合理参数设置,巧妙函数思维——一道解三角形最值题的探究

涉及解三角形中的最值(或取值范围)问题,是高考命题中比较常见的一类热点问题.本文结合一道解三角形中面积最值及其应用的求解,依托解三角形的应用情境创设,挖掘问题的本质与内涵,从不同数学思维角度切入,结合不同的技巧方法应用,总结解题思维方法与技巧规律,引领并指导数学教学与复习备考.

不同参物角两次成像全息摄影的实验研究

利用普通光路,改变参物角、调整全息干板角度,实现一张全息干板两次曝光、两次成像目前尚未见报道。本研究在全息台上,通过改变参物角、调整全息干板角度,在一张干板上,成功地拍出了两次曝光的全息图,并再现。能否一张干板多次曝光,记录更多的信息,还有待于进一步研究。

一种天然防腐剂对裸五角瓜参的保鲜效果研究

实验以裸五角瓜参为研究对象,研究了复合防腐剂的复配及对裸五角瓜参的保鲜功效。响应面法研究结果表明,最佳复合防腐剂的配比为Nisin 0.05%、乌梅0.3%、地肤子0.04%和马尾藻0.4%;以该配比制得的复合防腐剂可有效抑制光参的菌落总数,经复合防腐剂处理的光参10d之内菌落总数符合标准,且对光参主要腐败微生物的假单胞菌具有良好的抑制效果;此外,经复合防腐剂处理的光参的p H值和TVBN显著优于对照组,其中TVBN在10d后仅为5.12mg/100g。

东海裸五角瓜参胶原蛋白提取及其性质研究

本研究以舟山产裸五角瓜参为对象,研究了体壁组织的基本组成成分、酸溶与胃酶促溶胶原提取率、提取胶原蛋白特性以及其体外抗氧化性。结果表明:裸五角瓜参蛋白质含量较高,粗蛋白含量达到18.56%,且以胶原蛋白为主,该胶原蛋白经酸提法和酶提法处理后具有典型的水产品胶原蛋白特性,2%为Na Cl最佳添加浓度;电泳实验表明该胶原蛋白的链和β链分子量分别为98 k U和102 k U;此外,两种胶原蛋白还具有一定的抗氧化性,但其抗氧化能力较弱。

犀角地黄汤+参苓白术散+大补元煎鼻饲联合西药临床治愈呼吸机相关腹胀1例报告

报告1例犀角地黄汤＋参苓白术散＋大补元煎鼻饲联合西药临床治愈长期使用呼吸机导致相关性腹胀,出院后腹胀症状消失,大便1-2日一行。男,68岁。肢体活动不利,意识欠清1天。腹部膨隆、皮肤绷急,大便2-3日一行,脉沉细;白细胞15.06×10^9/L,中性粒细胞百分比88%,血红蛋白84g/L;C反应蛋白58.5mg/L,降钙素原0.43ng/m L,D二聚体2ug/m L;生化、凝血、肿瘤系列、心肌酶等未见明显异常;CT：双下肺炎症;颅脑左侧丘脑可见新发梗塞灶,放射冠可见陈旧性梗塞灶。西医诊断：1.脑梗塞,2.肺炎;中医诊断：1.中风（肝肾亏虚）,2.喘嗽。抗感染、营养支持等治疗,犀角地黄汤加减,水牛角、生地各30g,赤芍、丹皮、丹参、玄参各15g,麦冬20g,茯苓30g,白术15g,1剂/d,水煎200m L,早晚鼻饲,5d为1疗程。二诊以参苓白术散合大补元煎加减以健脾补肾,党参30g,茯苓20g,白术、山药各15g,薏苡仁30g,砂仁、桔梗各12g,生地、熟地各30g,杜仲、枸杞各15g,鹿角胶烊化10g,丹参15g,地龙12g,桃仁、红花各9g,甘草炙6g,1剂/d,水煎200m L,早晚鼻饲。此后每7d在此方基础上加减,服药2月,腹胀明显减轻,大便1-2日一行,服药4月,腹胀症状消失,大便1-2日一行,临床治愈。

