催化反应—示波极谱法测定痕量碘

催化反应－示波极谱分析^[1-5]系催化动力学分析的一个有待进一步研究的领域，金属元素的催化反应一示波极谱法已有研究报道^[1-7]，但非金属元素（碘）的催化反应－示波极谱法还少见。

购买法与权益集合法之争

一、购买法与权益集合法的特点 购买法(Purchse method),假定企业合并是一个企业取得其他参与合并的企业的净资产的一项交易,这一交易与企业直接从外界购入机器设备、存货等资产并无区别.其主要特点是:实施合并的企业要按公允价值记录所收到的资产和承担的债务;合并成本与所取得净资产的公允价值之间的差额记为商誉(若合并成本小于所取得净资产的公允价值则记为负商誉);实施合并企业的收益包括当年本身实现的收益,但仅包括合并日后被并企业所实现的收益,合并前被并企业的留存收益不能转入实施合并的企业;若是控股合并,则存在子公司账面净资产是否要调整为公允价值,并确认商誉的问题,也即是否要改变子公司的计价基础,若不改变,那么合并成本与子公司净资产账面价值则不等.

建立“始—终态”模型 巧解化学计算题

本文简要介绍“始—终态法”,认为此法是解决化学计算题的一种重要方法,对于多步反应和循环反应来说,只需要建立反应物和生成物及部分物质间的计量关系的模型,就不需要考虑反应过程,以例讲解利用此法解决循环型的计算题、多步反应类型计算题的具体步骤。

Catalytic performance of biological method seeds on jarosite process

The catalytic performance on jarosite process of jarosite seeds via biosynthesis and chemical processes were studied, respectively. The SEM and XRD results showed that biosynthetic jarosite seeds （BIO seeds） had smooth surface and mainly consisted of potassium jarosite. The chemical synthesis jarosite seeds （CHM seeds） had a loose cauliflower-like surface and mainly consisted of hydronium jarosite. The catalytic performance of BIO seeds was better than that of CHM seeds on the formation of final jarosite product. The induction time can be shortened to 20 min, the reaction temperature can be reduced to only 75 ℃, and the initial reaction speed was enhanced obviously, up to 3.933%/min. The crystallinity of final jarosite product using BIO seeds can achieve 97.22%, while it was only 12.89% without seeds. This indicates that the precipitation process of jarosite is more complete with BIO seeds.

Extension of analytical model of solid-state phase transformation

Departing from an analytical phase transformation model, a new analytical approach to deduce transformed fraction for non-isothermal phase transformation was developed. In the new approach, the effect of the initial transformation temperature and the accurate ＂temperature integral＂ approximations are incorporated to obtain an extended analytical model. Numerical approach demonstrated that the extended analytical model prediction for transformed fraction and transformation rate is in good agreement with the exact numerical calculation. The new model can describe more precisely the kinetic behavior than the original analytical model, especially for transformation with relatively high initial transformation temperature. The kinetic parameters obtained from the new model are more accurate and reasonable than those from the original analytical model.

考据学语境下的清中期戏曲理论

考据为中国古代传统治学方法,约萌芽于先秦,其法始用于治经,后用于治史,推而及其他学术门类。清代考据学为经学在清代的表现形态:明中后期明理学演变所呈现出的弊端引起部分学人重视,他们开始强调博学求是;明末清初,异族入主中原,江山易代,学界痛定思痛,将'亡天下'归因于宋明儒者抛弃元典,束书不学而空谈性理,故主返经复古,务经世致用之学,以求救国之道。这股学术思潮,在经历顺康之世后。

关于递归方程T(n)=a·T(n/c)+d(n)的一般解

本文讨论了递归方程 T(n)=a·T(n/c)+d(n)的一般解结构,对分治法中常见的 d(n)形式作了定性分析,并对其结果作了应用上的推广.

