超分子化合物{Cd(H_2dtca)(bipy)}的构筑及表征

利用1,3-二(2',4'-二羧酸苯基)苯、2,2'-联吡啶和氧化镉在水热条件下反应制备了一种新型超分子化合物{Cd(H2dtca)(bipy)}[H2dtca=1,3-二(2',4'-二羧酸苯基)苯,bipy=2,2'-联吡啶].通过X-射线单晶衍射测定了化合物的晶体结构,并利用元素分析、红外光谱等技术对其进行表征.结构研究发现该晶体属于单斜晶系P21/n空间群,a=1.604 06(7)nm,b=1.037 30(4)nm,c=1.720 97(7)nm;β=101.803 0(10)°;Z=4,wR1=0.034 2,wR2=0.079 5.晶体结构分析表明2个镉在1个1,3-二(2',4'-二羧酸苯基)苯的连接下形成了一个双核结构,再在氢键作用下,形成3维超分子结构.此外,还研究了配合物的固态荧光性质.     

电子商务环境下的会计报告

分析了电子商务时会计报告内容和时效性的影响,介绍了电子商务环境下的会计报告模式,阐述了事项法实时报告系统的会计处理流程以及实时报告系统的实现方式.     

电火花线切割加工中放电间隙状态的实时检测

通过对电火花放电状态的分析,提出了基于数字电路的电火花线切割(WEDM)放电间隙的实时检测方法。采用对单位时间内放电状态的统计,得到电火花线切割过程中各种状态的概率,为电火花线切割的智能控制提供控制依据。试验表明,该方法能有效检测WEDM加工中放电间隙的状态,为进一步研究WEDM智能加工控制系统提供了可靠的控制依据。     

Negatively and positively charged bacterial aerosol concentration and diversity in natural environments

Bioaerosol charge information is of vital importance for their electrostatic collection. Here, electrostatic means and molecular tools were applied to studying bioaerosol charge dynamics. Positively or negatively charged bioaerosols were collected using an electrostatic sampler operated with a field strength of 1.1 kV cm 1 at a flow rate of 3 L min 1 for 40 min. Those with fewer or no charges bypassing the sampler were also collected using a filter at the downstream of the electrostatic sampler in one environment. The experiments were independently conducted three times in three different environments. The collected bacterial aerosols were cultured directly on agar plates at 26°C, and the colony forming units (CFU) were manually counted. In addition, the CFUs were washed off from the agar plates, and further subjected to polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) for culturable diversity analysis. The results revealed remarkable differences in positively and negatively charged culturable bacterial aerosol concentration and diversity among the studied environments. In the office environment, negatively charged culturable bacterial aerosols appeared to dominate (P = 0.0489), while in outdoor and hotel environments both polarities had similar concentration levels (P = 0.078, P = 0.88, respectively). DGGE patterns for positively charged culturable bacterial aerosols were shown strikingly different from those of negatively charged regardless of the sampling environments. In addition, for each of the environments positively charged culturable bacterial aerosols collected were found to have more band pattern similarity with those positively charged for respective regions of agar plates than those negatively charged, and vice versa. The information developed here is useful for developing efficient electrostatic sampling protocols for bioaerosols.     

RTK技术在大比例尺地形图控制测量中的应用

随着社会经济的发展,人们的生活水平不断提高,各个城市、乡镇等对大比例尺地形图的需求日益增加,这就要求测绘科学技术能够很好的运用到大比例尺地形图中,按照准确、逼真、清晰的原则,保证成图的质量。本文就介绍了全球定位系统实时动态测量（RTK）技术在大比例尺地形图控制测量中的应用,因其精度高、实时性和高效性,使其在大比例尺地形图测绘中的应用越来越广。     

地震观测中的Cacti开源软件应用

近年来,随着地震观测技术迅速发展,地震台站数据的网络信息化管理成为地震观测体系的重中之重。如何实现对网络和服务器性能的实时监测、切实保障网络服务质量？上海地震局通过Cacti开源软件对地震观测数据进行实时、图形化监测的实践经验,或将为人们带来一些启发。     

二氧化硅荧光纳米颗粒的性质及应用

二氧化硅壳核型荧光纳米颗粒有良好的水溶性,易于制备、分离和表面修饰,具有无法比拟的特性,己经在生物分析的很多领域得到了广泛的应用,具有广泛的应用前景。     

奇妙的生物发光

灯笼鱼挂着绿色小灯笼,巨口鱼发射红色光束,萤火鱿在海水里翻腾起一片蓝色泡沫,"鬼火蘑菇"在密林深处发出幽幽荧光……生物发光是大自然最奇妙的现象之一。     

定量荧光录井技术在油气开发中的应用——以辽河油田为例

与传统的荧光录井相比,定量荧光录井技术在及时准确发现和精确的落实油气显示以及评价油气层方面有其独特的作用和优势。文章通过定量荧光录井技术在辽河油田沈257块的油气评价中的应用实例,阐述了定量荧光录井技术在储集层评价和勘探开的指导作用。     

韩国成功克隆出红色荧火转基因狗

克隆出的小狗在黑暗中它们的身体会发出红色荧光。研究的重要意义不是让小狗发出红色荧光，而是进行生物医学研究。