共查询到20条相似文献，搜索用时 46 毫秒
1.
Lei ZHANG Ping ZHENG Chongojian TANG Ren-cun JIN 《Journal of Zhejiang University. Science. B》2008,9(5)
The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest.The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists.Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters.Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control.Successful full-scale practice in the Netherlands will ac-celerate application of the process in future.This review introduces the microbiology and more focuses on application of the ANAMMOX process. 相似文献
2.
In an object-based storage system, a novel scheme named EAP （extending attributes page） is presented to enhance the metadata reliability of the system by adding the user object file information attributes page for each user object and storing the file-related attributes of each user object in object-based storage devices. The EAP scheme requires no additional hardware equipments compared to a general method which uses backup metadata servers to improve the metadata reliability. Leveraging a Markov chain, this paper compares the metadata reliability of the system using the EAP scheme with that using only metadata servers to offer the file metadata service. Our results demonstrate that the EAP scheme can dramatically enhance the reliability of storage system metadata. 相似文献
3.
Particle swarm optimization （PSO） is an efficient, robust and simple optimization algorithm. Most studies are mainly concentrated on better understanding of the standard PSO control parameters, such as acceleration coefficients, etc. In this paper, a more simple strategy of PSO algorithm called θ-PSO is proposed. In θ-PSO, an increment of phase angle vector replaces the increment of velocity vector and the positions are decided by the mapping of phase angles. Benchmark testing of nonlinear functions is described and the results show that the performance of θ-PSO is much more effective than that of the standard PSO. 相似文献
4.
The main principle and the characteristic of Predictive Functional Control (PFC) strategy are presented in this paper and
the corresponding control system aid design software APC-PFC is also introduced. For a chlorinated polyethylene (CPE) process,
a design scheme of cascade predictive functional control system is described and the control performance is improved obviously.
Project (No. 69974035) supported by the National Natural Science Foundation of China 相似文献
5.
6.
Carbon fiber reinforced polymer （CFRP） bars were prestressed for the structural strengthening of 8 T-shaped reinforced concrete （RC） beams of a 21-year-old bridge in China. The ultimate bearing capacity of the existing bridge after retrofit was discussed on the basis of concrete structures theory. The flexural strengths of RC beams strengthened with CFRP bars were controlled by the failure of concrete in compression and a prestressing method was applied in the retrofit. The field construction processes of strengthening with CFRP bars including grouting cracks, cutting groove, grouting epoxy and embedding CFRP bars, surface treating, banding with the U-type CFRP sheets, releasing external prestressed steel tendons-were introduced in detail. In order to evaluate the effectiveness of this strengthening method, field tests using vehicles as live load were applied before and after the retrofit. The test results of deflection and concrete strain of the T-shaped beams with and without strengthening show that the capacity of the repaired bridge, including the bending strength and stiffness, is enhanced. The measurements of crack width also indicate that this strengthening method can enhance the durability of bridges. Therefore, the proposed strengthening technology is feasible and effective. 相似文献
7.
Resources publication and discovery in manufacturing grid 总被引：3，自引：0，他引：3
TAO Fei HU Ye-fa DING Yu-feng SHENG Bu-yun ZHOU Zu-de 《浙江大学学报(A卷英文版)》2006,7(10):1676-1682
INTRODUCTION Manufacturing Grid (MGrid) is a new concept proposed to meet the practical demands in the manufacturing industry and is a new technology enabling broad geographical distribution of all sorts of manufacturing resources through the Internet or other specific nets, using grid technology. With the MGrid platform, we can realize common sharing of manufacturing resources including human resources, equipment resources, material resources, applicable software systems, etc., and can … 相似文献
8.
CAI Jing ZHENG Ping MAHMOOD Qaisar ISLAM Ejazul HU Bao-lan WU Dong-lei 《浙江大学学报(A卷英文版)》2007,8(7):1149-1156
The optimal operation conditions in an anoxic sulfide oxidizing (ASO) bioreactor were investigated. The maximal removal rates for sulfide and nitrate were found to be 4.18 kg/(m3·d) and 1.73 kg/(m3·d), respectively. The volumetrical volumetric loading rates (LRs) observed through decreasing hydraulic retention time (HRT) at fixed substrate concentration are higher than those by increasing substrate concentration at fixed HRT. The sulfide oxidation in ASO reactor was partially producing both sulfate and sulfur; but the amount of sulfate produced was approximately one third that of sulfur. The process was able to tolerate high sulfide concentration, as the sulfide removal percentage always remained near 99% when influent concentration was up to 580 mg/L. It tolerated relatively lower nitrate concentration because the removal percentage dropped to 85% when influent con- centration was increased above 110 mg/L. The process can tolerate shorter HRT but careful operation is needed. Nitrate conversion was more sensitive to HRT than sulfide conversion since the process performance deteriorated abruptly when HRT was decreased from 3.12 h to 2.88 h. In order to avoid nitrite accumulation in the reactor, the influent sulfide and nitrate concentrations should be kept at 280 mg/L and 67.5 mg/L respectively. Present biotechnology is useful for removing sulfides from sewers and crude oil. 相似文献
9.
