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121.
传统的海洋水声环境观测通常是大范围的随机观测,缺少针对性,非常时期观测平台在交战海区实施系统观测困难,如何利用有限的观测资源获取有效的观测数据提高观测效率是目前亟需解决的问题。本文提出海洋声学敏感区诊断与适应性观测概念,介绍了相关研究进展,该项研究有助于我们改进目前传统的观测系统设计,提高观测网建设效益,根据敏感区位置,可建立移动的补充观测系统开展适应性观测,从而发展我国新型的海洋观测体系,为改善海洋水声环境预报质量提供有效观测数据。  相似文献   
122.
Four‐way junctions (4WJs) are supramolecular DNA assemblies comprising four interacting DNA strands that in biology are involved in DNA‐damage repair. In this study, a new mononuclear platinum(II) complex 1 was prepared that is capable of driving the crystallization of the DNA oligomer 5′‐d(CGTACG)‐3′ specifically into a 4WJ‐like motif. In the crystal structure of the 1 –CGTACG adduct, the distorted‐square‐planar platinum complex binds to the core of the 4WJ‐like motif through π–π stacking and hydrogen bonding, without forming any platinum–nitrogen coordination bonds. Our observations suggest that the specific molecular properties of the metal complex are crucially responsible for triggering the selective assembly of this peculiar DNA superstructure.  相似文献   
123.
The mechanism of interaction between the energy flows of the far-field ship noise and the near-field platform is studied, and the characteristics of frequency-time azimuth spectrum is discussed. Based on normal modes theory in acoustic vector fields, the model of the near-field platform is established, and the simulated result is similar to the investigation in shallow water. The frequency-time azimuth spectrum of the energy flow is investigated by the vector hydrophone changes with frequency. The energy flow of the far-field ship noise interacts with the near-field platform, so four kinds of stripes are shown in the frequency-time azimuth spectrum, which is the same with the investigation of sea trial. The estimation of direction of arrival appears inaccuracy, and varies with frequency. The main factor that affects the characteristics of frequency-time azimuth spectrum of resultant energy flow is the difference of sound pressure level. The estimation of the direction of arrival benefits from this when a number of sources exist in shallow water.  相似文献   
124.
 激光束光路自动准直系统用于高功率激光装置光束精密准直。基于某激光原型装置总体对腔镜准直调整流程,针对高功率激光系统腔镜准直过程光斑图像,仿真处理并定量分析了光斑边缘特征;结合腔镜准直监测单元光传输分析,使用激光光斑边缘不同部分曲率的相似性和光斑圆形度实现了对腔镜调节的量化评估。在腔镜准直结束时圆形度指标为12.222;边缘相似度达到99.62%。  相似文献   
125.
一个油田,在肯定了它们的工业价值、初步探明了油田的分布面积以后,就要着手迅速地将油田投入开发。但是原油储集在地下的岩层中,油层的地质结构是非常复杂的。要合理开发油田,首先要有一个好的开发方案,要按照油田地下的实际情况确定开发方式、划分与组合开发层系、对不同的开发层系采用不同的井网布置和注水方式等等,力争打较少的井数,得到较好的开发效果。  相似文献   
126.
Eight neutral cyclodextrins were tested for the enantiomeric separation of alanyl and leucyl dipeptides by capillary electrophoresis at pH 3, and seven out of the eight cyclodextrins proved suitable for the separation of one or more of the dipeptide enantiomer pairs. The best results were obtained with heptakis(2,6-di-O-methyl)-beta-cyclodextrin. The dipeptides that were separated were mainly the aromatic and the more lipophilic aliphatic dipeptides. Mobility difference plots at pH 3.0 with malonic acid-triethanolamine as background electrolyte showed that the aromatic dipeptides had higher affinities for the cyclodextrin than the nonpolar, aliphatic dipeptides. The results suggested that, under the conditions applied, the C-terminal amino acid rather than the N-terminal one is involved in the chiral discrimination.  相似文献   
127.
