投射模

We give a theorem for the stable range of endomorphism rings of finitely generated projective modules over a formal triangular matrix ring T when T is an exchange ring.

2.6节对有有限exchange性质的形式三角矩阵环T给出了有限生成投射T-模的自同态环有稳定度n的一个具体关系。

It is proved that a left R-module P is pure projective if and only if for any pure epimorphism E→M→0, where E is pure injective, Hom→Hom→0 is exact.

证明了左R-模P是纯投射的当且仅当对任意纯满射E→M→0，其中E是纯内射的，Hom→Hom→0是正合的。

Open Linear Encoder includes main grating scale and optical encoder head. This optical encoder head includes LED light source, optical detector module, and secondary phase-grating. LED light will pass through the plano-convex lens and produces parallel light. As the parallel light pass through secondary grating, the quadratic image display on the main grating scale. And the Moire interference will be reflected from the main grating scale and detected by optical detector module, as there is a relative shift between the main and secondary grating. From detecting the periodic sinusoidal signal with phase difference 90°, the period represents the grating pitch, using the counter to detect the number of periodic signals to get the displacement, and we can adapt the technology of electron subdivide further to increase the resolution of measurement .

反射式光学尺包括主光栅尺及光学读头，光学读头包含LED光源、光侦测器模组及相位式副光栅，LED光源经平凸透镜，产生平行光穿透副光栅后，副光栅之二次成像投射在反射主光栅尺上，当主、副光栅因相对运对产生之Moire干涉经主光栅尺反射至光电检测器，检出相位差90°之周期性弦波讯号，其周期代表栅距，因此可用计数器检出周期性讯号数目得到位移量，可进一步采用电子细分割技术提高解析度。

By this equality,we prove that the amplitude of a compact DG module M over a cohomologically bounded DG algebra A is just the sum of the amplitude of A and the projective dimension of M.

对于一个同调有界的连通DG代数上的紧的DG模，我们由此等式可得其振幅与DO代数的振幅的差恰是它的投射维数。

A new equivalent characterization of pure projective left R-modules is given by applying homological methods.

通过同调的方法，给出了纯投射左R-模的一个新的等价刻画。

Dissociate cortex cells from early postnatal wistar rats (postnatal hour 24) with DMEM were supplemented by horse serum and N〓 medium, and non-neuronal cell division was halted by cytosine arabinoside. As the result, enough neurons with extensive and synaptically active network were produced.

实验各组分别在造模后3、7、15天取材，观察动物一般情况、脑系数、脑组织含水量、脑组织HE、Nissl's、Mallory染色、投射电镜形态学变化以及TUNEL染色显示凋亡细胞等指标变化，并采用计算机图像分析系统对相关形态学指标进行定量分析。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。