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Chinatown's Community Organizations Reflected in Louis Chu's Eat a Bowl of Tea
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作者 王琼 《海外英语》 2019年第4期206-207,共2页
Louis Chu's novel Eat a Bowl of Tea(1961) is widely recognized as a pioneer masterpiece in Chinese American litera-ture. It pictures the bachelor society of Chinatown in New York City after the Second World War. S... Louis Chu's novel Eat a Bowl of Tea(1961) is widely recognized as a pioneer masterpiece in Chinese American litera-ture. It pictures the bachelor society of Chinatown in New York City after the Second World War. Several characteristics of China-town's community organizations are reflected in this novel: kinship-based; responsible for protecting and caring for the members;led by commercial elites; rule of man, rather than rule of law. It offers us a precious chance to take a glimpse of the Chinese-Ameri-can society in post-World War II era. 展开更多
关键词 Chinese AMERICAN LITERATURE EAT a BOWL of TEA Chinatown COMMUNITY Organizations Louis chu
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Oesophageal Mycosis: Epidemiological and Clinical Aspects and Risk Factors for Occurrence in the Digestive Endoscopy Unit of the Donka National Hospital, Conakry CHU
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作者 Diallo Mamadou Sarifou Youssouf Oumarou +7 位作者 Yaogo Abdoulatif Diallo Kadiatou Diallo Djéinabou Wann Thierno Amadou Bah Mamadou Lamine Yaya Diakhaby Mamadou Kanté Mamadou Aliou Sylla Djibril 《Open Journal of Gastroenterology》 CAS 2024年第2期31-40,共10页
Introduction: Oesophageal mycosis (OM) is one of the most common opportunistic infections in patients infected with HIV (Human Immunodeficiency Virus). However, this condition is increasingly observed in immunocompete... Introduction: Oesophageal mycosis (OM) is one of the most common opportunistic infections in patients infected with HIV (Human Immunodeficiency Virus). However, this condition is increasingly observed in immunocompetent subjects. The aim of this study was to determine the endoscopic prevalence, clinical characteristics and risk factors for the occurrence of oesophageal mycosis in our department. Patients and Method: This was a prospective cross-sectional study of all patients who underwent oeso-gastroduodenal fibroscopy during the period from 1<sup>st </sup>January to 31<sup>st</sup> December 2022, i.e. one year, at the digestive endoscopy unit of the hepato-gastroenterology department of the Donka CHU national hospital in Conakry. All patients found to have oesophageal mycosis by FOGD were included. The endoscopy was performed using appropriate equipment: A Fujinon 4400 video endoscopy column;Three