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基于Moldflow和UG的多腔异件叠层模具设计 被引量:13
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作者 殷小清 王阳 《塑料工业》 CAS CSCD 北大核心 2016年第7期67-70,共4页
针对普通注塑模具生产效率较低的现状,以3D眼镜框为研究对象,分析并设计3D眼镜框热流道叠层式注塑模具。利用Moldflow对多腔异件的型腔排布注塑方案进行填充分析,给出一套流动平衡较好的注塑方案。在UG的建模环境下对整体叠层模进行设计... 针对普通注塑模具生产效率较低的现状,以3D眼镜框为研究对象,分析并设计3D眼镜框热流道叠层式注塑模具。利用Moldflow对多腔异件的型腔排布注塑方案进行填充分析,给出一套流动平衡较好的注塑方案。在UG的建模环境下对整体叠层模进行设计,分别完成其热流道系统、冷却系统、导向机构、侧向联动开模机构、限位机构的设计。最终模具结构合理可行,为叠层模具设计提供了一定的指导意义。 展开更多
关键词 多腔异件 叠层注塑模具 模具设计 MOLDFLOW
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基于CAE鼠标多腔异件模具与流动平衡性设计 被引量:8
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作者 袁根华 《中国塑料》 CAS CSCD 北大核心 2014年第7期100-104,共5页
设计了鼠标左右盖与主盖3个上盖组成的多腔异件布局浇注系统,并借助于计算机辅助工程(CAE)的Moldflow软件,进行了填充分析,为取得流动平衡的最佳效果,运用软件的流道平衡分析,流道的截面尺寸得到了优化,并依照制造的实际圆整流道截面尺... 设计了鼠标左右盖与主盖3个上盖组成的多腔异件布局浇注系统,并借助于计算机辅助工程(CAE)的Moldflow软件,进行了填充分析,为取得流动平衡的最佳效果,运用软件的流道平衡分析,流道的截面尺寸得到了优化,并依照制造的实际圆整流道截面尺寸再改变浇口,基本实现了流动平衡。 展开更多
关键词 注塑模具 多腔 异件 浇注系统 流动平衡
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异件共型的压铸模设计
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作者 刘长友 《铸造技术》 CAS 北大核心 1994年第1期11-12,共2页
阐述了把形状和主要壁厚差别很大的几种零件放在一个压铸模上同时成形的设计方法。
关键词 异件共型 压铸模 设计
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多媒体创作软件实现异种课件对象格式相互调用的方法
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作者 丘威 黄建妮 《教育信息化》 CSSCI 2003年第9期56-57,共2页
1.引言 MCAI(Multimedia Computer-Assisted Instruction,多媒体计算机辅助教学)是利用多媒体计算机把文字、图像、声音、动画、影像等多种媒体综合起来教学的软件.
关键词 多媒体创作软 多媒体计算机辅助教学 种课 对象格式 调用方法 制作
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圆筒形异种钢焊接连接元件边缘应力分析计算
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作者 阚红元 《石油化工设备技术》 CAS 2007年第4期4-6,10,共4页
圆筒形异种钢焊接连接件在高温操作状态下,往往由于两种材料刚性和线膨胀系数的不同而导致破坏。该文提供了一种简化的应力分析方法,便于工程设计人员对此类结构的应力进行分析。
关键词 种钢焊接连接 应力分析 边缘应力
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6061-7075异种铝合金搅拌摩擦焊接件表面整体陶瓷防护膜的制备
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作者 吴蔺峰 朱政强 +2 位作者 陈燕飞 宋晓村 周吉学 《腐蚀与防护》 CAS 北大核心 2022年第7期92-97,共6页
通过微弧氧化处理,使6061与7075铝合金的搅拌摩擦焊接件(连接件)被一层陶瓷膜整体包裹,通过扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)和电化学工作站等分析了母材和焊缝区表面膜层的形貌和成分,并基于检测结果推导了整体陶瓷膜的生长... 通过微弧氧化处理,使6061与7075铝合金的搅拌摩擦焊接件(连接件)被一层陶瓷膜整体包裹,通过扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)和电化学工作站等分析了母材和焊缝区表面膜层的形貌和成分,并基于检测结果推导了整体陶瓷膜的生长机制。结果表明:整体微弧氧化后,连接件表面的膜层是致密的;6061和7075表面膜主要成分为α-Al_(2)O_(3)、γ-Al_(2)O_(3)和少量的Al_(2)SiO_(5),而焊缝区则主要由α-Al_(2)O_(3)和γ-Al_(2)O_(3)组成;微弧氧化降低了连接件不同区域间的腐蚀电位差,显著提高了连接件整体的耐蚀性。 展开更多
关键词 整体微弧氧化 陶瓷膜 种金属连接 搅拌摩擦焊 焊接接头
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一种异种金属板材的焊接工艺
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作者 黄和平 《焊接技术》 北大核心 2012年第4期32-35,共4页
介绍了异种板材的交流和逆变直流热压焊焊接工艺、工艺参数、程序及原理,列举了典型中高碳钢与弹簧钢、热双金、不锈钢不同厚度板材,在电真空管金属器件中的点焊应用实例,成功地解决了异种板材焊接产生的虚焊、脆断、晶间断裂纹、粘焊... 介绍了异种板材的交流和逆变直流热压焊焊接工艺、工艺参数、程序及原理,列举了典型中高碳钢与弹簧钢、热双金、不锈钢不同厚度板材,在电真空管金属器件中的点焊应用实例,成功地解决了异种板材焊接产生的虚焊、脆断、晶间断裂纹、粘焊、熔核不良、焊接裂纹等焊接缺陷,满足了相应产品设计焊核规格,具有一定的推广价值。对取得的效果进行了对比评析,证明了异种板材热压焊焊接工艺的可行性,并在工程上得到了良好的应用。 展开更多
关键词 种板 热压焊 焊接工艺 工艺参数 强度检验
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核岛设备异种钢焊接接头弯曲试验试样移位的分析和处理
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作者 单瑞来 冶金辉 +1 位作者 王力龙 赵明哲 《中文科技期刊数据库(全文版)工程技术》 2021年第5期286-288,共3页
公司在进行核岛设备一次侧接管与安全端异种钢焊接接头弯曲试验后,面弯试样和背弯试样移位,焊缝中心偏移了实际弯曲中心,出现长短边,弯曲试样受拉面无裂纹。通过对弯曲试样变形区外表面切向应变以及纤维伸长率进行分析,判断面弯及背弯... 公司在进行核岛设备一次侧接管与安全端异种钢焊接接头弯曲试验后,面弯试样和背弯试样移位,焊缝中心偏移了实际弯曲中心,出现长短边,弯曲试样受拉面无裂纹。通过对弯曲试样变形区外表面切向应变以及纤维伸长率进行分析,判断面弯及背弯试样合格。 展开更多
关键词 种钢焊接见证 焊缝 面弯/背弯试验 切向应变 伸长率
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一种复合多锥倾刃铰刀的设计和应用
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作者 杨树海 《工具技术》 北大核心 1993年第7期8-11,共4页
本文介绍同轴异件孔用复合多锥倾刃铰刀设计、制造和使用中的问题及解决措施,可满足高精度铰孔加工的需要。
关键词 同轴异件 复合铰刀 设计
