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181.
新型絮凝剂F-717对抗生素M-90发酵液预处理研究 总被引:1,自引:0,他引:1
本文设计了九种有机、无机絮凝剂对新抗M—90发酵液预处理的方法研究,探索了以新型絮凝剂F-717与ZnSO4、AlCl3等各种絮凝剂的加入量对发酵液滤速,光密度与效价的关系。 相似文献
182.
几种固态芳烃与银离子配合物形成常数的测定 总被引:2,自引:0,他引:2
作者曾报道用溶质蒸气循环方式制备液态芳烃的饱和溶液,测出苯、甲苯、二甲苯、卤代苯等液态芳烃在水和硝酸银体系中的溶解度,并计算了上述芳烃与Ag~+配合物的形成常数。 具有C=C双键的许多固态芳烃也象液态芳烃一样可与银离子形成配合物,我们设计了溶质蒸气循环方式制备固态芳烃的装置,该法的最大特点是固态溶质和溶剂不直接接触,可以避免固态溶质颗粒在溶剂中的分散和容器壁上的吸附现象,因此用本法测定的溶解度和配合物的形成常数数据可靠、精确。 相似文献
183.
Hai-Guang Li Yong Cai Yun-Song Piao 《The European Physical Journal C - Particles and Fields》2016,76(12):699
In the bounce inflation scenario, the inflation is singularity-free, while the advantages of inflation are preserved. We analytically calculate the power spectrum of its primordial gravitational waves (GWs), and show a universal result including the physics of the bounce phase. The spectrum acquires a cutoff at large scale, while the oscillation around the cutoff scale is quite drastic, which is determined by the details of bounce. Our work highlights that the primordial GWs at large scale may encode the physics of the bounce ever happened at about \({\sim }60\) efolds before inflation. 相似文献
184.
Glass slides functionalized by 1‐carboxyethyl‐3‐methylimidazolium chloride for the determination of triazine herbicides in rice using high‐performance liquid chromatography 下载免费PDF全文
Xinpei Li Shigang Wei Ying Sun Qun Sun Li Liang Bo Zhang Huilan Piao Daqian Song Xinghua Wang 《Journal of separation science》2016,39(23):4585-4591
A novel and simple supported ionic‐liquid‐based solid‐phase extraction method for the determination of triazine herbicides in rice was developed. Glass slides were functionalized by an ionic liquid, 1‐carboxyethyl‐3‐methylimidazolium chloride, and were used for the simultaneous extraction of seven triazine herbicides in rice samples. The effects of the type of extraction solvent, the extraction time, the type and volume of loading solvent, and the type of eluting solvent on the extraction efficiency were investigated and optimized. Under the optimum operation conditions, the limits of detection for seven triazine herbicides in rice samples obtained by high‐performance liquid chromatography were 3.16–5.42 ng/g, which were lower than the maximum residue levels established by various organizations. The linear correlation coefficients were higher than 0.9975 in the concentration range of 0.015–1.08 μg/g for the seven triazine herbicides. The recoveries of the seven triazine herbicides at the two concentration levels of 0.15 and 0.45 μg/g are between 82.47 and 104.21%, with relative standard deviations of 0.69–9.19%. The intra‐ and inter‐day (n = 5) precisions for all triazine herbicides at the spiked level of 0.30 μg/g were 1.72–11.71%. 相似文献
185.
Preparation of a magnetic molecularly imprinted polymer by atom‐transfer radical polymerization for the extraction of parabens from fruit juices 下载免费PDF全文
A silica‐based surface magnetic molecularly imprinted polymer for the selective recognition of parabens was prepared using a facile and general method that combined atom‐transfer radical polymerization with surface imprinting technique. The prepared magnetic molecularly imprinted polymer was characterized by transmission electron microscopy, Fourier transform infrared spectrometry and physical property measurement. The isothermal adsorption experiment and kinetics adsorption experiment investigated the adsorption property of magnetic molecularly imprinted polymer to template molecule. The four parabens including methylparaben, ethylparaben, propylparaben, and butylparaben were used to assess the rebinding selectivity. An extraction method, which used magnetic molecularly imprinted polymer as adsorbents coupled with high‐performance liquid chromatography for the determination of the four parabens in fruit juice samples was developed. Under the optimal conditions, the limits of detections of the four parabens were 0.028, 0.026, 0.021, and 0.026 mg/L, respectively. The precision expressed as relative standard deviation ranging from 2.6 to 8.9% was obtained. In all three fortified levels, recoveries of parabens were in the range of 72.5–89.4%. The proposed method has been applied to different fruit juice samples including orange juice, grape juice, apple juice and peach juice, and satisfactory results were obtained. 相似文献
186.
Byun HS Won M Park KA Kim YR Choi BL Lee H Hong JH Piao L Park J Kim JM Kweon GR Kang SH Han J Hur GM 《Experimental & molecular medicine》2008,40(2):186-195
Previous studies have demonstrated that rottlerin, a specific PKCdelta inhibitor, potentiates death receptor- mediated apoptosis through a cytochrome c-dependent or -independent pathway. However, its ability to regulate necrotic cell death, as well as the underlying mechanism, remains unknown. We found that in murine fibrosarcoma L929 cells, treatment with rottlerin protected the cells against TNF-induced necrosis, whereas it sensitized the cells to apoptosis induced by co-treatment with Hsp90 inhibitor geldanamycin and TNF, in a manner independent of its ability to inhibit PKC-delta. TNF treatment induced rapid accumulation of mitochondrial superoxide (O2-) through the Nox1 NADPH oxidase when cells undergo necrosis. Moreover, pretreatment with rottlerin failed to induce the GTP-bound form of small GTPase Rac1 by TNF treatment, and subsequently suppressed mitochondrial O2- production and poly(ADP-ribose) polymerase activation, thus inhibiting necrotic cell death. Therefore, our study suggests that Nox1 NADPH oxidase is a new molecular target for anti-necrotic activity of rottlerin upon death-receptor ligation. 相似文献
187.
Porous carbon nanospheres have been widely used in different fields such as electric devices, catalysts, and water treatment. Here we will introduce a template-free process for the preparation of porous carbon nanospheres starting from a direct 3-aminophenol formaldehyde polymerization in a mixed solution. We identify that the addition of different alcohols, particularly ethanol and n-butanol, is able to change the growth habit of the polymer nanospheres and introduce a favorable inner compositional homogeneity for the preparation of porous structure. After the carbonization of the polymer nanospheres, the obtained porous carbon exhibits promising electrochemical performance when used as electrode material in super capacitor. 相似文献
188.
The system of Integrated-Optics Acousto-Optic RF Spectrum Analyzer (IOAOSA)consists of a laser diode, an Acousto-Optic (A-O) modulator, geodesic lenses and CCD detectorarray. The optical signal projected on the CCD array is converted into electrical signal andprocessed by the signal processing center which consists of a TMS 32010 system and an IBM-PC.The TMS 32010 with very high speed is used in a microcomputer system. A cycle sample methodis adopted to collect the data of the CCD video signal, sampling one per 40-point. After theprocessing, the frequency bandwidth, the resolution and the dynamic range of the system aremeasured to be 100 MHz, 8 MHz and 20 dB, respectively. 相似文献
189.
190.