The infrared absorption method for methane concentration detection is an ideal way to detect methane at present. However, it is difficult to spread this method due to its high cost. In this paper, by using a wideband ...The infrared absorption method for methane concentration detection is an ideal way to detect methane at present. However, it is difficult to spread this method due to its high cost. In this paper, by using a wideband infrared light emitting di- ode (LED) accompanied with a PIN photo electric diode, a low-cost methane detection system was designed. To overcome the shortcomings caused by the wide working band, a differential light path was designed. By means of a differential ratio algo- rithm, the stability and the accuracy of the system were guaranteed. Finally, the validity of the system with the proposed algo- rithm was verified by the experiment results.展开更多
A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-...A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-dibromoacetophenone(p-BPB), was added in the plasma samples. The samples were analyzed in a VP-ODS column with UV-detector. The calibration curve of captopril was linear within the range of 5~1000 ngmL-1 with r=0.9987, the recovery of this method was 98.652.04%, within day and between day RSD were no more than 3.4% and 8.4% respectively. To study the pharmacokinetics and the relative bioavailability of captopril tablets, two formulations of captopril tablets were given to 18 healthy male volunteers according to a randomized 2-way cross-over design with a 1-week washout period. The respective AUC0~6 , Cmax and Tmax values of the two formulations were 424.5125.7 and 439.4113.3 mghL-1; 505.9244.6 and 504.8172.2 mgL-1; 0.6620.181 and 0.5280.176 h. Results from statistics analysis showed that there were no significant difference between the AUC0~6 , Cmax and Tmax values of the two formulations, The relative bioavailability of tablets I with respect to II was 96.114.6% from AUC0~6 measurement. Bioequivalance was observed between the two tablets.展开更多
AIM:To compare the diagnostic yield of capsule endoscopy (CE) with that of double-balloon enteroscopy (DBE). METHODS:Pubmed,Embase,Elsevier ScienceDirect,the China Academic Journals Full-text Database,and Cochrane Con...AIM:To compare the diagnostic yield of capsule endoscopy (CE) with that of double-balloon enteroscopy (DBE). METHODS:Pubmed,Embase,Elsevier ScienceDirect,the China Academic Journals Full-text Database,and Cochrane Controlled Trials Register were searched for the trials comparing the yield of CE with that of DBE. Outcome measure was odds ratio (OR) of the yield. Fixed or random model method was used for data analysis. RESULTS:Eight studies (n = 277) which prospectively compared the yield of CE and DBE were collected. The results of meta-analysis indicated that there was no difference between the yield of CE and DBE 170/277 vs 156/277,OR 1.21 (95% CI:0.64-2.29). Based on sub analysis,the yield of CE was significantly higher than that of double-balloon enteroscopy without combination of oral and anal insertion approaches 137/219 vs 110/219,OR 1.67 (95% CI:1.14-2.44),P < 0.01),but not superior to the yield of DBE with combination of the two insertion approaches 26/48 vs 37/48,OR 0.33 (95% CI:0.05-2.21),P > 0.05). A focused meta-analysis of the fully published articles concerning obscure GI bleeding was also performed and showed similar results wherein the yield of CE was significantly higher than that of DBE without combination of oral and anal insertion approaches 118/191 vs 96/191,fixed model:OR 1.61 (95% CI:1.07-2.43),P < 0.05) and the yield of CE was significantly lower than that of DBE by oral and anal combinatory approaches 11/24 vs 21/24,fixed model:OR 0.12 (95% CI:0.03-0.52),P < 0.01). CONCLUSION:With combination of oral and anal approaches,the yield of DBE might be at least as high asthat of CE. Decisions made regarding the initial approach should depend on patient's physical status,technology availability,patient's preferences,and potential for therapeutic endoscopy.展开更多
Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on dete...Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.展开更多
