Hai Yan Kong

Lightning-Like Charged Jet Cascade in Bubble Electrospinning with Ultrasonic Vibration

Lightning is a natural phenomenon caused by an atmospheric electrical discharge, and lightning strikes are of hierarchical structure. Similar phenomenon is first observed in a charged jet in the presence of a high electrostatic field, the process is widely adopted for fabrication of superfine fibers, and its mechanism of lightning-like charged jet is still unknown. Our observation reveals that a daughter jet can be ejected from the surface of a micro/nanoscale charged jet to form an initial two-stage cascade, whereby the daughter charged jet can reduce size over three orders of magnitude, while at the ultimate stage, the jets have almost same size from several nanometers to dozens of nanometers. The origin of this phenomenon might be central to nanotechnology. Here we demonstrate that an electrostatic field can accelerate a charged jet, and the surface charge repels each other. When the repelling force reaches a threshold to overcome its surface tension, one or more daughter charged jets are ejected from the surface. The daughter jets behave similarly to the initial jet, the process is iterative, creating a lightning-like multi-stage cascade. This observation opens the door to mimicking the lightning to produce two dimensional superfine fiber web with hierarchical structure.

Style Design of Men’s Pants and Programming Realization

In the developing of 2D non-contact anthropometry and application system, automatic pattern generation of men’s pants system is important component. Styles of men’s pants are single, and can be devised simply. In this paper, 6 kinds of devised styles are summarized by observing styles of men’s pants, which divide into landscape orientation, lengthways orientation and slant segmentation all included straight line and curve. After the users enter into automatic pattern generation of men’s pants system, they can choose devised style in the interface of design, and then related pattern can be automatically generated in the interface of pattern. In this paper, VS software is used to make programming, ganged style of pants in human body is realized by MATLAB, so the pattern can be automatically generated according to the rules of pattern and devised styles. This study provides the basis for automatic pattern generation of men’s pants system.

Hierarchical Motion of Charged Jets in Electrospinning and Nanofibers with Minimal Diameter of about 5nm

Polyvinyl alcohol (PVA) with a degree of 1750±50 was successfully fabricated into nanofibers via the traditional electrospinning process. Daughter charged jets and combined fibers were observed. A combined fiber might be simple combination of two separate fibers without mass transfer, or it is a daughter cascade caused in hierarchical motion of a charged jet with mass/energy transfer. Minimal fiber reaches as small as 5nm (50 angstroms) in diameter, this might be the smallest artificial fiber, which might have excellent properties due to nanoeffect.

High Orientation Ordered Nanofibers Fabricated by Electrospinning

Nanofibers with high orientation are of significant applications. This paper demonstrates a method to fabricate high orientation ordered nanofibers by electrospinning. The distribution of the electric field is simulated by using computational fluid dynamics software ANSYS14.0 to illustrate its mechanism.

Change of Leaf Morphology along Altitudinal Gradients

It is the most effective way to study the effect of global warming on plant morphology by analyzing a plant species on a mount along altitudinal gradients. Altitudinal increase means decrease of temperature and metabolic rate as well. This might affect the leaf morphology greatly. The SEM study reveals that the size of nanopore on the epidermis changes gradually along altitudinal gradients, and the absorbed fine particles on the leaf have almost same size, exhibiting high selectivity over other particles. The study gives a strong proof that morphology change links to global warming.

Frequency of Bubble Formation in Modified Bubble Electrospinning

Bubble-electrospinning is one of the most straightforward ways to fabricate polymer solution into nanofibers. The key point of the technology is to control bubble size and formation frequency. A modified bubble electrospinning set-up is designed to control the size of polymer bubbles and frequency of bubble formation in the spinning process. A PVA (10wg %) solution is used in the experiment for fabricate polymer solution into nanofibers and superfine nanofibers are obtained with the average diameter of about 200nm.

Study on Calculating Methods of Young Women Body Circumferences Based on 3D Point-Cloud Data

In this research, 425 female students were selected as the research objects. Point clouds were obtained by 3D body scanner , then the characteristics of female lower body parts’ (waist, abdomen, buttock) section shapes were identified .And the sizes of the width and thickness were measured by a data acquisition software named Imageware.The front and back circumferences were analysed by software of SPSS16.0.This research is main to provide a new method to divide and calculate body front and back circumferences, laying the foundation for fitting of women clothes.

Study on Circumference Calculation Method of Characteristic Body Parts Based on Two-Dimensional Image

In this research, 425 female college students aged from 18 to 26 were selected as samples, using 3D body scanner to get the body Point-cloud image, and measure the thickness, width and girth size of characteristic body parts(waist, abdomen, hip) ; By studying the circumferences sections of characteristic body parts, body type is classified according to thickness / width ratio; The correlation of circumference with thickness and width is analyzed, the circumference calculating equations for different body size is obtained, then the reasonableness of the method is tested, which providing a reference for the human body circumference automatically generated from 2D images.

Girth Calculative Rules Research of Female Body Based on 2D Figures

In this paper, 357 female students in soochow university which are 18 to 26 years old were selected as subjects. Front, back and side photos are taken by using digital camera, and then photo manipulation was done to amplify the contrast between the human body and background. The width and thickness of human characteristic positions were measured by COREDRAW software. Meanwhile, the girth of each position was got by manual measurement, and the width and thickness of human characteristic positions were extracted by MATLAB. Finally the girth, width and thickness were analyzed by SPSS to obtain the girth calculative rules, and the error analysis was done to verify the veracity. The result showed that the regression fitting was feasible and accurate.

Difference Comparison of Girth Regression on Different Category Files

In the paper “Research of calculation method of young female body circumference based on 3d body scanning point and cloud diagrams”, regression value of each girth has a certain error. The reason might be different methods of classification. In order to analysis the reason, in the paper error distribution and comparison between girth regression value and actual measurement data were analyzed which classified with 0.1 and 0.05 category files by using SPSS16.0 software. More accurate methods can be obtained to simulate three dimensions which can provide effective applications to three dimension body scanner and lay a foundation to the research of pants and skirts auto-generation pattern system.