CRISPR-Cas System for RNA Detection and Imaging

The system of clustered regularly interspaced short palindromic repeats(CRISPR)and CRISPR-associated endonucleases(Cas)have been widely used in gene editing,disease treatment,molecular diagnosis and chromosome imaging.On account of the programmable target recognition of CRISPR-Cas system and the specific targeting function toward RNA of type Ⅵ class Ⅱ Cas proteins,CRISPR-Cas system has been deployed as RNA recognition and detection tools,exhibiting promising application potentials in the field of RNA detection and imaging.In this review,we summarize the latest research progresses as well as development prospects of CRISPR-Cas system in RNA diagnosis and live cell RNA imaging.     

Determination and comparison of agarwood from different origins by comprehensive two‐dimensional gas chromatography–quadrupole time‐of‐flight mass spectrometry

Agarwood, a species of resinous heartwood, is a precious medicinal plant and a type of rare natural spice, which is widely used in medicine, cosmetics, religious activities, and other fields. In this study, agarwood samples from eight different regions across four countries were analyzed by comprehensive two‐dimensional gas chromatography?quadrupole time‐of‐flight mass spectrometry. A total of 232 species were identified (the match factors of these compounds were above 750). The main compounds of agarwood are oxygenated sesquiterpenes and chromones. The compositions of India1 and Malaysia2 were significantly different from those of other samples, which might be attributed to the different production processes of agarwood. For further investigation, factor analysis was conducted for six agarwood samples. The results showed that the data classification possessed a regional characteristic; according to the retention time and relative content, characteristic compositions were determined by factor scores. Finally, the differences of characteristic compositions were simply analyzed, and the reasons were speculated.     

四阶整数辛群中扭元的共轭类

本文给出四阶整数辛群中扭元的全部共轭等价类.总共有55个不同的扭元等价类,它们的阶数分别是2, 3, 4, 5, 6, 8, 10, 12.没有其它阶的扭元.     

Resolution of composite fuzzy relation equations based on Archimedean triangular norms

Lately, the sup-t-norm composition of fuzzy relations has been used instead of the well-known max–min. Thus, there is a need for methods of studying and solving sup-t-norm fuzzy relation equations (t is any t-norm). In this paper, the solution existence problem is first studied and solvability criteria for composite fuzzy relation equations of any t-norm are given. Then, a methodology for solving fuzzy relation equations based on sup-t composition, where t is an Archimedean t-norm, is proposed. This resolution method is simpler and faster than those proposed for covering all the continuous t-norms. The result is important, since, as is shown in the paper, the only continuous t-norm that is not Archimedean is the “minimum”.     

变比热气体和变比热有离解气体热力学过程的计算

变比热气体和变比热有离解气体热力学过程的计算张世铮，纪军（中国科学院工程热物理研究所北京１０００８０）关键词离解气体；变成分气体；热力学过程１前言在热机和热设备的循环分析、设计计算和实验研究中要求按照工质的真实热力学性质作准确的气动热力学计算。在喷气...     

Composition constants for raising the orders of unconventional schemes for ordinary differential equations

Many models of physical and chemical processes give rise to ordinary differential equations with special structural properties that go unexploited by general-purpose software designed to solve numerically a wide range of differential equations. If those properties are to be exploited fully for the sake of better numerical stability, accuracy and/or speed, the differential equations may have to be solved by unconventional methods. This short paper is to publish composition constants obtained by the authors to increase efficiency of a family of mostly unconventional methods, called reflexive.

     

The effect of UV-irradiation on composting of polyethylene modified by cellulose

LDPE and its blend with cellulose, obtained by extrusion, were UV-irradiated with different doses or biodegraded in soil up to 1 year. Simultaneously, the same samples were 1 year biodegraded after 20 h UV pre-irradiation in the same conditions. The course of photo- and biodegradation was monitored by estimation of average molecular weights and polydispersity, gel amount, changes of PE crystallinity and mechanical properties. Moreover, the biodegradation degree was calculated on the basis of carbon dioxide evolved and surface morphological changes were observed by SEM. It was found that biodegradation of PE + cellulose is hampered by intermolecular crosslinking of both components. Although, the rate of decomposition of PE + cellulose blends is low it is enough for disintegration of such materials in the natural environment.     

大型电站煤粉炉自身固硫灰渣的微观晶相分析

研究了电站1 025 t/h煤粉炉燃用Ca/S(摩尔比)=2.02的神木煤自身固硫灰渣的晶相组成，XRD分析表明,入炉煤中无定形的非晶相质量分数高达91.2%，CaCO3晶相质量分数为2.1%。满负荷下飞灰中因高温熔融形成的玻璃态非晶相质量分数高达70.5%，煤灰自身固硫产物CaSO4质量分数为3.4%，CaCO3和CaO质量分数为6.9%，使其仍具有进一步固硫的能力。满负荷下炉底渣中钠长石质量分数高达59.2%，非晶相质量分数为25.7%，未发现CaSO4、CaCO3或CaO晶相。当锅炉负荷降低时，飞灰中非晶相质量分数相应降低，炉底渣中非晶相质量分数升高。