We tested and modified the quasi-analytical algorithm (QAA) using 57 groups of field data collected in the spring of 2003 in the Yellow Sea and East China Sea. The QAA performs well in deriving total absorption coef...We tested and modified the quasi-analytical algorithm (QAA) using 57 groups of field data collected in the spring of 2003 in the Yellow Sea and East China Sea. The QAA performs well in deriving total absorption coefficients of typical coastal waters. The average percentage difference (APD) is in a range of 13.9%-38.5% for the total absorption coefficient (13.9% at 440 nm), and differences in particle backscattering coefficient bbp(2) are less than 50% (in the case of the updated QAA). To obtain improved results, we modified the QAA by adjusting the empirical relationships. The modified algorithm is then applied to the field data to test its performance. The APDs were 44.7%-46.6% for bbp(λ) and 9.9%-32.8% (9.9% at 555 nm) for the total absorption coefficient. This indicates that the modified QAA derives better results. We also used the modified model to derive phytoplankton pigment absorption (aph) and detritus and CDOM absorption (aug) coefficients. The APDs for aph and a dg at 440 nm are 37.1% and 19.8%. In this paper, we discuss error sources using the measured dataset. More independent field data can improve this algorithm and derive better results.展开更多
The use of vehicle- or air-borne Ground Penetrating Synthetic Aperture Radar (GPSAR) to quickly detect landmines over large areas is becoming a trend. However, producing too many false alarms in GPSAR landmine detecti...The use of vehicle- or air-borne Ground Penetrating Synthetic Aperture Radar (GPSAR) to quickly detect landmines over large areas is becoming a trend. However, producing too many false alarms in GPSAR landmine detection is a major challenge in practical applications of GPSAR. Support Vector Machine (SVM), employing structural risk minimization theory, does not need large amounts of training data, which makes it suitable for solving the landmine detection problem. In this paper, a novel SVM with a hypersphere instead of a hyperplane classification boundary is proposed for landmine detection in GPSAR. The HyperSphere-SVM (HS-SVM) can be trained with both landmine and clutter data, or with landmine data only, which are called the two-class HS-SVM and the one-class HS-SVM, respectively. The HS-SVM has better generalization capability than the traditional HyperPlane-SVM (HP-SVM) with respect to varying operating conditions. Quantitative comparisons have been made using real data collected with the rail-GPSAR landmine detection system, which show that both the two-class and the one-class HS-SVMs have better detection performance than the HP-SVM.展开更多
AIM:To outline the appropriate diagnostic methods and therapeutic options for acquired bronchobiliary fistula(BBF).METHODS:Literature searches were performed in Medline,EMBASE,PHMC and LWW(January 1980August 2010)usin...AIM:To outline the appropriate diagnostic methods and therapeutic options for acquired bronchobiliary fistula(BBF).METHODS:Literature searches were performed in Medline,EMBASE,PHMC and LWW(January 1980August 2010)using the following keywords:biliobronchial fistula,bronchobiliary fistula,bronchobiliary fistula,biliarybronchial fistula,tracheobiliary fistula,hepatobronchial fistula,bronchopleural fistula,and biliptysis.Further articles were identified through crossreferencing.RESULTS:Sixtyeight cases were collected and reviewed.BBF secondary to tumors(32.3%,22/68),including primary tumors(19.1%,13/68)and hepatic metastases(13.2%,9/68),shared the largest proportion of all cases.Biliptysis was found in all patients,and other symptoms were respiratory symptoms,such as irritating cough,fever(36/68)and jaundice(20/68).Half of the patients were treated by lessinvasive methods such as endoscopic retrograde biliary drainage.Invasive approaches like surgery were used less frequently(41.7%,28/67).The outcome was good at the end of the followup period in 28 cases(range,2 wk to 72 mo),and the recovery rate was 87.7%(57/65).CONCLUSION:The clinical diagnosis of BBF can be established by sputum analysis.Careful assessment of this condition is needed before therapeutic procedure.Invasive approaches should be considered only when noninvasive methods failed.展开更多
In this paper we investigate the impact of the Atmospheric Infra-Red Sounder (AIRS) temperature retrievals on data assimilation and the resulting forecasts using the four-dimensional Local Ensemble Transform Kalman Fi...In this paper we investigate the impact of the Atmospheric Infra-Red Sounder (AIRS) temperature retrievals on data assimilation and the resulting forecasts using the four-dimensional Local Ensemble Transform Kalman Filter (LETKF) data assimilation scheme and a reduced resolution version of the NCEP Global Forecast System (GFS).Our results indicate that the AIRS temperature retrievals have a significant and consistent positive impact in the Southern Hemispheric extratropics on both analyses and forecasts,which is found not only in the temperature field but also in other variables.In tropics and the Northern Hemispheric extratropics these impacts are smaller,but are still generally positive or neutral.展开更多