Da-wei Xue Ming-can Chen Mei-xue Zhou Song Chen Ying Mao Guo-ping Zhang 《Journal of Zhejiang University. Science. B》2008,9(12):938-943
To understand genetic patterns of the morphological and physiological traits in flag leaf of barley, a double haploid (DH)
population derived from the parents Yerong and Franklin was used to determine quantitative trait loci (QTL) controlling length,
width, length/width, and chlorophyll content of flag leaves. A total of 9 QTLs showing significantly additive effect were
detected in 8 intervals on 5 chromosomes. The variation of individual QTL ranged from 1.9% to 20.2%. For chlorophyll content
expressed as SPAD value, 4 QTLs were identified on chromosomes 2H, 3H and 6H; for leaf length and width, 2 QTLs located on
chromosomes 5H and 7H, and 2 QTLs located on chromosome 5H were detected; and for length/width, 1 QTL was detected on chromosome
7H. The identification of these QTLs associated with the properties of flag leaf is useful for barley improvement in breeding
programs.
Project supported by the National Natural Science Foundation of China (No. 30630047) and the Project on Absorption of Intellects
by Institutions of Higher Education for Academic Disciplinary Innovations (the 111 Project) (No. B06014), China 相似文献
10.
Texture classification based on EMD and FFT 总被引：2，自引：0，他引：2
XIONG Chang-zhen XU Jun-yi ZOU Jian-cheng QI Dong-xu 《浙江大学学报(A卷英文版)》2006,7(9):1516-1521
INTRODUCTION Multi-scale is one of the main features of natural images, a series of methods for representing the quality of images are presented, such as multi-scale technique based on diffusion equation (Perona and Malik, 1990), image pyramid (Burt and Adelson, 1983) and wavelet (Mallat, 1989). Bidimensional empirical mode decomposition (BEMD) (Nunes et al., 2005; Linderhed, 2004) is a new multi-scale analysis method proposed recently. The difference between BEMD and traditional mul… 相似文献
11.
综合口径雷达的宽频带双极化口径耦合微带阵 总被引：1，自引：0，他引：1
An 8×1-element wideband dual-polarized slot-coupled microstrip antenna array with high isolation and low cross-polarization in X-band is presented. The array antenna offers an impedance bandwidth (VSWR≤2) of 23% and 21% for dual polarization ports, respectively. The measured isolation between two polarization ports is better than 35 dB and the measured cross-polarization level below -25 dB in the main beam over the operation frequency band of 9.35 GHz to 9.75 GHz. This array is well suitable for X-band SAR (synthetic aperture radar) antenna application. 相似文献
12.
A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and
its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discussed and constructed. An example was given
to illustrate its application.
Project supported by the National Natural Science Foundation of China (Grant No. 10271074) 相似文献
13.
INTRODUCTION Image fusion can be defined as the process by which several images, or some of their features, are combined together to form different modalities or instruments, and is of great importance in many ap- plications (Hall and Llinas, 1997; Zhou et al., 1998), such as object detection, ATR (Automatic Target Recognition), remote sensing, computer vision, and robotics. Recently some researchers recognized that it seems more meaningful to combine objects/regions rather than pixels… 相似文献
14.
The objective of the present study was to compare the toxicity and availability of Fe(II) and Fe(III) to Caco-2 cells. Cellular
damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative
enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were
determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated
to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(II) is significantly higher
than that of the cells treated with Fe(III) (P<0.05). Fe(II) at a concentration >1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(III).
LDH release investigation suggests that Fe(II) can reduce stability of the cell membrane. The activities of SOD and GPx of
the cells treated with Fe(II) were higher than those of the cells treated with Fe(III), although both of them increased with
raising iron supply levels. The results indicate that both Fe(II) and Fe(III) could reduce the cellular antioxidase gene expression
at high levels.
Project supported by the International Cooperative Project from the Ministry of Science and Technology of China (No. 2006DFA31030),
the Bureau of Science and Technology of Zhejiang Province (No. 2006C32019) and HarvestPlus-China (No. 8022), and the Program
for Changjiang Scholars and Innovative Research Team in University of China (No. IRT0536) 相似文献
15.
