RELATIONSHIP BETWEEN THE CHANGES OF THE FAST PHASE OF MILLISECOND DELAYED LIGHT EMISSION AND THE PROTON RELEASED BY THE OXIDATION OF WATER

The phosphorylation uncouplers suppressing the proton gradient across the thylakoidmembrane can also affect the fast phase of millisecond delayed light emission (ms-DLE) atflash light intensity strong enough to saturate the Hill reaction. At the concentration ofsame uncoupling degree, nigericin decreases the fast phase DLE much more than NH_4Cl.Omitting the terminal acceptor in the reaction mixture or adding DBMIB to inhibit PQ oxi-dation diminishes the slow phase DLE and affects the fast phase slightly, while DCMU orHOQNO which inhibits electron transport between PSII and PQ, diminishes both phases ofms-DLE. These results indicate that the proton gradient responsible for the enhancement ofthe fast phase DLE is more intimately linked to the thylakoid membrane, and is mainlyrelated to the proton release from water oxidation and not to the turnover of plastoquinone.     

转基因水稻表达的Bt毒蛋白Cry I Ab溶液构象的研究

用荧光光谱法研究了毒蛋白Cry I Ab在溶液中的构象。结果表明，pH值增大时，毒蛋白的荧光强度也增大，至pH=11时荧光强度已达最大值；甲醇、乙醇及异丙醇等有机溶剂引起毒蛋白荧光发射波长蓝移和荧光强度增大，至有机溶剂的浓度超过某一阈值后荧光发射波长不再蓝移；丙酮能完全猝灭毒蛋白Cry I Ab的荧光，丙烯酰胺能猝灭Cry I Ab86%的荧光，而KI对毒蛋白的荧光无猝灭作用，由此推断Cry I Ab的大部分色氨酸残基位于分子表面富含负电荷的区域中。     

A CLUSTER COMPOUND WITH DI-ENDOXYGEN LIGANDS——THE CRYSTAL AND MOLECULAR STRUCTURE OF [Fe(MOS_4O)_2][N(C_2H_5)_4]3

[Fe(MoS_4O)_2] [N(C_2H_3)_4]_3 cluster compound with di-end-oxygen ligands has been prepared and characterized by the X-ray diffraction method. The compound crystallizes in a monoclinic space group P2_1/n with lattice parameters a=13.019(4), b=16.959(5), c=18.234(5), β=97.34(2)(°), Z=4. The final agreement factors are R=0.0740, Rw=0.0598. The terminal bond length, Mo-S_t and bridged one, MO-S_b for the compound are much longer than the counterpart without end-oxygen ligand. It possibly suggests that low valence of molybdenum and smaller electronegativity of sulphur than oxygen lead to the charge transfer as S→Mo→O.     

具有咖啡酰基和没食子酰基的β-二酮酸及喹噁啉酮类HIV整合酶抑制剂的设计合成及其对Cu2+的选择性识别

An efficient procedure for the synthesis of caffeoyl-and galloyl-containing β-diketoacid derivatives linked byarylamide was reported by,in the key step,dissolving the corresponding phenyl methyl ketone in THF/DME in thepresence of NaOMe as base and dimethyl oxalate as oxalylation reagent,and then separating the sodium ketoe-nolate ester.The resulting β-diketoacids underwent further condensation reaction with o-phenylenediamine to gen-erate quinoxalone derivatives in good yield,rather than 2-benzimidazol.The preliminary ion binding properties ofquinoxalone derivatives were also investigated.UV-Vis spectra showed that these compounds could selectively rec-ognize Cu~(2 )ion in ethanol and form a 1∶2 complex.     

