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小麦抗白粉病基因Pm12的RFLP标记 被引量:23
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作者 贾继增 T. E. Miller +1 位作者 S. M. reader M. D. Gale 《中国科学(B辑)》 CSCD 北大核心 1993年第6期589-594,共6页
春小麦品系Line 31携带有一个来自斯卑尔脱山羊草的显性抗白粉病基因Pm 12(Miller等,1988)。16个RFLP(restriction fragment length polymorphism)探针用于鉴定Line 31及其亲本,结果表明Line 31是一个6B/6S易位系。用5个探针所进行的连... 春小麦品系Line 31携带有一个来自斯卑尔脱山羊草的显性抗白粉病基因Pm 12(Miller等,1988)。16个RFLP(restriction fragment length polymorphism)探针用于鉴定Line 31及其亲本,结果表明Line 31是一个6B/6S易位系。用5个探针所进行的连锁分析进一步揭示Pm 12位于易位染色体的着丝点附近,与6S长臂上的α-淀粉酶位点(α-Amy-S1)紧密连锁,遗传距离仅为1.1 cM。本研究结果表明RFLP技术在鉴定小麦外源染色体及外源基因上具有广阔的应用前景。 展开更多
关键词 小麦 基因 多态性 抗白粉病
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用基因组原位杂交技术检测小麦-新麦草杂交后代 被引量:11
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作者 周荣华 贾继增 +4 位作者 董玉琛 T.Schwarzacher T.E.Miller S.reader Sh.B.WuM.D.Gale 《中国科学(C辑)》 CSCD 1997年第6期543-549,共7页
利用基因组原位杂交(Gonome in-situ hybridzation,简称GISH)技术鉴定小麦(Triticum aestivum)-新麦草(Psathyrostachys juncea(Fisch.)Nevski)属间杂交后代,计有易位附加系7份,易位-易位附加系6份,双端体附加系2份,易位系1份.其中易位... 利用基因组原位杂交(Gonome in-situ hybridzation,简称GISH)技术鉴定小麦(Triticum aestivum)-新麦草(Psathyrostachys juncea(Fisch.)Nevski)属间杂交后代,计有易位附加系7份,易位-易位附加系6份,双端体附加系2份,易位系1份.其中易位附加系和易位-易位附加系两种类型在此之前未见报道.研究未发现有代换系和二体附加系,所鉴定出的新麦草染色体均发生了断裂.研究证明改进后的原位杂交技术具有快速、经济的优点. 展开更多
关键词 小麦 新麦草 易位附加 基因组 原位杂交
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Technical and conceptual considerations forusing animated stimuli in studies of animalbehavior 被引量:10
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作者 Laura CHOUINARD-THULY Stefanie GIERSZEWSKI +10 位作者 Gil G. ROSENTHAL Simon M. reader Guillaume RIEUCAU Kevin L. Woo Robert GERLAI Cynthia TEDORE Spencer J. INGLEY John R. STOWERS Joachim G.FROMMENI Francine L. DOLINS Klaudia WITTE 《Current Zoology》 SCIE CAS CSCD 2017年第1期5-19,共15页
Rapid technical advances in the field of computeropened new avenues in animal behavior research.animation (CA) and virtual reality (VR) haveAnimated stimuli are powerful tools as theyoffer standardization, repeata... Rapid technical advances in the field of computeropened new avenues in animal behavior research.animation (CA) and virtual reality (VR) haveAnimated stimuli are powerful tools as theyoffer standardization, repeatability, and complete control over the stimulus presented, thereby"reducing" and "replacing" the animals used, and "refining" the experimental design in line withthe 3Rs. However, appropriate use of these technologies raises conceptual and technical questions.In this review, we offer guidelines for common technical and conceptual considerations related tothe use of animated stimuli in animal behavior research. Following the steps required to create ananimated stimulus, we discuss (I) the creation, (11) the presentation, and (111) the validation of CAsand VRs. Although our review is geared toward computer-graphically designed stimuli, consider-ations on presentation and validation also apply to video playbacks. CA and VR allow both new be-havioral questions to be addressed and existing questions to be addressed in new ways, thus weexpect a rich future for these methods in both ultimate and proximate studies of animal behavior. 展开更多
关键词 ANIMAL behavior animated stimulus COMPUTER animation experimental design virtual reality visual communication.
