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81.
Model checking based on the causal partial order semantics of Petri nets is an approach widely applied to cope with the state
space explosion problem. One of the ways to exploit such a semantics is to consider (finite prefixes of) net unfoldings—themselves
a class of acyclic Petri nets—which contain enough information, albeit implicit, to reason about the reachable markings of
the original Petri nets. In [19], a verification technique for net unfoldings was proposed, in which deadlock detection was reduced to a mixed integer linear
programming problem. In this paper, we present a further development of this approach. The essence of the proposed modifications
is to transfer the information about causality and conflicts between the events involved in an unfolding, into a relationship
between the corresponding integer variables in the system of linear constraints. Moreover, we present some problem-specific
optimisation rules, reducing the search space. To solve other verification problems, such as mutual exclusion or marking reachability
and coverability, we adopt Contejean and Devie's algorithm for solving systems of linear constraints over the natural numbers
domain and refine it, by taking advantage of the specific properties of systems of linear constraints to be solved.
Another contribution of this paper is a method of re-formulating some problems specified in terms of Petri nets as problems
defined for their unfoldings. Using this method, we obtain a memory efficient translation of a deadlock detection problem
for a safe Petri net into an LP problem. We also propose an on-the-fly deadlock detection method.
Experimental results demonstrate that the resulting algorithms can achieve significant speedups.
相似文献
Maciej KoutnyEmail: |
82.
Constraint-based deductive model checking 总被引:2,自引:0,他引:2
Giorgio Delzanno Andreas Podelski 《International Journal on Software Tools for Technology Transfer (STTT)》2001,3(3):250-270
We show that constraint logic programming (CLP) can serve as a conceptual basis and as a practical implementation platform
for the model checking of infinite-state systems. CLP programs are logical formulas (built up from constraints) that have
both a logical interpretation and an operational semantics. Our contributions are: (1) a translation of concurrent systems
(imperative programs) into CLP programs with the same operational semantics; and (2) a deductive method for verifying safety
and liveness properties of the systems which is based on the logical interpretation of the CLP programs produced by the translation.
We have implemented the method in a CLP system and verified well-known examples of infinite-state programs over integers,
using linear constraints here as opposed to Presburger arithmetic as in previous solutions.
Published online: 18 July 2001 相似文献
83.
84.
Formal approaches to the design of interactive systems rely on reasoning about properties of the system at a very high level
of abstraction. Specifications to support such an approach typically provide little scope for reasoning about presentations
and the representation of information in the presentation. In contrast, psychological theories such as distributed cognition place a strong emphasis
on the role of representations, and their perception by the user, in the cognitive process. However, the post-hoc techniques
for the observation and analysis of existing systems which have developed out of the theory do not help us in addressing such
issues at the design stage. Mn this paper we show how a formalisation can be used to investigate the representational aspects
of an interface. Our goal is to provide a framework to help identify and resolve potential problems with the representation
of information, and to support understanding of representational issues in design. We present a model for linking properties
at the abstract and perceptual levels, and illustrate its use in a case study of a ight deck instrument. There is a widespread
consensus that proper tool support is a prerequisite for the adoption of formal techniques, but the use of such tools can
have a profound effect on the process itself. In order to explore this issue, we apply a higher-order logic theorem prover
to the analysis.
Received May 1999 / Accepted in revised form July 2000 相似文献
85.
M. Claeys-Bruno O. Vandenabeele-Trambouze M. Sergent M. Geffard D. Bodet M. Dobrijevic A. Commeyras R. Phan Tan Luu 《Chemometrics and Intelligent Laboratory Systems》2006,80(2):186-197
In a previous paper (part I), new strategy was used for raising antibodies against hapten (< 300 Da) and the quantification of these hapten by ELISA using derivatization by chloroethyl nitrosourea (CENU). After raising antibodies against histamine, they were characterized and used for ELISA measurements. Optimal detection conditions were determined for the histamine quantification by ELISA method. The present study investigates the derivatization step of the histamine by chloroethylnitrosourea (CENU). Five factors (2 qualitative: nature of the solvent and nature of the antibodies and 3 quantitative: pH, % of solvent and time of derivatization) have been considered. Optimal reaction conditions were established by calculation of a validated model. 相似文献
86.
In order to simplify the structure of the cold end of the pulse tube refrigerator (PTR) and have a better utilization of the cold energy of the system, a single stage four-valve pulse tube refrigerator (FVPTR) with a ‘L’ type pulse tube structure and two orifice valves at the hot end of pulse tube has been constructed. Verification experiments show that a two-orifice valve structure gives different adjustments to the gas flow rate of the hot end of the pulse tube than that of the one-orifice valve structure, a lowest temperature of 72 K was obtained at a frequency of 2.5 Hz under a system average pressure of 1.6 MPa with 200 mesh bronze screens as regenerator material, 20 mesh copper screens as stuffing material of heat exchanger. Due to the difficulty in manufacturing the thin ‘L’ type pulse tube, the wall thickness of the pulse tube in the experiment is relatively bigger than that of the ordinary pulse tube, which resulted in relatively big system loss and affected the minimum temperature of the system to a certain degree. 相似文献
87.
通过对无刷直流电动机调速系统基本原理和控制方法的研究,结合数字信号处理器TMS320LF2407的特点,设计了一种小功率无刷直流电机调速系统实验平台,论述了平台的软、硬件设计,该实验平台能满足对无刷直流电机研究需要。 相似文献
88.
89.
SoC功能验证的特点和方法 总被引:3,自引:0,他引:3
简要分析了传统集成电路(ASIC)验证方法的特点以及将这些方法应用于系统级芯片(SoC)验证时所面临的问题。在此基础上,论述说明了模块级验证是提高SoC验证效率的基础;而基于随机测试激励的验证方法能够提升SoC的功能验证的覆盖率。另外,还介绍了用于SoC功能验证的关键方法,包括断言和RTL形式验证,Farm,随机化测试激励和功能覆盖等。 相似文献
90.
在图像处理中,图像分割是一类重要的研究方向。图像分割算法的好坏,影响到分割结果的优劣,因此对分割算法的性能评估十分重要。本文提出了一种图像分割算法性能的评价方法——精度依据准则,该准则是对原始特征量值和实际特征量值做比较,通过对绝对值的大小来判断算法的好坏。通过实验比较,该方法具有不错的算法性能评估准确度。 相似文献