Protein separation can be achieved with different modes of capillary electrophoresis, such as with capillary gel electroporesis (CGE) or with capillary zone electrophoresis (CZE). CZE protein mapping of peanut extract was approached in four different ways, combining neutral-coated or multilayer-coated capillaries with pHs well over or under the isoelectric point range of the proteins of interest. At acidic pHs, the mobility ranges of the major peanut allergens Ara h1, Ara h2, Ara h3, and Ara h6 were identified. Although the pH is a major factor in CZE separation, buffers with different compositions but with the same pH and ionic strength showed significantly different resolutions. Different components of the electrolyte were studied in a multifactorial design of experiment. CE-SDS and CZE proved to be suitable for protein mapping and we were able to distinguish different batches of peanut extract and burned peanut extract.  相似文献   
128.
A broad range of CE applications from our organization is reviewed to give a flavor of the use of CE within the field of vaccine analyses. Applicability of CE for viral vaccine characterization, and release and stability testing of seasonal influenza virosomal vaccines, universal subunit influenza vaccines, Sabin inactivated polio vaccines (sIPV), and adenovirus vector vaccines were demonstrated. Diverse CZE, CE-SDS, CGE, and cIEF methods were developed, validated, and applied for virus, protein, posttranslational modifications, DNA, and excipient concentration determinations, as well as for the integrity and composition verifications, and identity testing (e.g., CZE for intact virus particles, CE-SDS application for hemagglutinin quantification and influenza strain identification, chloride or bromide determination in process samples). Results were supported by other methods such as RP-HPLC, dynamic light scattering (DLS), and zeta potential measurements. Overall, 16 CE methods are presented that were developed and applied, comprising six adenovirus methods, five viral protein methods, and methods for antibodies determination of glycans, host cell-DNA, excipient chloride, and process impurity bromide. These methods were applied to support in-process control, release, stability, process- and product characterization and development, and critical reagent testing. Thirteen methods were validated. Intact virus particles were analyzed at concentrations as low as 0.8 pmol/L. Overall, CE took viral vaccine testing beyond what was previously possible, improved process and product understanding, and, in total, safety, efficacy, and quality.  相似文献   
129.
化妆品中挥发性有机溶剂的通用检测方法   总被引:1,自引:0,他引:1  
达晶  黄湘鹭  王钢力  曹进  张庆生 《色谱》2014,32(11):1251-1259
以化妆品配方中常见及禁用的36种有机溶剂为研究模板,建立了化妆品中挥发性有机溶剂残留评价初筛知识库、确证知识库和定量方法。初筛知识库包括双柱保留指数知识库和NIST质谱库。双柱保留指数知识库以保留指数为定性指标,选择极性的VF-1301ms和非极性的DB-5ms两根色谱柱,用顶空气相色谱-质谱法考察了36种有机溶剂在两种色谱分离系统中的保留特性。利用NIST MS search 2.0作为检索工具,同时建立了36种挥发性有机溶剂的顶空气相色谱-质谱定量方法。样品经60 ℃、30 min静态顶空后以连接了VF-1301ms石英毛细管色谱柱的气相色谱-质谱仪检测,外标法定量。方法检出限为0.01~3.3 μg/g,加标回收率为60.77%~126.60%。该方法从通用性的角度,为化妆品中挥发性有机溶剂残留的筛查、鉴别和定量提供方法,部分解决了测定化妆品中挥发性有机溶剂时需要针对不同检测目标建立不同方法以及潜在溶剂存在备选筛查的问题。  相似文献   
130.
用低温溶剂热法合成了2种分立结构的有机杂化硫代碲(Ⅳ)酸盐化合物(H2en)TeS31)和[Ni(en)3]TeS32)(en=乙二胺),通过X-射线单晶衍射,红外光谱,元素分析等手段对它们的结构进行了表征。晶体结构解析结果表明:2个化合物均属单斜晶系,空间群分别为P21P21/c。化合物12具有孤立三角锥[TeS3]2-阴离子,化合物1的平衡阳离子为双质子化乙二胺[H2en]2+,阴离子基团[TeS3]2-和阳离子基团[H2en]2+之间通过N-H…S氢键连接。化合物2的阳离子基团为过渡金属Ni与乙二胺的配合物[Ni(en)3]2+。另外,对该2种晶体进行了紫外-可见漫反射光谱测试和热重分析。  相似文献   
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