盐酸贝那普利片近红外光谱定性分析模型的建立

目的建立盐酸贝那普利片的定性分析模型。方法利用近红外漫反射技术采集全国4家生产企业61批样品的近红外光谱,利用化学计量学分析软件OPUS建立2层定性分析模型串联确证模型,并验证模型的准确性和专属性。结果模型的准确性和专属性好,能准确识别21批验征集样品,区分出4个结构类似物片、假冒A企业样品及21个非结构类似物片。结论该试验中建立的模型能快速、准确识别盐酸贝那普利片的真伪,适用于药品检测车对该品种的现场快速检测。

废旧涤/棉混纺织物NIRS定性分析模型的建立与外部验证（英文）

利用近红外光谱技术对354个废旧涤/棉混纺织物进行研究,通过偏最小二乘法(partial least squares,PLS)和定性鉴别系数建立了不同光谱特征的涤/棉混纺织物近红外定性分析模型。染色涤/棉混纺织物NIR光谱主要有两大类,一类具有正常涤/棉光谱特征,另一类光谱由于样本中染料、颜料和消光剂等化学助剂的影响,使光谱谱线成斜线,失去其光谱特征。如以全部样本建模,模型识别率较低。故将样本分为两类:斜线光谱样本和正常光谱样本,分别建立NIR定性分析模型。NIR定性分析模型建立后,根据验证结果分别对建模的谱区、预处理方法和主因子数进行优化,以提高模型的稳健性和可靠性。结果表明,样本分别建模后,模型的识别率大大提高,用验证集样本进行内部验证,正常光谱和斜线光谱所建模型的识别率均达99%,其校正集相关系数RC均为0.991,验证集相关系数RP分别为0.983和0.984、校正标准差SEC分别为0.887和0.453、预测标准差SEP分别为1.131和0.573。用150个界外样本分别对正常光谱样本模型和斜线光谱样本模型进行外部预测检验,模型识别率分别达91.33%和88.00%,表明所建NIR定性分析模型能够较好地在回收现场进行涤/棉混纺织物的鉴别。

西洛他唑片近红外光谱定性分析模型的建立

目的采用近红外光谱(NIR)技术和化学计量学分析软件,建立西洛他唑片的定性分析模型。方法近红外漫反射光谱法结合OPUS软件,建立定性鉴别模型,并进行外部验证。结果模型能准确鉴别西洛他唑片并区分不同的生产厂家。结论该模型可以快速方便地进行西洛他唑片的鉴别区分,并可以有效地应用于药品检测车的现场筛查。

注射用甘草酸二铵近红外光谱定性分析模型的建立

目的采用近红外光谱(NIR)技术和化学计量学分析软件,建立注射用甘草酸二铵的定性分析模型。方法近红外漫反射光谱法结合OPUS软件,建立定性鉴别模型,并进行外部验证。结果模型能准确鉴别注射用甘草酸二铵并区分不同的生产厂家。结论该模型可以快速方便地进行注射用甘草酸二铵的鉴别区分,并可以有效地应用于药品检测车的现场筛查。

改性明胶注射液近红外定性分析模型的建立

目的:建立准确快速地识别不同交联剂的改性明胶注射液以及不同厂家生产的琥珀酰明胶注射液的近红外定性分析模型。方法:以全国范围内不同企业生产的改性明胶注射液为分析对象,用光纤测定近红外漫反射光谱,结合OPUS软件建立近红外定性分析模型。结果:选择合适的谱段,采用一阶导数(或二阶导数)结合矢量归一化预处理方法,平滑点数选择9,分两层建立的定性分析模型,正确识别率为100%。结论:模型准确地区分不同交联剂的改性明胶注射液,可以用于监控厂家生产工艺,控制制剂的质量,适合药品现场快速筛查,有效的打击假劣药品。

相互干扰的捕食与被捕食者种群的Hassall模型定性分析

本文证明了Ｈａｓｓａｌｌ模型的渐近稳定性、有界性、全局稳定性．解决了文献［１］对 该模型的三个猜想：（１）模型在某种条件下，正平衡点（ｘ＊，ｙ＊）是渐近稳定的；（２）模型的一切 正初始条件的解有界；（３）模型在一定条件下，正平衡点（ｘ＊，ｙ＊）是全局稳定的．

资金时间价值的几何定性分析方法

在平面直角坐标系中，以时间变量为横轴，资金变量为纵轴，按照投资收益率的内涵定义一个资金时间价值分析模型。该模式用最直观的几何表达方式沟通资金流量、投资收益率、净现值等经济变量间的内在转换关系。运用此种数量转换关系分析和验证若干资金时间价值的定性理论，可使定性理论更具科学性。只有成功地将定性分析和定量分析结合在一起，才有可能使经济理论的研究向定量化的方向发展取得新的突破。

