科技论文中英文摘要的重要性

在我国几千种科技期刊中,被SCI及EI作为期刊源收录的期刊只有100多家,其中高校学报20多家.这并不能反映我国科技期刊的整体水平.究其原因,它同出版者不够重视与国外检索机构的联系、出版不及时、一稿多投造成期刊内容雷同等有关;但作者对中英文摘要的重要性认识不够,摘要不能说明论文研究的主要问题,英文摘要不符合英文表达习惯,从而导致这些研究成果不能被转摘或收录,也是一个重要原因.     

On the importance of direct resistance heating in thermo-mechanical fatigue

A computationally efficient method of determining the temperature distribution and stress intensity factor induced by the resistance heating method of cycling temperature in thermo-mechanical fatigue is presented. It is further used to evaluate the importance of the singularity of the heat source caused by the electric current. Results indicate the thermally induced stress intensity factor of cracked components cycled by the direct resistance method of heating increases with the frequency of the thermal loading and may become quite large at higher frequencies.     

On the importance of cross-sectional warping in solid composite beams

The relative importance of the cross-sectional warping components in composite beams is studied and demonstrated using an exact solution for solid orthotropic beam of arbitrary cross-sectional geometry that undergoes a bending moment. In light of the effort required for warping modeling in general numerical schemes of composite beams, the present study contributes to the understanding of the importance of modeling the in-plane and the out-of-plane warping components.     

The scientific economy of attention: A novel approach to the collective rationality of science

Science is the core sector of present-day knowledge production. Yet, the mechanisms of science as an industry are poorly understood. The economic theory of science is still in its infancy, and philosophy of science has only sparsely addressed the issue of economic rationality. Research, however, is costly. Inefficient use of resources consumed by the scientific industry is as detrimental to the collective advancement of knowledge as are deficiencies in method. Economic inefficiency encompasses methodological inadequacy. Methods are inadequate if they tend to misallocate time and effort. If one omits the question of how inputs are transformed into outputs in self-organised knowledge production, this means neglecting an essential aspect of the collective rationality of science. A self-organised tendency towards efficiency comes to the fore as soon as science is described as an economy in which researchers invest their own attention in order to obtain the attention of others. Viewed like this, scientific communication appears to be a market where information is exchanged for attention. Scientific information is measured in terms of the attention it earns. Since scientists demand scientific information as a means of production, the attention that a theory attracts is a measure of its value as a capital good. On the other hand, the attention a scientist earns is capitalised into the asset called reputation. Elaborating the ideas introduced in Franck (1998) and (1999), the paper describes science as a highly developed market economy. Science conceived as capital market covers the specific conditions under which scientists, while maximising their reputation, optimise output in the eyes of those competent to judge. Attention is not just any resource. It is the resource whose efficient use is called intelligence. Science, as an industry transforming attention into cognitive output, is bound to miss the hallmark of rationality if it does not pass a test of collective intelligence. The paper closes with considering the prospective outcome of such a test. This revised version was published online in June 2006 with corrections to the Cover Date.     

On the Enhancement of the SNR of Repetitive Signals by Digital Averaging

A simplified technique to improve the signal-to-noise ratio (SNR) of repetitive signals by digital averaging is presented. The technique uses a threshold detector and a memory instead of the analog-to-digital converter and memory, which is the common practice. It is shown that if the SNR of the measurements is small and the number of averaged measurements is large then the SNR of the resulting signal is smaller but comparable to that obtained by the usual procedure. The nonlinear distortion introduced by the process is also discussed.     

On the importance of viscoelastic response consideration in structural design optimization

In this paper we present a series of mathematical proofs that demonstrate the importance of accounting for viscoelastic effects in structural optimization algorithms. Focusing specifically on mass minimization problems with stiffness and deflection constraints, we show that standard techniques based on linear elastic analysis overestimate the long-term stiffness of the structure, leading to designs that become infeasible after sustained loading due to viscoelastic creep. Conversely, assuming maximum creep deflection, which also allows for linear analysis, leads to an overly conservative design that is unnecessarily heavy and therefore suboptimal. We prove both propositions for both constant and time-varying load histories. We also present proofs for generalized continuum mechanics problems as well as for a finite element formulation, which can be applied to any arbitrary geometry. Lastly, we present two numerical examples in which the conclusions derived in the proofs are verified empirically.     

The importance of the Strasbourg period in L. I. Mandelstam's life for his further work in science

L.I. Mandelstam, the outstanding Soviet physicist, leader of a prominent and productive scientific community, was educated as a physicist and started as a researcher and an university teacher at Strasbourg University. We consider the intellectual influence of the main currents in contemporary German science on Mandelstam's work in science. This article represents the results of research which is supported by a fellowship of the Deutsches Museum and the Russian Foundation of Scientific Research in Humanities grant.     

On the supplementary functions of science and technology indicators

Starting from a simple phase model for scientific and technological progress the supplementary functions of various science and technology indicators are discussed. In particular, patent and literature indicators in the field of telecommunicationsR&D in West Germany are presented and compared. In addition, a few selected technometric,R&D expenditure, and trade data are included for the sake of completeness. This network of science and technology indicators is employed to analyse the institutional set up and the trends in telecommunicationsR&D on the macro-level (national level) as well as for singleR&D actors (institutional or micro-level). Further, the role of academic and other publicR&D in West Germany, including the regional distribution of activities and the specialization with respect to telecommunication subfields, are assessed. It is concluded that the various science and technology indicators — at least in the case of West German telecommunications —supplement each other. Synergisms between indicators do exist and should be explored better in future work. The case of telecommunications is ideal for such an exploratory assessment as it includes basic and applied research as well as strong industrial development activities.     