Semantic role labeling based on conditional random fields

Due to the fact that semantic role labeling （SRL） is very necessary for deep natural language processing, a method based on conditional random fields （CRFs） is proposed for the SRL task. This method takes shallow syntactic parsing as the foundation, phrases or named entities as the labeled units, and the CRFs model is trained to label the predicates＇ semantic roles in a sentence. The key of the method is parameter estimation and feature selection for the CRFs model. The L-BFGS algorithm was employed for parameter estimation, and three category features： features based on sentence constituents, features based on predicate, and predicate-constituent features as a set of features for the model were selected. Evaluation on the datasets of CoNLL-2005 SRL shared task shows that the method can obtain better performance than the maximum entropy model, and can achieve 80. 43 % precision and 63. 55 % recall for semantic role labeling.

Flow measurement and parameter optimization of right-angled flow passage in hydraulic manifold block

This study was conducted to investigate the flow field characteristics of right-angled flow passage with various cavities in the typical hydraulic manifold block.A low-speed visualization test rig was developed and the flow field of the right-angled flow passage with different cavity structures was measured using 2D-PIV technique.Numerical model was established to simulate the three-dimensional flow field.Seven eddy viscosity turbulence models were investigated in predicting the flow field by comparing against the particle image relocimetry(PIV)measurement results.By defining the weight error function K,the S-A model was selected as the appropriate turbulence model.Then,a three-factor,three-level response surface numerical test was conducted to investigate the influence of flow passage connection type,cavity diameter and cavity length-diameter ratio on pressure loss.The results show that the Box-Benhnken Design(BBD)model can predict the total pressure loss accurately.The optimal factor level appeared in flow passage connection type II,14.64 mm diameter and 67.53%cavity length-diameter ratio.The total pressure loss decreased by 11.15%relative to the worst factor level,and total pressure loss can be reduced by 64.75%when using an arc transition right-angled flow passage,which indicates a new direction for the optimization design of flow passage in hydraulic manifold blocks.

A family of quasi-cubic blended splines and applications

A class of quasi-cubic B-spline base functions by trigonometric polynomials are established which inherit properties similar to those of cubic B-spline bases. The corresponding curves with a shape parameter a, defined by the introduced base functions, include the B-spline curves and can approximate the B-spline curves from both sides. The curves can be adjusted easily by using the shape parameter a, where dpi（a,t） is linear with respect to da for the fixed t. With the shape parameter chosen properly, the defined curves can be used to precisely represent straight line segments, parabola segments, circular arcs and some transcendental curves, and the corresponding tensor product surfaces can also represent spherical surfaces, cylindrical surfaces and some transcendental surfaces exactly. By abandoning positive property, this paper proposes a new C^2 continuous blended interpolation spline based on piecewise trigonometric polynomials associated with a sequence of local parameters. Illustration showed that the curves and surfaces constructed by the blended spline can be adjusted easily and freely. The blended interpolation spline curves can be shape-preserving with proper local parameters since these local parameters can be considered to be the magnification ratio to the length of tangent vectors at the interpolating points. The idea is extended to produce blended spline surfaces.

Mechanical properties and microstructure evolution in incremental forming of AA5754 and AA6061 aluminum alloys

This study performs single point incremental forming(SPIF)on two aluminum alloys(i.e.AA5754 and AA6061),and analyzes their post forming mechanical properties and microstructure evolution.The forming parameters namely wall angle(35°-55°),feed rate(1-4 m/min),spindle rotational speed(50-1000 r/min),and lubricant(grease and hydraulic oil)are varied to probe detailed processing effects.The pre-and post-SPIF mechanical properties and microstructures are characterized by conducting tensile tests and optical microscopy,respectively.It is shown that an increase in the wall angle,feed rate and rotational speed causes microscopic variations in the alloys such that the grains of AA5754 and the second phase particles of AA6061 elongate.As a result,the ultimate tensile strength of the formed parts is increased by 10%for AA5754 and by 8%for AA6061.And,the ductility of AA5754 is decreased from 22.9%to 12%and that of AA6061 is decreased from 16%to 10.7%.Regarding the lubricant effect,it is shown that the mechanical properties remain insensitive to the type of lubricant employed.These results indicate that SPIF processing modifies the microstructure of Al alloys in a way to enhance the strength at the cost of ductility.

