既有曲线群地段曲线测设和计算方法研究

本文介绍一种既有曲线群地段曲线测设和拨距计算的新方法，通过曲线连测解决了夹直线过短所引起误差等问题，用枚举法优化公切线使拨道量最小，测设方法和计算方法简单实用。

In-situ measurement and distribution of flue gas mercury for a utility PC boiler system

The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM) consistent with American standard test methodtogether with the semi-continuous emissions monitoring (SCEM) system as well as a mobile laboratoryfor mercury monitoring. The mercury and its speciation concentrations including participate mercuryat three locations of before air preheater, before electrostatic precipitator (ESP) and after ESPwere measured using the OHM and SCEM methods under normal operation conditions of the boiler systemas a result of firing a bituminous coal. The vapor-phase total mercury Hg(VT) concentration declinedwith the decrease of flue gas temperature because of mercury species transformation from oxidizedmercury to particulate mercury as the flue gas moved downstream from the air preheater to the ESPand after the ESP. A good agreement for Hg°, Hg^(2+) and Hg( VT) was obtained between the twomethods in the ash-free area. But in the dense particle-laden flue gas area, there appeared to be abig bias for mercury speciation owing to dust cake formed in the filter of OHM sampling probe. Theparticulateaffinity to the flue gas mercury and the impacts of sampling condition to accuracy ofmeasure were discussed.

Adaptive multiple subtraction using a constrained L1-norm method with lateral continuity

The Lt-norm method is one of the widely used matching filters for adaptive multiple subtraction. When the primaries and multiples are mixed together, the L1-norm method might damage the primaries, leading to poor lateral continuity. In this paper, we propose a constrained L1-norm method for adaptive multiple subtraction by introducing the lateral continuity constraint for the estimated primaries. We measure the lateral continuity using prediction-error filters （PEF）. We illustrate our method with the synthetic Pluto dataset. The results show that the constrained L1-norm method can simultaneously attenuate the multiples and preserve the primaries.

Research and implementation of continuous wave radar ranging method based on tri-frequency

In the traditional dual-frequency radar ranging system,there is a contradiction between ranging precision and ranging distance.So a tri-frequency ranging method is proposed.The principle of the tri-frequency ranging is that the distance can be achieved by transmitting the three frequencies and then measuring the three phase difference and calculating the number of wavelength.What's more,range ambiguity will not occur within a certain distance.The experimental results show that,if the waveband is 0.47 ~0.57 m,the measurement of unambiguous distance of 25 ~500m can be realized.If the wavelength tolerance error is less than ± 10^(-7) and the phase error is less than ± 10^(-3),the precision of the distance ranging can reach 10^(-6).

Measurement of Mass Transfer Coefficients and Their Modelling of Continuous Counter-Current Aqueous Two-Phase System in a Packed Extraction Column

Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The average relative deviation between calculated values and experimental data ranges from 8% to 14%.

Real-Time Front Vehicle Detection Algorithm Based on Local Feature Tracking Method

This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of the vehicle are vertical and horizontal edges,shadow and symmetry.By comparing local features using the fixed window size,the features in the continuous images are tracked.A robust and fast Haarlike mask is used for detecting vertical and horizontal edges,and shadow is extracted by histogram equalization,and the sliding window method is used to compare both side templates of the detected candidates for extracting symmetry.The features for tracking are vertical edges,and histogram is used to compare location of the peak and magnitude of the edges.The method using local feature tracking in the continuous images is more robust for detecting vehicle than the method using single image,and the proposed algorithm is evaluated by continuous images obtained on the expressway and downtown.And it can be performed on real-time through applying it to the embedded system.

Melatonin ameliorates experimental hepatic fibrosis induced by carbon tetrachloride in rats