A KNN-based two-step fuzzy clustering weighted algorithm for WLAN indoor positioning

Although k-nearest neighbors （KNN） is a popular fingerprint match algorithm for its simplicity and accuracy, because it is sensitive to the circumstances, a fuzzy c-means （FCM） clustering algorithm is applied to improve it. Thus, a KNN-based two-step FCM weighted （KTFW） algorithm for indoor positioning in wireless local area networks （WLAN） is presented in this paper. In KTFW algorithm, k reference points （RPs） chosen by KNN are clustered through FCM based on received signal strength （RSS） and location coordinates. The right clusters are chosen according to rules, so three sets of RPs are formed including the set of k RPs chosen by KNN and are given different weights. RPs supposed to have better contribution to positioning accuracy are given larger weights to improve the positioning accuracy. Simulation results indicate that KTFW generally outperforms KNN and its complexity is greatly reduced through providing initial clustering centers for FCM.

Effects of Different Time-Dependent Couplings on Two-Atom Entanglement

The effects of different time-independent and time-dependent couplings on two-atom entanglement are studied. The results show that the effects depend on the initial state. For the initial state ｜eeO〉, it is found that different time-independent couplings make the case without entanglement exhibit entanglement, and time-dependent couplings turn the irregular entanglement regions into regular one. Under the case of decay, for the initial state ｜eg0〉, the different time-dependent couplings have disbenefit.

Limit equilibrium method for slope stability based on assumed stress on slip surface

In the limit equilibrium framework, two- and three-dimensional slope stabilities can be solved according to the overall force and moment equilibrium conditions of a sliding body. In this work, based on Mohr-Coulomb(M-C) strength criterion and the initial normal stress without considering the inter-slice(or inter-column) forces, the normal and shear stresses on the slip surface are assumed using some dimensionless variables, and these variables have the same numbers with the force and moment equilibrium equations of a sliding body to establish easily the linear equation groups for solving them. After these variables are determined, the normal stresses, shear stresses, and slope safety factor are also obtained using the stresses assumptions and M-C strength criterion. In the case of a three-dimensional slope stability analysis, three calculation methods, namely, a non-strict method, quasi-strict method, and strict method, can be obtained by satisfying different force and moment equilibrium conditions. Results of the comparison in the classic two- and three-dimensional slope examples show that the slope safety factors calculated using the current method and the other limit equilibrium methods are approximately equal to each other, indicating the feasibility of the current method; further, the following conclusions are obtained: 1) The current method better amends the initial normal and shear stresses acting on the slip surface, and has the identical results with using simplified Bishop method, Spencer method, and Morgenstern-Price(M-P) method; however, the stress curve of the current method is smoother than that obtained using the three abovementioned methods. 2) The current method is suitable for analyzing the two- and three-dimensional slope stability. 3) In the three-dimensional asymmetric sliding body, the non-strict method yields safer solutions, and the results of the quasi-strict method are relatively reasonable and close to those of the strict method, indicating that the quasi-strict method can be used to obtain a reliable slope safety factor.

Stress initialization methods for dynamic numerical simulation of rock mass with high in-situ stress

In the context of deep rock engineering,the in-situ stress state is of major importance as it plays an important role in rock dynamic response behavior.Thus,stress initialization becomes crucial and is the first step for the dynamic response simulation of rock mass in a high in-situ stress field.In this paper,stress initialization methods,including their principles and operating procedures for reproducing steady in-situ stress state in LS-DYNA,are first introduced.Then the most popular four methods,i.e.,explicit dynamic relaxation(DR)method,implicit-explicit sequence method,Dynain file method and quasi-static method,are exemplified through a case analysis by using the RHT and plastic hardening rock material models to simulate rock blasting under in-situ stress condition.Based on the simulations,it is concluded that the stress initialization results obtained by implicit-explicit sequence method and dynain file method are closely related to the rock material model,and the explicit DR method has an obvious advantage in solution time when compared to other methods.Besides that,it is recommended to adopt two separate analyses for the whole numerical simulation of rock mass under the combined action of in-situ stress and dynamic disturbance.

Optimal nonlinear excitation of decadal variability of the North Atlantic thermohaline circulation

Nonlinear development of salinity perturbations in the Atlantic thermohaline circulation(THC) is investigated with a three-dimensional ocean circulation model,using the conditional nonlinear optimal perturbation method.The results show two types of optimal initial perturbations of sea surface salinity,one associated with freshwater and the other with salinity.Both types of perturbations excite decadal variability of the THC.Under the same amplitude of initial perturbation,the decadal variation induced by the freshwater perturbation is much stronger than that by the salinity perturbation,suggesting that the THC is more sensitive to freshwater than salinity perturbation.As the amplitude of initial perturbation increases,the decadal variations become stronger for both perturbations.For salinity perturbations,recovery time of the THC to return to steady state gradually saturates with increasing amplitude,whereas this recovery time increases remarkably for freshwater perturbations.A nonlinear(advective) feedback between density and velocity anomalies is proposed to explain these characteristics of decadal variability excitation.The results are consistent with previous ones from simple box models,and highlight the importance of nonlinear feedback in decadal THC variability.