Fujinon EG 590 video gastroscopes;A hoover;Data were collected using a pre-established survey form and analysed using Epi info software version 6.0.4;Pearson’s Chi2 test as a test of independence and the exact 5% threshold ficher test. Results: Out of 1343 upper gastrointestinal endoscopies performed, 107 cases of oesophageal mycosis were found, representing a prevalence of 7.96%. The mean age was 40 years, with a male predominance of 55.42%. The sex ratio M/F was 1.24. The 45 and over age group was the most affected, with a prevalence of 40.43%, followed by the [35 - 45] age group, with a prevalence of 22.43%. Clinical symptoms were dominated by epigastralgia in 74.76% of cases, followed by odynophagia in 37.38% of cases, nausea and vomiting in 28.03% of cases, and pyrosis in 26.16% of cases. Oesophageal mycosis without oesophagitis was the most common endoscopic finding in 70% of cases. The main associated endoscopic lesions were erythemato-erosive and congestive gastropathy in 28.03% of cases, peptic oesophagitis (9.34%) and gastric ulcer (5.60%). The main risk factors found were positive HIV serology in 39.25% of cases, and diabetes in 24.30% of cases, with a statistically significant relationship of 0.02 and 0.01 respectively. Conclusion: Oesophageal mycosis is the most common opportunistic infection in patients with impaired cellular immunity. The prevalence of oesophageal mycosis in our series was 7.96%. This study enabled us to identify the main risk factors for the occurrence of oesophageal mycosis. Our country needs to step up its programme to combat and prevent immunodeficiency diseases, particularly HIV and diabetes. 展开更多
关键词 ENDOSCOPY chu Conakry Risk Factors IMMUNOSUPPRESSION Oesophageal Mycosis
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Evaluation of Hepatic Fibrosis and Hepatic Steatosis by Pulse Elastography (FIBROSCAN/CAP) in Asymptomatic Patients about 170 Cases at the Donka CHU National Hospital in Conakry
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作者 Mamadou Sarifou Diallo Oumarou Youssouf +8 位作者 Abdoulatif Yaogo Djenabou Diallo Kadiatou Diallo Thierno Amadou Wann Ahmed Tidiane Diallo Mamadou Lamine Yaya Bah Mamdou Diakhaby Mamadou Aliou Kanté Djibril Sylla 《Open Journal of Gastroenterology》 CAS 2024年第4期125-138,共14页
Introduction: Fibroscan is a recent, non-invasive and non-irradiating diagnostic method. It is based on the principle of ultrasound, which enables liver tissue elasticity to be quantified using a probe, and fibrosis t... Introduction: Fibroscan is a recent, non-invasive and non-irradiating diagnostic method. It is based on the principle of ultrasound, which enables liver tissue elasticity to be quantified using a probe, and fibrosis to be