Showing papers in "Journal of Zhejiang Sci-Tech University in 2013"

Household Registration System and Urbanization Process in China

Abstract: Household registration system is the most influencing policy factor in the urbanization process of China.Chinese household registration system has experienced three stages-strict control,gradual relaxation and pertinent relaxation or control.As the specific product of a special Chinese historical period,household registration system has ever had the function of preventing excessive urbanization phenomenon,but made cities fail to reach the population size required by its economic development.This paper organizes different opinions of scholars on the reform direction of household registration system and puts forward the principle and assumption of household registration system reform based on urbanization process.

A Generalization of an Important Trigonometric Inequality

Abstract: This paper investigates the problem of the weakening conditions which are necessary to an important trigonometric inequalityPeople have generalized that sequence to mean value bounded variation sequenceBy Abel’s transformation,appropriate scalability and other methods,the authors generalize the trigonometric inequality and come to the conclusion in the supremum bounded variation condition

Experimental Study on the Polyester-Cotton Blended Fabric’s Flame Retardancy

Abstract: In the light of the problem that it’s difficult to apply flame retardant finish to cotton-polyester blended fabric as a result of wick effect,the authors adopt a new type of flame retardant to finish the fabric.Additionally,the compositions of fire retardant will coordinate to achieve flame retardancy.Based on this,the authors utilize orthogonal experiment to analyze the way in which how blending ratio,fabric density and fabric structure affect the flame retardant performance of cotton-polyester blended fabric.It turns out that the vertical burning damage length is from 40 to 47 mm,which is less than 50 mm,and the limiting oxygen index is greater than 27.5,which reaches the requirements for flame retardancy.The flame retardant performance of cotton-polyester blended fabric is closely related to the contents of the fire retardant and the way to apply fire retardant finish.It also proves that the flame retardant performance of cotton-polyester blended fabric increases and then decreases when the contents increase,the performance is positively correlated to the density of fabric,while the fabric structure does not significantly connect with it.

Research on Shape and Texture Feature Extraction of Plant Leaf Images

Abstract: This paper introduces a method of shape and texture feature extraction based on leaf images for the classification of plant leaves.This method first conducts pre-processing on leaf image,extracts leaf outline and obtains the shape and texture feature parameters;then analyzes and roughly classifies shape parameters and finally classifies leaves with similar shape by using BP neural network.The experiment classifies 20 kinds of leaves and the average recognition rate reaches 92%.

Research on Learners' Responsive Repetition Strategies of English Conversation and Inspirations on Oral English Teaching

Abstract: In conversation,the behavior that one repeats the other's words in order to continue the conversation is called responsive repetition.It is an important discourse strategy with which both parties successfully complete the conversation and establish a relation.This research analyzes the frequency,category,distribution and gender difference of English responsive repetition of learners with college students' oral test linguistic data as data source.The research finds that the frequency of learners' use of responsive repetition is lower than those speaking native language;learners are more willing to use responsive repetition to show listening or make their own attitude vague so as to maintain the harmony of the conversation.The gender comparison shows that female learners more often use responsive repetition to show their listening to and understanding of the other's words and male learners use responsive repetition to show their position and opinions more directly.

Aerodynamic Performance Study on Small Axial Fan with Perforation Blades

Abstract: By using a certain type of small fans as prototype,this thesis designs a fan model with perforation blades and uses N-S equations coupled with κ-e turbulence model to simulate the three-dimensional flow field of small axial flow fans.In addition,it analyzes static characteristics and pneumatic acoustic characteristics of the two fans based on the results of numerical simulation.The results show,as a leaf perforation fan,the static pressure decreases in the whole calculation flow but rises just the same as the prototype fan at the best condition point;the position of vortex shedding is closer to the blade tip,vanishing point of vortex moves downstream in the export zones eddy and vorticity weakens,so all the noise of the fan decreases.However,there is a different noise reduction at different frequency bands and the noise reduction is the largest in the 35～45 kHz frequency range.These results suggest that using some fan blade perforation methods to reduce the noise is feasible on the best condition.