The type specimens of European butterflies from the Linnaeus collection(Lepidoptera:Rhopalocera)

The status of primary types of European butterflies established by C.Linnaeus is revised.Lectotype status is confirmed for 38 taxa.Lectotypes of the following taxa are designated in this paper:Papilio apollo Linnaeus,1758;P.daplidice Linnaeus,1758 and P.palaeno Linnaeus,1761.For the following 18 species-group taxa,the status of primary types changed from lectotypes to holotypes(by monotypy)due to their presence in the Linnean collection by single specimens:Papilio aglaja Linnaeus,1758;P.atalanta Linnaeus,1758;P.boeticus Linnaeus,1767;P.cardui Linnaeus,1758;P.cinxia Linnaeus,1758;P.deianira Linnaeus,1764;P.euphrosyne Linnaeus,1758;P.hero Linnaeus,1761;P.janira Linnaeus,1758;P.jurtina Linnaeus,1758;P.lathonia Linnaeus,1758;P.levana Linnaeus,1758;P.megera Linnaeus,1767;P.paphia Linnaeus,1758;P.polychloros Linnaeus,1758;P.rhamni Linnaeus,1758;P.rubi Linnaeus,1758 and P.sinapis Linnaeus,1758.Butterflies that do not have a pronounced sexual dimorphism and bright and contrasting coloration in the Linnean collection are represented in most cases by a single type specimen.The largest,brightest and most beautiful butterflies in the Linnean collection have a type series of the maximum size(4 specimens).There are no series of 5 or more specimens for European butterflies in Linnaeus’collection.

Modified homogeneous parameterization for monocular SLAM

Feature initialization is an important issue in the monocular simultaneous locahzation ana mapping （SLAM） literature as the feature depth can not be obtained at one observation. In this paper, we present a new feature initialization method named modified homogeneous parameterization （MHP）, which allows undelayed initialization with scale invariant representation of point features located at various depths. The linearization error of the measurement equation is quantified using a depth estimation model and the feature initialization process is described. In order to verify the performance of the proposed method, the simulation is carried out. Results show that with the proposed method, the SLAM algorithm can achieve better consistency as compared with the existing inverse depth parameterization （IDP） method.

A Retrievable Data Perturbation Method Used in Privacy-Preserving in Cloud Computing

With the increasing popularity of cloud computing,privacy has become one of the key problem in cloud security.When data is outsourced to the cloud,for data owners,they need to ensure the security of their privacy;for cloud service providers,they need some information of the data to provide high QoS services;and for authorized users,they need to access to the true value of data.The existing privacy-preserving methods can't meet all the needs of the three parties at the same time.To address this issue,we propose a retrievable data perturbation method and use it in the privacy-preserving in data outsourcing in cloud computing.Our scheme comes in four steps.Firstly,an improved random generator is proposed to generate an accurate "noise".Next,a perturbation algorithm is introduced to add noise to the original data.By doing this,the privacy information is hidden,but the mean and covariance of data which the service providers may need remain unchanged.Then,a retrieval algorithm is proposed to get the original data back from the perturbed data.Finally,we combine the retrievable perturbation with the access control process to ensure only the authorized users can retrieve the original data.The experiments show that our scheme perturbs date correctly,efficiently,and securely.

Time domain system identification of unknown initial conditions

System identification is a method for using measured data to create or improve a mathematical model of the object being tested. From the measured data however, noise is noticed at the beginning of the response. One solution to avoid this noise problem is to skip the noisy data and then use the initial conditions as active parameters, to be found by using the system identification process. This paper describes the development of the equations for setting up the initial conditions as active parameters. The simulated data and response data from actual shear buildings were used to prove the accuracy of both the algorithm and the computer program, which include the initial conditions as active parameters. The numerical and experimental model analysis showed that the value of mass, stiffness and frequency were very reasonable and that the computed acceleration and measured acceleration matched very well.