Microcalorimetric Evaluation of the Effect of Kanamycin： An Analysis Based on the Median-Effect Principle

A study of the effect of drug, kanamycin, on the growth metabolism of recombinant Escherichia coli B 1 was carded out by microcalorimeter monitoring of the metabolic activity of treated cells. Power-time curves of growing recombinant Escherichia coli cell suspensions, treated with different kanamycin doses, were recorded. The extent of the effect was evaluated by changes in the slopes of the microcalorimetric curves and the kinetics of the drug action was interpreted from the time at which these changes reached their maximum values and maintained their maximum values. Experimental dose-effect relationships conform to the median-effect principle of the mass-action law： fa/（1-fa）=（D/D50）^m. A plot of y=lg[（fa）^1-1]^-1 versus x=lg D gives the slope m, D50 and R∞. The experimental results revealed that high concentration of kanamycin had an inhibitory effect on the growth of recombinant Escherichia coli B 1 in the lg phase, and had a promoting effect in the stationary period. Moreover, it was demonstrated that microcalorimetry was a reliable method for the detection of modulatory effects in biology.     

“退位减心算（3）”教学预案

<正>【教学内容】《珠心算》第三册第60～63页。【教材简析与说明】“退位减心算（3）”是《珠心算》第三册第二单元的内容,是在学生已经学习掌握了实拨、空拨100减两位数、一位数和心算两位数减一位数的退位减基础上安排的学习内容。根据珠算在前、心算在后的循序渐进原则,遵循实拨是基础、空拨是关键、看拨是过渡、     

含有草酸配体的钼硫(氧)配合物的合成、光谱及晶体结构

草酸是重要的有机配体,它能和许多金属形成配合物,并具有不同的分子结构[。1-3]其中,钼与草酸形成的配合物研究一直是人们关注的焦点。主要有以下原因:1、钼与草酸形成的配合物在结构上形式多样,即使同一组成的配合物,也有不同结构。如K2[MoO3(C2O4)]·H2O[4],由于合成方法不同     

浅谈酶标分析仪检定规程中存在的一些问题

酶标分析仪作为一种快速,灵敏度、准确度较高的测试分析仪器,广泛地应用于医疗卫生、检验检疫等行业。它的主要原理是依据酶与底物产生显色反应,不同物质有其各自的特征吸收谱线,并遵守朗伯-比耳定律。理论上某种物质若能与特定酶发生反应并能产生颜色均可用酶标分析仪进行定性     

银在质子交换膜燃料电池空气阴极内促进氧传递研究

利用离子交换及随后的氢还原,将单质银负载在质子交换膜(Nafion)孔道内.TEM、XRD表征载银Nafion膜的结构,电化学极限电流法测定氧在载银Nafion膜内的扩散系数.结果表明,因银晶颗粒大于Nafion孔道直径,致使Nafion孔道有所扩张;氧在载银Nafion膜内的扩散系数是无银Nafion膜的4倍.据此,把银引入质子交换膜燃料电池空气阴极催化剂表面的Nafion薄层,则电池的性能在高电流密度下有明显的提高,显示了银对该电极内氧传递的促进作用.     

选区激光熔化成形区粗糙表面对铺粉质量的影响:离散元模拟

选区激光熔化中, 铺粉质量会极大地影响产品的最终质量. 然而, 成形区粗糙表面对铺粉质量影响的研究较少. 因此, 本文以成形区粗糙表面作为新的铺粉基板, 通过离散元法, 研究铺粉过程中成形区的表面形貌和工艺参数对铺粉质量的影响, 并分析铺粉过程中金属粉末在成形区粗糙表面的颗粒动力学和颗粒沉积机制. 结果表明, 将激光扫描方向与铺粉方向旋转一定角度可有效提高粉末层质量, 增加铺粉层厚可减小成形区粗糙表面对铺粉质量的影响. 减小搭接率可提高成形区对颗粒的滞留能力, 从而使更多的颗粒沉积在成形区, 提高粉床填充密度, 但是粉末颗粒会与成形区的粗糙表面碰撞, 产生颗粒迸溅现象. 此外, 铺粉过程中, 由于成形区粗糙度的增大, 成形区粗糙表面上的粉堆产生的强力链、力拱数量多于表面光滑的成形区. 在滚轮作用下, 力拱断裂导致颗粒重新排列, 形成致密的粉末层. 在成形区边界处, 力拱的产生会最终导致边界处的粉末层出现空斑缺陷. 本研究有助于通过优化工艺提高粉床质量.