalinized the tubular pH in TRPC3-/- mice by oral acetazolamide (0.08%) to develop mixed urinary crystals akin to clinical signs of calcium nephrolithiasis (CaNL). Our ratiometric (λ340/380) intracellular [Ca2+] measurements reveal that such alkalization not only upsurges Ca2+ influx into PT cells, but the mode of Ca2+ entry switches from receptor-operated to store-operated pathway. Electrophysiological experiments show enhanced bicarbonate related current activity in treated PT cells which may determine the stone-forming phenotypes (CaP or CaP/CaOx). Moreover, such alkalization promotes reactive oxygen species generation, and upregulation of calcification, inflammation, fibrosis, and apoptosis in PT cells, which were exacerbated in absence of TRPC3. Altogether, the pH-induced alteration of the Ca2+ signaling signature in PT cells from TRPC3 ablated mice exacerbated the pathophysiology of mixed urinary stone formation, which may aid in uncovering the downstream mechanism of CaNL. 相似文献
9.
van Dam 《Algorithmica》2008,34(4):413-428
Abstract. In this article we investigate how we can employ the structure of combinatorial objects like Hadamard matrices and weighing
matrices to devise new quantum algorithms. We show how the properties of a weighing matrix can be used to construct a problem
for which the quantum query complexity is significantly lower than the classical one. It is pointed out that this scheme captures
both Bernstein and Vazirani's inner-product protocol, as well as Grover's search algorithm.
In the second part of the article we consider Paley's construction of Hadamard matrices, which relies on the properties of
quadratic characters over finite fields. We design a query problem that uses the Legendre symbol χ (which indicates if an element of a finite field F
q
is a quadratic residue or not). It is shown how for a shifted Legendre function f
s
(i)=χ(i+s) , the unknown s ∈ F
q
can be obtained exactly with only two quantum calls to f
s
. This is in sharp contrast with the observation that any classical, probabilistic procedure requires more than log q + log ((1-ɛ )/2) queries to solve the same problem. 相似文献
10.
Runtime monitoring is an established technique to enforce a wide range of program safety and security properties. We present a formalization of monitoring and monitor inlining, for the Java Virtual Machine. Monitors are security automata given in a special-purpose monitor specification language, ConSpec. The automata operate on finite or infinite strings of calls to a fixed API, allowing local dependencies on parameter values and heap content. We use a two-level class file annotation scheme to characterize two key properties: (i) that the program is correct with respect to the monitor as a constraint on allowed program behavior, and (ii) that the program has a copy of the given monitor embedded into it. As the main application of these results we sketch a simple inlining algorithm and show how the two-level annotations can be completed to produce a fully annotated program which is valid in the standard sense of Floyd/Hoare logic. This establishes the mediation property that inlined programs are guaranteed to adhere to the intended policy. Furthermore, validity can be checked efficiently using a weakest precondition based annotation checker, thus preparing the ground for on-device checking of policy adherence in a proof-carrying code setting. 相似文献