The results indicate straight ∑3 coherent twin boundaries of over 60%(all values are given as a length fraction of the total boundary length) are introduced in the alloy when annealed at 220℃ for 72 hours after cold rolling to 10% reduction in thickness. Such boundaries are not distributed in a network of general high angle boundaries(HABs) and the GBCD is not optimized.

This card mainly uses a DSP TMS320C6416 from TI and FPGA XC2V1000 of VIRTEX2 series from XILINX ,which could flexibly realize many kinds of signal processing algorithm program in FPGA and DSP, so meet the general high requirement of four-channel high speed AD data acquisition and real-time processing.

The paper makes programs for software design with general high language VC++6.0 and simulates for control system by MATLAB 6.1, and avoids using costly professional development software in price.

Experimental results show that the method to prepare BOPA is similar with general high viscosity Nylon 6. Adopted two-step way,by the evaluation system and (ordinary) decompression system of the pressure polymerization and the addition of special catalyst,Nylon6 slab with viscosity 3.5 could be obtained.

At general high-angle grain boundaries, on the other hand, the effects of boundary structure are simpler and better understood.

Under simple shear loading conditions, however, the highest stresses were observed at general high-angle grain boundaries.

Long-term exposure to water vapor results in an irreversible decrease in local deformations and in lowering the excessive negative charge of the skeleton, which manifests itself in a general high-frequency shift of the bands by 5-7 cm-1.

The general high-frequency, rough-surface reflection process is treated by the method of stationary phase.

In general high heat input welds showed low ductility mainly on account of the strain localization effects at the grain boundary alpha phase.

The synthetic catalogue of right ascensions for time service (CTC) was compi- led through the synthesis of time determination data obtained with five photoelectric transits and a visual transit in five observatories or observation stations (Shanghai Observatory, Purple Mountain Observatory, Peking Observatory, Shensi Observatory, and the provisional observation station of Shanghai Observatory in Hainan Island). This catalogue lists 1156 stars with magnitude interval 0.~m1~6.~m6, and declination interval -30°~+66°.In...

The synthetic catalogue of right ascensions for time service (CTC) was compi- led through the synthesis of time determination data obtained with five photoelectric transits and a visual transit in five observatories or observation stations (Shanghai Observatory, Purple Mountain Observatory, Peking Observatory, Shensi Observatory, and the provisional observation station of Shanghai Observatory in Hainan Island). This catalogue lists 1156 stars with magnitude interval 0.~m1~6.~m6, and declination interval -30°~+66°.In compiling the catalogue, corrections and systematic smooth- ing of the right ascensions of stars were carried out on the basis of FK_4 catalogue, but no corrections of the vernal equinox were made, and no attempt was made to establish our own system of proper motions, therefore CTC is a relative catalogue. Observational data spreading ove, 3-5 years were utilized, the total number of star observations reached 76847, so the catalogue has a rather high precision, especially within the declination zone -5°-+56°, having 1043 stars, the precision of position determination in this zone is in general higher than ±4 ms. In this paper, the method of compiling the CTC catalogue is described, and the precision discussed. As the CTC catalogue has been separately published, in this paper only the right ascensions (1975. 0 equinox) which have been determined by three observatories or stations are given for future reference, together with the epoch of observation, number of observation, total standard error, and internal standard error.

In order to determine comprehensively the quality of Yusu 1, a newly improved breed of sweet potato, we have measured the nutritional composition of its stem, leaf and stem apex by biochemical analysis, and compared them with the corresponding parts of other two improved breeds, Su-potato-18 and Nong-Da-Hong, We have also compared some of their root tubers. The results indicate that, except some differences in the content of a few components, generally there is no obvious difference in the content of carbohydrate,...

In order to determine comprehensively the quality of Yusu 1, a newly improved breed of sweet potato, we have measured the nutritional composition of its stem, leaf and stem apex by biochemical analysis, and compared them with the corresponding parts of other two improved breeds, Su-potato-18 and Nong-Da-Hong, We have also compared some of their root tubers. The results indicate that, except some differences in the content of a few components, generally there is no obvious difference in the content of carbohydrate, thick protein, amino acid, and vitamin C. But the content of reducing sugar, soluble sugar and total sugar in the stem is always higher than that in the leaf in the same breed, and that in the leaf is always higher than that in the stem apex:think protein and amino acid are in general higher in the stem apex in the leaf, and those in the leaf are higher than those in the stem; and all are higher than those In the corresponding root tuber. The stem, the leaf, and the stem apex don't contain cy-steine. As for the content of vitamin C, it is always higher in the leaf than in the stem apex, and in the stem apex than in the stem. There is no obvious law about the content of calcium, phosphorus and iron in either the corresponding parts of the three different breeds or the stem, the leaf and the stem apex of the same breed. In the stem, the leaf and the stem apex of each breed, there are abundant calcium, phosphorus and iron, and the content is higher than that in the correspondng root tuber

To verify the extreme value of function f(x,y) at the stat-ionary point (x.,y.) with second -order partial derivatives, sometimes the probable result is that the discriminant f2xy (x.,y.) - x(x. ,y.) ·fyy(x.,y.) is equal to zero. In that case, the original test is not effective and the further inspection will be needed. Thus, this paper gives a method of test which makes use of the general higher-order partial derivatives.Suppose that function f(x,y) at the point (x.,y.) can be expanded ia n th-order...

To verify the extreme value of function f(x,y) at the stat-ionary point (x.,y.) with second -order partial derivatives, sometimes the probable result is that the discriminant f2xy (x.,y.) - x(x. ,y.) ·fyy(x.,y.) is equal to zero. In that case, the original test is not effective and the further inspection will be needed. Thus, this paper gives a method of test which makes use of the general higher-order partial derivatives.Suppose that function f(x,y) at the point (x.,y.) can be expanded ia n th-order Taylor formula, and it is written in the form △f = Pn (h,k) +ε,herethis ε tends to zero when p tends to zero. And suppose that either all the partial derivatives of f(x,y) at (x.,y.) in which the numerals of order is not bigger than some positive integer N are equal to zero, or all the partial derivatives of f(x,y) in some neighborhood at (x.,y.) in which the numerals of order is bigger than N+l are identically zero. As such the higher-order partials test for extreme value of function of two variables can be phrased this way.If PN(h,k) is either positive identically or negative identically, then f(x,y) has an extreme value at (x.,y.);If PN(h,k) is both positive and negative, then f(x,y) has no extreme value at (x.,y.).

用二阶偏导数来判定函数f(x,y)在其驻点(x,y_0)处的极值,有时可能有判别式f_(xy)~2(x_0,y_0)-f_(xx)(X_0,y)·f_y(x,y_0)等于零的情况.这时,原来的判别法失效,从而需要作出进一步的考察.为此,本文特给出一种利用一般的高阶偏导数的判别方法.设函数f(x,y)在点(x,y_0)处可展开成n阶泰勒公式,并将其写成△f=P(h,k)+ε.式中P_n(h,k)=sum from m=1 to n(1/(m+1)!)(h((?)/(?)x)+(k(?)/(?)y))~(m 1)f(x,y_0);当ρ趋于零时ε趋于零.同时还设函数f(x,y)在点(x,y_0)处所有阶数不大于某个正整数N的偏导数都等于零,或在点(x,y_0)的某个邻域内所有阶数大于N+1的偏导数都恒等于零.那末,二元函数极值的高阶偏导数判别法可简单地归结为:若P_N(h,k)恒正或恒负,则f(x,y)在点(x_0,y_0)取得极值;若P_N(h,k)有正有负,则f(x,y)在点(x_0,y_0)处不取极值.