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Characterization of QTL for unique agronomic traits of new-plant-type rice varieties using introgression lines of IR64 被引量:3
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作者 Analiza G.Tagle Daisuke Fujita +5 位作者 Leodegario A.Ebron Mary Jeanie Telebanco-Yanoria Kazuhiro Sasaki Tsutomu Ishimaru Yoshimichi Fukuta Nobuya Kobayashi 《The Crop Journal》 SCIE CAS CSCD 2016年第1期12-20,共9页
To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomicall... To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomically valuable characteristics such as large panicles,few unproductive tillers,and large leaves inherited from NPT.To identify the genetic basis of these traits,we used 167 F_2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits:days to heading(DTH),culm length(CL),flag leaf length(FLL),flag leaf width(FLW),and filled spikelet number per panicle(FSN).Six putative QTL were detected:four on chromosome4(for CL,FLL,FLW,and FSN) and two on chromosome 2(for DTH and FLL).All QTL with the IR66215-44-2-3 allele,except that for FLL on chromosome 2,had positive effects on each trait.To confirm the effects of these putative QTL,we developed NILs with the IR64 genetic background by marker-assisted selection.We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4.Additionally,four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropic To enhance the yield potential of an elite indica rice cultivar, an introgression(BC3-derived) line of IR64, YTH288, was developed using a new-plant-type cultivar,IR66215-44-2-3, as a donor parent. YTH288 has agronomically valuable characteristics such as large panicles, few unproductive tillers, and large leaves inherited from NPT.To identify the genetic basis of these traits, we used 167 F2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits: days to heading(DTH), culm length(CL), flag leaf length(FLL), flag leaf width(FLW), and filled spikelet number per panicle(FSN). Six putative QTL were detected: four on chromosome4(for CL, FLL, FLW, and FSN) and two on chromosome 2(for DTH and FLL). All QTL with the IR66215-44-2-3 allele, except that for FLL on chromosome 2, had positive effects on each trait. To confirm the effects of these putative QTL, we developed NILs with the IR64 genetic background by marker-assisted selection. We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4. Additionally, four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropiceffects for unique agronomic traits. These NILs can be used as research materials for studying each trait and as breeding materials for yield improvement of indica rice cultivars. 展开更多
关键词 Agronomic traits Quantitative trait loci Near-isogenic lines New-plant-type RICE variety PLEIOTROPIC effect
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Type Synthesis of 4-DOF Parallel Kinematic Mechanisms Based on Grassmann Line Geometry and Atlas Method 被引量:22
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作者 XIE Fugui LI Tiemin LIU Xinjun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第6期1073-1081,共9页
Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms(PKMs), but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method fo... Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms(PKMs), but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method for engineering application is a very challenging issue, which should be further studied in the field. Grassmann line geometry, which can investigate the dimensions of spatial line-clusters in a concise way, is taken as the mathematic foundation. Atlas method is introduced to visually describe the degrees of freedom(DOFs) and constraints of a mechanism, and the dual rule is brought in to realize the mutual conversion of the freedom-space and constraint-space. Consequently, a systematic method based on Grassmann line geometry and Atlas method is generated and the entire type synthesis process is presented. Three type 4-DOF PKMs, i.e., 1T3R, 2T2R and 3T1R(T: translational DOF; R: rotational DOF), are classified according to the different combinations of the translational DOFs and rotational DOFs. The type synthesis of 4-DOF PKMs is carried out and the possible configurations are thoroughly investigated. Some new PKMs with useful functions are generated during this procedure. The type synthesis method based on Grassmann line geometry and Atlas method is intuitive and concise, and can reduce the complexity of the PKMs' type synthesis. Moreover, this method can provide theoretical guidance for other PKMs' type synthesis and engineering application. A novel type synthesis method is proposed, which solves the existing methods' problems in terms of complicated, not intuitive and unsuitable for practical application. 展开更多
关键词 type synthesis parallel kinematic mechanism Grassmann line geometry atlas method
