查询词典 difference frequency

The multipath effect is an avoidless problem which the tracking radar and the searching radar among CIWS has to face. This paper analyses the form of the multipath effect on geometry, emphasizes the distance difference between the direct wave and the reflected wave, according to this inherent characteristic, the paper introduces the theory of HRR to the design of radars among CIWS, discusses the spike pulse technology and ultra wide hand technology which often be used, finally proposes the method of time-frequency code to obtain the high range resolution and avoid the multipath effect.

多路径效应是近程反导武器系统中的搜索雷达和跟踪雷达均无法避免的问题，文中分析了多路径效应形成的几何原理，并根据多路径效应中的直射波与反射波具有路程差的固有特性，将高距离分辨率雷达信号理论引入到近程反导武器系统的雷达中，讨论了实现高距离分辨率的窄脉冲和超宽带技术，最后提出了目前较易实现的时间－频率码合成高距离分辨率的办法。

These antennas can cover GSM900/DCS/PCS/UMTS operation. In the chapter 2, the antenna is designed based on the concept of monopole antenna. Furthermore, the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching. In addition, to raise distance between radiation plane and ground will avoid capacitative effect effectually. In the chapter 3, the antenna is designed based on the concept of planar inverted-F antenna. Furthermore, that the antenna structure have two radiant paths and coupled each other at tail end to do impedance matching is similar to chapter 2. But there is a difference in them. We can choose the short position to change input impedance at this structure. In the chapter 4, the antenna is designed based on the concept of planar inverted-F antenna which takes coupled-fed. It will produce the first mode and high-order mode near the frequency, 900MHz. The feature of this type is to reduce the volume effectually. This antenna can not only cover GSM900/DCS/PCS/UMTS operation but maintain good radiation efficiency. Finally, we will compare three antennas, and develop procedure with industrial view, and propose the prospect of the GSM/GPRS antenna in PND, as a conclusion.

在第二章中，我们使用单极天线设计概念，使用双路径架构并於末端耦合来对天线阻抗做匹配，产生涵盖GSM900/DCS/PCS/UMTS四频操作频带，并提高与接地面的辐射高度，以避免电容效应，使天线具有良好的辐射特性；在第三章中，使用倒F形天线设计概念，使用双路径架构於末端耦合，并於辐射臂上采取适当接地点电感效应作输入阻抗匹配，达成涵盖GSM900/DCS/PCS/UMTS系统的四个操作频带；在第四章中，采用倒F形架构并使用耦合馈入方式，使得长辐射金属臂在低频900 MHz附近产生共振，产生低频基频模态及高阶模态，以达成宽频及频宽涵盖GSM900/DCS/PCS/UMTS频带操作，并有效缩减使用体积；最后，分别比较此三种架构的优缺点，再加以业界角度来思考，研发产品天线的流程及思考方向，以及天线应用於可携式导航装置中未来的展望作为本论文的总结。

Three donor wheat all show good character and had little genotypical difference in the aspect of inducement、differentiation、regeneration etc. They could all nice genotypical cultivars for wheat transformation. 3160 embryos have been used to transformation (960 embryos belongs to Atlas66, 1000 embryos belongs to EM12, 1200 embryos belongs to Scout66 respectively), At last, we got twenty-six of which were positive cultivars through PCR. The preliminary whole transformation frequency was 0.82 percent. Also the citrate synthase activities of the leaves of T_0 progeny show 5～9 higher than the control lines.

转化过程中分别使用了960个Atlas66、1000个EM12和1200个Scout 66幼胚(总记3160个)，经抗性筛选、CS与标记基因的PCR检测初步表明有26株为阳性植株，总转化率为0.82%；同时进一步对T_0代植株叶片柠檬酸合酶以及T_1代植株经铝胁迫后对其根尖分泌物进行检测，结果在上述转化植株中检测到了柠檬酸合酶的活性，且转化材料比对照材料平均高出了5～9倍；同时铝胁迫后，T_1植株根尖检测到了苹果酸及柠檬酸的分泌。

Results: There was significant difference in the haplotype of the 4 SNPs frequency between two groups.

结果：联合统计发现，PRODH基因的4个位点的单倍型频数两组分布差异有统计学意义(P05)。

The difference is releasing and letoff unit vector pond?athis, and the feeding frequency conversion motor traction and the traction unit takes a servo motor.

所差别的是不播卷和播卷单位拔取了互换矢量变频电机，而进料牵引和不入料牵引单位却拔取了伺服电机。

The clinical characters of oligodontia concluded from this study are following:(1) There is significant difference that more teeth absent and more existent teeth anomalies in patients of oligodontia/S group than in patients of oligodontia/I group, and the peg-shaped upper lateral incisor is the most frequently affected teeth with shape anomaly.(2) Both of the two groups have no significant differences in number of teeth missing between maxilla and mandible as well as that between left and right side.(3) The distribution of teeth missing is bilateral symmetry in both groups, but the frequency of teeth lost are different: excluding the third molar, in oligodontia/I group, the lower second premolar is the most frequently congenitally missing tooth followed by the upper lateral incisor, while in oligodontia/S group, the most frequently missing teeth are mandibular canine and maxillary lateral incisor. Nevertheless, the first molars are the most stable teeth in both groups.(4) In oligodonita/I group, the mean mesiodistal dimensions of all type of existent teeth are significantly smaller than normal value. It is implied that oligodontia is not an isolated phenomenon, but is related to a complex of other dental changes.