Blow-up of Solution for the Nonlinear Sobolev-Galpern Equation

In this paper,the initial boundary value problems of the nonlinear Sobolev-Galpern equation are studied.The existence,uniqueness of local solution for the problem are obtained by means of a special Green's function and the contraction mapping principle.Finally,the blow-up of solution in finite time under some assumed conditions is proved with the aid of Jensen's inequality.

A novel synthesis of fluvoxamine maleate

Fluvoxamine maleate is an excellent antidepressive drug. In the literatures, it was synthesized by the use of 4-（trifluoromethyl） aniline or 4-（trifluoromethyl） benzonitrile as starting materials and 5-methoxy-4＇-（trifluoromethyl-phenyl） valerophenone as a key intermediate. However, the methods in literatures have some disadvantages, such as the use of expensive materials, heavy pollution of environment, long reaction time and low yield of the product （only 30-40% overall yield）. We herein report an environmentally friendly synthetic method of fluvoxamine maleate, which used 4-（trifluoromethyl） benzoic acid and tetrahydrofuran as starting materials and FeCI3 as catalyst for the coupling of acid chloride with Grignard reagent. The fluvoxamine maleate was synthesized in 46% overall yield, through the oximation, etheration and salification of the intermediate successively.This method has some advantages, such as the use of commercially available materials, low cost, short production period （12-14 h）, high yield and light pollution.

Discrete element analysis on press and fracture mechanism of propellant grain

To analyze fracture mechanism of propellant grain and study the mechanical properties of propellant grain, the press and fracture processes of propellant grain with and without initial defects are modeled using the discrete element method. On the basis of the appropriate constitutive relationships, the discrete element model of the propellant grain was established. Compared with experimental measurements, the micro-parameters of the bonded-particle model of the propellant grain under unconfined uniaxial compression tests were calibrated. The propellant grains without initial defects, with initial surface defects, and with initial internal defects were studied numerically through a series of unconfined uniaxial compression tests. Results show that the established discrete element model is an efficient tool to study the press and fracture processes of the propellant grain. The fracture process of the propellant grain without initial defects can be divided into the elastic deformation phase, crack initiation phase, crack stable propagation phase, and crack unstable propagation phase. The fracture mechanism of this grain is the global shear failure along the direction of the maximum shear stress. Initial defects have significant effects on both the fracture mechanism and peak strength of the propellant grain. The major fracture mechanism of the propellant grain with initial surface defects is local shear failure, whereas that of the propellant grain with initial internal defects is global tensile failure. Both defects weaken the peak strengths of the propellant grain. Therefore, the carrying and filling process of the propellant grain needs to minimize initial defects as far as possible.

Limit equilibrium analysis for rock slope stability using basic Hoek–Brown strength criterion

Hoek–Brown(HB)strength criterion can reflect rock’s inherent failure nature,so it is more suitable for analyzing the stability of rock slopes.However,the traditional limit equilibrium methods are at present only suitable for analyzing the rock slope stability using the linear equivalent Mohr–Coulomb(EMC)strength parameters instead of the nonlinear HB strength criterion.Therefore,a new method derived to analyze directly the rock slope stability using the nonlinear HB strength criterion for arbitrary curve slip surface was described in the limit equilibrium framework.The current method was established based on certain assumptions concerning the stresses on the slip surface through amending the initial normal stressσ0 obtained without considering the effect of inter-slice forces,and it can satisfy all static equilibrium conditions of the sliding body,so the current method can obtain the reasonable and strict factor of safety(FOS)solutions.Compared with the results of other methods in some examples,the feasibility of the current method was verified.Meanwhile,the parametric analysis shows that the slope angleβhas an important influence on the difference of the results obtained using the nonlinear HB strength criterion and its linear EMC strength parameters.Forβ≤45°,both of the results are similar,showing the traditional limit equilibrium methods using the linear EMC strength parameters and the current method are all suitable to analyze rock slope stability,but forβ>60°,the differences of both the results are obvious,showing the actual slope stability state can not be reflected in the traditional limit equilibrium methods,and then the current method should be used.