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A catalog of early-type emission-line stars and Hα line profiles from LAMOST DR2 被引量:1
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作者 Wen Hou A-Li Luo +9 位作者 Jing-Yao Hu Hai-Feng Yang Chang-De Du Chao Liu Chien-De Lee Chien-Cheng Lin Yue-Fei Wang Yong Zhang Zi-Huang Cao Yong-Hui Hou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第9期39-50,共12页
We present a catalog including 11 204 spectra of 10436 early-type emission-line stars from LAMOST DR2, among which 9752 early-type emission-line spectra are newly discovered. For these early- type emissionqine stars, ... We present a catalog including 11 204 spectra of 10436 early-type emission-line stars from LAMOST DR2, among which 9752 early-type emission-line spectra are newly discovered. For these early- type emissionqine stars, we discuss the morphological and physical properties of their low-resolution spectra. In this spectral sample, the Hα emission profiles display a wide variety of shapes. Based on the Hα line profiles, these spectra are categorized into five distinct classes: single-peak emission, single-peak emission in absorption, double-peak emission, double-peak emission in absorption, and P-Cygni profiles. To better understand what causes the Hc~ line profiles, we divide these objects into four types from the perspective of physical classification, which include classical Be stars, Herbig Ae/Be stars, close binaries and spectra contaminated by H n regions. The majority of Herbig Ae/Be stars and classical Be stars are identified and separated using a (H-K, K-W1) color-color diagram. We also discuss 31 binary systems that are listed in the SIMBAD on-line catalog and identify 3600 spectra contaminated by HⅡ regions after cross-matching with positions in the Dubout-Crillon catalog. A statistical analysis of line profiles versus classifications is then conducted in order to understand the distribution of Hc~ profiles for each type in our sample. Finally, we also provide a table of 172 spectra with Fen emission lines and roughly calculate stellar wind velocities for seven spectra with P-Cygni profiles. 展开更多
关键词 STARS early-type - stars emission-line Be -- stars pre-main sequence -- binaries close
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Type Synthesis of Spatial Straight Line Mechanisms with only Revolute Joints
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作者 杨加伦 高峰 +2 位作者 朱宽军 刘彬 司佳钧 《Journal of Donghua University(English Edition)》 EI CAS 2012年第2期134-138,共5页
Spatial straight line mechanisms are a class of spatial mechanisms whose end-effectors generate the trajectory with the form of exact straight lines, which have potential applications in many industrial sectors. This ... Spatial straight line mechanisms are a class of spatial mechanisms whose end-effectors generate the trajectory with the form of exact straight lines, which have potential applications in many industrial sectors. This study aims to synthesis the spatial straight line mechanisms with only revolute joints, meaning that no prismatic joints are included. According to the generalized function sets and the law of one dimensional rotation, the type of compositions of characteristic and the corresponding conditions are derived. Furthermore, some novel symmetrical and asymmetrical spatial straight line mechanisms are synthesized through assembling specific kinematic chains under the corresponding conditions. Finally, several synthesized spatial straight line mechanisms are illustrated to show the effectiveness of the synthesis methodology. 展开更多
关键词 spatial straight line mechanisms type synthesis generalized function set law of one dimensional rotation
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Activation of Sonic Hedgehog Signaling Pathway in S-type Neuroblastoma Cell Lines
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作者 周昱男 戴若连 +4 位作者 毛玲 夏远鹏 姚玉芳 杨雪 胡波 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第3期271-277,共7页
The effects of Sonic hedgehog(Shh) signaling pathway activation on S-type neuroblastoma(NB) cell lines and its role in NB tumorigenesis were investigated.Immunohistochemistry was used to detect the expression of Shh p... The effects of Sonic hedgehog(Shh) signaling pathway activation on S-type neuroblastoma(NB) cell lines and its role in NB tumorigenesis were investigated.Immunohistochemistry was used to detect the expression of Shh pathway components— Patched1(PTCH1) and Gli1 in 40 human primary NB samples.Western blotting and RT-PCR were used to examine the protein expression and mRNA levels of PTCH1 and Gli1 in three kinds of S-type NB cell lines(SK-N-AS,SK-N-SH and SHEP1),respectively.Exogenous Shh was administrated to activate Shh signaling pathway while cyclopamine was used as a selective antagonist of Shh pathway.S-type NB cell lines were treated with different concentrations of Shh