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171.
Mohammed Hawa Jamal S. Rahhal Dia I. Abu-Al-Nadi 《Peer-to-Peer Networking and Applications》2012,5(3):279-291
Peer-to-Peer (P2P) traffic has increased rapidly over the past few years, with file sharing providing the main drive behind
such traffic. In this work we perform a measurement study of the content shared over the popular BitTorrent P2P file sharing
network. We mathematically model the file size distributions of shared files after categorizing them into Audio, Video, Archive
and CD image classes. For each of these categories we look into the most popular shared file formats and investigate their
file size statistics. This provides an important milestone to building a realistic simulation framework for P2P systems, and
for future analytical modeling of P2P networks. 相似文献
172.
D. Cenk Erdil 《Peer-to-Peer Networking and Applications》2012,5(3):219-230
Resource scheduling in large-scale distributed systems, such as grids and clouds, is difficult due to the size, dynamism,
and volatility of resources. These resources are eclectic and autonomous, and may exhibit different usage policies, levels
of participation, capabilities, local load, and reliability. Moreover, applications are likely to exhibit various patterns
and levels, and distributed resources may organize into various different overlay topologies for information and query dissemination.
Researchers have proposed a wide variety of approaches and policies for mapping offered load onto resources and for solving
the various component parts of the scheduling problem. However, production clouds and grids may be underutilized, and may
not exhibit the load to effectively characterize all of the scheduling system inputs. The composition of large-scale systems
is also changing, potentially to include more individual and peer-to-peer resources. These factors will influence the effectiveness
of proposed scheduling solutions. Therefore, a simulation environment is necessary to study different approaches under different
scenarios, especially those that are expected, but that are not currently characteristic of existing systems. This article
describes a general-purpose peer-to-peer simulation environment that allows a wide variety of parameters, protocols, strategies
and policies to be varied and studied. To provide a proof of concept, utilization of the simulation environment is presented
in a large-scale distributed system problem that includes a core model and related mechanisms. In particular, this article
presents a definition and possible peer-to-peer solutions for the large-scale scheduling problem. Moreover, this article describes
a general simulation model, some policies that can be varied, an implementation, and some sample results. 相似文献
173.
In this paper, we present an efficient way of implementing OpenGL ES 1.1 3D graphics API library for the environments with
hardware-supported OpenGL facility, typically as desktop PCs. Although OpenGL ES was started from the existing OpenGL features,
it rapidly became the standard 3D graphics library customized for embedded systems through introducing fixed-point arithmetic
operations, buffer management with fixed-point data type supports, completely new texture mapping functions and others. Currently,
it is the official 3D graphics API for Google Android, Apple iPhone, Sony PlayStation3, etc. In this paper, we achieved improvements
on the arithmetic operations for the fixed-point number representation, which is the most characteristic data type for OpenGL
ES 1.1. For the conversion of fixed-point data types to the floating-point number representations for the underlying OpenGL,
we show the way of efficient conversion processes even with satisfying OpenGL ES standard requirements. We also introduced
a specialized memory management scheme to manage the converted data from the buffer containing fixed-point numbers. In the
case of texture processing, the requirements in both standards are quite different, and thus we used completely new software-implementations.
Our final implementation of OpenGL ES library provides all of more than 200 functions in the standard specification and passed
its conformance test, to show its compliance with the standard. From the efficiency point of view, we measured its execution
times for several OpenGL ES-specific application programs and achieved remarkable improvements. 相似文献
174.
Bettina Berendt 《Data mining and knowledge discovery》2012,24(3):697-737
Over the last decade, privacy has been widely recognised as one of the major problems of data collections in general and the
Web in particular. This concerns specifically data arising from Web usage (such as querying or transacting) and social networking
(characterised by rich self-profiling including relational information) and the inferences drawn from them. The data mining
community has been very conscious of these issues and has addressed in particular the inference problems through various methods
for “privacy-preserving data mining” and “privacy-preserving data publishing”. However, it appears that these approaches by
themselves cannot effectively solve the privacy problems posed by mining. We argue that this is due to the underlying notions
of privacy and of data mining, both of which are too narrow. Drawing on notions of privacy not only as hiding, but as control
and negotiation, as well as on data mining not only as modelling, but as the whole cycle of knowledge discovery, we offer
an alternative view. This is intended to be a comprehensive view of the privacy challenges as well as solution approaches
along all phases of the knowledge discovery cycle. The paper thus combines a survey with an outline of an agenda for a comprehensive,
interdisciplinary view of Web mining and privacy. 相似文献
175.
