查询词典 stratified sample

Solid-phase extraction technique has become increasingly popular in recent years because it is experienced with several major advantages: the fast, simple and direct sample application in very small size without any sample loss; higher preconcentration factor; rapid phase separation; the ability of combination with different detection techniques in the form of on-line or off-line mode; time and cost saving.

而固相萃取与原子光谱检测技术联用在痕量元素的分离富集和形态分析中也发挥着日益重要的作用。

In order to deal with the problem of face recognition with one sample per person, a method called sub-block Principal Component Analysis based on partitions of the sample is presented in this paper.

针对单样本人脸识别问题，本文提出了一种基于单样本切割的子模块主成分分析方法。

Comparing with the previous stimulus-response method with only one sample port, the new method has the advantages of more reliable, simpler algorithm and more flexible for position of the sample ports.

与一点取样的动态响应曲线法相比，新的两点动态法具有数学模型的边界条件简单，对取样点的放置位置比较灵活，结果可靠等优点。

Product fashionable, comfortable and generous, can be ordered sample, style can be customized for different sizes of our style code number may also be in accordance with the incoming sample custom make.

产品款式新颖，舒适大方，可来样订购，款式可按我方款式定做不同大小码数，也可以按照来样定做。

When outputting parameters were five grades,the correct rate (82.5%) in primitive sample of Ordered Logit model was higher than test sample of the Back-Propagation Network model one and model four (64.583% and 60.417%).

四、当输出变数为五个等级时，Ordered Logit模型原始样本分类正确率（82.5％）高於倒传递类神经网路模型一及模型四之测试样本（64.583％及60.417％）。

But if you compare the outturn sample of the present parcel with that of your previ9ous supplies - a sample of which I've brought with me - you will readily see a marked difference in colour.

但是你如果把这批货的抽样同上一批货比较一下（我把上批货的抽样带来了）就容易看出颜色明显不同。

Unlike the existing literature which uses only the sample of workers in studying, the incidence of overeducation, this thesis further takes into account the role of non-workers and compares the results estimated by both the Probit Model and Probit Model with Sample Selection.

另外有别於过去在讨论个人发生超额教育机率议题的文献，其皆只采用有工作者样本，在此本文兹将无工作者样本纳入考量，并利用考虑与未考虑样本选择 Probit模型相互比较。

A microcomputer is used to communicate with the controller of electron probe to control the spectrometers and the sample stages as well as the scalers. Data of X-ray intensity are acquisited when the sample stages are scanning in a certain step and time period. X-ray images were formed and shown in colors or in 3 dimensions, and have no distortion at low magnification. Hidden zonate phenomena of a picrite were found.

摘 要：用微型计算机与电子探针控制机通讯，实现对各道波谱仪和样品台的实时控制，以及对各道定标器的数据采集；在选定的样品区域上设定采样步长和时间，边移动样品台边采集各道X射线强度；用伪彩色、三维视图和内插放大等方式显示图像，解决了低倍X射线像失真问题，观察到了辉石的隐环带等现象。

A device for measuring bidirectional reflectance and transmittance distribution of a leaf in the plane of incidence was designed with a micro-powered laser diode for illuminating and a silicon photocell detector rotating around sample for recording scattering light intensity from the sample.

采用微功率激光管作为光源，围绕被测样品旋转的硅光电池作为检测器，研制了一种可以测定植物单个叶片反射和透射光在入射面上分布的装置。

Irradiation from a Q-switched Nd: YAG laser (pulse duration: 12 ns, repetition rate: 10 Hz) was focused onto the sample surface by a plano-convex lens with a spot diameter of about 1 mm to ablate a portion of sample and generate a micro plasma.

一个平凸透镜把斑直径大约为1 mm的光量开关Nd： YAG激光器（脉宽：12 ns；重复频率：10 Hz）辐照聚焦于样品表面，用来烧蚀样品的一部分，形成一个微等离子体。

This paper designs the communication system of radio telescope FAST.

针对500m口径球面射电望远镜FAST分布式控制系统的特点完成了其通信系统的设计。

Political sheep's step-by-step a large number of fossils unearthed in the county soil Ma Ali after rural village in the middle of sallow pelitic siltstone.

步氏和政羊化石大量出土于广河县阿力麻土乡后山村，产于灰黄色泥质粉砂岩中。