assessed. Fibroscan measures both elasticity correlated with hepatic fibrosis and CAP correlated with steatosis. The aim of this study was to evaluate hepatic fibrosis and steatosis using pulse elastometry (Fibroscan/CAP). Methods: This was a descriptive and analytical cross-sectional study in which 170 patients were included. It was conducted from October 1 2021 to December 31 2023, i.e. 27 months, in an outpatient clinic in the hepato-gastroenterology department of the Donka national hospital of the CHU Conakry. Results: Of the 170 patients identified, 87 were male (51%) and 83 female (49%), giving a M/F sex ratio of 1.04. The average age of our patients was 40. The 30 - 50 age group was the most affected, with a frequency of 58.23% (n = 99), followed by the 50 age group with a frequency of 29.41% (n = 50). Hepatomegaly, steatotic liver on ultrasonography, transaminase elevation and obesity were the main indications, respectively: (21.76%), (17.65%), (14.71%), and (13.53%). The examinations were requested by hepatogastroenterologists (47.06%), diabetologists (35.88%) and general practitioners (29%). Of the 170 patients, 100 patients (58.82%) had no significant fibrosis F0F1, 39 (22.94%) had moderate fibrosis F2, 20 patients (11.76%) had severe fibrosis F3 and 11 patients (6.47%) had fibrosis F4. Hepatic steatosis: 62 patients (36.47%) had no S0 steatosis;29.41% had S1 steatosis, 20% had S2 steatosis and 24 patients (14.11%) had S3 steatosis. Abdominal ultrasound revealed a normal liver in 67.05% of patients, hepatic steatosis in 29.41% and non-decompensated cirrhosis in 6 cases. Thus, 108 patients had the parameters required to calculate the Fatty Liver Index (FLI), steatosis was present in 20% of our patients, while 29.41% had an undetermined status and 24 14.11% had a normal FLI. Conclusion: Identifying subjects at risk of metabolic steatopathy, diagnosing and managing these patients is a public health issue and one of the future challenges of hepato-gastroenterology. Fibroscan is an increasingly popular screening tool for hepatic fibrosis and steatosis. The fight against obesity must be a priority. 展开更多
关键词 Cirrhosis Fibrosis Fibroscan/CAP Non-Alcoholic Hepatic Steatosis STEATOSIS chu Conakry
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Prevalence of Refractive Errors among School Children Aged 5 to 15 Years Old at CHU-IOTA
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作者 Kadiatou Ba Aichata Tall +19 位作者 Mory Coulibaly Cheick Sogodogo Zoumana Bagayogo Aoua Ibrahim Toure Ousmane Toure Brainima Coulibaly Fatoumata Tata Sidibe Aly Konipo Roucky Sangare Seydou Diallo Moro Sidibe Oumar Diallo Assiatou Simaga Gounon Saye Modibo Sissoko Mamadou Kole Sidibe Sidi Diarra Nouhoum Guirou Abdoulaye Napo Adama Guindo 《Surgical Science》 2024年第8期480-491,共12页
