查询词典 X-unit

On the basis of the conclusion above, the nonlinear weak controllable vectors can be obtained, which compose the second class of weak controllable matrix, by means of matrix transfermations of the first class of weak controllable matrix. Furthmore the second criterion of weak controllability, accessibility and strong accessibility, which is more standard, more succinct and more practical, is obtained. On the basis of the first criterion and the second criterion, several important problems about nonlinear controllability are discussed, which include 1 local controllability; 2 three classes of local controllable decomposition, separately by means of local coordinate changes in the neighborhood of a nonsingular point, a point on a singular surface or a designated point x〓 with a designated input u〓; 3 the character of controllability of the ith state variable x〓 in different controllable areas and their boundaries.

在第一判别定理和第二判别定理的基础上，我们分析了非线性系统受控性质中的几个重要问题，所得到的结论包括i得到了非线性系统在可平衡点附近的能控性判别定理；ii分别给出了非线性系统在非奇异点、s阶奇面以及在状态空间内给定的一点x〓和输入u〓上的三种状态分解形式以及相应的求解方法；利用系统的Ⅰ型弱能控矩阵与Ⅱ型弱能控矩阵秩相等的条件，得到了只用系统的前n个弱能控向量来判断系统的弱能控性的判别定理；iii通过引入系统状态分量的三类受控区域边界的定义及相应的求解方法，初步探讨了非线性系统各个状态分量在不同的受控区域及其边界上的受控性质。

The value of the cosine function at argument x.

参数为x的情形下余弦（在原正弦函数中x取余角）函数的数值。

The required opeartion is called cross product, and it is represented by "x".

这个需要的运算叫做叉乘，我们把它表示为"X" v = v1 x v2

It is showed that in the X-ray diffraction patterns of the interlayer solid solution Ti3Si0.9Al0.3C1.93 and Ti3Si0.8Al0.4C1.93 bulk samples,which were in-situ reactively synthesized by hot-pressing the elemental Ti,Si,Al and C mixed powders,the diffraction peaks of [00L] crystal planes are very weak,there is only a small diffraction peak belonging to the [008],and the diffraction peaks belonging...

结果发现，用热压Ti、Si、Al和C混合粉末原位反应合成的Ti3Si0.9Al0.3C1.93和Ti3Si0.8Al0.4C1.93层间固溶体块体样品的X射线衍射谱中[00L]晶面的衍射峰极其微弱，只有[008]面有一个小的衍射峰，[002]、[004]和[006]面几乎没有衍射峰存在，而该块体样品的粉末的X射线衍射谱中所有[00L]晶面的衍射峰均存在。

However, Crick and Watson might not have been able to discover the DNA double helix as quickly as they had without the work of the x-ray crystallographer X Rosalind Franklin, who died before the Nobel Prize was awarded.

然而，如果没有 X 射线晶体学专家罗莎琳德·富兰克林的工作，克里克和沃森也许不会这么快就发现 DNA 的双螺旋结构。

External dimensions : 600 x 400 x 200 mm Two colour printing as indicated below: The following text must be in Univers 66 Bold, logo in cyan blue and text in black.

外部尺寸： 600乘四百x 200毫米两种颜色印刷，如下所示：以下文字必须在宇宙66大胆，标识青色蓝色和文字为黑色。

External dimensions : 600 x 400 x 200 mm Two colour printing as indicated below: The following text must be in Univers 65 Bold, logo in cyan blue and text in black.

外部尺寸： 600乘四百x 200毫米两色印刷，如下所示：以下文字必须在宇宙65大胆，标识青色蓝色和文字为黑色。

Radiation from X ray also can affect the developing embryo and fetus ,with the most dangerouse time bing the first several weeks after conception,when women do not yet know they are pregnant .it is important for women and their physicians to weigh the risk of an X ray when an actual or potential pregnancy is involvel.

在有了胎儿这个概念的前几个星期，有很多危险的时刻，因为女人们还不知道他们已经怀孕。X射线对于女人和她们的身体有致命的危害。当然也包括胚胎和胎儿在内。

The degree of a polynomial is equal to the highest power of x in it; here it is 2 because of the x2 term.

一个多项式的阶与其中x的最高次幂相等；这里是2因为x^2项。

objective to evaluate the value of infrared thermography in the diagnosis of injuries in such soft tissues as neck,shoulder,waist,leg,elbow and wrist.methods infrared thermograph (type wp-95) was used to do general physical check up for 221 young soldiers with a regular military training history ranging from 1 to 5 years,whose infrared thermograms were then compared with those of 100 new recruits without any military training experience.results there were abnormal thermograms on 180 (81.45%) of the 221 cases and 6 (6%) of the 100 new recruits （p.05.all of the 186 cases with abnormal thermograms were x-rayed with only 28 cases(i.e.15.05%) abnormal.there was a distinct difference between the two methods of physical check-up (p.05).conclusion infrared thermography manifests distinctive abnormal thermograms of soft tissue injuries suffered from military training,providing definite diagnostic message for clinic.to utilize infrared thermography correctly is of vital importance in ensuring the health of servicemen.

目的 探讨软组织损伤颈、肩、腰、腿、肘、腕红外热像图的诊断价值。方法应用wp-95型红外热像仪，对221例常规军事训练1～5年的年轻干部及战士进行红外热像仪的全身检查，并与刚入伍未参加训练的新兵100例进行对照。结果 221例经红外热像图检查发现颈、肩、腰、肘、腕出现异常热像图的有180例，占81.45%；而100例新战士仅有6例颈、肩、腰、肘、腕出现异常热像图，占6.00%，两者比较差异有显著性（p＜0.05）。186例异常热像图受检者全部做x线摄片检查，x线摄片异常者仅28例，占15.05%，两者检查比较差异有显著性（p.05）。结论红外热像图对军事训练所致软组织损伤有其独特的异常热像图，为临床提供明确的诊断信息，正确的使用红外热像图，对保证部队广大指战员的健康水平有着重要作用。

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。