The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Polybutadiene-graft-polystyrene (PB-g-PS) latex with a core-shell weight ratio of 50/50 was used to modify cement mortar. In the constant water-cement ratio of 0.5, and curing 24h at 20 °C, RH90% air followed using two curing methods (6d immersed in 20°C water followed by 21d at 20°C, RH 65%air or 27d at 20°Cwater). At the different polymer-cement weight ratios (P/C), polymer-modified mortars (PMMs)...
Sustainable development principle is a creative and practical idea, which organically combines the needs of environment protection and economic development. The conflicts between environment and development are obvious and intense in climate change issue. The international regime of climate change has already successfully introduced sustainable development principle into the legal instruments and...
In designing high-speed system, signal reflection and crosstalk often cause many signal integrity issues. We are using Mentor PADS2007/HyperLynx to design a high-speed system with TMS320DM6446, a high performance video processing chip. The pre-layout high-speed signal lines of this DSP image processing system are throughout simulated. These widespread issues of signal integrity, especially reflection...
The sheet beam klystron (SBK) is characterized by a large rectangular drift tube, which allows the use of a high current, low voltage beam, resulting in a low beam current density, and hence high efficiency and the possibility of Periodic Permanent Magnet (PPM) focusing. Our research group has designed a 5-Cavity X-Band SBK recently. In this paper, we discusses the general design of this X-Band SBK...
The transport of an elliptic sheet electron beam with uniform density in uniform magnetic field is investigated by making use of a macroscopic cold-fluid model. General envelope equations and beam twisted angles are derived. In particular, the tilt of the elliptic sheet beam was numerically calculated by an example of W-band sheet beam klystron.
Locally Linear Embedding (LLE) is a popular dimension reduction technique due to its nonlinearity property. However, LLE is restricted to its unsupervised nature and “out-of-sample problem” in which suboptimal to face recognition problem. Hence, we propose a supervised and linear approximation of LLE, known as Neighborhood Preserving Discriminant Embedding (NPDE). Using the class information, NPDE...
Based on the N-S and Maxwell equation, a mathematical model describing the arc behavior in SF6 circuit breaker (CB) has been deduced. The effect of Lorentz force, turbulent and physical parameters on the characteristic of arc plasma was considered in the model. Using the finite volume method, the distributions of controlling parameters for arc in SF6 circuit breaker, such as viscosity, electric conductivity,...
Space heating accounts for the greatest energy consumption in cold regions of China. Proper application of thermal insulation is one of the most effective energy conservation measures for residential buildings. Therefore, determining and selecting the optimum thickness of insulation is important not only for the environment but also for the energy costs. In this paper, a mathematical model demonstrating...
Energy efficiency retrofit for existing residential buildings is facing a fast development in China. As the first set demonstrative buildings of the Sino-German “Chinese existing Building Energy Efficiency Improvement” project, economic efficiency analysis has been made in this paper. The scheme and cost of Hebei No.1 Residential Quarter are summarized in this paper. Heating energy consumption of...
In this paper, the ponderomotive focusing forces are derived for a sheet electron beam in both periodic cusped magnetic and wiggler magnetic field configurations, which has a large aspect ratio, using two-time scale analytical method.
At millimeter wavelengths, there is a growing need for a small size and weight, high average power RF source. The sheet beam klystron (SBK) is ideally suited to many of these needs. The SBK is characterized by a large rectangular drift tube, which allows the use of a high current, low voltage beam, resulting in a low beam current density, and hence high efficiency and the possibility of PPM focusing.
However with China entering into the WTO, the big clearance in national seaport will soon realize, immigration traveler's number will be fast increasing, at the same time, anti-illegal immigrant conflict would also be more intense and complicated. Under such condition the analysis of anti-illegal immigrant intelligence has many difficulties. So data mining technology will be introduced in anti-illegal...
Wind erosion is an important environmental problem, thus researchers have used many methods to study it. The methods that have been used mainly involved theoretical analysis, experimental measurements under artificial conditions (e.g., in wind tunnels), and numerical simulations using a range of models. However, the results of these studies differ, and are not always satisfactory, particularly in...
Snow dynamic change is the hot issue of global climate change. Qilian Mountain located in the southern of Hexi Corridor, and is the sensitive and key area of climatic change in arid regions. Its snow's dynamic distribution has the important meaning to climatic change's influence and the response. Under the background of the climate warming, snow area of the Qilian Mountains has changed. This paper...
Freshwater environments contribute more than 20% of total CH4 flux to the atmosphere, and the lakes are one of the major natural sources of atmospheric CH4, mainly in boreal lakes. So, we present and analyze the temporal and spatial variations of CH4 VMRs over Lake Baikal, the only freshwater body, the unique large and high latitude lake, based on the retrieved monthly CH4 data from SCIAMACHY spectra...
DICOM standard is an indispensable component ofPACS, but due to non-DICOM images can be fast loaded and portable with compression, many non-DICOM medical imaging equipments are still widely used in the hospital system, which has led to existence of many non-DICOM medical images. However, the non-DICOM images are unsuitable for doctors to diagnose and study. In this paper, a low-load architecture is...
Graph Embedding (GE) along with its linearization outperforms the traditional linear dimension reduction techniques in face recognition, but there is still room for improvement on GE. This paper proposes an eigenvector weighting technique for a realization of linear GE, namely Neighbourhood Preserving Embedding (NPE) in face verification. The proposed method is called Eigenvector Weighting Function...
For most people, majority of their lives are spent in an indoor environment. With the improvement of living, indoor air pollution is impacting human health. In this paper, through analysis of sources and adverse health effects of several common indoor air pollutants, air pollutants are major contributing factors to chronic diseases and mortality. It should be treated urgently with the people's standard...
The sheet beam klystron (SBK) uses a high aspect ratio, thin rectangular beam to reduce space charge effects, increase power capability and beam-wave interaction efficiency. In this paper, a Rod model for the sheet beam was studied, and a 2.5D large signal program based on this model was developed to calculate the beam-wave interaction of SBK.
The paper has put forward an idea about the teaching reformation to course of probability and statistics in agriculture and forestry universities. We have paid attention to the theory contact with practice. We also present a new teaching method that the idea of mathematical modeling is applied in the teaching process of application cases to reform teaching methods and seek new teaching modes. Students'...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.