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斜L形异形截面环件轧制过程三维动态数值模拟
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作者 袁海伦 王乘 +2 位作者 王泽武 丁海泉 史宇麟 《矿山机械》 北大核心 2007年第1期128-130,共3页
针对环件轧制动态三维仿真的一些关键技术问题开展研究,基于通用动力显示有限元软件Ansys/Ls-dyna建立了RAW200/160-5径轴向轧环机轧制斜L形异形截面环件有限元模型,实现了斜L形异形截面环件轧制全过程的动态仿真。实时观测了环件在轧... 针对环件轧制动态三维仿真的一些关键技术问题开展研究,基于通用动力显示有限元软件Ansys/Ls-dyna建立了RAW200/160-5径轴向轧环机轧制斜L形异形截面环件有限元模型,实现了斜L形异形截面环件轧制全过程的动态仿真。实时观测了环件在轧制过程中成形和缺陷生成的动态过程,绘制了不同时刻环件节点的位移、应力、应变、速度云图,结合计算结果对毛坯结构尺寸、主轴转速、芯辊进给、锥辊进给等轧制工艺进行了比较。 展开更多
关键词 彤截面环 径轴向轧环机 数值模拟
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RESEARCH ON T SHAPED HIGH STRENGTH CONCRETE MEMBERS SUBJECTED TO AXIAL COMPRESSION AND BIAXIAL BENDING
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作者 赵彤 戴自强 翁维素 《Transactions of Tianjin University》 EI CAS 1998年第1期68-71,共4页
Based on experiments, a computer program is developed. The calculated results agree well with the experimental results. The flexural behavior of T shaped high strength concrete members subjected to axial compression ... Based on experiments, a computer program is developed. The calculated results agree well with the experimental results. The flexural behavior of T shaped high strength concrete members subjected to axial compression and biaxial bending is studied. The main factors affecting the flexural behavior of T shaped high strength concrete members are loading angle, axial compression ratio and reinforcement ratio. 展开更多
关键词 high strength concrete irregularly shaped member flexural behavior
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Research on 1-3 Orthogonal Anisotropic Piezoelectric Composite Material Sensors- 被引量:1
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作者 熊克 张为公 骆英 《Journal of Southeast University(English Edition)》 EI CAS 2002年第2期136-140,共5页
Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental... Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental mechanics theories, a kind of 1-3 orthogonalanisotropic PCM (OAPCM) sensor is developed, and the sensing principle is analyzed to describesensor behaviors. In order to determine strain and stress on isotropic or orthogonal anisotropiccomponent surface, the relationships between strain and stress are established. The experimentalresearch on 1-3 OAPCM sensor is carried out in uniaxial and biaxial stress states. The results showthat 1-3 OAPCM sensors offer orthotropic properties of piezoelectricity, and sensing equations canbe used for strain or stress measurement with good accuracy. 展开更多
关键词 1-3 PCM orthogonal anisotropic SENSOR strain-stress relationship
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国债期限风险溢价的ARCH模型族研究
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作者 谈华君 《统计与决策》 CSSCI 北大核心 2008年第15期125-127,共3页
国债期限风险溢价是指国债投资回报率与无风险资产收益率之间的差值。分析国债期限风险溢价的影响因素及可预测性,具有较强的理论与实践意义。文章利用ARCH模型族对上交所国债期限风险溢价的周序列建立了回归模型,取得了显著的统计效果。
关键词 风险溢价 自回归奈方差模型 长短期利差
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Dependent mechanism of Chinese prepositions processing in the brain:evidence from event-related potentials
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作者 方环海 张荣萍 +3 位作者 方环非 高明阳 郑敏 孙潇羽 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第5期282-286,共5页
Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "... Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "preposition". Results Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and fight hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. Conclusion These may demonstrate that prepositions in modem Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions (or closed-class words). 展开更多
关键词 CHINESE PREPOSITIONS VERBS event-related potentials difference waves