On the importance of the structure in the electrical conductivity of fishbone carbon nanofibers

Carbon nanofibers (CNFs) have a remarkable electrical conductivity resulting highly attractive for different applications such as composites or electronics due to their high quality/price ratio. Although it is known that their graphitic character provides a high conductivity, very little is known about the influence of the nanofibers structure on that property. In this study, CNFs characterized by different physical properties are prepared at diverse synthesis temperatures within a range (550–750 °C) in which significant structural and dimensional changes are accomplished and homogeneous nanofiber growth takes place. The electrical conductivity is determined on the powdery as-grown materials modifying the compaction degree by applying pressure. Because of a combination of structural features, the apparent electrical conductivity increases with synthesis temperature of CNFs, ranging from 50 S m^?1 for the worst conducting CNFs at a low compaction degree (25 % of solid volume fraction) to 3 × 10³ S m^?1 for the best conducting CNFs at a high compaction degree (60 % of solid volume fraction). Further analysis is carried out applying the percolation theory to analyze the experimental data and the results suggest that both the orientation of the graphenes and the filament diameter distribution play a determining role in the intrinsic electrical conductivity with values in the interval 1.5 × 10³ to 1.3 × 10⁴ S m^?1. These intrinsic values of electrical conductivity are found between one and two orders of magnitude higher than that of the powder, highlighting the also important effect of porosity.     

On the Use of Machine Learning to Detect Shocks in Road Vehicle Vibration Signals

The characterization of transportation hazards is paramount for protective packaging validation. It is used to estimate and simulate the loads and stresses occurring during transport that are essential to optimize packaging and ensure that products will resist the transportation environment with the minimum amount of protective material. Characterizing road transportation vibrations is rather complex because of the nature of the dynamic motion produced by vehicles. For instance, different levels of vibration are induced to freight depending on the vehicle speed and the road surface; which often results in non‐stationary random vibration. Road aberrations (such as cracks, potholes and speed bumps) also produce transient vibrations (shocks) that can damage products. Because shocks and random vibrations cannot be analysed with the same statistical tools, the shocks have to be separated from the underlying vibrations. Both of these dynamic loads have to be characterized separately because they have different damaging effects. This task is challenging because both types of vibration are recorded on a vehicle within the same vibration signal. This paper proposes to use machine learning to identify shocks present in acceleration signals measured on road vehicles. In this paper, a machine learning algorithm is trained to identify shocks buried within road vehicle vibration signals. These signals are artificially generated using non‐stationary random vibration and shock impulses that reproduce typical vehicle dynamic behaviour. The results show that the machine learning algorithm is considerably more accurate and reliable in identifying shocks than the more common approaches based on the crest factor. Copyright © 2016 John Wiley & Sons, Ltd.     

On the Extraction of Signals from Environments Containing Additive-Noise and Multiplicative Characteristics

The purpose of this paper is to present an applications-oriented discussion of the Kalman filter theory. The subject has received extensive treatment in the fields of orbit estimation and deterministic control system theory. This paper will emphasize the extraction of information from an additive-noise environment, i.e., the classical observation problem and its relation to the estimation theory. This subject is chosen in order to make the discussion concrete, and because of the general lack of application of the newer Kalman theory to this important area. Engineering application of the filter theory is discussed by working through a filter design that involves both compensation and estimation.     

On the importance of path for phase unwrapping in synthetic aperture radar interferometry

Phase unwrapping is a key procedure in interferometric synthetic aperture radar studies, translating ambiguous phase observations to topography, and surface deformation estimates. Some unwrapping algorithms are conducted along specific paths based on different selection criteria. In this study, we analyze six unwrapping paths: line scan, maximum coherence, phase derivative variance, phase derivative variance with branch-cut, second-derivative reliability, and the Fisher distance. The latter is a new path algorithm based on Fisher information theory, which combines the phase derivative with the expected variance to get a more robust path, potentially performing better than others in the case of low image quality. In order to compare only the performance of the paths, the same unwrapping function (phase derivative integral) is used. Results indicate that the Fisher distance algorithm gives better results in most cases.     

基于Wigner-Hough变换改进算法的多分量LFM信号检测

Wigner-Hough变换可以很好的抑制多分量LFM信号Wigner-Ville分布中严重的交叉项,但是在低信噪比时,Wigner-Hough变换完全被噪声淹没.本文提出一种改进算法,用基于信号的自适应高斯核时频分布代替Wigner-Hough变换中的Wigner-Ville分布.仿真表明,对于多分量信号在信噪比为-3dB,单分量信号在-17dB时该算法仍然有很好的性能.     

On the importance of FIB-SEM specific segmentation algorithms for porous media

A new algorithmic approach to segmentation of highly porous three dimensional image data gained by focused ion beam tomography is described which extends the key-principle of local threshold backpropagation described in Salzer et al. (2012). The technique of focused ion beam tomography has shown to be capable of imaging the microstructure of functional materials. In order to perform a quantitative analysis on the corresponding microstructure a segmentation task needs to be performed. However, algorithmic segmentation of images obtained with focused ion beam tomography is a challenging problem for highly porous materials if filling the pore phase, e.g. with epoxy resin, is difficult. The gray intensities of individual voxels are not sufficient to determine the phase represented by them and usual thresholding methods are not applicable. We thus propose a new approach to segmentation that pays respect to the specifics of the imaging process of focused ion beam tomography. As an application of our approach, the segmentation of three dimensional images for a cathode material used in polymer electrolyte membrane fuel cells is discussed. We show that our approach preserves significantly more of the original nanostructure than a thresholding approach.     

建筑材料放射性现场检测

本文对影响建材表面γ空气比释动能率测量的几个因素作了研究，提出 了一种建材放射性现场检测力法和剂量限制要求，并对实验和理论计算结果进行了讨论，二者之间有较好的一致性。