Efficient compression and network adaptive video coding for distributed video surveillance 总被引:1,自引:1,他引:0
The availability of cheap network based video cameras and the prevalence of wireless networks has lead to a major thrust towards
deployment of large scale Distributed Video Surveillance (DVS) systems. This has opened up an important area of research to
deal with the issues involved in DVS system for efficient collection and transmission of large scale video streams from the
cameras at the guarded sites, to the end users in possibly constrained network conditions. In this paper, we propose a framework
based on content-based video classification and scalable compression scheme to provide a robust bandwidth efficient video
transmission for DVS. The scheme builds on a Discrete Wavelet Transform (DWT) based Color-Set Partitioning for Hierarchical
Trees (CSPIHT) coding to obtain a scalable bitstream. Wavelet domain segmentation and compression assists in development of
a DVS architecture. The architecture includes a novel module for dynamic allocation of Network bandwidth based on the current
available resources and constraints. Different frame constituents are optimally coded based on their relative significance,
perceptual quality, and available estimate of network bandwidth. Experimental result over different video sequences and simulations
for Network conditions demonstrate the efficient performance of the approach. 相似文献
176.
177.
Jung Nam Bae Jin Young Kim Geon Kim Yong Tae Lee Jae Sang Cha 《Multimedia Tools and Applications》2012,57(2):359-372
Recently, watermarking based data transmission techniques using terrestrial digital TV signal have been proposed since they
are also cost-free and can overcome the limitations of GPS. However, in the previous watermarking based methods, the detection
accuracy is low and additional data rate is too low. Thus, we propose the throughput enhancement method by employing the TZCD-MBOK
watermarking technique in T-DMB system. By applying the proposed scheme to T-DMB, it allows additional data transmission for
disaster broadcasting and improves efficiency of data transmission in shadow region and indoor to mobile environment through
watermarking spread code. From the simulation results, we confirm the proposed watermarking scheme affected on the existing
T-DMB signal. Moreover, it was also confirmed that the system capacity increases as the power of additional watermarking signal
rose. The results of the paper can be applied to wireless multimedia digital broadcasting systems. 相似文献
178.
Many video service sites headed by YouTube know what content requires copyright protection. However, they lack a copyright
protection system that automatically distinguishes whether uploaded videos contain legal or illegal content. Existing protection
techniques use content-based retrieval methods that compare the features of video. However, if the video encoding has changed
in resolution, bit-rate or codec, these techniques do not perform well. Thus, this paper proposes a novel video matching algorithm
even if the type of encoding has changed. We also suggest an intelligent copyright protection system using the proposed algorithm.
This can serve to automatically prevent the uploading of illegal content. The proposed method has represented the accuracy
of 97% with searching algorithm in video-matching experiments and 98.62% with automation algorithm in copyright-protection
experiments. Therefore, this system could form a core technology that identifies illegal content and automatically excludes
access to illegal content by many video service sites. 相似文献
179.
180.
In this paper we have proposed a dynamic pricing scheme for the contributing peers in the Video on Demand (VoD) system. The
scheme provides an effective mechanism to maximize the profit through the residual resources of the contributing peers. A
utilization function is executed for each contributing peer to estimate the utility factor based on the parameters such as
initial setup cost, holding cost, chaining cost and salvage cost. In this paper, we urge an effective dynamic pricing algorithm
that efficiently utilizes a range of parameters with a varying degree of complexity. The key findings of the algorithm are
(i) each contributing peers are benefitted by the monetary based on its resource contributions to the VoD system and (ii)
a high degree of social optimum is established by proficiently aggregating the contributing peer’s resources with the overall
resources of the VoD system. We validate our claim by simulating the proposed dynamic pricing scheme with other standard pricing
schemes such as altruism, cost model and game theory perspective. The result of our dynamic pricing scheme shows the best
utility factor than other standard pricing schemes. 相似文献