Introduction: Undetected refractive errors constitute a health problem among school children who cannot take advantage of educational opportunities. The authors studied the prevalence of refractive errors in school ch... Introduction: Undetected refractive errors constitute a health problem among school children who cannot take advantage of educational opportunities. The authors studied the prevalence of refractive errors in school children aged 5 to 15 at CHU-IOTA. Patients and Method: This is a prospective, descriptive cross-sectional study carried out in the ophthalmic-pediatrics department of CHU-IOTA, from October to November 2023. Results: We received 340 school children aged 5 to 15, among whom 111 presented ametropia, i.e. a prevalence of 32.65%. The average age was 11.42 ± 2.75 years and a sex ratio of 0.59. The average visual acuity was 4/10 (range 1/10 and 10/10). We found refractive defects: astigmatism 73.87%, hyperopia 23.87% of cases and myopia 2.25%. The decline in distance visual acuity was the most common functional sign. Ocular abnormalities associated with ametropia were dominated by allergic conjunctivitis (26.13%) and papillary excavation (6.31%) in astigmatics;allergic conjunctivitis (9.01%) and papillary excavation (7.20%) in hyperopic patients;turbid vitreous (0.90%), myopic choroidosis (0.45%) and allergic conjunctivitis (0.45%) in myopes. Conclusion: Refractive errors constitute a reality and a major public health problem among school children. 展开更多
关键词 Refractive Errors PREVALENCE CHILD chu-IOTA
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Maternal Death before Admission to the Sylvanus Olympio University Hospital Center (CHU SO): Epidemiological and Etiological Aspects
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作者 Baguilane Douaguibe Sitou Togbonou +1 位作者 Dédé Régina Ajavon Pankéyédou Tongou 《Advances in Reproductive Sciences》 CAS 2024年第4期205-212,共8页
Background: In Togo, the maternal mortality rate in 2017 was estimated at 396/100,000 live births. Maternal death before admission is an increasingly growing phenomenon in the gynecology-obstetrics clinic of the CHU S... Background: In Togo, the maternal mortality rate in 2017 was estimated at 396/100,000 live births. Maternal death before admission is an increasingly growing phenomenon in the gynecology-obstetrics clinic of the CHU SO. No epidemiological data is available on the subject. Objective: Determine the epidemiological and etiological profiles of a pregnant, parturient, or woman who has given birth dead before or within 10 minutes of her admission. Methods: This was a descriptive cross-sectional study from January 