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921.
922.
Mike Tien-Chien Lee Yu-Chin Hsu Ben Chen Masahiro Fujita 《Design Automation for Embedded Systems》1997,2(3-4):319-338
ATM switch, the core technology of an ATM networking system, is one of the major products in Fujitsu telecommunication business. However, current gate–level design methodology can no longer satisfy its stringent time–to–market requirement. It becomes necessary to exploit high–level methodology to specify and synthesize the design at an abstraction level higher than logic gates. This paper presents our prototyping experience on domain–specific high–level modeling and synthesis for Fujitsu ATM switch design. We propose a high–level design methodology using VHDL, where ATM switch architectural features are considered during behavior modeling, and a high–level synthesis compiler, MEBS, is prototyped to synthesize the behavior model down to a gate–level implementation. Since the specific ATM switch architecture is incorporated into both modeling and synthesis phases, a high–quality design is efficiently derived. The synthesis results shows that given the design constraints, the proposed high–level design methodology can produce a gate–level implementation by MEBS with about 15 percent area reduction in shorter design cycle when compared with manual design. 相似文献
923.
UART通信的FPGA实现设计 总被引:1,自引:0,他引:1
阐述了UART异步串行通信原理,介绍了实现UART异步串行通信的硬件接口电路及各部分硬件模块,介绍了用硬件描述语言Verilog来开发UART通信接口电路的FPGA实现。本设计使用Xilinx的FPGA器件,将UART的核心功能嵌入到FPGA内部,不但实现了电路的异步通讯的主要功能,而且使电路更加紧凑、稳定、可靠。 相似文献
924.
Yen-Liang Chen Ming-Feng Hsu Jyh-Ting Lai An-Yeu Wu 《Journal of Signal Processing Systems》2008,52(1):59-73
Echo canceller plays an important role in the full-duplex communication system. Conventional implementations of echo cancellers
are often the adaptive transversal filter architectures due to the simplicity and robustness of stability and convergence.
However, the conventional echo cancellers suffer from high cost problem especially when the response time of the echo is long.
In this paper, a new cost-efficient architecture of echo cancellers, targeting on 10GBase-T Ethernet System, is presented.
The proposed scheme inherits the concept of channel shortening which is widely employed in DSL systems. A shortened impulse
response filter is implemented at the receiver to shorten the impulse response of the echo signal. Hence, the overall cost
of echo cancellers can be reduced. We generalize the channel shortening architecture to a joint multi-channel shortening scheme.
The joint multi-channel shortening architecture can be applied to multiple-input multiple-output wireline communication systems
to further reduce both the cost of echo and near-end crosstalk (NEXT) cancellers. We apply the proposed scheme to 10GBase-T
Ethernet system. The simulation results show that the proposed echo and NEXT cancellers can save up to 35% hardware cost compared
to the conventional transversal implementations.
相似文献
Yen-Liang ChenEmail: |
925.
926.
InAs/Ga(In)SbⅡ类超晶格材料由于特殊的二型能带结构,可以通过人造低维结构获得类似于体材料的带间吸收,从而获得较高的量子效率;另外,通过调节材料参数调节能带结构,器件响应波段可调;通过能带结构设计抑制俄歇复合,获得较小的暗电流和较高的器件性能。因为以上特有的材料性能和器件特性,Sb基二类超晶格在国际上被认为是第三代红外焦平面探测器的优选材料。对二类超晶格材料的设计和器件特性进行了研究,设计了峰值波长4μm的nBn结构的中波红外探测器,在没有蒸镀抗反膜的条件下,77 K温度下测试得到的峰值探测率为2.4×1011cm Hz1/2W-1,计算得到的量子效率为47.8%,峰值探测率已经接近目前的碲镉汞中波红外探测器器件性能。研究结果充分显示了二类超晶格优越的材料和器件性能。 相似文献
927.
Unlu M.S. Strite S. Won T. Adomi K. Chen J. Mohammad S.N. Biswas D. Morkoc H. 《Electronics letters》1989,25(20):1359-1360
Reports the nearly ideal electrical characteristics of p-Ge/N-GaAs heterojunction diodes grown by molecular beam epitaxy. The temperature and device size dependencies of the current-voltage characteristics have been investigated. At room temperature, unity ideality factor has been demonstrated over almost six decades of current.<> 相似文献
928.
Chen T.-h. Chang K.W. Bui S.B. Wang H. Dow G.S. Liu L.C.T. Lin T.S. Titus W.S. 《Microwave Theory and Techniques》1991,39(12):1980-1986
The design and fabrication of four broadband monolithic passive baluns including CPW Marchand, multilayer MS Marchand, planar-transformer and broadside-coupled line baluns are presented. Operational frequencies range from 1.5 GHz to 24 GHz. Maximum relative bandwidths in excess of 3:1 are achieved. Simulated performances using full wave electromagnetic analysis are shown to agree with the measured results. Two accurate equivalent circuit models constructed from either electromagnetic simulated or measured S-parameters are developed for the MS Marchand and transformer baluns making the optimization of baluns and circuit design using the baluns much more efficient. The design of monolithic double-balanced diode mixer using two planar-transformer baluns is also presented. Without DC bias, the mixer shows a minimum conversion loss of 6 dB with the RF at 5 GHz and a LO drive of 15 dBm at 4 GHz. The measured input IP3 of this mixer is better than 15 dBm over the 4 to 5.75 GHz frequency band 相似文献
929.
CdTe/GaAs是HgCdTe分子束外延的重要替代衬底材料。用X双晶衍射和光致发光测试研究了分子束外延生长的CdTe(211)B/GaAs(211)B的晶体结构质量,表明外延膜晶体结构完整,具有很高的质量。用高分辨率的透射电镜研究其界面特性,观察到CdTe(211)B相对于GaAs(211)B向着[111]方向倾斜一个小角度(约3°),界面的四面体键网发生扭曲,由于晶格失配,在界面存在很高的失配位错密度。用二次离子质谱分析仪分析了GaAs衬底中的Ga和As向CdTe外扩散的情况。结果表明:如果要在GaAs衬底上生长HgCdTe外延膜,必须先生长一层具有一定厚度的CdTe来阻止Ga和As向HgCdTe的外扩散和失配位错的延伸。 相似文献
930.
封铎 《电信工程技术与标准化》2004,(1):69-72
2002年6月,IEEE通过的10Gbit/s以太网(10GE)标准,不仅提高了原有以太网技术的带宽和传输距离,并且也为以太网技术的应用扩展到广域网开辟了道路. 相似文献