The detection performance is evaluated for our proposed analog multiuser receiver in Ultra-WideBand (UWB) transmitted-reference system. In the presence of dense multipath and multi-access signals,the performance analy...The detection performance is evaluated for our proposed analog multiuser receiver in Ultra-WideBand (UWB) transmitted-reference system. In the presence of dense multipath and multi-access signals,the performance analysis is difficult due to the complicated waveform of received impulse. We develop an approach to analyze the steady-state Signal-to-Interference-plus-Noise (SINR) of the detector output. The multipath-spread impulse is fitted to an exponentially decaying profile in the analysis. A closed-form expression of steady-state SINR is further deduced for the proposed Least Minimum Square (LMS) detector. The analysis is validated by simulations in Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) channel respectively. Based on the theoretical results,the multipath delay spread is employed to determine the optimal width of the integration window of the detector.展开更多
Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography (HPLC) for determination. Mo...Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography (HPLC) for determination. Mobile phase is: V(Methanol): V(Water)=90: 10; determination wavelength is 245 nm; flow rate is 0.8 mL/min. Avermectin is completely separated in 17min, linear range is 5 - 0.3 g/L, correlation coefficient is 0.9997, average recovery rates of Avermectin in milk and beef are respectively 91.20 %- 100.32 % and 89.93 %-99.15 %, the relative standard deviations are respectively less than 7% and 4%. This method is simple, sensitive and accurate, so is suitable for determination of Avermectin residues in milk and beef, and it can meet domestic and foreign testing requirements.展开更多
The essence of empirical test of Wagner characteristic in new public management countries' tax revenue is to test the influence of economic growth on tax growth since new public management movement. Under IMF statist...The essence of empirical test of Wagner characteristic in new public management countries' tax revenue is to test the influence of economic growth on tax growth since new public management movement. Under IMF statistical framework, by using E-G two-step method in co-integration test and Granger causality test and empirically testing of the gross tax revenue and classified tax revenue in Australian, Canada, France, America, Britain these five countries, we can find that most indicators in most countries do not confirm to Wagner' s law. With the growth of GDP, tax revenue as a percentage of GDP rises periodically but not permanently. This period can be called the validity period of Wagner' s law in financial scale.展开更多
Based on theoretical calculation and Monte Carlo simulation,this paper proposes a new method for the diagnosing of 16.7 MeV high-energy pulse gamma,named "scattering absorption method". The ratio of the sens...Based on theoretical calculation and Monte Carlo simulation,this paper proposes a new method for the diagnosing of 16.7 MeV high-energy pulse gamma,named "scattering absorption method". The ratio of the sensitivity of high-energy gamma to that of the low-energy background gamma can reach 106 to 108 by this new method. The sensitivity of 16.7 MeV high-energy gamma ranges from 10-21 to 10-16 C·cm2. It's better than the traditional method which is based on the magnetic analyzer and Cherenkov detector on some aspects.展开更多
For high resolution radar, the echoes of target come from several points rather than one point as in low resolution radar. In this case the target is called an extended target. This paper presents two CFAR detectors f...For high resolution radar, the echoes of target come from several points rather than one point as in low resolution radar. In this case the target is called an extended target. This paper presents two CFAR detectors for such a target in non Gaussian clutter, which are CA CFAR and OS CFAR detectors. The detection performances of the two detectors are evaluated.展开更多
The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applica...The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applications. There is an urgent need to develop effective and economically viable alternative treatments to replace current phytosanitary and quarantine practices in order to maintain the competitiveness of US agriculture in domestic and international markets. With the reliable heating block system, the thermal death kinetics for fifth-instar codling moth, Indianmeal moth, and navel orangeworm were determined at a heating rate of 18℃/min. A practical process protocol was developed to control the most heat resistant insect pest, fifth-instar navel orangeworm, in in-shell walnuts using a 27 MHz pilot scale radio frequency (RF) system. RF heating to 55℃ and holding in hot air for at least 5 min resulted in 100% mortality of the fifth-instar navel orangeworm. Rancidity, sensory qualities and shell characteristics were not affected by the treatments. If this method can be economically integrated into the handling process, it should have excellent potential as a disinfestation method for in-shell walnuts.展开更多