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Experimental Investigation of Thermal Performance of Novel Finned Radiators for Automotive Cooling System
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作者 SINGH Hardeep TING David S-K +3 位作者 reader Graham ESHTIAGHI Nicky ICHIYANAGI Mitsuhisa SUZUKI Takashi 《Journal of Thermal Science》 SCIE EI CAS CSCD 2024年第5期1726-1743,共18页
This research investigates innovative fin-type radiators for automobile engine cooling system.Micro-channel and helical radiators,along with straight type,were analyzed for heat transfer characteristics under various ... This research investigates innovative fin-type radiators for automobile engine cooling system.Micro-channel and helical radiators,along with straight type,were analyzed for heat transfer characteristics under various conditions.The uniqueness of this study is evident in the design of microchannel and helical radiators.For helical radiators,the inner rod features 4/8 helical-shaped water galleries,while the outer tube frame with embedded fins remains consistent.In contrast,the microchannel radiators have compact trapezoidal-shaped water galleries with separate fin strips.Furthermore,the novelty of the research is enhanced by the utilization of 3D printing technology in the manufacturing process.In constant fin height analysis at varied water and air flow rate,Microchannel Water Air Radiator with fin height 10.5 mm(MCWAR10.5)depicted a higher heat transfer rate amongst the radiators.In comparison to Straight Water Air Radiator with fin height 9.5 mm(SWAR9.5),the heat transfer rate is 30.3%and 1.3 times higher.However,in constant fin surface area analysis,microchannel radiator(MCWAR3.2)illustrates lower heat dissipation than Helical radiator(HWAR138)but higher than HWAR134 and Straight radiator(SWAR6).The examination of pumping loss indicated that the Micro-channel radiator outperformed helical radiators due to its lower pressure loss.The average pressure loss for Micro-channel radiators was 0.74 kPa,making it 1.2 times higher than that of a straight radiator(0.62 kPa),indicating a better trade-off. 展开更多
关键词 heat exchangers multi-channel helical heat exchanger heat transfer 3D printing
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Characterization of progenies of Triticum aestivum- Psathyrostachys juncea derivatives by using genomic in-situ hybridization 被引量:3
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作者 周荣华 贾继增 +5 位作者 董玉琛 T. Schwarzacher T. S. Miller S. reader Sh. B. Wu M. D. Gale 《Science China(Life Sciences)》 SCIE CAS 1997年第6期657-664,共8页
Using genomic in-situ hybridization (GISH) technique, 7 translocation-addition lines, 6 transloca-tion and translocation-addition lines, 2 ditelosomic addition lines and 1 translocation line were identified from Triti... Using genomic in-situ hybridization (GISH) technique, 7 translocation-addition lines, 6 transloca-tion and translocation-addition lines, 2 ditelosomic addition lines and 1 translocation line were identified from Triticum aestivum L.-Psathyrostachys juncea (Fisch. ) Nevski intergeneric hybrids, of which translocation-addition and translocation and translocation-addition lines were not found in other reports. No substitutions and disomic additions were detected in the hybrids and breakages occurred in all P. juncea chromosomes studied. Results have shown that the improved GISH technique is a rapid and economical method for use in this field. 展开更多
关键词 Triticum AESTIVUM Psathyrostachys JUNCEA translocation-addition TRANSLOCATION and transloca-tion-addition in-situ hybridization.