1, 2014, to December 31, 2021. All maternal deaths occurring before admission and within 10 minutes of admission to the clinic were included in the study of gynecology and obstetrics at CHU SO. The data were processed by Epi info version 7 software. Results: In total, 654 maternal deaths, including 153 maternal deaths before admission, were recorded, corresponding to 23.4% of all maternal deaths. The median age was 30.2 years. 37.2% of women were uneducated. 41.2% were resellers. 79.1% of women were cohabiting. 47.1% of women had performed less than 3 ANC. 43.8% of the women who died had completed their ANC in a medical center. 54.3% by a midwife, 37.3% by unqualified personnel. 62.7% of deaths occurred postpartum and 36.3% during pregnancy. 79.1% were referrals. 88.9% of the women who died arrived in a non-medical taxi car. Among the 57 patients who died during their pregnancy, 40.3% were carrying a pregnancy of 28 to 36 weeks, and 36.3% were full-term pregnancies. Among the 96 women who died postpartum, 93.3% had given birth vaginally. Among the 121 referrals, 34.7% came from a birthing center, 56.2% were referred by a state midwife and 30.6% by unqualified personnel;46.3% were referred without a reference form, 94.3% were referred without venous access. In 10.7%, the reason for evacuation was bleeding from the delivery, with an average evacuation time of one-hour 5minutes. 60.3% of women who died had an evacuation delay of more than one hour. 94.8% of patients died of direct obstetric causes, including immediate postpartum hemorrhage in 60.1% of cases. Conclusion: Deaths before admission constitute an increasingly growing problem at CHU SO. A late referral is a determining factor in maternal deaths before admission. 展开更多
关键词 Maternal Death Before Admission REFERENCE chu SO
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Chu空间下的粗糙集与证据理论结合进行内燃机诊断 被引量:3
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作者 宋立军 胡政 +1 位作者 杨拥民 温熙森 《内燃机学报》 EI CAS CSCD 北大核心 2007年第3期271-276,共6页
证据理论是处理不确定性问题的有效工具,但其依赖专家知识提供证据,并要求各证据体相互独立,致使实际应用困难。借助粗糙集理论,剔除冗余成分,应可克服证据获取主观性和证据体相关性的缺陷。Chu空间理论提供了一种通用的代数框架,是用... 证据理论是处理不确定性问题的有效工具,但其依赖专家知识提供证据,并要求各证据体相互独立,致使实际应用困难。借助粗糙集理论,剔除冗余成分,应可克服证据获取主观性和证据体相关性的缺陷。Chu空间理论提供了一种通用的代数框架,是用于诊断信息融合的一种新方法;针对此问题,研究了Chu空间表达下的粗糙集与证据理论可集成性,并提出了基于二者集成的故障诊断推理策略。柴油机的实际诊断结果验证了将粗糙集与证据理论相结合进行故障诊断的良好效果。 展开更多
关键词 chu空间 粗糙集 证据理论 故障诊断
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产虾青素菌株CHU-R的鉴定及其培养条件优化 被引量:5
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作者 陈敏纯 廖美德 《西北农林科技大学学报(自然科学版)》 CSCD 北大核心 2012年第6期153-160,共8页
