实时直接分析质谱在农药检测中的应用

实时直接分析(Direct analysis in real time,DART)作为一种原位电离技术发展迅猛,其与质谱联用已成为热门的分析技术并广泛应用于法庭科学领域,如食品安全、爆炸物检测、毒物毒品分析和药物分析等方面。目前农药的常规检测方法已非常成熟,但引入原位电离-质谱联用技术可以拓宽检测范围,缩短检测时限。该文从实时直接分析质谱(DART-MS)技术的工作原理、检测条件优化及其在农药检测方面的应用进行综述,并对DART-MS的应用前景进行了展望。     

A Real Number Structure that is Effectively Categorical

On countable structures computability is usually introduced via numberings. For uncountable structures whose cardinality does not exceed the cardinality of the continuum the same can be done via representations. Which representations are appropriate for doing real number computations? We show that with respect to computable equivalence there is one and only one equivalence class of representations of the real numbers which make the basic operations and the infinitary normed limit operator computable. This characterizes the real numbers in terms of the theory of effective algebras or computable structures, and is reflected by observations made in real number computer arithmetic. Demanding computability of the normed limit operator turns out to be essential: the basic operations without the normed limit operator can be made computable by more than one class of representations. We also give further evidence for the well-known non-appropriateness of the representation to some base b by proving that strictly less functions are computable with respect to these representations than with respect to a standard representation of the real numbers. Furthermore we consider basic constructions of representations and the countable substructure consisting of the computable elements of a represented, possibly uncountable structure. For countable structures we compare effectivity with respect to a numbering and effectivity with respect to a representation. Special attention is paid to the countable structure of the computable real numbers.     

值域有界的一类非线性算子不动点的带误差迭代逼近

设Ｘ为一致光滑实Ｂａｎａｃｈ空间·Ｔ：Ｘ→Ｘ为连续强增生算子·ｆ∈Ｘ·定义算子Ｓ：Ｘ→Ｘ为Ｓｘ＝ｆ－Ｔｘ＋ｘ,ｘ∈Ｘ·设αｎ｛｝∞ｎ＝０与βｎ｛｝∞ｎ＝０为两个给定的实数列在（０,１）中且满足条件：（ⅰ）αｎ→０,βｎ→０（ｎ→∞）·（ⅱ）∑∞ｎ＝０αｎ＝∞·假设ｕｎ｛｝∞ｎ＝０和ｖｎ｛｝∞ｎ＝０为Ｘ中两个序列且满足‖ｕｎ‖＝ｏ（αｎ）,‖ｖｎ‖→０（ｎ→∞）·ｘ０∈Ｘ,迭代序列ｘｎ｛｝定义为：（ＩＳ）ｘｎ＋１＝（１－αｎ）ｘｎ＋αｎＳｙｎ＋ｕｎｙｎ＝（１－βｎ）ｘｎ＋βｎＳｘｎ＋ｖｎ（ｎ≥０）｛若Ｓｘｎ｛｝,Ｓｙｎ｛｝有界,则ｘｎ｛｝强收敛于Ｓ的唯一不动点     

Real and imaginary quadratic representations of hyperelliptic function fields

A hyperelliptic function field can be always be represented as a real quadratic extension of the rational function field. If at least one of the rational prime divisors is rational over the field of constants, then it also can be represented as an imaginary quadratic extension of the rational function field. The arithmetic in the divisor class group can be realized in the second case by Cantor's algorithm. We show that in the first case one can compute in the divisor class group of the function field using reduced ideals and distances of ideals in the orders involved. Furthermore, we show how the two representations are connected and compare the computational complexity.