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指南儿童毛细支气管炎:NICE指南概要 被引量:4
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作者 Valentina Ricci research fellow Vanessa Delgado Nunes senior research fellow and guideline lead +3 位作者 M Stephen Murphy clinical director for children's guidelines Steve Cunningham consultant and honorary reader in paediatric respiratory medicine 许菲 梁志欣 《英国医学杂志中文版》 2015年第12期737-740,共4页
本文是英国医学杂志发布的基于现有最佳证据得出的系列新指南概要之一。它们重点对临床实践提供重要建议,尤其是尚无定论或存有争议的领域。
关键词 支气管炎 指南 儿童
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野生二粒小麦抗白粉病基因向普通小麦的转入 被引量:4
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作者 S.M.reader 刘树玉 《国外农学(麦类作物)》 CSCD 1992年第2期1-3,共3页
一个新的抗小麦白粉病(Erysiphe graminis)基因,已从野生四倍体小麦(Triticum dicoccoides)转移到六倍体普通小麦(Triticum aestivum)中.使该基因供体与普通小麦杂交,然后使五倍体的后代自交.从F_3代选出具有接近稳定的六倍染色体组的植... 一个新的抗小麦白粉病(Erysiphe graminis)基因,已从野生四倍体小麦(Triticum dicoccoides)转移到六倍体普通小麦(Triticum aestivum)中.使该基因供体与普通小麦杂交,然后使五倍体的后代自交.从F_3代选出具有接近稳定的六倍染色体组的植株,并将它们与第2个小麦品种顶交(topcross)和回交以改良其表现型.早代回交系的单体分析表明转移的基因定位于4A染色体上,该基因已被定名为Pm16. 展开更多
关键词 小麦 野生 白粉病 抗性 基因转入
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通过废气再循环实现柴油低温燃烧的实验研究(英文) 被引量:3
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作者 郑明 韩晓野 Graham T.reader 《汽车安全与节能学报》 CAS 2010年第3期219-228,共10页
应用废气再循环(EGR)能够降低缸内氮氧化物(NOx)生成,是实现柴油低温燃烧的一种有效方法。以同时降低NOx和碳烟为目的,恰当的喷油策略和进气增压控制则是除EGR之外的两个关键因素。该文的实验是在先进的发动机实验平台上完成的,该实验... 应用废气再循环(EGR)能够降低缸内氮氧化物(NOx)生成,是实现柴油低温燃烧的一种有效方法。以同时降低NOx和碳烟为目的,恰当的喷油策略和进气增压控制则是除EGR之外的两个关键因素。该文的实验是在先进的发动机实验平台上完成的,该实验平台可以精确并单独控制这三项参数,以单独研究每一个参数对发动机排放的影响。实验结果表明:在本研究的低温燃烧范围内,应用EGR是降低NOx排放的最有效手段;然而,喷油压力和进气压力对NOx仅有轻微影响。另一方面,在不同EGR条件下,可以通过提升喷油压力来减少碳烟排放;针对高碳烟情况,提升进气压力可以有效降低碳烟峰值。但是,随EGR率的增加,由于氧气含量减少和火焰温度降低,导致较高的碳氢和一氧化碳排放。 展开更多
关键词 柴油机 废气再循环(EGR) 低温燃烧(LTC) 碳烟增压控制 喷油策略 NOx和碳烟排放
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水性汽车漆表面缺陷的消除 被引量:2
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作者 Reinartz Roger +2 位作者 reader Jim 陈进伟 《上海涂料》 CAS 2008年第3期35-38,共4页
水性汽车修补涂料的开发对于涂料配方设计师而言是一个挑战,因为他们将面对大量的原本在传统溶剂型涂料中并不突显的问题:较差的基材润湿性、涂膜缩孔、过多的泡沫、桔皮表面,针孔和溶剂爆孔。用有代表性的标准底漆、色漆和罩光漆配方... 水性汽车修补涂料的开发对于涂料配方设计师而言是一个挑战,因为他们将面对大量的原本在传统溶剂型涂料中并不突显的问题:较差的基材润湿性、涂膜缩孔、过多的泡沫、桔皮表面,针孔和溶剂爆孔。用有代表性的标准底漆、色漆和罩光漆配方进行涂布研究,结果表明:高性能表面活性剂和分子消泡剂可以帮助配方师解决这些问题,而不会对涂料的再涂性、层间附着力或涂膜性能产生不良影响。 展开更多
关键词 水性汽车漆 表面活性剂 漆膜缺陷
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RFLP Tagging of a Gene Pm12 for Powdery Mildew Resistance in Wheat (Triticum aestivum L. ) 被引量:1
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作者 贾继增 T.E.Miller +1 位作者 S.M.reader M.D.Gale 《Science China Chemistry》 SCIE EI CAS 1994年第5期531-537,共7页
A dominant gene, Pml2, conferring the resistance to powdery mildew (Erysiphe graminis) has been transferred to wheat from Aegilops speltoides. Sixteen RFLP probes were used to test Line 31 and its parents, showing tha... A dominant gene, Pml2, conferring the resistance to powdery mildew (Erysiphe graminis) has been transferred to wheat from Aegilops speltoides. Sixteen RFLP probes were used to test Line 31 and its parents, showing that Line 31 is a 6B/6S translocation lines. The linkage analysis by five probes indicates that Pm12 is located on the chromosome 6B/6S, and tightly flanked by an RFLP marker α-Amy-1 (1.1 cM), identified by RFLP and isozyme analysis. This approach is equally applicable to the identification of other transferred alien genes and the segments of alien chromosome introgressed into wheat. 展开更多
关键词 WHEAT powdery MILDEW resistance RFLP linkage.
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AVS Intellectual Property Rights (IPR) Policy 被引量:1
