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药品抽检收检环节常见问题分析
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作者 李杏芳 胡碧波 +2 位作者 林瑶琪 张昕 何宇峰 《广东化工》 CAS 2024年第15期85-86,103,共3页
目的:汇总药品抽检中收检环节发现的问题,提出改进方法和建议,进一步规范药品收检工作,从而提高收检工作效率。方法:介绍药品收检工作流程,以2019~2023年国家药品收检工作实践为基础,汇总分析样品接收、样品核对、样品受理、样品购买等... 目的:汇总药品抽检中收检环节发现的问题,提出改进方法和建议,进一步规范药品收检工作,从而提高收检工作效率。方法:介绍药品收检工作流程,以2019~2023年国家药品收检工作实践为基础,汇总分析样品接收、样品核对、样品受理、样品购买等多个节点容易出现的问题,提出注意事项。结果与结论:提高抽样队伍和收检人员的知识技能和专业水平,规范收检工作流程,端正工作态度,明确个人职责分工,全面提升抽检工作质量。 展开更多
关键词 药品抽 收检环节 样品接 样品核对 样品受理 样品购买
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药品质量抽查检验的组织、抽样和收检要求新旧对比研究 被引量:6
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作者 刘文 王翀 +1 位作者 朱炯 胡增峣 《中国药事》 CAS 2020年第6期619-624,共6页
目的:加深相关人员对《药品质量抽查检验管理办法》的理解,以有效地落实抽检规定,加强药品监管。方法:对比研究《药品质量抽查检验管理办法》和《药品质量抽查检验管理规定》中组织、抽样和收检要求,分析新增和修订内容的必要性与意义,... 目的:加深相关人员对《药品质量抽查检验管理办法》的理解,以有效地落实抽检规定,加强药品监管。方法:对比研究《药品质量抽查检验管理办法》和《药品质量抽查检验管理规定》中组织、抽样和收检要求,分析新增和修订内容的必要性与意义,提出实施建议。结果与结论:《药品质量抽查检验管理办法》基于药品监管需要,相对于《药品质量抽查检验管理规定》新增和修订的组织、抽样和收检相关内容,对加强抽检管理,提高抽样、收检工作效能,进而打击假冒伪劣药品,防控潜在质量安全隐患具有重要意义。 展开更多
关键词 药品抽 组织 抽样 收检
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药品检验所检品管理问题探讨 被引量:7
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作者 肖羽 曾文珊 《中国药事》 CAS 2015年第10期1036-1040,共5页
目的:为确保检品能够满足检验要求、实验结果具有可追溯性、降低检验风险,探讨科学合理规范地对检品的接收、识别、流转、储存及处置过程各个环节进行严格的控制和有效的管理。方法:通过跟踪检品在药检机构中的流转路径,查找所有环节中... 目的:为确保检品能够满足检验要求、实验结果具有可追溯性、降低检验风险,探讨科学合理规范地对检品的接收、识别、流转、储存及处置过程各个环节进行严格的控制和有效的管理。方法:通过跟踪检品在药检机构中的流转路径,查找所有环节中可能存在的问题,分析现状并结合检品受理、保存等涉及的法律法规,联系实际,阐述和解决需要注意的问题。结果与结论:通过建立并严格执行完整有效的检品管理制度,消除检品管理过程中可能存在的不安全因素和薄弱环节,提出疑难问题的解决方案,使各项工作更加科学有序地进行。 展开更多
关键词 品管理 收检 留样 标识
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Methane concentration detection system based on differential infrared absorption 被引量:1
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作者 宋林丽 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第2期193-196,共4页
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
关键词 methane detection infrared absorption differential light path differential ratio algorithm
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HPLC Determination of Captopril in Human Plasma with Pre-column Derivation and Solid-phase Extraction and Studies on Its Pharmacokinetic and Relative Bioavailability
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作者 丁劲松 张毕奎 +2 位作者 李焕德 刘义钊 邓航 《Journal of Chinese Pharmaceutical Sciences》 CAS 2001年第3期152-156,共5页
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
关键词 CAPTOPRIL Solid-Phase Extraction HPLC PHARMACOKINETICS BIOAVAILABILITY
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A meta-analysis of the yield of capsule endoscopy compared to double-balloon enteroscopy in patients with small bowel diseases 被引量:26
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作者 Xiang Chen Zhi-Hua Ran Jin-Lu Tong 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第32期4372-4378,共7页
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
关键词 Capsule endoscopy Double balloon enteroscopy YIELD META-ANALYSIS
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Gel Filtration Chromatography Combined with Bradford Method for Determination of Total Residual Protein in Ferment Antibiotics 被引量:6
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作者 许明哲 马仕洪 胡昌勤 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第4期262-266,共5页
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
关键词 Gel filtration chromatography bradford assay residual protein ferment antibiotics lincomycin hydrochloride
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Retrieval of inherent optical properties of the Yellow Sea and East China Sea using a quasi-analytical algorithm 被引量:7
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作者 青松 唐军武 +1 位作者 崔廷伟 张杰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第1期33-45,共13页
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
关键词 inherent optical properties Yellow Sea and the East China Sea quasi-analytical algorithm
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A NOVEL SVM FOR GROUND PENETRATING SYNTHETIC APERTURE RADAR LANDMINE DETECTION 被引量:5
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作者 Jin Tian Zhou Zhimin Song Qian Chang Wenge 《Journal of Electronics(China)》 2008年第1期70-75,共6页
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
关键词 Synthetic Aperture Radar (SAR) Ground penetrating Support Vector Machine (SVM) Landmine detection
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Management of acquired bronchobiliary fistula:A systematic literature review of 68 cases published in 30 years 被引量:31
