用石英微粒为载体的SCOT柱分离细菌体内代谢产物中的脂肪酸

从细菌体的代谢产物中所含脂肪酸的类别进行细菌分类,这是细菌分类的新课题。我们对来源不同的七株E型肉毒梭菌代谢产物中提取的脂肪酸作了分析,从而为E型肉毒校菌分类提供了依据。 为了选出适合分离脂肪酸的SCOT柱,我们在载体的选择、处理以及制柱的程序(先涂层后拉伸或先拉伸后涂层),仪器的     

基于灰色动态模型的丽江旅游人数预测研究

介绍了累加数列的生成,以及GM(1,1)模型的建立.通过丽江市统计局获得从2005到2011年的旅游人数.以2005年至2011年的旅游人数为基础建立GM(1,1)模型,通过ma,tlab软件进行求解,可得丽江旅游人数的规律.通过分析模型的残差、相对误差、级比偏差,可以看出该模型的精度较高,可以用来预测2012年以及以后丽江每年的旅游人数.     

Cryptanalysis of an Improved Flexible Ping-Pong Protocol in Perfect and Imperfect Quantum Channels

We recently proposed a flexible quantum secure direct communication protocol [Chin. Phys. Lett. 23 （2006） 3152]. By analyzing its security in the perfect channel from the aspect of quantum information theory, we find that an eavesdropper is capable of stealing all the information without being detected. Two typical attacks are presented to illustrate this point. A solution to this loophole is also suggested and we show its powerfulness against the most general individual attack in the ideal case. We also discuss the security in the imperfect case when there is noise and loss.     

窄带薄层色谱-表面增强拉曼光谱联用法的建立及应用

建立窄带薄层色谱-表面增强拉曼光谱(narrow-band TLC-SERS)分析方法来改善传统薄层色谱-表面增强拉曼光谱法(TLC-SERS)在色谱展开过程中斑点横向扩散以及由于滴加SERS基底而导致的斑点二次扩散的不足,进一步提高TLC-SERS方法的检测灵敏度。本文采用色谱层析硅胶GF254制备并优化出宽度为2mm的窄带TLC板,待样品在窄带TLC板上分离后,在分离斑点表面喷洒银溶胶,然后对斑点进行SERS检测。结果表明,narrow-band TLC-SERS法具有简便、快速、灵敏的特点,不仅改善了传统TLC-SERS方法斑点横向扩散的不足,而且降低了固定相的用量,节约了成本,具有非常广阔的应用前景。     

对转超音压气机低压转子尾迹对高压转子的作用研究

本文采用数值方法针对对转超音压气机转子叶片排间的相互干涉效应进行了研究,分析了超音转子在两级转子叶片排间具有三种不同轴向间距情况下的性能和前排转子叶片尾迹影响下的超音转子非定常特征。研究结果表明,轴向间距的增大使得尾迹在较长的间距内经过了较为充分的掺混,超音转子最大压比和最高效率随轴向间距的变大而增大;前排叶片尾迹的影响范围从超音转子叶片压力面直至吸力面,横贯整个叶片通道,较高叶展处的尾迹强于较低叶展处;横贯超音转子通道内的低压动叶尾迹先后与斜激波和正激波相互作用,尾迹区内熵进一步增大,并且由于尾迹区的传播速度由主流速度决定,尾迹在通道内继续向下游传播且传播显著延迟于通道外。     

Enhancing the security of quantum secret sharing against multiphoton attack

It is generally believed that nonorthogonal operations which can realize the state transformation between two nonorthogonal bases may ensure the security of many quantum communication protocols. However, in this paper, we present a powerful attack against quantum secret sharing protocols of these kinds. Applying entangled photons as fake signals, Eve can successfully steal the exact information without being revealed. We also give our effective modification to improve it. Under the suggested checking strategy, even to Eve's most general attack, it is robust and secure.     

Partially secret broadcasting, partially secret splitting with quantum entanglement

In this paper, we propose a classical secret broadcasting and splitting joint protocol in a quantum scenario. With those genuinely entangled states, the boss can always broadcast some of his secrets and split some others to multi-receivers at the same time. The efficiency of the joint protocol is also compared with that of two separate ones which realise classical secret broadcasting and classical secret splitting respectively, and based on the comparison we can see the promising advantage of our joint protocol is that it can realise the two tasks more efficiently and more conveniently.     

离子对色谱-抑制电导法测定6-溴己基三甲基溴化铵中相关物质北大核心CSCD

建立了离子对色谱法测定6-溴己基三甲基溴化铵中相关物质的分析方法。样品经超纯水溶解后过0.22μm滤膜进样分析,选用Shinesil C18色谱柱进行色谱分离,高氯酸和乙腈作为淋洗液进行梯度洗脱,采用电导检测器检测,外标法定量。结果表明,6-溴己基三甲基溴化铵和溴化六甲铵的峰面积与其质量浓度在一定范围内呈良好线性关系,检出限分别为1.076 mg/L、0.2327 mg/L,定量限分别为3.587 mg/L、0.7757 mg/L。以6-溴己基三甲基溴化铵样品进行加标回收试验,回收率在95.8%~103.3%之间,测定值的相对标准偏差(RSD,n=6)均小于1.10%。该方法简单快速,可用于6-溴己基三甲基溴化铵样品中主成分6-溴己基三甲基溴化铵和杂质溴化六甲铵的定性和定量分析。