选稿合理性问题初论

选稿合理性问题是指：在编辑活动中是否存在着一种选稿方法，它保证所选用的稿件一定“优于”未选用的稿件。选稿方法为编辑活动中应用的方法，它包括选稿程序和选稿标准。选稿合理性问题是编辑学研究中的中心问题，它要求我们理解编辑活动并使之合理化。

Effects of heat treatment on microstructure and mechanical properties of ZK60 Mg alloy

The microstructure and mechanical properties of ZK60 Mg alloy were investigated under different solution treatments and artificial aging conditions. When as-cast ZK60 alloy was solution treated at 400 ℃for 10 h and artificially aged at 150 ℃, the volume fraction of precipitates increased with the aging time up to 30 h. When the as-cast ZK60 alloy was solution treated at 400 ℃ for 10 h and artificially aged at 200 ℃ for 15 20 h, the volume fraction of precipitates reached a peak value. Tensile test at room temperature showed that a high density of the second phase precipitates was beneficial to improving the strength and elongation. Solution treatment at 400 ℃ for 10 h and artificial aging at 150 ℃ for 30 h is considered the optimum heat treatment condition to obtain a good combination of strength and ductility.

Comparison among Growth, Photosynthesis and Yield in Nanjing 9108 and Its Parents during the Late Development Stage

A good quality, high yield, slow mature and middle season Japonica rice variety, Nanjing 9108 and its parents Guandong 194 and Wuxiangjing 14,were taken as the materials for the study. The growth and photosynthetic characteristics of the rice plants at the post-flowering stage were compared and the rice yield components were examined at harvest. The results showed that as compared with Wuxiangjing 14, the per plant yield of Nanjing 9108 was 7.70% higher, and much higher than that of Guandong194. The large total grain per plant and heavy grain weigh of Nanjing 9108 were the important structure basis for its yield. Further analysis o the growth indicators showed that Nanjing 9108 had a large leaf area of upper three green leaves area and a smaller leaf base angle in the third leaf from the bottom blades, which helped get a higher photosynthetic capacity in groups. On the14 thday after flowering, Nanjing 9108 had similar value of net photosynthetic rate（Pn） to that of Wuxianjing 14, but lower than that of Guandong 194. Viewing from the parameters obtained from light response of photosynthesis on the modified model of rectangular hyperbola, Pn of Nanjing 9108 was more aptated to be saturated by light intensity and sensitive to photoinhibition. On the whole, Nanjing 9108 with high yield mainly resulted from its good plant type, grain structure and higher photosynthetic capacity in groups. Further improving its photosynthetic capacity o single leaf in Nanjing 9108 would be an important way for its super high yield po tential in the future.

Microstructure and tensile properties of Mg-Li-Al-Zn based alloys with Ce addition

Mg-5Li-3Al-2Zn-xCe（x=0-2.5;mass fraction,%） alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried out.The microstructure and tensile properties of as-cast alloys and their evolutions after solid solution were investigated.The results show that with the increase of Ce content,Al2Ce/Al3Ce precipitates are formed and the alloys mainly consist of α-Mg,Al2Ce,Al3Ce and AlLi phases,and the amount of AlLi and Al-Ce intermetallics decreases after solid solution.The content and morphology of the second phases have important effects on the mechanical properties of the alloys;the alloy with 1.0%Ce content exhibits excellent tensile strength.The tensile strength and elongation of Mg-5Li-3Al-2Zn-0.5Ce alloy is remarkably improved by the solution strengthening effect because of the addition of Ce.

A Criterion for Stability of Synchronization and Application to Coupled Chua's Systems

We investigate synchronization in an array network of nearest-neighbor coupled chaotic oscillators. By using of the Lyapunov stability theory and matrix theory, a criterion for stability of complete synchronization is deduced. Meanwhile, an estimate of the critical coupling strength is obtained to ensure achieving chaos synchronization. As an example application, a model of coupled Chua＇s circuits with linearly bidirectional coupling is studied to verify the validity of the criterion.

Some conditional results for conditionally strong mixing sequences of random variables

The relation between strong mixing and conditionally strong mixing is answered by examples,that is,the strong mixing property of random variables does not imply the conditionally strong mixing property,and the opposite implication is also not true.Some equivalent definitions and basic properties of conditional strong mixing random variables are derived,and several conditional covariance inequalities are obtained.By means of these properties and conditional covariance inequalities,a conditional central limit theorem stated in terms of conditional characteristic functions is established,which is a conditional version of the earlier result under non-conditional case.