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作者 Guan-Qun Liao Hao Wang Guang-Yong Zhu Kai-Bin Zhu Fu-Xin Lv Sheng Tai 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第33期3842-3849,共8页
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
关键词 Bronchobiliary fistula Digestive endoscopy Endoscopic retrograde cholangiopancreatography Magnetic resonance cholangio Percutaneous transhepatic cholangio Iatrogenic damage Congenital diaphragma defects Hepatobiliary iminodiacetic acid scan
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IMPROVED ANALYSES AND FORECASTS WITH AIRS TEMPERATURE RETRIEVALS USING THE LOCAL ENSEMBLE TRANSFORM KALMAN FILTER 被引量:3
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作者 李泓 柳俊杰 +3 位作者 艾莲娜.费尔蒂歌 尤金尼亚.康奈 埃瑞克.考斯特里奇 伊斯万.苏纽 《Journal of Tropical Meteorology》 SCIE 2011年第1期43-49,共7页
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
关键词 AIRS retrievals data assimilation LETKF observation impact
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ON THE PERFORMANCE OF ANALOG MULTIUSER DETECTION IN ULTRA-WIDEBAND TRANSMITTED-REFERENCE SYSTEM
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作者 Ge Wei Zheng Lin Qiu Hongbing 《Journal of Electronics(China)》 2009年第6期798-803,共6页
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
关键词 Multiuser detection Minimum Mean Square Error (MMSE) Transmitted reference Ultra-WideBand (UWB)
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SPE-HPLC Method for the Determination of Avermectin Residues in Milk and Beef
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作者 GAO Xu-Dong HE Xin-Rui +3 位作者 WU Zhong-Yong CHEN Shi-En YE Yong-Li MA Zhong-Ren 《International Journal of Technology Management》 2015年第11期67-70,共4页
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
关键词 HPLC BEEF MILK AVERMECTIN
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Empirical Test of Wagner's law in New Public Management Countries' Tax Revenue
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作者 Hao Xiao-wei Liu Hua-ping 《International Journal of Technology Management》 2015年第11期87-92,共6页
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
关键词 New Public Management Wagner' s law Tax Revenue Validity Period of Wagner' s law
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Scattering-absorbing method for the detection of 16.7 MeV high-energy pulse gamma
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作者 Tan Xinjian Ouyang Xiaoping Wang Qunshu 《Engineering Sciences》 EI 2009年第3期55-58,共4页
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
关键词 high-energy gamma Cherenkov detector scattering absorption method
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CFAR DETECTORS FOR HIGH RESOLUTION RADAR IN NON-GAUSSIAN CLUTTER
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作者 唐劲松 朱兆达 +1 位作者 蒋兴舟 李江南 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1998年第2期98-102,共5页
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
关键词 high resolution radar signal detection constant false alarm receivers non Gaussian spherical invariant random process(SIRP)
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Science Letters: Radio frequency heating: a potential method for post-harvest pest control in nuts and dry products 被引量:3
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作者 WANGShao-jin TANGJu-ming 《Journal of Zhejiang University Science》 CSCD 2004年第10期1169-1174,共6页
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
关键词 DISINFESTATION Heat NUT POSTHARVEST Radio frequency
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Discussions about the differences and credibility on grape wine scoring
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作者 ZHENG Wei-shuo 《International Journal of Technology Management》 2013年第4期33-36,共4页
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
关键词 CHI-SQUARE DIFFERENCES CREDIBILITY gray correlation
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Novel transmitter of dark RZ signal based on external modulator
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作者 SHAO Yu-feng CHEN Lin WEN Shuang-chun 《Optoelectronics Letters》 EI 2007年第2期109-111,共3页
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
关键词 外调制器 光暗RZ信号 发射机 直接测式光接
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ITERATIVE RECEIVER FOR OFDM-SDMA SYSTEM
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作者 ShanShuwei LuoHanwen SongWentao 《Journal of Electronics(China)》 2004年第5期359-365,共7页
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
关键词 Orthogonal Frequency Division Multiplexing (OFDM) Space Division Multiple Access (SDMA) Expectation-Maximization(EM) algorithm Channel estimation Multiuser detection
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