Embossing is the art of decorating metals in relief from the reverse side. This article describes how virtual embossing can
be done using a functionally based representation of the metal plate and the tools. The program is implemented as an interactive
shape modeler where a functional model of the metal plate is subsequently modified with offset and set-theoretic operations.
For visualization, interactive ray tracing is used. Bounding boxes together with the spatial organization of the functional
model provide the required fast function evaluation that is usually a bottleneck for functionally based shape modeling systems.
The program runs on a personal computer. 相似文献
A theory is developed for describing liquid chromatography of ring diblock and multiblock copolymers. The chromatographic behavior of ring block copolymers at different adsorption interactions is analyzed theoretically and compared with that of linear block copolymers; typical chromatograms are simulated by using the theory. In particular, it is shown that under the critical interaction condition for one block the chromatographic retention of a ring diblock copolymer is dependent of the length of the ‘critical’ block; this behavior differs qualitatively from that of a linear diblock copolymer. Ring copolymers are always more retained than linear ones, therefore such copolymers can be separated. Especially good separation of heterogeneous ring and linear block copolymers is predicted at near-critical interaction conditions. According to the theory, ring diblocks and multiblocks can be separated as well, if one component of a copolymer is adsorbing, while the other one is not adsorbing. 相似文献
The second largest national consumer of commercial energy in the world, the USSR also emits large quantities of energy-related CO2. This study uses four long-term scenarios of energy use and related emissions to investigate opportunities for reducing the USSR's greenhouse gas emissions over the next 30 years. This paper shows that if no measures are taken to control these emissions, CO2 and methane will increase by 1.5 to 2 times the 1990 level by the year 2020. However, this growth can be restrained dramatically through structural changes in the Soviet economy, improved energy efficiency and interfuel substitutions. Abating emissions of carbon in the USSR would entail the widespread implementation of energy policies and, for more substantial reductions, higher investments from the Soviet economy. Achieving these goals would also require broad support from the international community. 相似文献
Many categories of objects, such as human faces, can be naturally viewed as a composition of several different layers. For example, a bearded face with glasses can be decomposed into three layers: a layer for glasses, a layer for the beard and a layer for other permanent facial features. While modeling such a face with a linear subspace model could be very difficult, layer separation allows for easy modeling and modification of some certain structures while leaving others unchanged. In this paper, we present a method for automatic layer extraction and its applications to face synthesis and editing. Layers are automatically extracted by utilizing the differences between subspaces and modeled separately. We show that our method can be used for tasks such beard removal (virtual shaving), beard synthesis, and beard transfer, among others. 相似文献
Loading of gases in diamond anvil cells is a complicated but necessary task to obtain hydrostatic conditions for high-pressure measurements. A simple in operation, safe, and universal gas-loading system has been designed and constructed. Innovations were introduced to simplify the loading procedure up to the "three-button" mode. 相似文献
The design of a novel Schönflies-motion generator (SMG) is the focus of the paper. Schönflies motions are characterized by four degrees of freedom: three independent translations and one rotation about one axis of fixed orientation. The two driving modules of the manipulator are intended to produce, each, two independent motions, pan and tilt. The design philosophy and the layout of the SMG are discussed, along with the design procedure, which includes: (i) part-modelling and visualization, with animation of the device; (ii) evaluation of the main parameters and the characteristics of the different structural realizations, as well as the selection of one single structure meeting best the design specifications; (iii) the design of the main components for the selected variant of the structure; (iv) the structural and modal analyses and determination of the inertial and elastic parameters of the device and its components; and (v) the production of detailed manufacturing drawings. Further results of structural and modal analyses of the SMG are considered, while the link geometry is defined based on the design specifications. 相似文献
Nanoparticles of different metals (Pt, Pd, Au) or a metal hydroxide (Ru) have been immobilized on the surface of mesoporous
titanate nanotubes produced by alkali hydrothermal treatment of TiO2, and have been characterized by HRTEM. Two different approaches have been utilised for the deposition of metal particles
into the internal pores of titanate nanotubes: (i) deposition from solution confined inside the nanotubes and (ii) blocking the external surface of the nanotubes. A third method, ion-exchange of protons onto metal cations in titanate nanotubes
followed by reduction or alkali treatment (in the case of Ru hydroxide), has been used for deposition of metal nano-particles
on both the internal and external surfaces of the nanotubes. Nanoparticles of metal or metal hydroxide deposited by the ion-exchange
method are characterised by an average size in the range of 1.2–5 nm, and deposits are uniformly distributed on the surface,
resulting in a very high loading density. An increase in the amount of deposited metal resulted predominantly in a higher
nanoparticle loading density, without growth in the particle size. This was correlated with the retention of high specific
catalytic activity of ruthenium hydrated oxide deposited on titanate nanotubes in the reaction of selective oxidation of benzyl
alcohol over a wide range (0.6–8.7 wt%) of ruthenium loading. The methods for metallization of titanate nanotubes are critically
discussed. 相似文献
Scaling up from prototype systems to dense arrays of ions on chip, or vast networks of ions connected by photonic channels, will require developing entirely new technologies that combine miniaturized ion trapping systems with devices to capture, transmit, and detect light, while refining how ions are confined and controlled. Building a cohesive ion system from such diverse parts involves many challenges, including navigating materials incompatibilities and undesired coupling between elements. Here, we review our recent efforts to create scalable ion systems incorporating unconventional materials such as graphene and indium tin oxide, integrating devices like optical fibers and mirrors, and exploring alternative ion loading and trapping techniques.