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The Necessary and Sufficient Conditions for Two Kinds of Matrix Equtions Having Semipositive Subdefinite Solutions 被引量:1
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作者 何楚宁 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第4期62-68,共7页
Finding solutions of matrix equations in given set SR n×n is an active research field. Lots of investigation have done for these cases, where S are the sets of general or symmetric matrices and symmetric posit... Finding solutions of matrix equations in given set SR n×n is an active research field. Lots of investigation have done for these cases, where S are the sets of general or symmetric matrices and symmetric positive definite or sysmmetric semiposite definite matrices respectively . Recently, however, attentions are been paying to the situation for S to be the set of general(semi) positive definite matrices(called as semipositive subdefinite matrices below) . In this paper the necessary and sufficient conditions for the following two kinds of matrix equations having semipositive, subdefinite solutions are obtained. General solutions and symmetric solutions of the equations (Ⅰ) and (Ⅱ) have been considered in in detail. 展开更多
关键词 semipositive subdefinite symmetric semipositie definite generalized singualr value decomposition
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Approach to evaluating exception handling of programs
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作者 姜淑娟 徐宝文 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期524-528,共5页
To solve the problems that the exception handling code is hard to test and maintain and that it affects the robustness and reliability of software, a method for evaluating the exception handling of programs is present... To solve the problems that the exception handling code is hard to test and maintain and that it affects the robustness and reliability of software, a method for evaluating the exception handling of programs is presented. The exception propagation graph (EPG) that describes the large programs with exception handling constructs is proposed by simplifying the control flow graph and it is applied to a case to verify its validity. According to the EPG, the exception handling code that never executes is identified; the points that are the most critical to controlling exception propagation are found; and the irrational exception handling code is corrected. The constructing algorithm for the EPG is given; thus, this provides a basis for automatically constructing the EPG and automatically correcting the irrational exception handling code. 展开更多
关键词 software robustness exception handling exception propagation evaluating program control flow graph
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Study on the Fermentation Conditions of a Mucopolysaccharide-producing Bacterium LV-1 被引量:25
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作者 梁玉丽 郭继强 +2 位作者 陈晓艺 刘志文 李宪臻 《Agricultural Science & Technology》 CAS 2009年第2期29-32,40,共5页
bacterium LV-1 which isolated from soil sample were studied bacterium was isolated by serial dilution method, the effects of carbon source, nitrogen source, the initial pH and temperature on producing polysaccharide b... bacterium LV-1 which isolated from soil sample were studied bacterium was isolated by serial dilution method, the effects of carbon source, nitrogen source, the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions. [ Result] The physicochemical properties showed that the polysaccharide was water-soluble, but insoluble in organic solvents including ethanol, butanol, and chloroform. It was neutral polysaccharide with negative charge and without reducing terminal. The pH of its solution was pH =7.5. There were no protein, fructose, uronic acid, sulphate and starch-like structure included in po/ysacchadde molecules. The optimum fermentation conditions for po/ysaccharide produc- tion were 3% mannitol as carbon source, 0.25% yeast extract as nitrogen source, culture temperature 28 ~(3 and pH =7.5. [Coadu^en] The re- search could provide basis for development and utilization of LV-1 and industrialized production of mucopolysaccharide. 展开更多