The scores of grape wine given by wine critics have differences, therefore, for which its credibility differs. Firstly, our paper analysis differences of overall and individual for the two groups of raters. The analys...The scores of grape wine given by wine critics have differences, therefore, for which its credibility differs. Firstly, our paper analysis differences of overall and individual for the two groups of raters. The analysis method is: first check the score whether meets the normal distribution or not by Chi-square and then test whether the mean of the two group's ratings is equal or not, through t-test, to illustrate the differences of the two groups' ratings. Secondly this paper respectively characterizes the credibility of each group's rating with the variance and gray correlation. Both the results are highly consistent on the credibility, so they can support each other. This score comparison method can be further extended to a similar scoring system.展开更多
A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of preceding, modulating and coding, A dark RZ signal is generated simply by using on...A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of preceding, modulating and coding, A dark RZ signal is generated simply by using one dual-arm Mach-Zehnder LiNbO3 modulator. We demonstrate experimentally that this optical dark RZ signal can be directly measured by a conventional binary intensity modulation direct detection (IM-DD) receiver. When different values of duty cycles at 2.5 Gbit/s are adjusted, the experimental results show different BER curves and eye diagrams of the optical dark RZ signal.展开更多
An iterative receiver is proposed based on the EM (Expectation-Maximization)algorithm for an OFDM-SDMA (Orthogonal Frequency Division Multiplexing-Space Division Multiple Access) system. By using a few pilots in every...An iterative receiver is proposed based on the EM (Expectation-Maximization)algorithm for an OFDM-SDMA (Orthogonal Frequency Division Multiplexing-Space Division Multiple Access) system. By using a few pilots in every OFDM symbol, both channel estimation and multiuser detection can be simultaneously obtained by iteration. The computer simulation results show this receiver can track channel variations and detect multiuser symbols for different number of users under time-varying multipath channels.展开更多
文摘The infrared absorption method for methane concentration detection is an ideal way to detect methane at present. However, it is difficult to spread this method due to its high cost. In this paper, by using a wideband infrared light emitting di- ode (LED) accompanied with a PIN photo electric diode, a low-cost methane detection system was designed. To overcome the shortcomings caused by the wide working band, a differential light path was designed. By means of a differential ratio algo- rithm, the stability and the accuracy of the system were guaranteed. Finally, the validity of the system with the proposed algo- rithm was verified by the experiment results.
文摘A new pre-column derivation HPLC method with solid-phase extraction to determine captopril in human plasma was established. Derivation products were extracted by a solid-phase extraction method after the reagent, p-a-dibromoacetophenone(p-BPB), was added in the plasma samples. The samples were analyzed in a VP-ODS column with UV-detector. The calibration curve of captopril was linear within the range of 5~1000 ngmL-1 with r=0.9987, the recovery of this method was 98.652.04%, within day and between day RSD were no more than 3.4% and 8.4% respectively. To study the pharmacokinetics and the relative bioavailability of captopril tablets, two formulations of captopril tablets were given to 18 healthy male volunteers according to a randomized 2-way cross-over design with a 1-week washout period. The respective AUC0~6 , Cmax and Tmax values of the two formulations were 424.5125.7 and 439.4113.3 mghL-1; 505.9244.6 and 504.8172.2 mgL-1; 0.6620.181 and 0.5280.176 h. Results from statistics analysis showed that there were no significant difference between the AUC0~6 , Cmax and Tmax values of the two formulations, The relative bioavailability of tablets I with respect to II was 96.114.6% from AUC0~6 measurement. Bioequivalance was observed between the two tablets.
