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Application of stochastic method to optimum design of energy-efficient induction motors with a target of LCC
FANG You-tong, FAN Cheng-zhi, YE Yun-yue, CHEN Yong-xiao
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 270-275.
https://doi.org/10.1631/jzus.2003.0270
For an energy-efficient induction machine, the life-cycle cost (LCC) usually is the most important index to the consumer. With this target, the optimization design of a motor is a complex nonlinear problem with constraints. To solve the problem, the authors introduce a united random algorithm. At first, the problem is divided into two parts, the optimal rotor slots and the optimization of other dimensions. Before optimizing the rotor slots with genetic algorithm (GA), the second part is solved with TABU algorithm to simplify the problem. The numerical results showed that this method is better than the method using a traditional algorithm.
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Noise and linearity optimization methods for a 1.9GHz low noise amplifier
GUO Wei, HUANG Da-quan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 281-286.
https://doi.org/10.1631/jzus.2003.0281
Noise and linearity performances are critical characteristics for radio frequency integrated circuits (RFICs), especially for low noise amplifiers (LNAs). In this paper, a detailed analysis of noise and linearity for the cascode architecture, a widely used circuit structure in LNA designs, is presented. The noise and the linearity improvement techniques for cascode structures are also developed and have been proven by computer simulating experiments. Theoretical analysis and simulation results showed that, for cascode structure LNAs, the first metallic oxide semiconductor field effect transistor (MOSFET) dominates the noise performance of the LNA, while the second MOSFET contributes more to the linearity. A conclusion is thus obtained that the first and second MOSFET of the LNA can be designed to optimize the noise performance and the linearity performance separately, without trade-offs. The 1.9GHz Complementary Metal-Oxide-Semiconductor (CMOS) LNA simulation results are also given as an application of the developed theory.
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Geotechnical behavior of the MSW in Tianziling landfill
ZHU Xiang-rong, JIN Jian-min, FANG Peng-fei
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 324-330.
https://doi.org/10.1631/jzus.2003.0324
The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.
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Expression of a fusion protein of human ciliary neurotrophic factor and soluble CNTF-Receptor and identification of its activity
SUN Yi, Marz Pia, Otten Uwe, GE Ji-guang, Rose-John Stefan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 340-345.
https://doi.org/10.1631/jzus.2003.0340
Ciliary neurotrophic factor (CNTF) has pleiotropic actions on many neuronal populations as well as on glia. Signal transduction by CNTF requires that it bind first to CNTF-R, permitting the recruitment of gp130 and LIF-R, forming a tripartite receptor complex. Cells that only express gp130 and LIF-R, but not CNTF-R are refractory to stimulation by CNTF. On many target cells CNTF only acts in the presence of its specific agonistic soluble receptors. We engineered a soluble fusion protein by linking the COOH-terminus of sCNTF-R to the NH2 -terminus of CNTF. Recombinant CNTF/sCNTF-R fusion protein (Hyper-CNTF) was successfully expressed in COS-7 cells. The apparent molecular mass of the Hyper-CNTF protein was estimated from western blots to be 75 kDa. Proliferation assays of transfected BAF/3 cells in response to CNTF and Hyper-CNTF were used to verify the activity of the cytokines. The proliferative results confirmed that CNTF required homodimerization of the gp130, CNTF-R and LIF-R receptor subunit whereas Hyper-CNTF required heterodimerization of the gp130 and LIF-R receptor subunit. We concluded that the fusion protein Hyper-CNTF had superagonistic activity on target cells expressing gp130 and LIF-R, but lacking membrane-bound CNTF-R.
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Agrobacterium-mediated transformation of herbicide resistance in creeping bentgrass and colonial bentgrass
CHAI Ming-liang, WANG Bing-liang, KIM Jae-yeoul, LEE Jong-min, KIM Doo-hwan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 346-351.
https://doi.org/10.1631/jzus.2003.0346
Embryogenic calli were induced from the seeds of creeping bentgrass (Agrostis palustris Huds.) cv. Regent and colonial bentgrass (Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co-cultivated with Agrobacterium tumefaciens, LBA4404, which contains plasmid vector-pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co-cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4-D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of \'Regent\' and \'Tiger\' were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.
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CH4 emission and recovery from Municipal Solid Waste in China
XU Xin-hua, YANG Yue-ping, WANG Da-hui
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 352-357.
https://doi.org/10.1631/jzus.2003.0352
Methane (CH4) is an important greenhouse gas and a major environmental pollutant, second only to carbon dioxide (CO2) in its contribution to potential global warming. In many cases, methane emission from landfills otherwise emitted to the atmosphere can be removed and utilized, or significantly reduced in quantity by using cost-effective management methods. The gas can also be used as a residential, commercial, or industrial fuel. Therefore, emission reduction strategies have the potential to become low cost, or even profitable. The annual growth rate of Municipal Solid Waste (MSW) output in China is 6.24%, with the highest levels found in South China, Southwest China and East China. Cities and towns are developing quickly in these regions. MSW output was only 76.36 Mt in 1991 and increased to 109.82 Mt in 1997, registering an average increase of 43.8%. In China, methane emission from landfills also increased from 5.88 Mt in 1991 to 8.46 Mt in 1997; so the recovery of methane from landfills is a profitable project.
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Polymorphisms in the genes for coagulation factor II,V,VII in patients undergoing coronary angiography
XU Geng, JIN Guo-dong, FU Guo-sheng, MA Ji, SHAN Jiang, WANG Jia-nan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 369-373.
https://doi.org/10.1631/jzus.2003.0369
Objective: To determine whether polymorphisms in the genes for coagulation factor II,V, VII could predispose an individual to increase risk for coronary artery disease (CAD) and/or myocardial infarction (MI) in Chinese. Methods: We screened coagulation factor II(G20210A), V(G1691A), VII (R353Q and HVR4) genotype in 374 patients undergoing coronary angiography by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay. Results: The R353Q and HVR4 genotype of the factor VII distribution was in accordance with Hardy-Weinberg equilibrium. The frequencies of FVII genotype or allele did not show statistically significant differences between CAD group and controls or between male and female. The frequencies of the Q allele and (RQ+QQ) genotype were significantly higher among the CAD patients without myocardial infarction (MI) history than among those with MI history (P<0.05). However, HVR4 polymorphism was not significantly different within groups. We only find one normal control of factorII(G20210A) mutation. No coagulation factor V(G1691A) mutation was found in the CAD patients and controls. Conclusion: The factor II(G20210A),V(G1691A) mutation is absent and may not be a major genetic factor for CAD and/or MI; the Q allele of the R353Q polymorphism of the factor VII gene may be a protective genetic factor against myocardial infarction in Chinese.
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Comparison study of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography
ZHAO Bo-wen, TANG Fu-gang, SHOU Jin-duo, XU Hai-shan, LU Jiang-hong, FAN Miao-ying, FAN Xiao-min, PAN Mei
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2003, 4(3): 374-377.
https://doi.org/10.1631/jzus.2003.0374
Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P<0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P<0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P<0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P<0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.
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23 articles
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