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131.
过去几十年中差分吸收光谱技术(differential optical absorption spectroscopy,DOAS)在大气污染物监测方面取得了成功应用.文章提出了根据差分吸光度最大值(OD'm)设定阈值的思想,将传统DOAS算法与基于卡尔曼滤波的DOAS算法相结合,利用两种算法在相同信噪比下具有不同反演精度的特点,在保证测量精度的前提下提高了DOAS系统的检测极限,较好地解决了短光程下低浓度气体的测量精度问题.在常温常压和流动状态下,对烟气中的SO2浓度测量进行了理论和实验研究.研究结果表明,改进的DOAS算法在OD'm<0.048 1时,SO2浓度测量精度较高,测量下限可低于28.6 mg·m-3,零点漂移低于2.9 mg·m-3传统DOAS算法在0.048 1<OD'm<0.927 2时,SO2浓度测量精度较高;两种算法对OD'm>0.927 2时的SO2浓度测量都存在较大的误差,必须进行线性度校正. 相似文献
132.
蒋学勤 《贵州大学学报(自然科学版)》2005,22(1):96-99
对具体地面电波传播的信号进行测试。经比较,验证了在地面LOS范围的双斜率及室内对数距离路径损耗模式,并提出针对2.4GHz频段的拟合参数取值,对无线组网有参考价值。 相似文献
133.
本文研究纵向数据下非参数部分带有测量误差的部分线性变系数模型的估计.利用B样条函数近似模型中的变系数函数,构造偏差修正的二次推断函数,得到模型中未知参数和变系数函数的估计.证明变系数函数估计量的相合性和参数估计量的渐近正态性.数值模拟和实例分析结果表明所提估计方法在有限样本下的有效性. 相似文献
134.
运用"热-结构-光"耦合分析方法,计算典型星敏感器光学系统(6透镜光具组,f=56 mm,相对孔径1/1.3)恒星像斑理想质心位移和亚像元内插质心偏移量,研究温度分布对星敏感器测量准确度的影响.以20℃为光学系统标定温度,计算光学系统均匀温度分布、轴向温差分布和上下侧温差分布三种条件下,星敏感器测量误差.均匀分布温度变化20℃时,星敏感器测量误差约0.07″;轴向温差10℃和20℃时,测量误差分别约为0.17″和0.31″;上下侧温差仅2℃时,测量误差就高达1.46″.计算结果表明,上下侧温差分布对星敏感器准确度影响最大,均匀温度分布影响最小. 相似文献
135.
Daniel Lehmann 《International Journal of Theoretical Physics》2009,48(1):261-281
Similarity-Projection structures abstract the numerical properties of real scalar product of rays and projections in Hilbert
spaces to provide a more general framework for Quantum Physics. They are characterized by properties that possess direct physical
meaning. They provide a formal framework that subsumes both classical Boolean logic concerned with sets and subsets and quantum
logic concerned with Hilbert space, closed subspaces and projections. They shed light on the role of the phase factors that
are central to Quantum Physics. The generalization of the notion of a self-adjoint operator to SP-structures provides a novel
notion that is free of linear algebra.
This work was partially supported by the Jean and Helene Alfassa fund for research in Artificial Intelligence. 相似文献
136.
E. D. Vol 《International Journal of Theoretical Physics》2009,48(2):392-402
In the present paper we propose the way of passage from quantum theory of continuous measurements based on the Lindblad equation
to its “classical” analog. The last one describes the influence of continuous measurement on the behavior of macroscopical
Markov system. Such theory can be represented in the form of the Fokker-Planck equation for the distribution function of measured
system. The diffusion tensor of this equation is uniquely determined by a type of the measured quantity. As the example of
using of the approach proposed we describe the stationary states of linear dissipative systems induced by measurements in
them. We consider possible qualitative effects connected with measurements also. In particular we demonstrate on the simple
example, how in the macroscopic system, consisting of noninteracting parts, measurement of global integral of motion results
in relaxation to the quasi-thermodynamic equilibrium between parts of the system. The “temperature” of such state is determined
by the total energy of the system and by mean value of measured quantity.
相似文献
137.
X射线荧光能谱法测定贵金属含量的测量不确定度分析 总被引:3,自引:0,他引:3
研究了 X射线荧光能谱法测定贵金属含量的不确定度来源 ,通过 A类评定和 B类评定方法建立了测量结果不确定度的评定程序 ,使测量结果更具有科学性 ,从而能够规范地、定量地进行产品合格判定 相似文献
138.
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140.
Reliable determination of arsine (AsH3) in gases is of great importance due to stringent regulations associated with health, safety and environmental issues. It is, however, challenging for an analyst to determine trace airborne arsine concentrations without specifically designed collection procedures using adsorption, desorption, dissolution or impinging techniques. To circumvent such technical barrier, we have newly developed a direct analytical method, characterized by introduction of an arsine gas sample into stable plasma stream, followed by gas-phase oxidation of arsine with molecular oxygen in a dynamic reaction cell (DRC) equipped within the inductively coupled plasma-mass spectrometry (ICP/MS) system, followed by subsequent detection of AsO+ ion. This preliminary work used trace arsine concentrations (161 μg m−3, 322 μg m−3, and 645 μg m−3) gravimetrically prepared in N2 balance. The proposed method was optimized for the important experimental parameters such as the flow rates of the reaction gas, the arsine sample, and the carrier gas. This method was then validated by demonstrating good figure-of-merits including the low limit of detection (0.10 μg m−3), good linearity (r2 > 0.9915), low measurement uncertainty (0.66%), and high speed of analysis (<6 min). The proposed method is expected to be potentially applicable to the determination of arsine in real workplace air after appropriate modifications are made. 相似文献