文摘AIM:To compare the diagnostic yield of capsule endoscopy (CE) with that of double-balloon enteroscopy (DBE). METHODS:Pubmed,Embase,Elsevier ScienceDirect,the China Academic Journals Full-text Database,and Cochrane Controlled Trials Register were searched for the trials comparing the yield of CE with that of DBE. Outcome measure was odds ratio (OR) of the yield. Fixed or random model method was used for data analysis. RESULTS:Eight studies (n = 277) which prospectively compared the yield of CE and DBE were collected. The results of meta-analysis indicated that there was no difference between the yield of CE and DBE 170/277 vs 156/277,OR 1.21 (95% CI:0.64-2.29). Based on sub analysis,the yield of CE was significantly higher than that of double-balloon enteroscopy without combination of oral and anal insertion approaches 137/219 vs 110/219,OR 1.67 (95% CI:1.14-2.44),P < 0.01),but not superior to the yield of DBE with combination of the two insertion approaches 26/48 vs 37/48,OR 0.33 (95% CI:0.05-2.21),P > 0.05). A focused meta-analysis of the fully published articles concerning obscure GI bleeding was also performed and showed similar results wherein the yield of CE was significantly higher than that of DBE without combination of oral and anal insertion approaches 118/191 vs 96/191,fixed model:OR 1.61 (95% CI:1.07-2.43),P < 0.05) and the yield of CE was significantly lower than that of DBE by oral and anal combinatory approaches 11/24 vs 21/24,fixed model:OR 0.12 (95% CI:0.03-0.52),P < 0.01). CONCLUSION:With combination of oral and anal approaches,the yield of DBE might be at least as high asthat of CE. Decisions made regarding the initial approach should depend on patient's physical status,technology availability,patient's preferences,and potential for therapeutic endoscopy.
文摘Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.
基金Supported by the National Natural Science Foundation of China (Nos.40706060,60802089)the National High Technology Research and Development Program of China (863 Program) (No.2007AA092102)the Dragon Project (No.5292)
文摘We tested and modified the quasi-analytical algorithm (QAA) using 57 groups of field data collected in the spring of 2003 in the Yellow Sea and East China Sea. The QAA performs well in deriving total absorption coefficients of typical coastal waters. The average percentage difference (APD) is in a range of 13.9%-38.5% for the total absorption coefficient (13.9% at 440 nm), and differences in particle backscattering coefficient bbp(2) are less than 50% (in the case of the updated QAA). To obtain improved results, we modified the QAA by adjusting the empirical relationships. The modified algorithm is then applied to the field data to test its performance. The APDs were 44.7%-46.6% for bbp(λ) and 9.9%-32.8% (9.9% at 555 nm) for the total absorption coefficient. This indicates that the modified QAA derives better results. We also used the modified model to derive phytoplankton pigment absorption (aph) and detritus and CDOM absorption (aug) coefficients. The APDs for aph and a dg at 440 nm are 37.1% and 19.8%. In this paper, we discuss error sources using the measured dataset. More independent field data can improve this algorithm and derive better results.
