瓦楞原纸对瓦楞辊顶端动态包角的程序计算

讨论了瓦楞原纸对瓦楞辊顶端包角的计算方法 ,指出总包角的大小是一个动态变化的值 ,并通过实例编程计算 ,得到了一个周期内该值的变化规律     

高效紧凑的高频地波雷达天线阵列设计

分析了高频地波雷达阵列单元天线和阵列的设计原理,提出并成功设计出了一套高效紧凑、一发八收、收发共用的高频地波海洋环境监测雷达天线阵列.计算机模拟和现场试验结果说明了本文设计方案的合理性.     

并行开发加速无线互联

移动用户对无线终端功能的更高要求,使得缓慢的串行开发模式很难再持续下去     

Specification Diagrams for Actor Systems

Specification diagrams (SD's) are a novel form of graphical notation for specifying open distributed object systems. The design goal is to define notation for specifying message-passing behavior that is expressive, intuitively understandable, and that has formal semantic underpinnings. The notation generalizes informal notations such as UML's Sequence Diagrams and broadens their applicability to later in the design cycle. Specification diagrams differ from existing actor and process algebra presentations in that they are not executable per se; instead, like logics, they are inherently more biased toward specification. In this paper we rigorously define the language syntax and semantics and give examples that show the expressiveness of the language, how properties of specifications may be asserted diagrammatically, and how it is possible to reason rigorously and modularly about specification diagrams.     

Analysis and design of ribbon cables for high‐speed digital applications

Ribbon cables have been widely used as subsystem interconnections in a large number of digital systems, because they can convey numerous bits of a digital signal simultaneously. In this article, finite difference and finite difference time domain (FDTD) methods are used to analyze and optimize the electrostatic analysis design of ribbon cables, and measurements are used to verify the numerical results. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12: 148–158, 2002.     

Synthesis of mechanical networks: the inerter

The paper is concerned with the problem of synthesis of (passive) mechanical one-port networks. One of the main contributions of the paper is the introduction of a device, which win be called the inerter, which is the true network dual of the spring. This contrasts with the mass element which, by definition, always has one terminal connected to ground. The inerter allows electrical circuits to be translated over to mechanical ones in a completely analogous way. The inerter need not have large mass. This allows any arbitrary positive-real impedance to be synthesized mechanically using physical components which may be assumed to have small mass compared to other structures to which they may be attached. The possible application of the inerter is considered to a vibration absorption problem, a suspension strut design, and as a simulated.     

Charge reduction electrospray mass spectrometry

A new mass spectrometric technique, charge reduction electrospray mass spectrometry (CREMS), allowing the analysis of complex mixtures of biological molecules is described. The charge state of ions produced by electrospray ionization may be reduced in a controlled manner to yield predominantly singly charged ions through reactions with bipolar (i.e., both positively and negatively charged) ions generated using a 210Po alpha particle source. The electrospray-generated multiply charged ions undergo charge reduction in a "neutralization chamber" positioned before the entrance nozzle to the mass spectrometer. The ions are detected using a commercial orthogonal electrospray time-of-flight mass spectrometer, although the neutralization chamber can be adapted to virtually any mass analyzer. The CREMS results obtained exhibit a signal intensity drop-off with increasing oligonucleotide size similar to that observed with matrix-assisted laser desorption/ionization mass spectrometry. Proton-transfer reactions were found to be responsible for reducing charge on proteins and oligonucleotides in both positive and negative ion mode.     

Stepwise mobilization of focused proteins in capillary isoelectric focusing mass spectrometry

A stepwise mobilization strategy has been developed for the elution of complex protein mixtures, separated by capillary isoelectric focusing (CIEF) for detection using on-line electrospray ionization mass spectrometry (ESI-MS). Carrier polyampholytes are used to establish a pH gradient as well as to control the electroosmotic flow arising from the use of uncoated fused-silica capillaries. Elution of focused protein zones is achieved by controlling the mobilization pressure and voltage, leaving the remaining protein zones focused inside the capillary. Protein zones are stepwise eluted from the capillary by changing the mobilization conditions. Stepwise mobilization improves separation resolution and simplifies coupling with multistage MS (i.e., MSn) analysis since it allows more effective temporal control of protein elution from the CIEF capillary. We also describe a modified configuration for coupling CIEF with ESI-MS using a coaxial sheath flow interface that facilitate the automation of on-line CIEF-ESI-MS analyses. The stepwise mobilization strategy is demonstrated for the analysis of standard protein mixtures and soluble E. coli lysate proteins using CIEF-ESI-MS. These results indicate that inlet pressure or voltage programming to control the elution of the protein zones from the capillary (i.e., gradient mobilization) may allow for the optimization of the mobilization conditions and provide higher resolution for CIEF separation of complex mixtures with on-line MS.     

Work organization and ergonomics

This paper examines the impact of sociotechnical and business trends on work organization and ergonomics. This analysis is performed with the use of Balance Theory (Smith and Carayon-Sainfort, Int. J. Ind. Ergon. 1989, 4, 67–79. The impact on work organization and the work system of the following sociotechnical and business trends is discussed: re-structuring and re-organizing of companies, new forms of work organization, workforce diversity, and information and communication technology. An expansion of Balance Theory, from the design of work systems to the design of organizations, is discussed. Finally, the issue of change is examined. Several elements and methods are discussed for the design of change processes.     

Incidence of foodborne illnesses reported by the foodborne diseases active surveillance network (FoodNet)-1997. FoodNet Working Group

In 1997, the Foodborne Diseases Active Surveillance Program (FoodNet) conducted active surveillance for culture-confirmed cases of Campylobacter, Escherichia coli O157, Listeria, Salmonella, Shigella, Vibrio, Yersinia, Cyclospora, and Cryptosporidium in five Emerging Infections Program sites. FoodNet is a collaborative effort of the Centers for Disease Control and Prevention's National Center for Infectious Diseases, the United States Department of Agriculture's Food Safety and Inspection Service, the Food and Drug Administration's Center for Food Safety and Applied Nutrition, and state health departments in California, Connecticut, Georgia, Minnesota, and Oregon. The population under active surveillance for foodborne infections was approximately 16.1 million persons or roughly 6% of the United States Population. Through weekly or monthly contact with all clinical laboratories in these sites, 8,576 total isolations were recorded: 2,205 cases of salmonellosis, 1,273 cases of shigellosis, 468 cases of cryptosporidiosis, 340 of E. coli O157:H7 infections, 139 of yersiniosis, 77 of listeriosis, 51 of Vibrio infections, and 49 of cyclosporiasis. Results from 1997 demonstrate that while there are regional and seasonal differences in reported incidence rates of certain bacterial and parasitic diseases, and that some pathogens showed a change in incidence from 1996, the overall incidence of illness caused by pathogens under surveillance was stable. More data over more years are needed to assess if observed variations in incidence reflect yearly fluctuations or true changes in the burden of foodborne illness.