藏药冬虫夏草的近红外光谱分析及品质鉴定

近红外技术具有快速、准确、无损等优势,已在较多领域中得到广泛的应用,如水果品质检测、农产品和食品成份检测,还用于定性分析药材中的化学成分等。该研究采集30个来自不同产地、品级的虫草样品(那曲、玉树、林芝各10个),利用多种光谱预处理方法,结合化学计量法,对冬虫夏草进行了红外光谱分析,从而实现了对样品的快速测定。最终建立了“SG平滑+2阶求导”和“1001~1500 nm”组合的虫草分析模型,结果表明,那曲和林芝的虫草品质相近。

猕猴桃冷害近红外无损定性检测研究

通过近红外光谱技术对猕猴桃冷害导致的生理生化指标变化进行定性研究，建立了判定是否冷害的检测方法。结果表明：采用二阶导数＋矢量归一法进行预处理，用因子化法计算，在有效波段范围内可使定性测试结果的准确率提高至57．3％。在对光谱的聚类分析中，标准法、第一范围标定法和重现水平归一化法均可将样品分为两类，其中，重现水平归一化法的冷害分类准确率为97．1％；正常的分类准确率为60％，为最优模型。

维修配件库存控制策略的实证研究

因为不满足常规的库存控制模型所要求的条件 ,常规的库存控制方法不再适用 .针对维修配件的库存控制问题 ,研究三个基本的问题 :哪些维修配件必须有库存 ?库存量应该为多少 ?存放在哪里 ?以某工程机械公司的维修配件库存管理为背景 ,通过建立定性和定量分析模型 。

Determination of Melamine by Infrared Spectroscopy Based on Nonlinear Modeling

[Objective] The aim was to develop a nonlinear model of quantitative analysis of melamine content by infrared spectroscopy and provide theoretical basis for the nondestructive detection of melamine. [Method] According to dynamics,mathematical modeling and optimization theory,linear and nonlinear models were respectively set up by taking an absorption peak of 1 550 cm-1 as characteristic absorption peak. [Result] The correlation coefficient of nonlinear model was 0.922 7 and the recovery was 96%,which showed that the nonlinear model was more accurate than linearity model with correlation coefficient of 0.904 9 and recovery of 557%. [Conclusion] It is feasible to determine melamine content by using the nonlinear model quantitatively.

Stability analysis for affine fuzzy system based on fuzzy Lyapunov functions

An analysis method based on the fuzzy Lyapunov functions is presented to analyze the stability of the continuous affine fuzzy systems. First, a method is introduced to deal with the consequent part of the fuzzy local model. Thus, the stability analysis method of the homogeneous fuzzy system can be used for reference. Stability conditions are derived in terms of linear matrix inequalities based on the fuzzy Lyapunov functions and the modified common Lyapunov functions, respectively. The results demonstrate that the stability result based on the fuzzy Lyapunov functions is less conservative than that based on the modified common Lyapunov functions via numerical examples. Compared with the method which does not expand the consequent part, the proposed method is simpler but its feasible region is reduced. Finally, in order to expand the application of the fuzzy Lyapunov functions, the piecewise fuzzy Lyapunov function is proposed, which can be used to analyze the stability for triangular or trapezoidal membership functions and obtain the stability conditions. A numerical example validates the effectiveness of the proposed approach.

Development of fatigue analytical model of automotive dynamic parts made of semi-solid aluminum alloys

Automotive suspension control arm is used to join the steering knuckle to the vehicle frame. Its main function is to provide stability under fatigue stresses of loading and unloading in accelerating and braking. Conventionally, these parts were made of steel; however, fuel consumption and emission of polluting gases are strongly dependent on car weight. Recently, there is a try to develop and design much lighter and better fatigue resistant metal of semisolid A357 aluminum alloys. This work aims at a better understanding of identifying the fatigue strain-hardening parameters used for determining fatigue characteristics of aluminum suspension control arm using analytical and mathematical modeling. The most judicious method is to perform the fatigue tests on standardized test pieces and then plot two Wohler curves, mainly number of cycles as a function of the stress and as a function of the deformation. From these curves and following a certain mathematical and analytical methods, certain curves are plotted and then all of these coefficients are drawn. The new calculated parameters showed a clear improvement of the fatigue curve towards the experimental curve performed on the samples of aluminum alloy A357 compared with the same analytical curve for the same alloy.

Stability Analysis of Information Spreading on SNS Based on Refined SEIR Model

Investigating the stability of information spreading over SNS helps to understand the principles inherent in the spreading behavior.This paper explores the mechanisms of information spreading including stifling mechanism,latent mechanism and forgetting mechanism,establishes a refined SEIR model,and builds the corresponding mean-field equations.The methods of the differential dynamics and the next generation matrix are used to calculate the equilibriums and the basic reproductive number,and the asymptotical stability of the network equilibriums are proved theoretically.Simulation experiments are carried out to analyze the effect of the spreading mechanisms on the information spreading process and the results support our conclusions.