文摘The use of vehicle- or air-borne Ground Penetrating Synthetic Aperture Radar (GPSAR) to quickly detect landmines over large areas is becoming a trend. However, producing too many false alarms in GPSAR landmine detection is a major challenge in practical applications of GPSAR. Support Vector Machine (SVM), employing structural risk minimization theory, does not need large amounts of training data, which makes it suitable for solving the landmine detection problem. In this paper, a novel SVM with a hypersphere instead of a hyperplane classification boundary is proposed for landmine detection in GPSAR. The HyperSphere-SVM (HS-SVM) can be trained with both landmine and clutter data, or with landmine data only, which are called the two-class HS-SVM and the one-class HS-SVM, respectively. The HS-SVM has better generalization capability than the traditional HyperPlane-SVM (HP-SVM) with respect to varying operating conditions. Quantitative comparisons have been made using real data collected with the rail-GPSAR landmine detection system, which show that both the two-class and the one-class HS-SVMs have better detection performance than the HP-SVM.
文摘AIM:To outline the appropriate diagnostic methods and therapeutic options for acquired bronchobiliary fistula(BBF).METHODS:Literature searches were performed in Medline,EMBASE,PHMC and LWW(January 1980August 2010)using the following keywords:biliobronchial fistula,bronchobiliary fistula,bronchobiliary fistula,biliarybronchial fistula,tracheobiliary fistula,hepatobronchial fistula,bronchopleural fistula,and biliptysis.Further articles were identified through crossreferencing.RESULTS:Sixtyeight cases were collected and reviewed.BBF secondary to tumors(32.3%,22/68),including primary tumors(19.1%,13/68)and hepatic metastases(13.2%,9/68),shared the largest proportion of all cases.Biliptysis was found in all patients,and other symptoms were respiratory symptoms,such as irritating cough,fever(36/68)and jaundice(20/68).Half of the patients were treated by lessinvasive methods such as endoscopic retrograde biliary drainage.Invasive approaches like surgery were used less frequently(41.7%,28/67).The outcome was good at the end of the followup period in 28 cases(range,2 wk to 72 mo),and the recovery rate was 87.7%(57/65).CONCLUSION:The clinical diagnosis of BBF can be established by sputum analysis.Careful assessment of this condition is needed before therapeutic procedure.Invasive approaches should be considered only when noninvasive methods failed.
基金National Natural Science Foundation of China (40975067)973 Program (2009CB421500)+1 种基金CMA Grant GYHY200806029NASA grant NNX07AM97G in U.S.A
文摘In this paper we investigate the impact of the Atmospheric Infra-Red Sounder (AIRS) temperature retrievals on data assimilation and the resulting forecasts using the four-dimensional Local Ensemble Transform Kalman Filter (LETKF) data assimilation scheme and a reduced resolution version of the NCEP Global Forecast System (GFS).Our results indicate that the AIRS temperature retrievals have a significant and consistent positive impact in the Southern Hemispheric extratropics on both analyses and forecasts,which is found not only in the temperature field but also in other variables.In tropics and the Northern Hemispheric extratropics these impacts are smaller,but are still generally positive or neutral.
基金Supported by the Guangxi Natural Science Foundation (No.0731025, No.0731026)the Established Project by Guangxi Education Department (No.200808LX117)
文摘The detection performance is evaluated for our proposed analog multiuser receiver in Ultra-WideBand (UWB) transmitted-reference system. In the presence of dense multipath and multi-access signals,the performance analysis is difficult due to the complicated waveform of received impulse. We develop an approach to analyze the steady-state Signal-to-Interference-plus-Noise (SINR) of the detector output. The multipath-spread impulse is fitted to an exponentially decaying profile in the analysis. A closed-form expression of steady-state SINR is further deduced for the proposed Least Minimum Square (LMS) detector. The analysis is validated by simulations in Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) channel respectively. Based on the theoretical results,the multipath delay spread is employed to determine the optimal width of the integration window of the detector.
文摘Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography (HPLC) for determination. Mobile phase is: V(Methanol): V(Water)=90: 10; determination wavelength is 245 nm; flow rate is 0.8 mL/min. Avermectin is completely separated in 17min, linear range is 5 - 0.3 g/L, correlation coefficient is 0.9997, average recovery rates of Avermectin in milk and beef are respectively 91.20 %- 100.32 % and 89.93 %-99.15 %, the relative standard deviations are respectively less than 7% and 4%. This method is simple, sensitive and accurate, so is suitable for determination of Avermectin residues in milk and beef, and it can meet domestic and foreign testing requirements.
