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71.
72.
In this paper, we introduce a grouping approach for power allocation in the multi-user OFDM-DCSK (MU-OFDM-DCSK) system under the frequency selective fading channels. The suggested procedure is convenient also for the other comb-type non-coherent schemes with similar structure. Furthermore, we derive analytical bit error rate (BER) expression for the grouped scheme and offer an optimal power distribution policy for both the single- and multi-user scenarios. This power assignment strategy is formulated by a min–max problem with the target of the worst group BER minimization incorporating total power and interference constraints. Simulation results confirm the advantages of the proposed power allocation scheme. 相似文献
73.
傅里叶近红外反射光谱法快速测定大豆脂肪酸含量 总被引:8,自引:2,他引:6
目前大豆脂肪酸育种需要进行大量的气相色谱数据分析,因此建立近红外光谱(NIRS)快速测定脂肪酸组分技术具有重要意义。文章以108个中国大豆[Glycine max(L.)Merr.]品种或品系为材料,以傅里叶近红外光谱(FT-NIRS,4 000~12 500 cm-1)与气相色谱(GC)技术相结合,采用偏最小二乘(PLS)回归和交叉验证法,探讨利用FT-NIRS技术预测脂肪酸含量的可行性。依据OPUS 5.0软件针对不同脂肪酸组分筛选出最佳NIRS光谱区域为6 101.9~5 446.5 cm-1。交叉验证结果显示大豆主要脂肪酸组分,如油酸(C18∶1,R2CV=0.94)、亚油酸(C18∶2,R2CV=0.87)、亚麻酸(C18∶3,R2CV=0.85)和总饱和脂肪酸(C16∶0 C18∶0,R2CV=0.88)的预测准确率较高。外部验证结果证明大豆油酸预测模型的决定系数最高(R2val=0.91),其预测均方根误差(RMSEP)为2.47 g.kg-1干重,RMSEP/SD的比值为0.29,可保证大豆油酸辅助育种的准确性;而棕榈酸、硬脂酸、亚油酸、亚麻酸和总饱和脂肪酸的预测决定系数范围为0.66~0.76,RMSEP范围为0.37~2.74 g.kg-1干重,RMSEP/SD比值范围为0.47~0.53,表明可以进行大豆脂肪酸组分含量的初步筛选。该研究进一步证明利用FT-NIRS技术预测大豆主要脂肪酸组分是稳定可行的。 相似文献
74.
75.
AbstractWe generalize the outer subdifferential construction suggested by Cánovas, Henrion, López and Parra for max type functions to pointwise minima of regular Lipschitz functions. We also answer an open question about the relation between the outer subdifferential of the support of a regular function and the end set of its subdifferential posed by Li, Meng and Yang. 相似文献
76.
We analyse the tail behaviour of stationary response times in the class of open stochastic networks with renewal input admitting
a representation as (max,+)-linear systems. For a K-station tandem network of single server queues with infinite buffer capacity, which is one of the simplest models in this
class, we first show that if the tail of the service time distribution of one server, say server i
0 ∈ {1,...,K}, is subexponential and heavier than those of the other servers, then the stationary distribution of the response time until
the completion of service at server j ⩾ i
0 asymptotically behaves like the stationary response time distribution in an isolated single-server queue with server i
0. Similar asymptotics are given in the case when several service time distributions are subexponential and asymptotically
tail-equivalent. This result is then extended to the asymptotics of general (max,+)-linear systems associated with i.i.d.
driving matrices having one (or more) dominant diagonal entry in the subexponential class. In the irreducible case, the asymptotics
are surprisingly simple, in comparison with results of the same kind in the Cramér case: the asymptotics only involve the
excess distribution of the dominant diagonal entry, the mean value of this entry, the intensity of the arrival process, and
the Lyapunov exponent of the sequence of driving matrices. In the reducible case, asymptotics of the same kind, though somewhat
more complex, are also obtained. As a direct application, we give the asymptotics of stationary response times in a class
of stochastic Petri nets called event graphs. This is based on the assumption that the firing times are independent and that
the tail of the firing times of one of the transitions is subexponential and heavier than those of the others. An extension
of these results to nonrenewal input processes is discussed. Asymptotics of queue size processes are also considered.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
77.
78.
D. Jia B. H. Krogh O. Stursberg 《Journal of Optimization Theory and Applications》2005,127(2):347-365
This paper introduces a new approach to robust model predictive control (MPC) based on conservative approximations to semi-infinite
optimization using linear matrix inequalities (LMIs). The method applies to problems with convex quadratic costs, linear and
convex quadratic constraints, and linear predictive models with bounded uncertainty. If the MPC optimization problem is feasible
at the initial control step (the first application of the MPC optimization), it is shown that the MPC optimization problems
will be feasible at all future time steps and that the controlled system will be closed-loop stable. The method is illustrated
with a solenoid control example.
The authors thank the anonymous reviewers for suggestions that improved the presentation of this work. The work was supported
in part by the EPRI/DoD Complex Interactive Networks/Systems Initiative under Contract EPRI-W08333-05 and by the US Army Research
Office Contract DAAD19-01-1-0485. 相似文献
79.
The max algebra consists of the nonnegative real numbers equipped with two binary operations, maximization and multiplication. We characterize
the invertible linear operators that preserve the set of commuting pairs of matrices over a subalgebra of max algebra. 相似文献
80.
本通过辅助规划和Lagrange对偶,把带等式和不等式约束的极大极小问题转化为带线性约束的凸规划问题,给出了一个信赖域方法,并证明了方法的可行性。 相似文献