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Web-based data acquisition
HU Xu-dong, YU Hong, CHEN Ying
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 135-139.
https://doi.org/10.1631/jzus.2002.0135
The research work on Web-based long-distance data acquisition (DAQ) is valuable for application to tele-detection machine faults. With an expert system for machine fault detection, faults in a distantly located machine can be diagnosed through the internet. The distant user logs on to the expert system Web page, fills in the requirements, and starts-up the diagnose process. The system then connects to the DAQ server that is installed in the machine, samples data required for diagnoses through the internet, and sends back diagnose results. In such a long-distance system, Web-based DAQ plays an important role by automatic sampling and transferring of data through the internet. We have built an experimental data acquisition system using a National Instruments AT-MIO-16E-10 board running under Ch language environment. In this experimental example, the user can acquire data online. The principle of this experimental method is introduced in this paper. A detailed programming technique is described with an example.
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Estimation of financial loss ratio for E-insurance: a quantitative model
ZHONG Yuan-sheng, CHEN De-ren, SHI Min-hua
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 140-147.
https://doi.org/10.1631/jzus.2002.0140
In view of the risk of E-commerce and the response of the insurance industry to it, this paper is aimed at one important point of insurance, that is, estimation of financial loss ratio, which is one of the most difficult problems facing the E-insurance industry. This paper proposes a quantitative analyzing model for estimating E-insurance financial loss ratio. The model is based on gross income per enterprise and CSI/FBI computer crime and security survey. The analysis results presented are reasonable and valuable for both insurer and the insured and thus can be accepted by both of them. What we must point out is that according to our assumption, the financial loss ratio varied very little, 0.233% in 1999 and 0.236% in 2000 although there was much variation in the main data of the CSI/FBI survey.
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Mathematical model of the dynamics of countercurrent chromatography
LU Xiang-hong, REN Qi-long, WU Ping-dong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 151-156.
https://doi.org/10.1631/jzus.2002.0151
A mathematical model of the dynamic behavior of countercurrent chromatography was proposed, and the model parameters, including the partition coefficient, the axial dispersion coefficient, the intraparticle diffusion coefficient and the external mass ransfer coefficient were calculated by the method of chromatogram moment analysis. Comparison of the experimental chromatograms of caffeine and theophylline determined in this work with the simulated curves computed by the proposed model showed fairly good agreement. Further, the difference between the average identified the partition coefficients by chromatogram moment analysis and the experimental values was small also, and the relationship between the external mass transfer rate and the linear velocity was similar to that obtained with solid-liquid chromatography.
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Simulating confined swirling gas-solid two phase jet
JIN Han-hui, XIA Jun, FAN Jian-ren, CEN Ke-fa
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 157-161.
https://doi.org/10.1631/jzus.2002.0157
A k-ε-kp multi-fluid model was used to simulate confined swirling gas-solid two phase jet comprised of particle-laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. After considering the drag force between the two phases and gravity, a series of numerical simulations of the two-phase flow of 30 μm, 45 μm, 60 μm diameter particles were performed on a x×r=50×50 mesh grid respectively. The results showed that the k-ε-kp multi-fluid model can be applied to predict moderate swirling multi-phase flow. When the particle diameter is large, the collision of the particles with the wall will influence the prediction accuracy. The bigger the diameter of the particles, the stronger the collision with the wall, and the more obvious the difference between measured and calculated results.
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Optimum design of large span concrete filled steel tubular arch bridge based on static, stability and modal analysis
ZHAO Chang-jun, HU Jun, XU Xing
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 166-173.
https://doi.org/10.1631/jzus.2002.0166
A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib\'s axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib\'s vertical stiffness and that of out-of-plane is determined by the crossbeams\' stiffness and arch rib\'s lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.
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Shrinkage and cracking behavior of high performance concretes containing chemical admixtures
QI Meng, LI Zong-jin, MA Bao-guo
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 188-193.
https://doi.org/10.1631/jzus.2002.0188
Modern concretes often incorporate several chemical admixtures to alter the properties of fresh or hardened concrete. In this work, the influences of three types of chemical admixtures, calcium nitrite inhibitor (CNI), retarder (D-17) and superplasticizer (W-19) on free shrinkage and restrained shrinkage cracking of high performance concrete were experimentally investigated. The test results showed that, with the same water to binder ratio (0.4), mixtures containing D-17 of 0.25 percent or higher ratio of W-19 (2.76 percent) all exhibited a reduction in free shrinkage and shrinkage cracking width. However, the incorporations of various ratios of CNI into mixtures led to an increase in free shrinkage and shrinkage cracking width as compared to control mixture. In order to study the influence of CNI, the microstructure of concrete mixture containing CNI were investigated by Mercury Intrusion Porosimetry as well as Scanning Electronic Microscopy(SEM) technique.