AIM:To investigate the protective effects of melatonin on carbon tetrachloride(CCl4)-induced hepatic fibrosis in experimental rats.METHODS:All rats were randomly divided into normal control group,model control group treated with CCl4 for 12 wk,CCl4+NAC group treated with CCl4+NAC(100 mg/kg,i.p.)for 12 wk,CCl4+MEL-1 group treated with CCl4+melatonin(2.5 mg/kg)for 12 wk,CCl4+MEL-2 group treated with CCl4+ melatonin(5.0 mg/kg)for 12 wk,and CCl4+MEL-3 group treated with CCl4+melatonin(10 mg/kg).Rats in the treatment groups were injected subcutaneously with sterile CCl4(3 mL/kg,body weight)in a ratio of 2:3 with olive oil twice a week.Rats in normal control group received hypodermic injection of olive oil at the same dose and frequency as those in treatment groups.At the end of experiment,rats in each group were anesthetized and sacrificed.Hematoxylin and eosin(HE)staining and Van Gieson staining were used to examine changes in liver pathology.Serum activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST)and protein concentration weremeasured with routine laboratory methods using an autoanalyzer.Hydroxyproline(HYP)content in liver and malondialdehyde(MDA)and glutathione peroxidase(GPx)levels in liver homogenates were assayed by spectrophotometry.Serum hyaluronic acid(HA),laminin(LN),and procollagenⅢN-terminal peptide(PⅢNP)were determined by radioimmunoassay.RESULTS:Pathologic grading showed that the fibrogenesis was much less severe in CCl4+MEL3 group than in model control group(u=2.172,P<0.05),indicating that melatonin(10 mg/kg)can significantly ameliorate CCl4-induced hepatic fibrotic changes.The serum levels of ALT and AST were markedly lower in CCl4+MEL treatment groups(5,10 mg/kg)than in model control group(ALT:286.23 ±121.91 U/L vs 201.15±101.16 U/L and 178.67 ±103.14 U/L,P=0.028,P=0.007;AST:431.00 ±166.35 U/L vs 321.23±162.48 U/L and 292.42 ±126.23 U/L,P=0.043,P=0.013).Similarly,the serum laminin(LN)and hyaluronic acid(HA)levels and hydroxyproline(HYP)contents in liver were significantly lower in CCl4+MEL-3 group(10 mg/kg)than in model control group(LN:45.89±11.71μg/L vs 55.26± 12.30μg/L,P=0.012;HA:135.71±76.03μg/L vs 201.10±68.46μg/L,P=0.020;HYP:0.42±0.08 mg/g tissue vs 0.51±0.07 mg/g tissue,P=0.012).Moreover,treatment with melatonin(5,10 mg/kg)significantly reduced the MDA content and increased the GPx activity in liver homogenates compared with model control group(MDA:7.89±1.49 noml/mg prot vs 6.29±1.42 noml/mg prot and 6.25±2.27 noml/mg prot,respectively,P=0.015,P=0.015;GPx:49.13± 8.72 U/mg prot vs 57.38±7.65 U/mg prot and 61.39± 13.15 U/mg prot,respectively,P=0.035,P=0.003).CONCLUSION:Melatonin can ameliorate CCl4-induced hepatic fibrosis in rats.The protective effect of melatonin on hepatic fibrosis may be related to its antioxidant activities.

TESTING k-EDGE-CONNECTIVITY OF DIGRAPHS

This paper presents an algorithm that tests whether a given degree-bounded digraph is k-edge-connected or E-far from k-edge-connectivity. This is the first testing algorithm for k-edge- connectivity of digraphs whose running time is independent of the number of vertices and edges. A digraph of n vertices with degree bound d is ε-far from k-edge-connectivity if at least εdn edges have to be added or deleted to make the digraph k-edge-connected, preserving the degree bound. Given a constant error parameter ε and a degree bound d, our algorithm always accepts all k-edge-connected digraphs and reiects all digraphs that is ε-far from k-edge-connectivity with orobabilitv at least 2/3.It runs in O（d（εd^-c）^k logεd^-1O）（c〉1 is a constant）time when input digraphs are restricted to be （k-1）-edge connected and runs in O（d（εd^-ck）^klogεd^-kO）（c〉1 is a constant）time for general digraphs.

Estimating thermohaline variability of the equatorial Pacific Ocean from satellite altimetry

The vertical thermohaline structure in the western equatorial Pacific is examined with a Gravest Empirical Mode(GEM)diagnosis of in-situ mooring measurements. The poor GEM performance in estimating deep thermohaline variability from satellite altimetry confirms a lack of vertical coherence in the equatorial ocean. Mooring observation reveals layered equatorial water with phase difference up to 6 months between thermocline and sub-thermocline variations. The disjointed layers reflect weak geostrophy and resemble pancake structures in non-rotating stratified turbulence. A coherency theorem is then proved, stating that traditional stationary GEM represents in-phase coherent structure and can not describe vertically out-of-phase variability. The fact that stationary GEM holds both spatial and temporal coherence makes it a unique tool to diagnose vertical coherent structure in geophysical flows. The study also develops a non-stationary GEM projection that captures more than 40% of the thermohaline variance in the equatorial deep water.