A triaxial creep model for coal containing gas and its stability analysis

Triaxial creep tests on CCG specimens were systematically performed using aself-made creep seepage experimental apparatus for determining the creep law of CCG.An improved triaxial creep model of CCG was established on the basis of a Nishiharamodel and another visco-elasto-plastic model,parameters of which were fitted on test data.Furthermore,the creep model is validated according to the result of triaxial creep experiments,and the outcome shows that the proposed triaxial creep model can properly characterizethe properties of various creep deformation phases of CCG,especially the acceleratingcreep phase.At the same time,the instability conditions of CCG were presentedbased on the discussion of the improved model's stability in terms of stability theories ofdifferential equation solution.

A new method determining safe thickness of karst cave roof under pile tip

Cave roofs are used to support pile foundation in many engineering projects. Accurate stability analysis method of cave roof under pile tip is important in order to ensure the safety of the pile foundation structure. Firstly the mechanical model to analysis the stability of cave roof under pile tip is founded aiming to solve the problems that the simplified mechanical model has. Secondly, the boundary of cave roof is simply supposed to be supported according to the integrity of the rock mass in the boundary of cave roof. Thirdly, based on the theory of plates and shells, the simplified model is calculated and the theoretical calculation formula to determine the safe thickness of cave roof under pile tip can be obtained when the edges of the cave roof are simply supported. In the end, the analysis of the practical engineering project proves the feasibility and the rationality of the method which can be a new method to calculate the safe thickness of cave roof under pile tip.

Seismic stability analysis of slopes with pre-existing slip surfaces

In analyzing seismic stability of a slope with upper bound limit analysis method, the slip surface is often assumed as a log-spiral or plane slip surface. However, due to the presence of a weak layer and unfavorable geological structural surface or a bedrock interface with overlying soft strata, the preexisting slip surface of the slope may be irregular and composed of a series of planes rather than strictly logspiral or plane shape. A computational model is developed for analyzing the seismic stability of slopes with pre-existing slip surfaces. This model is based on the upper bound limit analysis method and can consider the effect of anchor bolts. The soil or rock is deemed to follow the Mohr-Coulomb yield criterion. The slope is divided into multiple block elements along the slip surface. According to the displacement compatibility and the associated flow rule, a kinematic velocity field of the slope can be obtained computationally. The proposed model allows not only calculation of the rate of external work owing to the combined effect of self-weight and seismic loading, but also that of the energy dissipation rate caused by the slip surface, interfaces of block elements and anchorage effect of the anchors. Considering a direct relationship between the rate of external work and the energy dissipation rate, the expressions of yield acceleration and permanent displacement of anchored slopes can be derived. Finally, the validity of this proposed model is illustrated by analysis on three typical slopes. The results showed that the proposed model is more easily formulated and does not need to solve complex equations or time consuming iterations compared with previous methods based on the conditions of force equilibrium.

A nonlinear bottom-following controller for underactuated autonomous underwater vehicles

The bottom-following problem for underactuated autonomous underwater vehicles （AUV） was addressed by a new type of nonlinear decoupling control law. The vertical bottom-following error and pitch angle error are stabilized by means of the stem plane, and the thruster is left to stabilize the longitudinal bottom-following error and forward speed. In order to better meet the need of engineering applications, working characteristics of the actuators were sufficiently considered to design the proposed controller. Different from the traditional method, the methodology used to solve the problem is generated by AUV model without a reference orientation, and it deals explicitly with vehicle dynamics and the geometric characteristics of the desired tracking bottom curve. The estimation of systemic uncertainties and disturbances and the pitch velocity PE （persistent excitation） conditions are not required. The stability analysis is given by Lyapunov theorem. Simulation results of a full nonlinear hydrodynamic AUV model are provided to validate the effectiveness and robustness of the proposed controller.

A nonlinear rheological model of backfill material for retaining roadways and the analysis of its stability

The long-term stability of backfill material is the key to retaining roadways successfully. In order to study the rheological deformation of backfill material and its long-term stability, given the visco-elastoplastic properties of this material, we introduced a softening and a hardening function for a new nonlinear the- ological model with time-varying parameters. Based on this, we presented the instability condition of this model by using the principle of minimum potential energy. Combined with engineering practice, we cal- culated the urlstable time period of backfill material. The results show that the time of instability of the backfill material relate to the initial parameters of the material, ＂the coefficients decided by temperature and the ratio of the plastic zone of the backfill material. Based on the results of our analysis from the point of view of energy, we can quickly obtain the time of instability of this model from our graphical analysis. The time of instability of the backfill material obtained from our investigation coincides with an actual project.

3D stability analysis method of concave slope based on the Bishop method

In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop method was employed. The sliding body was divided into strips in a three-dimensional model, and the lateral earth pressure was put into mechanical analysis and the three-dimensional stability analysis methods applicable for circular sliding in concave slope were deduced. Based on geometric structure and the geological parameters of a concave slope, the influence rule of curvature radius and the top and bottom arch height on the concave slope stability were analyzed. The results show that the stability coefficient decreases after growth, first in the transition stage of slope shape from flat to concave, and it has been confirmed that there is a best size to make the slope stability factor reach a maximum. By contrast with average slope, the stability of a concave slope features a smaller range of ascension with slope height increase, which indicates that the enhancing effect of a concave slope is apparent only with lower slope heights.