关键词 Microbial polysacchaddes Fermentation conditions ISOLATION
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Analysis of the Flanking Sequence and EventSpecific Detection of Transgenic Line W-4 of Brassica napus 被引量:1
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作者 陈松 申爱娟 +1 位作者 周晓婴 戚存扣 《Agricultural Science & Technology》 CAS 2014年第7期1089-1094,共6页
The genetically modified high-oleic rapeseed (Brassica napus L.) line W-4 was obtained by transforming a binary vector which harbored an inverted repeat expression cassette of fad2 gene into the rapeseed cultivar We... The genetically modified high-oleic rapeseed (Brassica napus L.) line W-4 was obtained by transforming a binary vector which harbored an inverted repeat expression cassette of fad2 gene into the rapeseed cultivar Westar.The transformation was mediated by Agrobacterium.The flanking sequences to both the left and right borders of T-DNA insertion site were amplified by thermal asymmetric interlaced PCR (TAIL-PCR) from the genomic DNA of the transgenic rapeseed line W-4.The flanking sequences to the right border was 290 bp in length and the nucleotide composition was 31.27% for G+C content while 68.73% for A+T content.The flanking sequence to the left border was 365 bp in length and the G+C content was 32.6% and the A+T content was 67.4%,indicating that the T-DNA was integrated in the A/T-rich region.Further more,sequence alignment analysis showed a deletion of 62 bp including the right border of pCNFIRnos and the integration of the whole left border except a change of G to A.That was to say,the integration of the T-DNA in the transgenic line W-4 not involved in the vector sequences.Based on both flanking sequences as well as the left and right borders of the T-DNA sequences,two pairs of specific primers TLF/TLR and TRF/TRR were designed.Using the primers the event-specific PCR detection method for transgenic rapeseed line W-4 was established.By the PCR,two fragments of 485 and 405 bp were amplified from the W-4 genomic DNA as expected,while no products were amplified from the genomic DNA of other transgenic rapeseed lines and non-transgenic rapeseed line.And by the PCR it is possible to detect the W-4 genomic DNA from a mixed sample of genomic DNA.The limit of the detection for the qualitative PCR assay was 0.1%.The method developed in this work is highly specific,sensitive and suitable for event-specific detection of the transgenic rapeseed line W-4. 展开更多
关键词 Transgenic rapeseed Flanking sequences Event-specific detection
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Postconditioning of sevoflurane and propofol is associated with mitochondrial permeability transition pore 被引量:48
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作者 Wei HE Feng-jiang ZHANG +3 位作者 Shao-ping WANG Gang CHEN Cong-cong CHEN Min YAN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第2期100-108,共9页
