高效液相色谱法测定地榆中金丝桃甙的含量

采用高效液相色谱法测定了地榆中金丝桃甙的含量。色谱柱为Ｓｈｉｍ－ｐａｃｋＣＬＣ－ＯＤＳ柱,以甲醇－０．０２５ｍｏｌ／Ｌ磷酸（５０５０）为流动相,检测波长３７０ｎｍ,测定组分与其它组分的色谱峰达到基线分离。加样回收率平均值为９８．７％,ＲＳＤ为１．９％。为控制中药地榆的内在质量提供了新的测定指标和可靠的方法。     

细胞线粒体状态的热力学分析

近年来,线粒体在一些重大的代谢性疾病如糖尿病和神经退行性病变中的作用倍受关注。由于线粒体是细胞生产能量的“工厂”。线粒体的能量代谢理论研究带动了线粒体热力学研究的进展,也向化学热力学研究提出新的问题。本文在总结了化学渗透理论和近年来线粒体有关的生物化学研究新结果的基础上,对线粒体的工作及其调节机制了进行了分析,提出了线粒体工作状态受化学热力学机制控制的新观点。     

单纵模Nd:YAG激光抽运CH4中强后向受激拉曼散射

用单纵模Nd:YAG二倍频激光[波长532 nm,线宽△vp＜100 MHz,脉宽(半峰全宽)6.5 ns]抽运CH4气体,观察到很强的后向一级斯托克斯(BS1)受激拉曼散射,这与前人采用脉宽30 ns的单纵模抽运激光得到的绝大部分为后向受激布里渊散射(SBS)完全不同,其原因是脉宽6.5 ns与本实验条件下CH4的受激布里渊散射声子寿命接近,受激布里渊散射处于瞬态.理论计算表明,这时的受激布里渊散射瞬态增益系数已略小于后向一级斯托克斯的增益系数,而被其竞争抑制.当脉冲重复频率为2 Hz,抽运能量为95 mJ时,在1.1 MPa CH4中,后向一级斯托克斯的量子转换效率高达73%,其时间波形出现张弛振荡,脉宽被压窄到1.2 ns,从而使后向一级斯托克斯峰值功率达到了抽运激光功率的2.7倍,而且其光束质量要大大优于抽运激光的光束质量.用编制的准二维计算机模型程序相当好地再现了实验中后向一级斯托克斯的时间波形张弛振荡.     

脱氢醋酸与氨的反应

脱氢醋酸(1)与氨反应生成2,6-二甲基-4-羟基吡啶(2)^[1]。IguChi等^[2]曾用纸层析法定性地研究了这反应的过程。为进一步了解(1)与氨反应的历程及影响反应的因素,我们用HPLC研究了在不同反应条件下得到的中间体和产物,研究了相互转变关系,并进行了分离和鉴定。初步提出了该反应的可能历程。     

单晶变角EPR谱的解释Ⅱ.掺Cr3+乙酰丙酮铝单晶的EPR

对掺Cr³⁺乙酰丙酮铝单晶的(001),(100)和(110)晶面进行晶面旋转EPR扫描,得到共振磁场随旋转角度变化的实验图形,根据本征插方法编写的程序,对实验谱图进行投合,得到下述顺磁参数,D=0.5870±O.005cm^-1,E=-0.00490±0.0001cm^-1,g_x=g_y=1.965±0.001,g₂=1.984±0.001.     

高剂量与高能量离了注入研究进展

综述了离子束材料实验室在高剂量与高能量离子注入研究方面的新进展,包括高剂量离子注入动态靶的模拟计算ＭＡＣＡ程序、多能离子注入深度分布计算、ＭｅＶ离子引起的ＨＯＰＧ表面操作、ＭｅＶ离子诱变右旋糖酐生产菌种、高剂量离子注入在４５号钢表面形成耐腐蚀的保护层以及在高速工具钢上形成含有大量超细碳化物的耐磨层. The development of high dose ion implantation and high energy ion implantation at the Ion Beam Application Group of IHIP in recent years is reviewed.     

Backstepping control for the optoelectronic stabilized platform based on adaptive fuzzy logic system and nonlinear disturbance observer

A composite controller based on a backstepping controller with an adaptive fuzzy logic system and a nonlinear disturbance observer is proposed in this paper to address the disturbance and uncertainty issues in the control of the optoelectronic stabilized platform. The matched and unmatched disturbances and system uncertainty are included in the stabilized platform model. The system's uncertainty and disturbance are approximated and estimated using an adaptive fuzzy logic system and a nonlinear disturbance observer. Moreover, the backstepping control algorithm is utilized to control the system. The simulations are performed in four states to confirm the viability of the proposed control technique. The proportional integral controller, proportional integral-disturbance observer controller, and fuzzy backstepping controller are contrasted with the proposed controller. It has been noted that the proposed controller's instantaneous disturbance's highest value is 5.1°/s. The maximal value of the coupling output for the two gimbals utilizing the proposed controller, however, is 0.0008°/s and 0.0018°/s, respectively. The findings presented here demonstrate that the backstepping controller, which is based on an adaptive fuzzy logic system and a nonlinear disturbance observer, is capable of precise tracking and dynamic tracking of a stabilized platform under disturbance and uncertainty.

     

异丙醇对油溶性CdSe团簇量子点荧光的影响

为了探究异丙醇对胶体CdSe团簇量子点荧光光谱的影响,使用胶体化学法在油酸-石蜡体系下合成CdSe团簇量子点,对团簇量子点和异丙醇采用不同的混合比例,得到了其修饰之后的荧光发光谱(PL)和紫外吸收(UV)光谱,并采用曲线拟合的方法对团簇量子点的光学性能进行了研究。通过对AFM和傅里叶红外光谱的分析,探讨了CdSe团簇量子点光学性能改变的内在联系。结果表明:随着异丙醇浓度的增加,量子点的荧光峰出现11 nm的蓝移,且蓝移曲线呈阶梯状变化;相对荧光强度也呈现出先上升再下降的波动性变化,且波动幅度最大能达到1 000 a.u.;量子点的第一吸收峰和第二吸收峰都会发生不同程度的红移,且最大红移达到12 nm。     

共沉淀法制备Co掺杂纳米ZnO及其表征

以ZnCl2、CoCl2和NaOH为原料,采用共沉淀法制备了纯ZnO和Co掺杂ZnO(ZnO: Co)纳米粉体.利用XRD、EDS和FESEM对样品的结构和形貌进行了表征,利用光致发光光谱(PL)研究了样品的发光性质.结果表明,控制退火温度600 ℃煅烧2 h能得到纯度较高的ZnO: Co纳米粉体,此粉体属于六方纤锌矿结构;部分Co2 +取代了Zn2 +进入ZnO的晶格,掺入量为2.2 at;;Co掺杂对产品的形貌影响不大,掺杂前后均为准球形颗粒,掺杂后颗粒粒径略有减小;Co掺杂使ZnO的禁带宽度变窄,紫外发光峰位产生显著红移.     

Photocurrent properties of high—sensitivity GaN ultraviolet photodetectors

GaN epilayers were grown on sapphire substrates by metal-organic chemical vapour deposition. Metal－semiconductor－metal photoconductive detectors were fabricated using this material. The photocurrent properties of the detectors were measured and analysed. The spectrum response shows a high sensitivity in the wavelength region from 330 to 360nm, with a peak at 358nm and a sharp cutoff near 360nm. The maximum responsivities at 358nm were 700A/W (2V) and 7000A/W (30V). The relationship between responsivity and bias indicates that the responsivity increases linearly with bias until 30V. The influence of the spacing between two electrodes on the detector responsivity was also studied.