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51.
The chromatographic fingerprint of Pinellia ternata was established by high performance liquid chromatography (HPLC) using an Agilent C18 (5 μm, 4.6×250 mm) column; CH3OH∶H2O as elution solvents; an ultraviolet detector at 254 nm; a flow rate of 1.0 mL/min. The guanosine peak was used as the reference and the relative retention value α and the relative area Sr as the parameters for the survey of the chromatographic fingerprint. Nine co possessing peaks were selected as the charaterizing fingerprint peaks to distinguish Pinellia ternata from false Pinellia ternata. The relative retention time of the 9 peaks were 1.00, 1.12, 1.50, 1.56, 1.60, 1.67, 1.71, 1.81 and 1.87, respectively. These peaks can be used to identify the quality of Pinellia ternata. 相似文献
52.
WEN Ming BAI Wei LI Bi bo HAN Zhong LU Yun feng LI Shao lin YANG Xue heng 《保鲜与加工》2008,(8):956-960
The c erbB2 oncogene antisense oligodeoxynucleotide probe was obtained by chemical cross linking approach. Its T2 relaxivity was 0.156×106 mo l－1·s－1 , which was determined with a 1.5T MR system. The saturated magnetization, specific saturated magnetization, specific retentivity and retentivity were 69.423 8emu/g Fe, 68.413 4e mu/g, 30.354 1e mu/g and 19.734 5 Gs, respectively. These measurements were obtained with a vibrating sample magnetometer. To test its effectiveness, highly expressive SK Br 3 oncocytes were transfected with the antisense oligodeoxynucleotide probe. Meanwhile, SK Br 3 oncocytes were transfected with the sense and non sense oligodeoxynucleotide probe, and normal mouse liver cells were transfected with the antisense oligodeoxynucleotide probe. The results show that the antisense probe could enter the SK Br 3 oncocytes effectively, and improve the magnetic properties and decrease the signal intensity in MR scanning obviously. 相似文献
53.
The concept of centralized filling and separate bottle displacement was introduced to reduce the inconvenience of filling compressed natural gas(CNG) vehicles. By taking a programmable logic controller (PLC) as the smart control unit and stepper motors as drive units, a mobile three dimensional table was designed as a working platform. The stepper motor control algorithm was studied, and the system model for the CNG vehicles automatic loading and unloading was constructed. A new automatic loading and unloading system for CNG vehicle bottles was developed. Theoretical analysis and experimental results show that the system can complete the automatic loading and unloading task in 1 or 2 minutes, thereby improving CNG vehicle filling efficiency. 相似文献
54.
A construction project letter of guarantee is used as financial credit to insure the smooth project execution. The construction project letter of guarantee system developed over one hundred years in the United States where a comprehensive system has been established. It is proven that the system played a vital role in controlling construction industry risk in the U.S. In contrast, the system developed later in P. R. China but has played an increasing role in the Chinese construction industry. Based on a discussion of the structure, meaning and condition of the letter of guarantee system in the U.S., a suitable framework is sought to promote development of the letter of guarantee system in the Chinese construction industry. 相似文献
55.
微生态制剂在鸵鸟育雏中的应用 总被引：2，自引：1，他引：1
为了减少雏鸵鸟的发病率、提高成活率和饲草利用率,在2004-2006年不同季节以3批分别70、140和70只商品雏鸵鸟为试验动物,研究在饲料中添加EM液(试验Ⅰ)和益生素(试验Ⅱ)对其生产性能的影响。结果表明,试验Ⅰ和试验Ⅱ发病率比对照组低24.07±10.70和15±7.23(P0.01);死亡率比对照组分别低3.81±0.67和2.62±0.55(P0.05),草料消耗分别比对照组低(8.35±0.86)kg/d和(1.11±0.12)kg/d(P0.05);日增体质量分别比对照组提高(26.04±5.70)g和(23.16±4.58)g(P0.01),制剂和药费上每只鸵鸟分别比对照组节约93和76元。使用添加EM制剂的饲料饲喂雏鸵鸟效果非常明显,是目前养殖业上比较好的微生态制剂。 相似文献
56.
为分析具有侧向自由度的半挂汽车列车行驶特性,建立了包含车身侧倾和转向系刚度的车辆模型,对车辆在典型工况下的运行状态进行仿真分析;并对模型中的牵引鞍座参数进行调试和匹配,分析这些参数变化对系统稳定性的影响,以期为车辆系统设计提供参考依据.研究结果表明,行驶状况和牵引鞍座参数的变化,可能造成车身侧倾、两车存在夹角等,应通过参数灵敏度进行分析判断;仿真结果说明所建模型适用于分析车辆行驶特性. 相似文献
57.
Stress wave effect in numerical simulation on rock breaking under high pressure water jet 总被引：1，自引：0，他引：1
The evolvement of rock damage struck by a high pressure water jet is characterized by nonlinear properties, thus making it a complicated dynamic problem. Based on a nonlinear finite element and elastic plasticity theory, a computational model was established. The dynamic load striking the rock by a high pressure water jet was simulated by the dynamic contact method. Furthermore, the propagation of a stress wave in the same rock was simulated at different impact velocities. The results show that the propagation velocity of a stress wave is proportional to the impact velocity of the high pressure water jet. The effects of a stress wave in sandstone and coal impacted by high pressure water jets of the same velocity were simulated.The effect of a stress wave in coal was stronger than in sandstone, while the region of propagation of stress wave in coal was smaller. 相似文献
58.
A two dimensional gray image of the material fault can be obtained without destruction by industrial computer tomography (ICT). This process is used to distinguish the seizure and the expansion of cracks within the initiation section. A fatigue life prediction method based on industrial CT images was studied. First, the crack initiation and expansion processes were divided into three phases: micro scale thinness sight crack, CT scale crack, and macroscopic crack. Second, different crack initiation and expansion standards were adapted to calculate material fatigue life. The fatigue life of the material was the sum of the three phase's fatigue lives. Compared with other methods, such as the fatigue cumulative damage theory method and the nominal stress method, the fatigue life predicted by this method is more precise. 相似文献
59.
WANG Hong jian XIAO Sha li SHI Jun TANG Chang huan LIU Shen ye QIAN Jia yu 《保鲜与加工》2008,(8):864-868
A new crystal spectrometer with high spatial and spectral resolution was designed to measure very low emissive X ray spectra of laser produced plasma in the 0.5 nm to 0.8 nm range. Twin channels collocated perpendicularly with two different crystal materials and forms were utilized for simultaneous measurement of spectral and spatial resolution. The imaging plate was employed to obtain high spatial resolution with effective area of 30 mm×80 mm. The basic parameters of crystals were analyzed and the design parameters of the spectrometer are presented herein. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, CAEP. X ray spectra were obtained from Al laser produced plasmas with a spectral resolution of 1 000 to 1 500 for the spherically bent mica crystal spectrometer and spatial resolutions of 1.73 mm to 6.88 mm for the flat PET crystal in the same condition. It is suggested that the device be used in high density plasma diagnostics of a single laser shot. 相似文献
60.
Piezoelectric material was used to establish a single input/single output (SISO) model of a lifting surface with distributed piezoelectric actuators and piezoelectric sensors. The flutter equations and state space equations of piezoelectric laminated structures were also derived. MATLAB, NASTRAN and other software programs compiled by the authors also were used to analyze the flutter and dynamic characteristics. The stability of the closed loop was analyzed for the SISO. The result indicates that the control law can be employed for flutter suppression. 相似文献