Background: Sevoflurane and propofol are effective cardioprotective anaesthetic agents, though the cardioprotection of propofol has not been shown in humans. Their roles and underlying mechanisms in anesthetic postcon... Background: Sevoflurane and propofol are effective cardioprotective anaesthetic agents, though the cardioprotection of propofol has not been shown in humans. Their roles and underlying mechanisms in anesthetic postconditioning are unclear. Mitochondrial permeability transition pore (MPTP) opening is a major cause of ischemia-reperfusion injury. Here we investigated sevoflurane- and propofol-induced postconditioning and their relationship with MPTP. Methods: Isolated perfused rat hearts were exposed to 40 min of ischemia followed by 1 h of reperfusion. During the first 15 min of reperfusion, hearts were treated with either control buffer (CTRL group) or buffer containing 20 μmol/L atractyloside (ATR group), 3% (v/v) sevoflurane (SPC group), 50 μmol/L propofol (PPC group), or the combination of atractyloside with respective anesthetics (SPC+ATR and PPC+ATR groups). Infarct size was determined by dividing the total necrotic area of the left ventricle by the total left ventricular slice area (percent necrotic area). Results: Hearts treated with sevoflurane or propofol showed significantly better recovery of coronary flow, end-diastolic pressures, left ventricular developed pressure and derivatives compared with controls. Sevoflurane resulted in more protective alteration of hemodynamics at most time point of reperfusion than propofol. These improvements were paralleled with the reduction of lactate dehydrogenase release and the decrease of infarct size (SPC vs CTRL: (17.48±2.70)% vs (48.47±6.03)%, P<0.05; PPC vs CTRL: (35.60±2.10)% vs (48.47±6.03)%, P<0.05). SPC group had less infarct size than PPC group (SPC vs PPC: (17.48±2.70)% vs (35.60±2.10)%, P<0.05). Atractyloside coadministration attenuated or completely blocked the cardioprotective effect of postconditioning of sevoflurane and propofol. Conclusion: Postconditioning of sevoflurane and propofol has cardio-protective effect against ischemia-reperfusion injury of heart, which is associated with inhibition of MPTP opening. Compared to propofol, sevoflurane provides superior protection of functional recovery and infarct size. 展开更多
关键词 SEVOFLURANE PROPOFOL POSTCONDITIONING Reperfusion injury Mitochondrial permeability transition pore (MPTP)
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Deletion of 93 bp Far-upstream Fragment of Rice Cytosolic Fructose- 1, 6-Bisphosphatase Promoter Completely Alter Its Expression Pattern 被引量:4
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作者 司丽珍 王力 +1 位作者 曹守云 储成才 《Acta Botanica Sinica》 CSCD 2002年第11期1339-1345,共7页
The 1 195 bp 5′ flanking region of rice ( Oryza sativa L.) cytosolic fructose_1, 6_bisphosphatase (cyFBPase) can direct tissue, cell specific expression in transgenic rice. In order to identify sequence elements ... The 1 195 bp 5′ flanking region of rice ( Oryza sativa L.) cytosolic fructose_1, 6_bisphosphatase (cyFBPase) can direct tissue, cell specific expression in transgenic rice. In order to identify sequence elements responsible for the regulation of mesophyll_specific expression, the 5′ flanking regions of -1 195 bp, -1 102 bp, -768 bp, and -644 bp upstream of the translation initiation ATG codon were fused to the reporter gene encoding β_glucuronidase (GUS) and transferred to rice via particle bombardment. Analysis of the 5′ promoter deletions identified that a 93 bp fragment between -1 195 bp and -1 102 bp is essential for directing mesophyll specific expression. High constitutive expression of GUS reporter gene was found in the -768 deletion lines and another two deletion series. These results indicate the great potential utility of the promoter in rice biotechnology. 展开更多
关键词 rice ( Oryza sativa ) cis _regulatory elements cytosolic fructose_1 6_bisphosphatase gene mesophyll_specific expression constitutive expression
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