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21.
Abstract. Rupture of a light cellophane diaphragm in an expansion tube has been studied by an optical method. The influence of the
light diaphragm on test flow generation has long been recognised, however the diaphragm rupture mechanism is less well known.
It has been previously postulated that the diaphragm ruptures around its periphery due to the dynamic pressure loading of
the shock wave, with the diaphragm material at some stage being removed from the flow to allow the shock to accelerate to
the measured speeds downstream. The images obtained in this series of experiments are the first to show the mechanism of diaphragm
rupture and mass removal in an expansion tube. A light diaphragm was impulsively loaded via a shock wave and a series of images
was recorded holographically throughout the rupture process, showing gradual destruction of the diaphragm. Features such as
the diaphragm material, the interface between gases, and a reflected shock were clearly visualised. Both qualitative and quantitative
aspects of the rupture dynamics were derived from the images and compared with existing one-dimensional theory.
Received 10 April 1999 / Accepted 17 April 2000 相似文献
22.
Dr. Dong‐Sik Shin Dr. Jungmok You Ali Rahimian Tam Vu Christian Siltanen Arshia Ehsanipour Dr. Gulnaz Stybayeva Prof. Julie Sutcliffe Prof. Alexander Revzin 《Angewandte Chemie (International ed. in English)》2014,53(31):8221-8224
Cells may be captured and released using a photodegradable hydrogel (photogel) functionalized with antibodies. Photogel substrates were used to first isolate human CD4 or CD8 T‐cells from a heterogeneous cell suspension and then to release desired cells or groups of cells by UV‐induced photodegradation. Flow cytometry analysis of the retrieved cells revealed approximately 95 % purity of CD4 and CD8 T‐cells, suggesting that this substrate had excellent specificity. To demonstrate the possibility of sorting cells according to their function, photogel substrates that were functionalized with anti‐CD4 and anti‐TNF‐α antibodies were prepared. Single cells captured and stimulated on such substrates were identified by the fluorescence “halo” after immunofluorescent staining and could be retrieved by site‐specific exposure to UV light through a microscope objective. Overall, it was demonstrated that functional photodegradable hydrogels enable the capture, analysis, and sorting of live cells. 相似文献
23.
B. T. Sutcliffe 《Theoretical chemistry accounts》1975,39(1):93-102
It is shown that in the LCAO-MO-MC-SCF problem, if the molecular orbital orthonormality constraints are introduced in the manner suggested by Kari and Sutcliffe or indeed by any similar method then the Hessian of the problem with respect to the linear coefficients is singular. The nature of this singularity is analysed and it is shown that in general it is possible to remove it in a level-shifting-like scheme, but that only in certain special cases is this procedure likely to be quickly convergent. 相似文献
24.
An exact, within the Born–Oppenheimer approximation, body-fixed Hamiltonian for the nuclear motions of a triatomic system is presented. This Hamiltonian is expressed in terms of two arbitrarily defined internal distances and the angle between them. The body-fixed axis system is related to these coordinates in a general fashion. Problems with singularities and the domain of the Hamiltonian are discussed using specific examples of axis embedding. A number of commonly used coordinate systems including Jacobi, bond-length-bond-angle, and Radau coordinates are special cases of this Hamiltonian. Sample calculations on the H2S molecule are presented using all these and other coordinate systems. The possibility of using this Hamiltonian for reactive scattering calculations is also discussed. 相似文献
25.
Circular plates that are stamped into a shallow, biaxially curved die by a matching punch develop radial wrinkles near the
periphery when the edge is not clamped. Thin ductile metal plates develop these wrinkles after some plastic deformation occurs
at the center of the plate. In comparison with elastic wrinkling, the center deflection to thickness ratio for wrinkling is
increased as a consequence of the plastic deformation. In elastoplastic plates, this critical deflection ratio is a decreasing
function of the plate thickness parameter ξo 相似文献
26.
27.
Dimensional reduction of the self-dual Yang-Mills equation in 2+2 dimensions produces an integrable Yang-Mills-Higgs-Bogomolnyi
equation in 2+1 dimensions. For theSU(1,1) gauge group, a t'Hooft-like ansatz is used to construct a monopole-like solution and an N-soliton-type solution, which
describes both the static deformed monopoles and the exotic monopole dynamics including a transmutation. How the monopole
solution results from the twistor formalism is shown. Multimonopole solutions are commented on.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 117, No. 3, pp. 339–350, December, 1998. 相似文献
28.
29.
A method of forming the CI Hamiltonian matrix directly from a list of Bonded Functions and the MO-SCF wavefunction is proposed. For small expansions (circa 500 members) this method is definitely more efficient than the normal symbolic techniques and can be more efficient than iterative energy construction techniques. 相似文献
30.
The structure of tomentin has been confirmed as 5-hydroxy-6,7-dimethoxycoumarin (2), the derived 3,3-dimethylallyl ether giving a para-Claisen rearrangement product. Relief of strain in the corresponding 1,1-dimethylallyl ether has been found to result in a novel regiospecific ortho-Claisen rearrangement occurring on silica at room temperature. The structure 18 of the stable ortho-dienone formed has been confirmed by conversion of the corresponding dehydrodienone (15), obtained from the rearrangement of tomentin 1,1-dimethylpropargyl ether, to alloxanthoxyletin (25). 相似文献