Method to determine installing angle of conical point attack pick

In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclination angle and the skew angle) were studied, and the static model of installing angles of the pick was built. The relationships among the impact angle, the tip angle of pick and the kinematics parameters of the pick were built, too. Moreover, the mechanic models of the maximum clearance angle and the wearing angle of the pick were set up. To research the relationships of the installing angles and the change law of the wearing angle along with the kinematics parameters, the simulation was done. In order to verify the correctness of the models, the cutting experiments were done by employing two picks with different pick tip angles. The results indicate that, the cutting force is the smallest when the direction of the resultant force of pick follows its axis, and the relationship derived among the installing angles should be satisfied. In addition, to decrease the cutting force and the wearing of the pick, the tip angle of pick should not be larger than the half of the difference between the minimum wearing angle and the impact angle of the pick, and the clearance angle must not be less than zero.

Simulation of Cefoselis hydrochloride adsorption on macroporous resin in a fixed-bed column using orthogonal collocation

Adsorption operation is of great importance for separation and purification of semi-synthetic cephalosporin compounds in pharmaceutical industry. The adsorption dynamics of Cefoselis hydrochloride(CFH) on XR 920 C adsorbent in fixed bed was predicted by the model of modified film-pore diffusion(MFPD). The intraparticle diffusion equation and mass balance equation in fixed bed are discretized into two ordinary differential equations(ODEs) using the method of orthogonal collocation which largely improves the calculation accuracy. The MFPD model parameters including the pore diffusion coefficient(Dp), external mass-transfer coefficient(kf), and the axial dispersion(DL) were estimated. The kfvalue was calculated by the Carberry equation, in which the effective diffusion coefficient Dewas fitted based on Crank Model through experimental data. Moreover, three key operating parameters(i.e., initial adsorbate concentration; flow rate of import feed, and bed height of adsorbent) and the corresponded breakthrough curves were systematically studied and optimized. Therefore,this research not only provides valuable experimental data, but also a successfully mathematical model for designing the continuous chromatographic adsorption process of CFH.

Application of joint elastic impedance inversion in the GD Oilfield

For the complicated reservoir description of the GD oilfield, P-wave and S-wave elastic impedance inversion was carried out using pre-stack seismic data to accurately identify the lithology of the reservoir. The joint inversion was performed using three or more partial stacks to overcome the singularity of post-stack seismic inversion that can not satisfy the requirements of complex reservoir description and to avoid the instability of the inversion result caused by low signal-noise ratio in the pre-stack gather. The basic theory of prestack elastic impedance inversion is briefly described in this paper and, using real data of the GD oilfield, the key steps of angle gather wavelet extraction, horizon calibration, S-wave velocity prediction, and elastic parameter extraction were analyzed and studied. The comprehensive interpretation of multiple elastic parameters determined from log analysis is a key to improving the effect ofprestack seismic inversion.

Selection of Measured Signals in the Navigation Measuring Complex

To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a selective method using principles of the functional systems.Selection of measured information is finished by original numeric criterion of observation level of state vector components.Prediction is realized by algorithm of self-organization that makes synthesis of the optimal complication.Therefore mechanism of self-regulation is realized and accuracy of the selective navigation complex is increased.

Influence of Blade Outlet Angles on Separation Performance of Guide Vane Type Axial Flow Cyclone Tube

The influences of the internal and external outlet angles on separation performance and flow field are compared and analyzed. Two arc functions are employed for controlling the internal and external angles. The separation process in the cyclone tube is calculated by using two-fluid model based on the Eulerian-Eulerian method.The results show that the structure with the internal outlet angle smaller than the external one is more beneficial to the separation performance. It is found that the small internal angle can help increase the swirl number,while the small external angle can help increase the friction coefficient. Several groups of numerical simulations are conducted for the air intake unit of the gas turbine in practice. When the internal outlet angle is 35° and the external outlet angle is 40°,the blade has sufficient cyclone strength and the separation rate of particles with diameters of 10—100 μm is between70%—98%. The small blade angle is more conducive to the separation of fine particles,leading to violent collision of large particles on the outer wall and reduction of separation efficiency. In addition,reducing the external angle is conducive to the discharge of large particles.