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作者 Cliff reader 《Journal of Computer Science & Technology》 SCIE EI CSCD 2006年第3期306-309,共4页
The AVS Workgroup has developed an IPR Policy to facilitate the adoption of standards in the marketplace The policy is based on consideration of IPR issues in parallel with the technical work for drafting the standard... The AVS Workgroup has developed an IPR Policy to facilitate the adoption of standards in the marketplace The policy is based on consideration of IPR issues in parallel with the technical work for drafting the standard. The paper describes the relationship between IPR and the standard, and how the goals for the standard must be complemented by goals for the IPR. The existing IPR policies of the ITU and ISO are outlined, and then the AVS IPR policy is described, organized by its three main components: commitment to license on declared basic terms, disclosure of intellectual property, and protection of IPR. 展开更多
关键词 intellectual property IPR patents and standards patent pool patent licensing
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Restraint Induces Sickness Responses Independent of Injection with Epstein-Barr Virus (EBV)-Encoded dUTPase
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作者 Taryn G. Aubrecht Bachir Abi Salloum +5 位作者 Maria Eugenia Ariza Marshall Williams Brenda reader Ronald Glaser John Sheridan Randy J. Nelson 《Journal of Behavioral and Brain Science》 2014年第11期491-505,共15页
Most adult humans have been infected by Epstein-Barr virus (EBV), a putative cause of chronic fatigue syndrome, and carry latent EBV. The EBV-encoded dUTPase can induce sickness responses in mice and chronic stress ex... Most adult humans have been infected by Epstein-Barr virus (EBV), a putative cause of chronic fatigue syndrome, and carry latent EBV. The EBV-encoded dUTPase can induce sickness responses in mice and chronic stress exacerbates this response. Because individuals often adapt to chronic stress, we tested the hypothesis that acute restraint stress would potentiate these sickness responses elicited by EBV-encoded dUTPase. Male CD-1 mice were injected daily for one or three days with either saline or EBV-encoded dUTPase. Additionally, mice from each condition were either restrained for three hours daily or left undisturbed during the light phase when mice are inactive. Restraint decreased weight gain during the one- and three-day experiments. Restraint in saline injected mice increased anxiety-like behavior in the open field during the three-day experiment. There were no behavioral differences during the one-day experiment. Restraint stress had no effect when experienced acutely on one day, but did produce a sickness response after three days of exposure regardless of saline or dUTPase injection. In contrast to the effects of chronic stress and EBV-encoded dUTPase on the sickness response, acute stress did not affect sickness responses in association with EBV-encoded dUTPase. Thus, dUTPase does not appear to provoke the same sickness responses after acute stress as compared to chronic stress. 展开更多
关键词 EPSTEIN-BARR Virus RESTRAINT Stress SICKNESS Response Anxiety-Like and Depressive-Like Behaviors
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Acute ethanol poisoning in a 6-year-old girl following ingestion of alcohol-based hand sanitizer at school
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作者 Madeline Matar Joseph Cristina Zeretzke +1 位作者 Sara reader Dawn R. Sollee 《World Journal of Emergency Medicine》 SCIE CAS 2011年第3期232-233,共2页