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Field investigation on effects of wheat-straw/corn-stalk mulch on ecological environment of upland crop farmland
DONG Zhi-yong, QIAN Bing-fa
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 209-215.
https://doi.org/10.1631/jzus.2002.0209
This work systematically investigates the effects of wheat-straw/corn-stalk mulch on the ecological environment in upland crops (winter wheat, summer corn) field from 1997 to 1998. With and without mulch soil moisture distribution, water demand, day and night variation of soil temperature, weeds control, crop yields, water and soil conservation, as well as improvement of soil texture were experimentally investigated. The optimal mulch rate for both water saving and yield-increase was determined. Ineffective interplant evaporation can be turned into effective transpiration of leaf by application of wheat-straw/corn-stalk mulch, which enhances the utility factor of soil moisture and reduces irrigation norm, and may also regulate soil temperature, increase soil fertility, and improve soil texture after being returned to the field. Wheat-straw/corn-stalk mulch inhibits evaporation of moisture so that accumulation of salinity near the soil surface is prevented, and thus ameliorates salinization of land. In the region of severe soil erosion, mulch is used to cover land so as to forestall hydraulic and wind erosion of the soil.
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cDNA cloning and sequence analysis of genome segments S8 from rice black-streaked dwarf virus
ZHANG Heng-mu, CHEN Jian-ping, XUE Qing-zhong, LEI Juan-li
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 216-222.
https://doi.org/10.1631/jzus.2002.0216
Genome segments S8 of two Chinese isolates of rice black-streaked dwarf virus (RBSDV), one from Zhejiang Province and another from Hebei Province, were amplified by RT-PCR and sequenced. Both segments consisted of 1936 nts in full length (EMBL accession numbers were AJ297431 and AJ297432, respectively) and contained only one big open reading frame which encoded a polypeptide with molecular weight of 68kD. The two Chinese isolates shared 94.0% and 96.5% identity at nucleotide and amino acid level, respectively. They shared 94.5-94.9% and 92.5-92.9% homology with S8 of RBSDV Japanese isolate at nucleotide and amino acid level, respectively; shared 85.1-87.6% and 91.7-91.9% homology with S7 of Italian MRDV (maize rough dwarf virus).
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A molecular biological study on identification of common septicemia bacteria using 16s-23s rRNA gene spacer regions
FU Jun-fen, YU He-yong, SHANG Shi-qiang, HONG Wen-lan, LU Miao-quan, LI Jian-ping
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 237-242.
https://doi.org/10.1631/jzus.2002.0237
In the search for a rapid and reliable method for identification of bacteria in blood and cerebrospinal fluid, we developed a unified set of primers and used them under polymerase chain reaction (PCR) to amplify the spacer regions between the 16s and 23s genes in the prokaryotic rRNA genetic loci. Spacer regions within these loci showed a significant level of length and sequence polymorphism across most of the species lines. A generic pair of priming sequences was selected from highly conserved sequences in the 16s and 23s genes occurring adjacent to these polymorphic regions. This single set of primers and reaction conditions were used for the amplification of the 16s-23s spacer regions for 61 strains of standard bacteria and corresponding clinical isolates belonging to 20 genera and 27 species, including Listeria, Staphylococcus and Salmonella species, et al. When the spacer amplification products were resolved by electrophoresis, the resulting patterns could be used to distinguish most of the bacteria species within the test group, and the amplification products of the clinical isolates clustered at the standard species level. Some species presenting similar pattern were further analyzed by HinfI or AluI digestion or DNA clone and sequences analysis in order to establish the specific 16s-23s rRNA gene spacer regions map. Analysis of 42 blood specimens from septicemic neonates and 6 CSF specimens from suspected purulent meningitis patients by bacterial culture and PCR-RFLP (Restriction Fregament Length Polymorphism) showed that 15 specimens of blood culture were positive (35.7%) in the 42 septicemic neonates; 27 specimens were positive (64.2%) by PCR, and that the positive rate by PCR was significantly higher than that by blood culture (P<0.01). Among the 6 CSF specimens, one specimen found positive by blood culture was also positive by PCR, two found negative by blood culture showed positive by PCR; all three were S. epidermidis according to the DNA map. One C. neoformans found positive by blood culture showed negative by PCR. The remaining two specimens were both negative by PCR and blood culture. These results indicated that the method of detecting bacterial 16s-23s rRNA spacer regions using PCR and RFLP techniques was rapid, sensitive and specific in the detection of bacterial infections; and so, has very important application in the clinical diagnosis of sepsis in neonates.
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Study of sEGF level in chronic atrophic gastritis with either Chinese traditional medicine or western medicine
SI Jian-min, SUN Lei-min, DAI Nin, QIAO Qiao, ZHOU Heng-de, ZHU Shu-dong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2002, 3(2): 243-246.
https://doi.org/10.1631/jzus.2002.0243
This study was aimed to investigate the level of sEGF in CAG with different therapies of either Chinese traditional medicine or western medicine. Patients were divided into spleen-reinforcing I, spleen-reinforcing II, dampness-resolving and western medicine group by Differentiation Syndrome. Healthy volunteers acted as controls. The sEGF was investigated before and after treatment. The level of sEGF in CAG was higher than that in control group (P<0.01). In patients of spleen-reinforcing I group and spleen-reinforcing II group, the symptoms and pathological manifestations were improved dramatically (P<0.01) and sEGF dropped markedly after treatment (P<0.01 and P<0.05).The level of sEGF in the dampness-resolving group increased after treatment (P<0.05). But the level of sEGF in the western-medicine group dropped a little after treatment (P>0.05). The inflammation of gastric mucosa may cause the elevation of sEGF in CAG reflectively. After being effectively treated with Chinese traditional medicine, the symptoms of CAG improved simultaneously with the return of sEGF. SEGF is a sensitive index to prognosis of CAG.
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22 articles
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