对于口腔多个恒牙先天缺失的临床特点有以下初步结论：(1)综合征型先天缺牙患者较单纯型先天缺牙患者恒牙缺失数目更多，平均分别为23.9个和14.9个，且现存牙齿有更多的形态异常，分别为7／10例（70％）和6／22例（27.3％），其中最常见的是上颌侧切牙畸形；(2)两种类型的多个恒牙先天缺失患者的缺牙数目在上下颌及左右侧之间均无差别；(3)两种类型的多个恒牙先天缺失患者在缺失牙位上均呈对称分布，但在具体牙位上有所差异：不计第三磨牙，单纯型先天缺牙最常缺失的牙位是下颌第二双尖牙、其次为上颌侧切牙；而综合征型先天缺牙最常缺失的牙位是下颌尖牙和上颌侧切牙；无论何种情况，第一磨牙均为牙列中最稳定的牙齿；(4)在单纯型先天缺牙患者中，现存恒牙的牙冠宽度较国人正常值偏小，差异显著，提示牙齿形态与多个牙先天缺失有一定相关性。

Moreover, the actual allele frequency of most varieties deviates far from Hardy-Weinberg equilibrium. All PPB、na 、I、h、Gi and Fst have proved to be the references to elucidate that ISSR is a most powerful tool to analyze genetic diversity, compared with the RAPD marker and the allozyme marker is less strong ordinally. We could divided the 70 samples into A, B, C, D and E five groups using three methods according to genetic distance clustering. There is a bit displacement for few varieties in different clustering maps, but the most are similar to morphological analysis despite that there is still a great difference among cultivars in the same one group. The above results imply that the three methods have the different sensitivity and resolution in genetic distance analysis of close varieties. The Mantel test indicates that the results from the three kinds of markers have the significant correlation, which demonstrates that the number of the used three kinds of markers is enough to exactly detect the diversity of all 70 samples to ideal extent. And these methods can be used to evaluate the diversity of the whole group using the miscellaneous samples instead of the individual sample, of the Gerbera jamesonii are mainly from tissue culture plants. In conclusion, the above study results provide a reference for the application of three kinds of molecular markers to molecular marker-assisted breeding of flower. 2. The genetic diversity among the eight introduced cut-flower varieties of Ranunculus asiatica was analyzed by the ISSR markers. Based on the genetic clustering tree, all the colorful flower varieties are clustered into one group, and the white flower varieties into another group. Moreover, among the former group the yellow flower varieties are clustered into one sub-group, and the reddish flower varieties, such as rose color, pink, nacarat, are clusetered into another sub-group.

由三种分子标记的分析结果可以看出，等位基因平均值、观察杂合度、Fis值、Fit值皆较高，表明非洲菊等位基因较丰富，杂合基因偏多，且绝大部份品种的实际等位基因频率在品种内偏离了Hardy-Weinberg equilibrium；PP8、na、Ⅰ、h、Gi及Fst皆表明，ISSR检测遗传多样性的能力最强，其次是RAPD，等位酶最低；根据遗传距离进行聚类，三种方法都把70个品种分成A、B、C、D、E五个大组，每一组中除少数品种发生位移外，大部份品种分类结果相似，且与形态分析结果有相似性，但在每一组中，品种间的聚类差别较大，表明这三种方法在近距离品种间检测遗传变异时灵敏度及分辨力不同；Mantel检测表明，三种标记的分析结果有显著相关性，表明所用的三种分子方法的标记数量已经可以相对无偏地检测到70个品种间遗传变异；非洲菊为组培苗，三种标记的检测结果皆表明，混合样品可以作为个体样品的代表，对整个居群的遗传多样性进行评价；这些研究结果可为三种分子标记方法在花卉分子辅助育种中的进一步应用提供借鉴。

The waveform , alternating frequency , induced potential magnitude as well as the phase angle difference of two neighbored branch circuits are analyzed in detail .

对发电特性的波形，交变频率，感应电势幅值，相邻2条支路的发电特性间的相位差进行了分析，确定了试验台结构参数与其相互关系。

The waveform, alternating frequency, induced potential magnitude as well as the phase angle difference of two neighbored branch circuits are analyzed in detail. The influences of the structural parameters of the test bench on them are discussed.

对发电特性的波形、交变频率、感应电势幅值、相邻2条支路的发电特性间的相位差进行了分析，确定了试验台结构参数与其相互关系。

We found that 1 mutant EG4 cells showed typical characteristics of pluripotent stem cells which had no obvious difference with wild cells; 2 When induced by 10〓 M retinoic acid , mutant EG4 cells differentiated into adipocytes with high frequency compared with mutant cells, suggested that EGFR plays a role in adipocyte differentiation; 3 when injected into nude mice, mutant teratocarcinomas contained a large amount of connective tissues as well as skeletal muscle, while wild EG4 cells produced frequently cartilage, keratinocyte and neuroepithelium.

我们建立了稳定表达胞内区功能缺失的外源EGFR cDNA片段的EG4细胞，分析其生长分化特性，发现 1）突变型细胞可在未分化状态下维持长时间的增殖，表明EGFR对EG多能干细胞表型无明显影响；2）〓 M的维甲酸A(retinoid acid A，RA)诱导后，大部分对照组细胞分化为脂肪细胞，而突变型细胞分化为脂肪细胞的比例明显较少，表明EGFR在脂肪细胞的发育分化中具有一定的调节作用；3）畸胎瘤切片分析显示，突变型瘤组织分布有大量的未分化细胞和结缔组织，分化细胞以肌肉细胞为主；对照组瘤组织含丰富的角质上皮、软骨、神经管等依赖EGFR的分化组织。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。