【目的】对产虾青素菌株CHU-R进行鉴定,并对其培养条件进行优化,为虾青素的规模化生产奠定基础。【方法】对产虾青素菌株CHU-R进行形态、生理生化及16SrDNA序列鉴定;以菌株CHU-R菌体生物量和虾青素产量为考察指标,对CHU-R菌株的碳源、... 【目的】对产虾青素菌株CHU-R进行鉴定,并对其培养条件进行优化,为虾青素的规模化生产奠定基础。【方法】对产虾青素菌株CHU-R进行形态、生理生化及16SrDNA序列鉴定;以菌株CHU-R菌体生物量和虾青素产量为考察指标,对CHU-R菌株的碳源、氮源、微量元素等培养基成分及温度、初始pH值、接种量、装液量、蔗糖含量等培养条件进行优化,并对优化条件进行正交试验,确定最佳的培养基组分。【结果】CHU-R为乳杆菌。CHU-R菌株培养基中的适宜氮源为铵盐和尿素;碳源为蔗糖和葡萄糖;培养基中缺少Fe2+不利于菌体生长和虾青素积累。CHU-R的适宜培养条件为:接种量≤50mL/L,装液量50mL/L,初始pH值7.0~7.5,发酵温度26~30℃,发酵时间48~72h,在此条件下,菌株CHU-R菌体生物量和虾青素产量均较高。【结论】乳杆菌CHU-R在优化培养条件下能够得到产量较高的虾青素,具有较好的应用潜力和经济价值。 展开更多
关键词 乳杆菌 chu-R菌株 虾青素
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CHU-R菌株虾青素稳定性及抗氧化活性研究 被引量:3
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作者 蹇华丽 宋光均 +1 位作者 陈敏纯 廖美德 《中国食品添加剂》 CAS 北大核心 2014年第2期114-119,共6页
通过对CHU-R虾青素稳定性进行测定,表明虾青素对短时受热有较好的稳定性,对光和氧非常敏感;有机溶剂中极性最小的石油醚有利于虾青素的保存,而极性最大的丙酮则十分不利于色素的保存,色拉油能很好的保护色素,因其较好地隔离了空气中的氧... 通过对CHU-R虾青素稳定性进行测定,表明虾青素对短时受热有较好的稳定性,对光和氧非常敏感;有机溶剂中极性最小的石油醚有利于虾青素的保存,而极性最大的丙酮则十分不利于色素的保存,色拉油能很好的保护色素,因其较好地隔离了空气中的氧,起到了一定的屏蔽作用。采用ORAC分析法对CHU-R虾青素进行抗氧化活性测定,结果表明CHU-R虾青素具有良好的抗氧化能力,平均抗氧化活性为13.80U/mg,且其抗氧化能力与浓度成正相关,通过CHU-R色素对鱼藤酮的光保护实验得出,CHU-R虾青素对鱼藤酮具有良好的保护性能。 展开更多
关键词 乳杆菌 chu-R菌株 虾青素 稳定性 抗氧化活性
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TD-LTE系统中Zadoff-Chu序列的研究与DSP实现 被引量:2
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作者 陈发堂 吴增顺 《电子技术应用》 北大核心 2012年第3期41-43,共3页
通过对Zadoff-Chu(ZC)序列生成算法的分析及理论推导,提出了一种快速、有效的Zadoff-Chu序列生成的DSP实现方案。该方案已经在TMS320C64xDSP中实现。通过在CCS3.3中运行程序,验证了方案的可行性和高效性。该方案在LTE-TDD无线综合测试... 通过对Zadoff-Chu(ZC)序列生成算法的分析及理论推导,提出了一种快速、有效的Zadoff-Chu序列生成的DSP实现方案。该方案已经在TMS320C64xDSP中实现。通过在CCS3.3中运行程序,验证了方案的可行性和高效性。该方案在LTE-TDD无线综合测试仪表的开发中已经得到应用。 展开更多
关键词 LTE系统 Zadoff—chu序列 DSP实现
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Zadoff-Chu序列的内插算法
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作者 刘月亮 蒋宇中 苏凯 《海军工程大学学报》 CAS 北大核心 2012年第1期91-96,共6页
脉冲压缩体制斜向短波信道探测主要利用Zadoff-Chu序列良好的周期自相关特性进行相关检测。为使Zadoff-Chu序列的频谱特性与信道探测收发信机的要求相匹配,提出一种适合Zadoff-Chu序列的FDI内插算法,以改善其频谱特性,并与一般内插算法... 脉冲压缩体制斜向短波信道探测主要利用Zadoff-Chu序列良好的周期自相关特性进行相关检测。为使Zadoff-Chu序列的频谱特性与信道探测收发信机的要求相匹配,提出一种适合Zadoff-Chu序列的FDI内插算法,以改善其频谱特性,并与一般内插算法内插后的序列频谱进行比较。仿真结果表明:采用FDI内插算法插值后序列的频谱滚降更快,且几乎没有旁瓣,能量十分集中,确认了FDI内插算法的优越性;在接收端,通过理论推导给出了一种实现采用FDI算法内插后的序列最佳抽取的方法。计算和仿真结果验证了该方法的有效性。 展开更多
关键词 短波 ZADOFF-chu序列 周期自相关 内插 抽取
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毛细管气相色谱法测定CHU-9126中有机溶剂残留量
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作者 吴小英 李慧义 +2 位作者 张启明 张尊健 田颂九 《中国药事》 CAS 2006年第12期744-745,771,共3页
建立CHU-9126中3种有机溶剂残留量的测定方法。使用毛细管气相色谱仪,采用DB-624毛细管色谱柱(94%二甲基聚硅氧烷和6%氰丙基苯聚硅氧烷);柱温70℃,保持3分钟;以3℃·min-1的速度升温至90℃,保持7分钟;以20℃·min-1的速度升温至... 建立CHU-9126中3种有机溶剂残留量的测定方法。使用毛细管气相色谱仪,采用DB-624毛细管色谱柱(94%二甲基聚硅氧烷和6%氰丙基苯聚硅氧烷);柱温70℃,保持3分钟;以3℃·min-1的速度升温至90℃,保持7分钟;以20℃·min-1的速度升温至220℃,保持3分钟。以氮气为载气,流速为2ml·min-1;FID检测器。乙醇,四氢呋喃和N,N-二甲基甲酰胺线性关系良好;平均回收率分别为99·9%,100·3%,99·6%;检出限分别为0·12ng,0·10ng,0·28ng。本方法简便,灵敏度高,重复性好,结果准确,适合于CHU-9126中有机溶剂残留量的测定。 展开更多