HU Xin ZHANG Pu HE Sailing 《浙江大学学报(A卷英文版)》2006,7(10):1777-1780
A dual structure of composite right/left handed （CRLH） transmission line （TL） is analyzed in which an inductance LR is in parallel with a capacitance CL and a shunt capacitance CR is in series with an inductance LL. Both the distributed and lumped cases are considered. The dispersion diagram and transmission properties of the dual CRLH TL are given and compared with those of a standard CRLH TL. Contrary to the frequency response of a standard CRLH TL, a dual CRLH TL has a left-handed （negative phase shift） band at higher frequencies and a right-handed （positive phase shift） band at lower frequencies. A novel dual-band balun is presented as an application. 相似文献
16.
Robust video foreground segmentation and face recognition 总被引：1，自引：0，他引：1
管业鹏 《上海大学学报(英文版)》2009,13(4):311-315
Face recognition provides a natural visual interface for human computer interaction (HCI) applications. The process of face
recognition, however, is inhibited by variations in the appearance of face images caused by changes in lighting, expression,
viewpoint, aging and introduction of occlusion. Although various algorithms have been presented for face recognition, face
recognition is still a very challenging topic. A novel approach of real time face recognition for HCI is proposed in the paper.
In view of the limits of the popular approaches to foreground segmentation, wavelet multi-scale transform based background
subtraction is developed to extract foreground objects. The optimal selection of the threshold is automatically determined,
which does not require any complex supervised training or manual experimental calibration. A robust real time face recognition
algorithm is presented, which combines the projection matrixes without iteration and kernel Fisher discriminant analysis (KFDA)
to overcome some difficulties existing in the real face recognition. Superior performance of the proposed algorithm is demonstrated
by comparing with other algorithms through experiments. The proposed algorithm can also be applied to the video image sequences
of natural HCI.
Project supported by the National Natural Science Foundation of China (Grant No.60872117), and the Leading Academic Discipline
Project of Shanghai Municipal Education Commission (Grant No.J50104) 相似文献
17.
In this letter, we introduce a novel passive transmission line of negative refractive index （i.e., left-handedness） based on identical symmetrical lattice type structures [thus called ＂lattice type transmission line＂ （LT-TL）]. The dispersion characteristic and the transmission response of the proposed LT-TL are analyzed. While all the other left-handed passive transmission lines are of high pass, the present passive left-handed transmission line is of low pass. Compared with a conventional transmission line, the LT-TL has a phase shift of 180° in the entire wide pass-band. 相似文献
18.
Objective To explore how arylamine N-acetyltransferases (NATs) is related to cell apoptosis.
Methods NAT activity in apoptotic HepG2 cells was measured using high performance liquid chromatography (HPLC); the apoptosis rate
of HepG2 cells acted upon by an NAT inhibitor was measured using flow cytometry.
Results NAT activity was lowered in apoptotic HepG2 cells; apoptosis rate induced by camptothecin (CAM) increased after inhibition
of NAT activity in HepG2 cells.
Conclusion NAT can inhibit apoptosis in HepG2 cells.
Project supported by the National Natural Science Foundation of China (No. 30400591), the Science Foundation of Heilongjiang
Province, China (Nos. D2004-13 and D200505), and the Young Scientist Fund of Harbin City, China (No. 2004AFQXJ035) 相似文献
19.
Unbalanced vibration in dual-rotor rotating machinery was studied with numerical simulations and experiments. A new method
is proposed to separate vibration signals of inner and outer rotors for a system with very little difference in rotating speeds.
Magnitudes and phase values of unbalance defects can be obtained directly by sampling the vibration signal synchronized with
reference signal. The balancing process is completed by the reciprocity influence coefficients of inner and outer rotors method.
Results showed the advantage of such method for a dual-rotor system as compared with conventional balancing.
Project supported by the National Natural Science Foundation of China (No. 59875078), and Zhejiang Provincial Natural Science
Foundation of China (No. 502092) 相似文献
20.
Ensemble learning HMM for motion recognition and retrieval by Isomap dimension reduction 总被引：1，自引：0，他引：1
XIANG Jian WENG Jian-guang ZHUANG Yue-ting WU Fei 《浙江大学学报(A卷英文版)》2006,7(12):2063-2072
INTRODUCTION Now more and more motion capture systems are used to acquire realistic human motion data. Due to the success of the Mocap systems, realistic and highly detailed motion clips are commercially available and widely used for producing animations of human-like characters in a variety of applications, such as simu- lations, video games and animation files. Therefore an efficient motion data recognition and retrieval technique is needed to support motion data processing, such as mot… 相似文献