离心的

The duration of centrifugation, the rotate speed of centrifugation in sucrose and the concentration of sucrose were tested.

分别对在蔗糖液中的离心时间、离心转速和蔗糖的浓度进行了单因素试验，并对效果较好的离心时间和离心转速进行了二因素组合设计试验。

This could be done in practice by using an alkaline CsCl gradient, as the two DNA strands will denature at high pH.

用同样的样品和相同的技术手段即CsCl梯度离心将半保留复制和弥散复制区分开来的方法是将DNA样品变性，然后利用碱性CsCl梯度离心技术对单链DNA进行离心，半保留复制会出现两条带，而若是弥散复制则出现一条带，如下图所示

By using the CFD software FLUENT, the inner-flow field of centrifugal fans with ruled-surface impeller versus with enveloping surface impeller has been simulated. The static pressure distribution, the dynamic pressure distribution, the total pressure distribution, the turbulent intensity and the speed vector of the two kinds of centrifugal fans are then analyzed and compared. From the calculating results, we found that the pressure distribution, the speed vector and other parameters of the two kinds of centrifugal fans are basically same. This implies that the tool-path generating arithmetic for the machining of the impeller can meet the aerodynamic requirements of the centrifugal fan. Furthermore the method can provide proof for designing department to establish sound manufacturing tolerance for impeller.

最后采用CFD软件FLUENT，利用标准k-ε湍流模型，采用分离隐式求解器，分别对直纹面叶轮离心通风机和包络面叶轮离心通风机整体风机内部三维流场和单个通道流场进行了数值模拟计算，在计算结果的后处理中，对相同坐标值处的静压力、动压力、湍流强度和速度矢量等参数进行了分析与比较，结果表明：在相同的计算参数条件下所得到直纹面叶轮离心通风机和包络面叶轮离心通风机内部流场差别不大，从而揭示所采用的叶轮数控加工的刀位规划方法的规划误差对流体机械动力性能的影响不大，这也为设计部门制定合理的叶轮加工公差提供了依据。

Chapter six, in consideration that the worm tongue structure is a key factor affecting noise generation, the mathematical model of centrifugal fan noise increment that is produced by worm tongue structure is established by using of the D—optimizng technology and dimension analysis method, and the spectral property of fan noise produced by worm tongue structure is analysed.

第六章，针对离心风机蜗舌是影响离心风机噪声的关键因素的特点，采用D—最优化技术并结合量纲分析法，建立了离心风机蜗舌引起的噪声增量与蜗舌结构参数的数学模型，并分析了蜗舌结构参数及其对叶轮声辐射频谱特性的影响。

METHODS: Bone of limbs were obtained under sterile condition, washed by PBS, centrifugalization, and dropwise into centrifuge tube containing 1.073 g/mL Percoll separating medium, centrifugalization, and then adding L-DMEM containing 10% fetal bovine serum, benzylpenicillin sodium and phytomycin, cultured in a incubator at 37 ℃ with 5% saturated humidity. The culture medium was renewed after 48 hours, and non-adhesive cells were removed.

无菌条件下截取流产胎儿双侧四肢骨，PBS冲洗髓腔，离心去脂肪及上清液，L-DMEM重悬细胞，沿管壁缓慢滴加至底部有等量1.073 g/mL Percoll分离液的离心管中，离心后吸取中间界面白膜层，加入含体积分数为10%的胎牛血清、青霉素钠、链霉素的L-DMEM完全培养基，接种后置于37 ℃、体积分数为5%的CO2饱和湿度孵箱内培养。48 h后换液，去除未贴壁细胞，以后每2 d换液一次。

The puerperant and her relatives all signed informed consents. METHODS: Bone of limbs were obtained under sterile condition, washed by PBS, centrifugalization, and dropwise into centrifuge tube containing 1.073 g/mL Percoll separating medium, centrifugalization, and then adding L-DMEM containing 10% fetal bovine serum, benzylpenicillin sodium and phytomycin, cultured in a incubator at 37 ℃ with 5% saturated humidity.

无菌条件下截取流产胎儿双侧四肢骨，PBS冲洗髓腔，离心去脂肪及上清液，L-DMEM重悬细胞，沿管壁缓慢滴加至底部有等量1.073 g/mL Percoll分离液的离心管中，离心后吸取中间界面白膜层，加入含体积分数为10%的胎牛血清、青霉素钠、链霉素的L-DMEM完全培养基，接种后置于37 ℃、体积分数为5%的CO2饱和湿度孵箱内培养。48 h后换液，去除未贴壁细胞，以后每2 d换液一次。

MethodThe extracts was prepared by grinding 800-1 000 mg fresh leaves of Clerodendron inerme and Vitex rotundifolia added with liquid nitrogen. The sample of total RNA was prepared by centrifugating the extracts added with reagent at 4 ℃, centrifugating at room temperature after ice bath and centrifugating at room temperature after adding reagent in order.

方法］取800～1 000 mg许树和单叶蔓荆的鲜叶，加液氮研磨后制成提取液，提取液加试剂4 ℃下离心，冰浴后室温下离心，依次添加试剂后室温下离心，即得total RNA样品。

A little of the diaylsed solution was dilluted with distilled water (1:4) and applied to metallic sample plate following negative staining with sodium phosphotungstate solution. The sample was freeze-dried and examined by transmission electron microscopy 1.4 IFvs size and size distribution measured 1.5 The shape morphology of IFvs 1.6 Measureing the encapsulation efficiency and loading capacity of Liposomal Gd-DTPA A sample volume of 5ml was sent to analyze (Zhongshan University Analytical Center, Guangzhou).

1.6 Gd-DTPA脂质体包封率及载药量的测定取5ml前述离心后所得上清液送交中山大学分析测试中心，采用高频电感耦合等离子发射光谱法测定离心液中Gd-DTPA含量，用加入总的Gd-DTPA量减去离心液中的Gd-DTPA含量即得包封量。

The flowfield and performance of a centrifugal compressor was predicted and analysed, which was composed of a Krain's impeller and two types of vaneless diffuser specially: one was constant area vaneless diffuser and the other was the straight-wall. The results show that the efficiency of the straight-wall vaneless diffuser is obviously lower than that of the constant area, and a separate flow occurs nearby the exit of the centrifugal impeller with the straight-wall diffuser. However, the type of vaneless diffuser has little influence on the aerodynamics performance of the centrifugal impeller. Finally, it is suggested that the constant-area vaneless diffuser should be selected as the downstream extended area of the centrifugal impeller during the prediction for the centrifugal impeller.

对Krain叶轮后带等面积与直壁两种形式的无叶扩压器离心压缩机内部流场进行了计算与分析，结果表明：直壁型无叶扩压器离心压缩机的效率低于等面积无叶扩压器离心压缩机的效率；直壁型无叶扩压器使得叶轮出口的流动出现分离；扩压器的形式对离心叶轮的整体气动性能影响并不大；在进行离心叶轮数值研究时，叶轮后的延伸区最好采用等面积无叶扩压器，以尽量减小无叶扩压器所引起的计算误差。

The methods of theory design and similar design for centrifugal fan are used in the article for the development and study of integrated CAD system for centrifugal fan.

本文研究了离心通风机的理论设计和相似设计原理，进行了离心通风机系列产品CAD系统快速响应的研究，基本实现了离心风机系列产品设计的自动化。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。