关键词 chu-9126 毛细管气相色谱法 有机溶剂残留
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基于补零的Zadoff-Chu序列检测算法
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作者 刘马飞 曾学文 倪宏 《计算机工程》 CAS CSCD 北大核心 2011年第16期14-16,20,共4页
介绍单载波频域均衡系统的随机接入方案,提出一种基于补零扩展的Zadoff-Chu序列的前导检测算法。使用素数Zadoff-Chu序列作为用户签名,接收端采用基于时域补零扩展的频域检测方法进行前导检测。仿真结果表明,与传统时域检测算法相比,该... 介绍单载波频域均衡系统的随机接入方案,提出一种基于补零扩展的Zadoff-Chu序列的前导检测算法。使用素数Zadoff-Chu序列作为用户签名,接收端采用基于时域补零扩展的频域检测方法进行前导检测。仿真结果表明,与传统时域检测算法相比,该算法能在保证检测效果的同时,降低90%计算复杂度。 展开更多
关键词 随机接入 ZADOFF-chu序列 前导检测 频域检测 补零
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“屈原赋二十五篇”到刘向《楚辞》成书的“聚合之势”考论——兼说今本《楚辞》篇次的来源之二
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作者 谢天鹏 《三峡大学学报(人文社会科学版)》 2025年第1期18-23,116,共7页
从屈原《离骚》化用自己《抽思》《涉江》《天问》《远游》《思美人》《惜往日》诸篇,以及宋玉、贾谊、司马迁、东方朔或化用或论及屈作分别达今存七卷中之五卷、六卷、四卷、五卷等情况看,一个共25篇的“屈原集”很可能早已存在,甚至... 从屈原《离骚》化用自己《抽思》《涉江》《天问》《远游》《思美人》《惜往日》诸篇,以及宋玉、贾谊、司马迁、东方朔或化用或论及屈作分别达今存七卷中之五卷、六卷、四卷、五卷等情况看,一个共25篇的“屈原集”很可能早已存在,甚至就是屈原自己所编。再从司马迁《屈原列传》、东方朔《七谏》看,今存《楚辞》中宋玉等人的拟屈之作也已围绕着屈原及其作品形成了一个“关系网”。因此,刘向编《楚辞》应是基于这样一个“屈原集”加“关系网”,合并、落实、调适而成的。就其“调适”而言,他主要受了司马迁影响,一是依循“时间”标准排列篇次,二是依据“悲其志”主旨进行再选拔;此外,他还引入了“代屈原设言”的写作标准。 展开更多
关键词 屈原 《楚辞》 司马迁 刘向
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基于Zadoff-Chu序列的移动数字电视接收系统频偏估计算法
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作者 王义君 梅禹珊 宫玉琳 《长春理工大学学报(自然科学版)》 2015年第1期148-151,157,共5页
针对移动数字电视接收系统频偏估计算法存在的频偏估计均方差和误码率高等问题,提出了一种基于Zadoff-Chu(ZC)序列频偏估计算法。首先通过建立信号模型,利用仿真分析了载波频率偏差对接收系统影响;其次,信标结构中的两个同步信号以半周... 针对移动数字电视接收系统频偏估计算法存在的频偏估计均方差和误码率高等问题,提出了一种基于Zadoff-Chu(ZC)序列频偏估计算法。首先通过建立信号模型,利用仿真分析了载波频率偏差对接收系统影响;其次,信标结构中的两个同步信号以半周期形式选择ZC序列,1个导频符号序列由2个ZC序列构成。因此,接收端接收的2个符号是完全相同的ZC序列,通过对1个ZC序列半周期进行自相关运算并计算频偏值,即可以完成对整个周期符号的频偏估计。仿真结果表明,相比于其它算法,频偏估计均方差可降低20~30%,增益提升约2d B。 展开更多
关键词 通信技术 同步算法 频偏估计 ZADOFF-chu序列 半周期
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《九月九日忆山东兄弟》中“登高处”的两种停顿方式辨析
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作者 张若菲 《语言与文化研究》 2025年第1期65-68,共4页
部编教材与教科版小学语文教材都将《九月九日忆山东兄弟》中“登高”看作一个动宾短语,作为一个词条来解释,即“登高处”的停顿方式当作“登高/处”,但同时还有很多现代注释将“登高处”作为一个词条,又有偏正结构“登高的地方”和动... 部编教材与教科版小学语文教材都将《九月九日忆山东兄弟》中“登高”看作一个动宾短语,作为一个词条来解释,即“登高处”的停顿方式当作“登高/处”,但同时还有很多现代注释将“登高处”作为一个词条,又有偏正结构“登高的地方”和动宾结构“登上高处”两种释义,“登高的地方”停顿方式是“登高/处”“登上高处”的停顿方式是“登/高处”。小学语文教材“登高/处”的停顿方式既存在语义的严谨性,也符合诗歌的节律,也更能体现诗意。 展开更多
关键词 《九月九日忆山东兄弟》 登高处 停顿 辨析
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利用Zadoff-Chu序列降低DCO-OFDM可见光系统的峰均比
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作者 燕慧英 高雅 《东莞理工学院学报》 2020年第5期20-24,共5页
为了降低直流偏置光正交频分复用(DCO-OFDM)可见光系统具有的高峰均比,对传统的部分传输序列(PTS)算法进行了改进,提出了基于Zadoff-Chu序列的PST改进算法。该算法的基本思路是先利用Zadoff-Chu序列构建一个正交的预编码矩阵,然后根据... 为了降低直流偏置光正交频分复用(DCO-OFDM)可见光系统具有的高峰均比,对传统的部分传输序列(PTS)算法进行了改进,提出了基于Zadoff-Chu序列的PST改进算法。该算法的基本思路是先利用Zadoff-Chu序列构建一个正交的预编码矩阵,然后根据传统的PTS算法将DCO-OFDM信号分割成互不相交的子块,接着将各个子块与预编码矩阵相乘,通过降低每个子块的自相关性达到降低DCO-OFDM可见光系统峰均比的目的。仿真结果表明,基于Zadoff-Chu序列的PTS改进算法明显降低了DCO-OFDM可见光系统的峰均比,达到了预期的效果。 展开更多