BACKGROUND: Alcohol-based hand sanitizers (ABHSs) have been widely used in homes, workplaces and schools to prevent the spread of infectious diseases. We report a young child unintentionally ingested ABHS at a scho... BACKGROUND: Alcohol-based hand sanitizers (ABHSs) have been widely used in homes, workplaces and schools to prevent the spread of infectious diseases. We report a young child unintentionally ingested ABHS at a school, resulting in intoxication. METHODS:The child was a 6-year-old girl who had been brought to the emergency department (ED) for hypothermia, altered mental status (AMS), periods of hypoventilation, hypothermia and vomiting. Computed tomography of her head revealed nothing abnormal in intracranial pathology. Urine drug screening was negative. Alcohol level was 205 mg/dL on admission. Other abnormal values included potassium of 2.8 mEq/L, osmolality of 340 mOsm/kg and no hypoglycemia. Further investigation revealed that the patient had gone frequently to the class restroom for ingestion of unknown quantities of ABHSs during the day. The patient was admitted for one day for intravenous fluid hydration and close observation of her mental status. RESULTS:The patient was discharged from the hospital the next day without any complications. CONCLUSION: Despite the large safety margin of ABHSs, emergency physicians need to be aware of the potential risk of ingestion of a large amount of such products in children and consider it in the assessment and management of school-age children with acute AMS. 展开更多
关键词 PEDIATRICS TOXICOLOGY ETHANOL Hand-sanitizer Altered mental status
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Chronic Physical Stress Does Not Interact with Epstein-Barr Virus (EBV)-Encoded Dutpase to Alter the Sickness Response
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作者 Taryn G. Aubrecht Zachary M. Weil +6 位作者 Bachir Abi Salloum Maria Eugenia Ariza Marshall Williams Brenda reader Ronald Glaser John Sheridan Randy J. Nelson 《Journal of Behavioral and Brain Science》 2015年第11期513-523,共11页
Most adult humans have been infected with Epstein-Barr virus (EBV), which is thought to contribute to the development of chronic fatigue syndrome. Stress is known to influence the immune system and can exacerbate the ... Most adult humans have been infected with Epstein-Barr virus (EBV), which is thought to contribute to the development of chronic fatigue syndrome. Stress is known to influence the immune system and can exacerbate the sickness response. Although a role for psychological stress in the sickness response, particularly in combination with EBV-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase) has been established, and the role of physical stressors in these interactions remains unspecified. In this study, we seek to determine the interaction of chronic physical (swim) stress and EBV-encoded dUTPase injection. We hypothesize that a chronic physical stressor will exacerbate the sickness response following EBV-encoded dUTPase injection. To test this hypothesis mice receive daily injections of EBV-encoded dUTPase or vehicle and are subjected to 15 min of swim stress each day for 14 days or left unmanipulated. On the final evening of injections mice undergo behavioral testing. EBV-encoded dUTPase injection alone produces some sickness behaviors. The physical swimming stress does not alter the sickness response. 展开更多
关键词 EPSTEIN-BARR Virus SWIM Stress SICKNESS RESPONSE
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The Chromosomal Control of Leaf Characteristics of Early-Stage Plants in Wheat (Triticum aestivum L.)