Helicity Amplitude Analysis of η_c Decays into Hyperon-Antihyperon Pairs

The helicity amplitudes for the processes of e^＋e^- →J/ψ→γηc→γYY（Y： hyperon） are presented, together with the joint angular distributions for ηc decays into ∧∧,∑^0 ∑^0, and [1]-[1]＋. The sensitivities to measure the hyperon decay parameters in these decays are evaluated based on the helicity amplitudes. The prospects to test the Bell inequality in experiment using the decay of ηc→∧∧ are discussed.

Particle stratification and penetration of a linear vibrating screen by the discrete element method

A simulation of stratification and penetration was performed over a range of structural parameters that included screen width, aperture size, inclination angle, and wire diameter. The discrete element method （DEM） was used for the simulations. The terms stratification and penetration are defined and the change in fine panicle concentration is discussed. Mathematical models relating fine particle ratio to time are established using the least squares method. The effect of structural parameters on fine panicle ratio is analyzed. Stratification and penetration rate are discussed by considering the time derivative of the fine panicle ratio. The conclusions are： an increase in inclination or wire diameter has a positive effect on par- ticle stratifying; The optimal screen width is 40 mm for panicle stratification; The inclination angle has a negative effect on the penetration; The effect of wire diameter and screen width on the penetration rate is negligible.

Upper gastrointestinal bleeding etiology score for predicting variceal and non-variceal bleeding

AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscopy within 72 h were enrolled. Clinical and basic laboratory parameters were prospectively collected. Predictive factors for the types of UGIB were identified by univariate and multivariate analyses and were used to generate the UGIB Etiology Score. The best cutoff of the score was defined from the receiver operating curve and prospectively validated in another set of patients with UGIB. RESULTS： Among 261 patients with UGIB, 47 （18%） had variceal and 214 （82%） had non-variceal bleeding. Univariate analysis identified 27 distinct parameters significantly associated with the types of UGIB. Logistic regression analysis identified only 3 independent factors for predicting variceal bleeding; previous diagnosis of cirrhosis or signs of chronic liver disease （OR 22.4, 95% CI 8.3-60.4, P 〈 0.001）, red vomitus （OR 4.6, 95% CI 1.8-11.9, P = 0.02）, and red nasogastric （NG） aspirate （OR 3.3, 95% CI 1.3-8.3, P = 0.011）. The UGIB Etiology Score was calculated from （3.1× previous diagnosis of cirrhosis or signs of chronic liver disease） ＋ （1.5× red vomitus） ＋ （1.2× red NG aspirate）, when 1 and 0 are used for the presence and absence of each factor, respectively. Using a cutoff ≥ 3.1, the sensitivity, specificity, accuracy, positive predictive value （PPV）, and negative predictive value （NPV） in predicting variceal bleeding were 85%, 81%, 82%, 50%, and 96%, respectively. The score was prospectively validated in cases （46 variceal and 149 another set of 195 UGIB non-variceal bleeding）. The PPV and NPV of a score ≥ 3.1 for variceal bleeding were 79% and 97%, respectively. CONCLUSION： The UGIB Etiology Score, composed of 3 parameters, using a cutoff ≥ 3.1 accurately predicted variceal bleeding and may help to guide the choice of initial therapy for UGIB before endoscopy.

Parametrization of Transfer Matrix:for One-Dimensional Anderson Model with Diagonal Disorder

In this paper, we developed a new parametrization method to calculate the localization length in one-dimensionalAnderson model with diagonal disorder.This method can avoid the divergence difficulty encountered in theconventional methods, and significantly save computing time as well.

Robust Integrated Models for Chinese Predicate-Argument Structure Analysis

Predicate-Argument （PA） structure anal- ysis is often divided into three subtasks： predicate sense disambiguation, argument identification and argument classification mostly been modeled in To date, they have isolation. However, this approach neglects logical constraints between them. We therefore exploite integrating predicate sense disambiguation with the latter two subtasks respectively, which verifies that the automatic predicate sense disambiguation could help the se- mantic role labeling task. In addition, a dual de- composition algorithm is used to alleviate the er- ror propagation between argument identification subtask and argument classification subtask by benefitting the argument identification subtask greatly. Experiment results show that our ap- proach leads to a better performance with PA a- nalysis than other pipeline approaches.