关键词 峰均比 部分传输序列:Zadoff-chu序列
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CHU-R菌株产虾青素的发酵工艺研究 被引量:4
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作者 谭颖嫦 廖美德 +1 位作者 秦鹏 夏枫耿 《现代食品科技》 EI CAS 北大核心 2012年第3期289-291,296,共4页
本文通过对获得的虾青素产生菌CHU-R进行最佳培养基、培养温度、接种量、初始pH等发酵工艺参数的优化研究,得到CHU-R菌产虾青素的最佳培养基为:6%蔗糖、1%糖蜜、0.5%硫酸铵、0.3%NazHPO4、0.05%KI、0.05%MgSO4·7H2O;... 本文通过对获得的虾青素产生菌CHU-R进行最佳培养基、培养温度、接种量、初始pH等发酵工艺参数的优化研究,得到CHU-R菌产虾青素的最佳培养基为:6%蔗糖、1%糖蜜、0.5%硫酸铵、0.3%NazHPO4、0.05%KI、0.05%MgSO4·7H2O;50L罐最适发酵工艺条件为:温度28℃,通风量1:0.1加.15(V/V/min)、初始转速120r/min、罐压0.054).08MPa、装液量30L、初始pH6.8-7.0、接种量6%,发酵过程维持溶氧量在40-60%之间。由此得到的虾青素含量近达23mg/g干菌体重。 展开更多
关键词 chu-R 虾青素 发酵 乳杆菌
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基于Zadoff-Chu序列的OFDM精确定时同步算法 被引量:9
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作者 周平 周思远 +1 位作者 刘思含 吴玉成 《信息技术》 2019年第1期1-5,共5页
针对OFDM系统在多径衰落环境下通过能量大小定时而产生定时误差的问题,文中提出了一种基于Zadoff-Chu序列的第一径检测算法,利用序列相关性得到信道冲激响应估计值,此外分析了残留频偏对定时同步的影响,并通过改进自适应门限抑制残留频... 针对OFDM系统在多径衰落环境下通过能量大小定时而产生定时误差的问题,文中提出了一种基于Zadoff-Chu序列的第一径检测算法,利用序列相关性得到信道冲激响应估计值,此外分析了残留频偏对定时同步的影响,并通过改进自适应门限抑制残留频偏来判定准确定时位置。算法在时域完成,实现简单且运算量小。通过仿真对比其他算法可以看出,文中所提算法在高速移动多径环境中第一径检测概率高、均方误差小,特别是低信噪比下仍能准确同步。 展开更多
关键词 OFDM 定时同步 ZADOFF-chu序列 多径衰落信道
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补料工艺对乳杆菌CHU-R产虾青素的影响 被引量:2
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作者 何俊杰 宋光均 +1 位作者 邓慧萍 蹇华丽 《食品与发酵工业》 CAS CSCD 北大核心 2019年第12期146-151,共6页
天然虾青素具有极强的抗氧化性,为满足虾青素的市场需求、实现其大规模工业化生产,有必要研发一种简单高效的发酵工艺。采用产虾青素乳杆菌CHU-R为供试菌株,在5L反应器中以分批发酵为对照,分别进行以过程pH、总糖消耗、过程DO为补糖依... 天然虾青素具有极强的抗氧化性,为满足虾青素的市场需求、实现其大规模工业化生产,有必要研发一种简单高效的发酵工艺。采用产虾青素乳杆菌CHU-R为供试菌株,在5L反应器中以分批发酵为对照,分别进行以过程pH、总糖消耗、过程DO为补糖依据的补料分批发酵。相对分批发酵,3种补料方式均可显著提高植物乳杆菌CHU-R的生物量和虾青素积累量,其中以过程DO为补糖依据的补料分批发酵中乳杆菌CHU-R的生物量和虾青素积累量可达到最高,分别为39.73g/L及1.88g/L,比对照分别提高2.6和2.8倍。该发酵全程保持较高的溶氧量和较低却足够的糖浓度,有利于乳杆菌CHU-R生长和虾青素积累,同时可为虾青素工业化生产提供数据参考和理论指导。 展开更多
关键词 乳杆菌chu-R 虾青素 补料工艺
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基于Zadoff-Chu序列的单载波抗截获波形设计 被引量:1
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作者 梁仕杰 孙志刚 王天雄 《电子测量技术》 2020年第21期142-148,共7页
单载波系统中,采用相同的UW字进行捕获、多普勒估计和信道估计。目前采用相同的UW字容易被非合作方进行盲参数估计和捕获,危及信号的安全性和私密性。为了防止电子对抗中的窃听攻击,保护信号的安全性和私密性,设计针对单载波系统的抗截... 单载波系统中,采用相同的UW字进行捕获、多普勒估计和信道估计。目前采用相同的UW字容易被非合作方进行盲参数估计和捕获,危及信号的安全性和私密性。为了防止电子对抗中的窃听攻击,保护信号的安全性和私密性,设计针对单载波系统的抗截获波形。首先进行UW字的选择,选择符合进行捕获、多普勒估计和信道估计的UW字。设计新的帧格式,使其具有抗截获能力并保持SC-FDE原有的良好性能。将传统的同步头去掉,采用PMF-FFT方法进行捕获和多普勒估计,采用SC-FDE方法进行信道估计。对该帧格式的波形进行多普勒估计性能、误码率和循环特性抑制的仿真测试。仿真结果表明,在误码率影响极小的情况下、不增加复杂度的前提下,实现了单载波循环自相关的峰均比性能提高了91.72%,提高了波形的抗截获性能。 展开更多
关键词 抗截获波形 ZADOFF-chu序列 单载波频域均衡 循环谱 循环自相关
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