     

ITERATIVE APPROXIMATION WITH ERRORS OF FIXED POINT FOR A CLASS OF NONLINEAR OPERATOR WITH A BOUNDED RANGE

1IntroductionandPreliminariesLetXbearealBanachspacewithnorm||·||andadualX*.ThenormalizeddualitymappingJ:X→2Xisdefinedbywhere<·,·>denotesthegeneralizeddualitypairing.Itiswell-knownthatifX*isstrictlyconvex,thenJissingle-valuedandsuchthatJ(tx)=tJxforallt≥0,x∈X.IfX*isunifomilyconvex,thenJisuniformlycontinuousonanyboundedsubsetsofX(of.Browder[1]andBarbu[2])OperatorTwithdomainD(T)andrangeR(T)inXissaidtobeaccretiveifforeveryx,y6D(T),thereexistsajeJ(x--y)suchthatTheconceptofaccretive…     

ON THE MAXIMAL LYAPUNOV EXPONENT FOR A REAL NOISE PARAMETRICALLY EXCITED CO-DIMENSION TWO BIFURCATION SYSTEM (Ⅰ)

For a real noise parametrically excited co-dimension two bifurcation system on three-dimensional central manifold, a model of enhanced generality is developed in the present paper by assuming the real noise to be an output of a linear filter system, namely, a zero-mean stationary Gaussian diffusion process that satisfies the detailed balance condition. On such basis, asymptotic expansions of invariant measure and maximal Lyapunov exponent for the relevant system are established by use of Arnold asymptotic analysis approach in parallel with the eigenvalue spectrum of Fokker-Planck operator. Foundation item: the National Natural Science Foundation of China (19602016)     

ON THE MAXIMAL LYAPUNOV EXPONENT FOR A REAL NOISE PARAMETRICALLY EXCITED CO-DIMENSION TWO BIFURCATION SYSTEM (Ⅱ)

For a co-dimension two bifurcation system on a three-dimensional central manifold, which is parametrically excited by a real noise, a rather general model is obtained by assuming that the real noise is an output of a linear filter system-a zeromean stationary Gaussian diffusion process which satisfies detailed balance condition. By means of the asymptotic analysis approach given by L. Arnold and the expression of the eigenvalue spectrum of Fokker-Planck operator, the asymptotic expansions of invariant measure and maximal Lyapunov exponent for the relevant system are obtained. Foundation item: the National Natural Science Foundation of China (19602016)     

Validation of an Aesthetic Assessment System for Commercial Tasks

Automatic prediction of the aesthetic value of images has received increasing attention in recent years. This is due, on the one hand, to the potential impact that predicting the aesthetic value has on practical applications. Even so, it remains a difficult task given the subjectivity and complexity of the problem. An image aesthetics assessment system was developed in recent years by our research group. In this work, its potential to be applied in commercial tasks is tested. With this objective, a set of three portals and three real estate agencies in Spain were taken as case studies. Images of their websites were taken to build the experimental dataset and a validation method was developed to test their original order with another proposed one according to their aesthetic value. So, in this new order, the images that have the high aesthetic score by the AI system will occupy the first positions of the portal. Relevant results were obtained, with an average increase of 52.54% in the number of clicks on the ads, in the experiment with Real Estate portals. A statistical analysis prove that there is a significant difference in the number of clicks after selecting the images with the AI system.     

一种血流变参数在体实时探测方法

介绍了一种新的在体实时监测血流变参数的光学方法——光散射法。设计了一种实用的同轴多光纤探针装置。在装置中间,其中一根光纤用于传输入射激光,周围多根光纤与中心光纤等间隔,用于接收血液中的散射光。用扫描法布里-珀罗干涉仪产生散射光谱。结果表明,用该装置测得了含成分的液体、实血和不同血液成分的光散射光谱。     

后路椎管减压内固定术治疗胸腰椎骨折并截瘫

为探讨后路椎管减压内固定治疗胸腰椎骨折并载瘫的治疗效果,从2000年2月至2003年12月,共手术治疗胸腰椎骨折并截瘫病人63例:T112例,T1211例,L124例,L215例,L38例,L43例;压缩性骨折21例,爆裂性骨折9列,旋转骨折16例,剪力骨折(切片状骨折)7例,椎体后部骨折(Chace骨折)10例;完全性截瘫21例,不完全性截瘫42例;全部病人采用后路椎管减压手术,Luque棒19例,双Harrington 12例,椎弓根螺钉32例。结果表明,本组63例无一例加重症状,获得随访的有51例,随访时间半年至2年,不完全截瘫患者均有明显的好转。提示后路减压内固定治疗胸腰椎骨折并截瘫可取得满意的临床疗效,尽早手术及彻底减压与疗效密切相关。