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作者 LI Cun-dong BAI Zhi-ying +4 位作者 Ye G Miyagi M Chapman S reader S M LIU Chun-ji 《Agricultural Sciences in China》 CAS CSCD 2011年第2期159-165,共7页
Rapid expansion of leaves of early-stage plants in wheat produced by chromosomal control of characteristics related to rapid expansion of the first six leaves of wheat were investigated using a set of single chromosom... Rapid expansion of leaves of early-stage plants in wheat produced by chromosomal control of characteristics related to rapid expansion of the first six leaves of wheat were investigated using a set of single chromosome substitution lines under two different temperature regimes(TRs).Results from this study indicated that several chromosomes could be responsible for each of the four characteristics studied(including leaf width,leaf length,leaf elongation rate and leaf appearance index) and that different chromosomes may be responsible for the same characteristics at different TRs.Only a small number of substitutions that showed the most significant effects on leaf length were found among those that showed the most significant effects on leaf width,providing further evidence that these two characteristics are likely controlled by different sets of genes.Substitutions 4B,4D,and 5A are among those that were repeatedly detected to having significant effects on different leaf characteristics at the lower-TR and genes residing on these three chromosomes could be homologous.This possibility and its implication are discussed. 展开更多
关键词 WHEAT LEAF CHARACTERISTICS chromosomal control
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全球诚信大比拼
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作者 reader’s Digest 马俊杰 《新东方英语(中英文版)》 2008年第Z1期112-115,共4页
2007年8月,《读者文摘》做了一项有趣的调查,他们派记者到全球32个人口稠密的城市中去,在每个城市"丢失"30部手机,每个手机里预先设置可以联系的号码,看看最后每个城市能有多少部手机被送还,以此来测试各城市居民的诚信程度... 2007年8月,《读者文摘》做了一项有趣的调查,他们派记者到全球32个人口稠密的城市中去,在每个城市"丢失"30部手机,每个手机里预先设置可以联系的号码,看看最后每个城市能有多少部手机被送还,以此来测试各城市居民的诚信程度。试验的结果有些在人们的意料之中,有些则颇让人意外…… 展开更多
关键词 手机 物归原主 诚信 城市居民 测试 全球 丢失 记者 文摘 欧洲城市
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English Christmas Pantomime: Theatre or Community Activism
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作者 Pete reader, MFA 《Journal of Literature and Art Studies》 2016年第7期804-810,共7页
How is English Christmas panto community activism? The structure of pantomime has not changed in a hundred years, but allows for local creativity to work within its framework to be both family entertainment and socia... How is English Christmas panto community activism? The structure of pantomime has not changed in a hundred years, but allows for local creativity to work within its framework to be both family entertainment and social satire This basic structure is founded on a children's story like Puss 'n 'boots or Cinderella. The story and character types remain the same; but the community can add their own jokes and commentary to make the play relevant to themselves and their community. What is added by the community says a lot about who they are and what they care about. The company Price-Waterhouse-Coopers produces their pantomime as management training and team building while engaging the community. The Basel Swiss panto raises money for African Charities. The Maplewood, NJ panto raises money for the homeless and the Jaguar Charity panto in Birmingham performs to disadvantaged children and adults. The productions can be extravagant or threadbare, but share the same goal of raising cheer and goodwill to the benefit of the community. What is it, then, about panto that brings a community together in such civic mindedness? 展开更多
