Comparison of vander lugt and joint transform correlators

A generalized optical correlator is used to analyze the performances of the Vander Lugt and the joint transform architectures. Noise performance and the effects caused by the differences between the input and the reference functions are analyzed. It is found that the modulation index of the joint transform filter decreases due to the presence of noise as well as the differences between the input and the reference functions. However, it is found that, in general, the joint transform correlator would perform better than the Vander Lugt correlator and certainly has the advantage for real-time implementation.     

The synthesis of 1,2,5-thiadiazolo[3,4-d] pyridazines

A number of previously unreported 1,2,5-thiadiazolo[3,4-d]pyridazines in this relatively unexplored ring system have been reported, charaeterized and screened for antibacterial and antifungal activity.     

Anomalous ultrasonic attenuation in vitreous silica at low temperatures

The attenuation of longitudinal sound waves of 750 and 970 MHz has been determined in vitreous silica down to 0.4 K. The unsaturated attenuation observed at the smallest incident acoustic intensities allows a quantitative comparison with the “tunneling model” for glasses.     

Differential cross section,analyzing power and phase shifts for p-3He elastic scattering below 1.0 MeV

Differential cross sections and analyzing powers for the elastic scattering of polarized protons by unpolarized ³He nuclei have been measured at eight energies between 0.3 MeV and 1.0 MeV for scattering angles θ_c.m. = 52.4°–173.3°. The cross-section values were normalized to the Rutherford cross section for proton-krypton scattering. The analyzing powers have been measured with a statistical accuracy of about 0.001. The phase-shift analysis based on these data included all phases for orbital angular momenta l ≦ 1 and the channel-spin mixing parameter for the P waves. An energy parametrization of the phase shifts by an effective-range approximation allowed a simultaneous utilization of all data.     

Two-wavelength operation of a tunable KrF excimer laser — A promising technique for combustion diagnostics

A KrF excimer laser was operated on two independently tunable lines. This was achieved by a double-resonator configuration with two gratings. Tuning range and gain competition were investigated. The narrow line width (<1 cm^–1) and the independent tunability make this laser ideal for simultaneous spectroscopic detection of two species and temperature measurements in combustion processes.     

Hexamethylsilirane: II. Ring-opening reactions with some simple reagents

Ring-opening reactions formally of the type Me₂SiCMe₂CMe₂ ? X-H→ Me₂XSiCMe₂CMe₂H occur on reaction of hexamethylsilirane with water, alcohols, ammonia, amines, HCl and car?ylic acids and germanium and tin hydrides. More complicated ring opening reactions are observed with halogens, tetrahalomethanes and molecular oxygen. The oxidation and protolysis (H₂O, ROH, HCl, RCO₂H, NH₃, amines) reactions of hexamethylsilirane are exothermic at room temperature.     

Nuclear electric quadrupole moment of41Ca by laser-RF spectroscopy

Zeitschrift für Physik A Hadrons and nuclei - The nuclear electric quadrupole moment of41Ca, which contains a single neutron outside closed proton and neutron shells (N=Z=20) has been...     

Optimization in Mean and Phase Transitions in Controlled Dynamical Systems

The time mean of a smooth objective function along a phase trajectory of a controlled dynamical system is maximized. The simplest singularities of the dependence of the optimal mean value on the parameter in generic one-parameter families of controlled systems of this kind are listed. It turns out that the most common generic stable singularity is the discontinuity of the first or second derivative of the optimal mean value with respect to the parameter.     

Convergence of the multigrid full approximation scheme for a class of elliptic mildly nonlinear boundary value problems

Summary The multigrid full approximation scheme (FAS MG) is a well-known solver for nonlinear boundary value problems. In this paper we restrict ourselves to a class of second order elliptic mildly nonlinear problems and we give local conditions, e.g. a local Lipschitz condition on the derivative of the continuous operator, under which the FAS MG with suitably chosen parameters locally converges. We prove quantitative convergence statements and deduce explicit bounds for important quantities such as the radius of a ball of guaranteed convergence, the number of smoothings needed, the number of coarse grid corrections needed and the number of FAS MG iterations needed in a nested iteration. These bounds show well-known features of the FAS MG scheme.