Facial Expression Recognition Based on Improved LBP

Abstract: LBP(Local Binary Pattern) is an effective texture description operator which can well extract facial expression feature information.This paper improves the original LBP operator in allusion to the problem that it only considers gray difference between central pixel and neighborhood pixel,puts forward multiple local binary patterns MLBP and applied the improved MLBP operator in facial expression recognition.Through the experimental comparison in JAFFE face database before and after improvement,this method achieves a good effect in terms of the recognition rate.

Effect of Different Soil Moistures on Total Phenolic Acid Composition Accumulation and Relevant Enzymatic Activity of Salvia Miltiorrhiza Lamina

Abstract: This paper studies total phenolic acid composition accumulation and change rules of relevant enzymatic activity of salvia miltiorrhiza lamina under the condition of different soil moistures(35%,55% and 75% of field capacity) through pot experiment with Salvia miltiorrhiza Bunge as the material.The result shows that,in the later period of drought stress,the total phenolic acid composition accumulation of salvia miltiorrhiza lamina significantly increases.The total phenolic acid content is the highest when treated at 55%,followed by 35% and 75%.The total phenolic acid content treated at 55% is 1.50 times of that at 75%;that at 35% is 1.31 times of that at 75%.In the earlier stage of treatment,55% soil moisture can promote the increase of PAL enzymatic activity,while 55% and 35% soil moisture in the later period of treatment can promote the increase of TAT enzymatic activity,but drought stress doesn't have significant influence on C4H enzymatic activity.The accumulation of total phenolic acid composition of salvia miltiorrhiza lamina is related to PAL and C4H enzyme and its obvious relation with TAT is not found.This provides theoretical reference for the development of salvia miltiorrhiza lamina resources and standard plantation and irrigation of salvia miltiorrhiza and provides guidance for the quality control of salvia miltiorrhiza medicinal material.

Establishment and Application of Scientific Research Innovation Capability Evaluation Index System for Postgraduates of Science and Engineering in Colleges and Universities

Abstract: In allusion to characteristics of postgraduates of science and engineering in colleges and universities currently,this paper conducts a result analysis with questionnaire method;establishes scientific research innovation capability evaluation system for postgraduates by using SPSS;calculates the weight of related factors;establishes a comprehensive evaluation model of scientific research innovation capability with AHP method;and realizes fuzzy comprehensive evaluation of scientific research innovation capability of postgraduates on this basis.This method can provide references for the reasonable evaluation of scientific research innovation capability of postgraduates in colleges and universities.

Study on Waterproof Textile Materials Used for Earphone Membrane of Mobile Phone

Abstract: Polymethacrylate membrane-forming agent and fluoric water-proofing agent are used to process polyester fabrics and earphone membrane of mobile phone with waterproof property is prepared through rolling-roasting process.This paper measures the sound insulation,hydraulic pressure resistance and water contact angle of fabrics respectively using reverberation room-dead room method,hydraulic pressure resistance tester and water contact angle meter and observes microstructure through field emission scanning electron microscopy.The result shows that the acoustic insulation property of fabrics improves with the decrease of its aperture and that the hydraulic pressure resistance and sound insulation increase with the increase of concentration of membrane-forming agent and water-proofing agent.When the volume fraction of membrane-forming agent is 30%,the volume fraction of water-proofing agent is 10%,roasting temperature is 180℃ and roasting time is 300 s,earphone membrane material with hydraulic pressure resistance 3000 Pa and sound insulation3 dB within the frequency range 0～20000 Hz.

Study on Influence of Flame-retardant Plasticizer on Flame Retardation

Abstract: This study plastifies PVC resin by using flame-retardant plasticizer diphenyl benzyl phosphate(DPK)and normal plasticizer DINP with different proportions and makes the corresponding coating material for PVC building membrane materials;investigates their effect for flame retardation and processing performance of the material;studies the influence of DPK on thermal degradation process of PVC material with thermogravimetric analysis method;uses scanning electron microscope to observe the morphology of carbon residue of the material and analyzes the flame-retardant mechanism of DPK.The result shows that flame-retardant plasticizer DPK can promote PVC gas dehydrochlorination and form a dense carbonization membrane on the surface of the material and has excellent flame retardation.In complex use w(DPK)∶w(DINP)=10∶50,it can effectively improve the flame retardation and workability of PVC coating material.