关键词 English Christmas pantomine community engagement THEATRE ACTIVISM
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含氧清洁燃料DMC在柴油机上的应用研究 被引量:7
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作者 张煜盛 G.T.reader 《华中理工大学学报》 CSCD 北大核心 2000年第7期68-70,共3页
阐明了含氧清洁燃料DMC的生产及理化性质 ,探讨了柴油机掺烧一定比例DMC的排放特性 .实验结果表明 ,DMC对发动机燃烧过程影响的程度虽与其在柴油中掺混的比例有关 ,但与纯柴油相比 ,在试验范围内 ,不同DMC的掺烧量均可显著降低柴油机的N... 阐明了含氧清洁燃料DMC的生产及理化性质 ,探讨了柴油机掺烧一定比例DMC的排放特性 .实验结果表明 ,DMC对发动机燃烧过程影响的程度虽与其在柴油中掺混的比例有关 ,但与纯柴油相比 ,在试验范围内 ,不同DMC的掺烧量均可显著降低柴油机的NOx,CO和HC和碳烟的排放量 .DMC以其良好的燃烧和排放性能 。 展开更多
关键词 代用燃料 含氧清洁燃料 柴油机 DMC 应用
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基于网络环境的图书馆图书借阅服务和推广创新
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作者 陈敏 《移动信息》 2023年第5期233-234,237,共3页
随着信息化网络技术的迅速发展,图书馆的图书借阅服务和推广工作发生了极大变化,并在网络环境下产生了许多新功能。在全民阅读背景和互联网技术的不断普及下,传统图书馆图书借阅服务和推广工作已经无法满足人们的实际阅读需求,严重影响... 随着信息化网络技术的迅速发展,图书馆的图书借阅服务和推广工作发生了极大变化,并在网络环境下产生了许多新功能。在全民阅读背景和互联网技术的不断普及下,传统图书馆图书借阅服务和推广工作已经无法满足人们的实际阅读需求,严重影响了人们获取知识的便捷性。文中立足于网络环境,指出了图书馆借阅服务与推广工作的特点,分析了当今图书馆图书借阅服务与推广工作存在的主要问题,创新了图书馆图书借阅服务与推广工作,进一步提升了相关工作的质量,为图书馆图书借阅服务和推广工作的创新发展提供了经验指导及借鉴。 展开更多
关键词 网络环境 图书馆 图书借阅服务 图书借阅推广 创新
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A Comparative Study of Morphological Responses of Seedling Roots to Drying Soil in 20 Species from Different Habitats 被引量:1
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作者 刘志民 K.THOMPSON +1 位作者 R.E.SPENCER R.J.reader 《Acta Botanica Sinica》 CSCD 2000年第6期628-635,共8页
Rooting depth and root and shoot biomass were measured for seedlings of 20 species in both watered and unwatered sand columns. The species were from habitats of widely varying moisture status, ranging from marsh to de... Rooting depth and root and shoot biomass were measured for seedlings of 20 species in both watered and unwatered sand columns. The species were from habitats of widely varying moisture status, ranging from marsh to desert. Moisture status of the species' habitats was quantified as Ellenberg moisture number. Seedlings were allowed to grow in moist sand for 21 days and were then exposed to the treatments (watered and unwatered) for a further 21 days. Rooting depth of control plants was not correlated with Ellenberg number. Root depth of plants from dry habitats tended to increase in drying sand, while roots of plants from wet habitats decreased in depth. Plasticity of rooting depth (depth in unwatered / depth in watered sand) was significantly correlated with Ellenberg number ( r 2 = 0.56). Plasticity of shoot/root ratio was also correlated with Ellenberg number, but the relationship was weaker than for rooting depth plasticity. Species that showed the greatest plasticity in rooting depth also showed the greatest ability to sustain shoot growth in unwatered sand. There was some evidence that growth of plants from very dry habitats was reduced in the watered treatment. Results of this study suggest that a major, although not the only, adaptation of plants of dry habitats is the ability of their seedlings to exploit deeply buried water resources. 展开更多
关键词 DROUGHT Ellenberg number PLASTICITY regenerative strategy root growth SEEDLINGS shoot growth
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