文摘The essence of empirical test of Wagner characteristic in new public management countries' tax revenue is to test the influence of economic growth on tax growth since new public management movement. Under IMF statistical framework, by using E-G two-step method in co-integration test and Granger causality test and empirically testing of the gross tax revenue and classified tax revenue in Australian, Canada, France, America, Britain these five countries, we can find that most indicators in most countries do not confirm to Wagner' s law. With the growth of GDP, tax revenue as a percentage of GDP rises periodically but not permanently. This period can be called the validity period of Wagner' s law in financial scale.
文摘Based on theoretical calculation and Monte Carlo simulation,this paper proposes a new method for the diagnosing of 16.7 MeV high-energy pulse gamma,named "scattering absorption method". The ratio of the sensitivity of high-energy gamma to that of the low-energy background gamma can reach 106 to 108 by this new method. The sensitivity of 16.7 MeV high-energy gamma ranges from 10-21 to 10-16 C·cm2. It's better than the traditional method which is based on the magnetic analyzer and Cherenkov detector on some aspects.
文摘For high resolution radar, the echoes of target come from several points rather than one point as in low resolution radar. In this case the target is called an extended target. This paper presents two CFAR detectors for such a target in non Gaussian clutter, which are CA CFAR and OS CFAR detectors. The detection performances of the two detectors are evaluated.
文摘The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applications. There is an urgent need to develop effective and economically viable alternative treatments to replace current phytosanitary and quarantine practices in order to maintain the competitiveness of US agriculture in domestic and international markets. With the reliable heating block system, the thermal death kinetics for fifth-instar codling moth, Indianmeal moth, and navel orangeworm were determined at a heating rate of 18℃/min. A practical process protocol was developed to control the most heat resistant insect pest, fifth-instar navel orangeworm, in in-shell walnuts using a 27 MHz pilot scale radio frequency (RF) system. RF heating to 55℃ and holding in hot air for at least 5 min resulted in 100% mortality of the fifth-instar navel orangeworm. Rancidity, sensory qualities and shell characteristics were not affected by the treatments. If this method can be economically integrated into the handling process, it should have excellent potential as a disinfestation method for in-shell walnuts.
文摘The scores of grape wine given by wine critics have differences, therefore, for which its credibility differs. Firstly, our paper analysis differences of overall and individual for the two groups of raters. The analysis method is: first check the score whether meets the normal distribution or not by Chi-square and then test whether the mean of the two group's ratings is equal or not, through t-test, to illustrate the differences of the two groups' ratings. Secondly this paper respectively characterizes the credibility of each group's rating with the variance and gray correlation. Both the results are highly consistent on the credibility, so they can support each other. This score comparison method can be further extended to a similar scoring system.
基金This work is supported by the National Natural Science Founda-tion of China (Grant No.10576012)the Specialized ResearchFund for the Doctoral Program of Higher Education of China(Grant No.20040532005)
文摘A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of preceding, modulating and coding, A dark RZ signal is generated simply by using one dual-arm Mach-Zehnder LiNbO3 modulator. We demonstrate experimentally that this optical dark RZ signal can be directly measured by a conventional binary intensity modulation direct detection (IM-DD) receiver. When different values of duty cycles at 2.5 Gbit/s are adjusted, the experimental results show different BER curves and eye diagrams of the optical dark RZ signal.
基金Supported by the National Natural Science Foundation of China (No. 60272079)
文摘An iterative receiver is proposed based on the EM (Expectation-Maximization)algorithm for an OFDM-SDMA (Orthogonal Frequency Division Multiplexing-Space Division Multiple Access) system. By using a few pilots in every OFDM symbol, both channel estimation and multiuser detection can be simultaneously obtained by iteration. The computer simulation results show this receiver can track channel variations and detect multiuser symbols for different number of users under time-varying multipath channels.