or/and cyclopamine for different durations.Cell viability was measured by using MTT method.Apoptosis rate and cell cycle were assayed by flow cytometry.The xenograft experiments were used to evaluate the role of Shh pathway in tumor growth in immunodeficient mice.High-level expression of PTCH1 and Gli1 was detected in both NB samples and S-type NB cell lines.Cyclopamine decreased the survival rate of the three cell lines while Shh increased it,and the inhibition effects of cyclopamine could be partially reversed by shh pre-treatment.Cyclopamine induced the cell apoptosis and the cell cycle arrest in G0/G1 phase,while Shh induced the reverse effects and could partially prevent effects of cyclopamine.Cyclopamine could also inhibit the growth of NB in vivo.Our studies revealed that activation of the Shh pathway is important for survival and proliferation of S-type NB cells in vivo and in vitro through affecting cell apoptosis and cell cycle,suggesting a new therapeutic approach to NB. 展开更多
关键词 S-type neuroblastoma cell lines Sonic hedgehog signaling pathway CYCLOPAMINE
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Riemann Boundary Value Problem of Non-Normal Type on the Infinite Straight Line 被引量:2
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作者 Lixia Cao 《Applied Mathematics》 2013年第8期1226-1230,共5页
Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions hav... Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions have been widely investigated in [1-8]. The main ap- proach is to use the decomposition of polyanalytic functions and their generalization to transform the boundary value problems to their corresponding boundary value problems for analytic functions. Recently, inverse Riemann BVPs for generalized analytic functions or bianalytic functions have been investigated in [9-12]. In this paper, we consider a kind of Riemann BVP of non-normal type on the infinite straight line and discuss the solvable conditions and the general solution for it. 展开更多
关键词 Non-Normal type RIEMANN BOUNDARY VALUE Problem The INFINITE STRAIGHT line
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Human Embryonic St me Cell Lines fromthe Chinese Population and Differentiation to Liver and Muscle Cell Types
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作者 Hui Z. SHENG Zhen F. FONG Jun K. ZHENG Qian WANG(Center for Developmental Biology, Xinhua Hospital, Shanghai Second Medical University, Shanghai, 200092, China) 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2005年第S1期21-,共1页
关键词 CELL Human Embryonic St me Cell lines fromthe Chinese Population and Differentiation to Liver and Muscle Cell types CELL St
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Meshless Method of Lines for Numerical Solution of Kawahara Type Equations
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作者 Nagina Bibi Syed Ikram Abbas Tirmizi Sirajul Haq 《Applied Mathematics》 2011年第5期608-618,共11页
In this work, an algorithm based on method of lines coupled with radial basis functions namely meshless method of lines (MMOL) is presented for the numerical solution of Kawahara, modified Kawahara and KdV Kawahara eq... In this work, an algorithm based on method of lines coupled with radial basis functions namely meshless method of lines (MMOL) is presented for the numerical solution of Kawahara, modified Kawahara and KdV Kawahara equations. The motion of a single solitary wave, interaction of two and three solitons and the phenomena of wave generation is discussed. The results are compared with the exact solution and with the results in the relevant literature to show the efficiency of the method. 展开更多
关键词 Kawahara type EQUATIONS MESHLESS Method of lines (MMOL) RADIAL Basis Functions (Rbfs)
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浙江省山区输电线路塔位边坡变形破坏主要类型与防治建议
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作者 周欢良 胡谢飞 孙义杰 《山西建筑》 2025年第1期75-79,88,共6页
山区输电线路铁塔基础施工改变了塔位附近原始微地形、覆盖植被等环境地质条件,岩土体内部原有应力状态发生了变化,在各种自然营力作用下,每年在浙江省山区会发生一定数量塔位边坡的变形与破坏。根据影响因素、变形破坏机理分析,结合现... 山区输电线路铁塔基础施工改变了塔位附近原始微地形、覆盖植被等环境地质条件,岩土体内部原有应力状态发生了变化,在各种自然营力作用下,每年在浙江省山区会发生一定数量塔位边坡的变形与破坏。根据影响因素、变形破坏机理分析,结合现场勘查及实际情况,划分为坍塌、滑坡、流坍等边坡变形破坏类型,经研究总结得出其主要发育特征,并提出了防治建议。 展开更多
关键词 输电线路 边坡 变形破坏类型 发育特征 防治建议
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微带交指带通滤波器小型化结构设计
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作者 蒋建华 张杨 +1 位作者 侯明 李晓珍 《现代电子技术》 北大核心 2025年第1期112-116,共5页
文中提出在终端短路式交指带通滤波器的开路端引入一段微带加载线,使谐振器产生尺寸跳变。通过改变微带加载线的线宽,增加谐振器的等效电感值,从而实现降低该带通滤波器中心频率的目的,并且给出了在设计指标下,随加载线宽变化中心频率... 文中提出在终端短路式交指带通滤波器的开路端引入一段微带加载线,使谐振器产生尺寸跳变。通过改变微带加载线的线宽,增加谐振器的等效电感值,从而实现降低该带通滤波器中心频率的目的,并且给出了在设计指标下,随加载线宽变化中心频率变化的经验公式。对X波段的微带交指带通滤波器和微带线尺寸跳变进行了研究,研究数据表明:谐振器越短,中心频率往高频偏移越多;微带线尺寸跳变越大,中心频率往低频偏移越多。通过合理减小谐振器长度和增加微带加载线线宽,滤波器整体长度减小而宽度不变,且改进前后滤波特性不发生改变,达到了滤波器小型化的目的。通过在HFSS中建立滤波器模型并进行仿真,改进后增加了传输零点,回波损耗更加稳定,谐振器长度减小10%,微带加载线线宽增加0.15 mm,整体滤波器尺寸减小10%,验证了所提出结构的可行性。 展开更多
关键词 带通滤波器 交指型 微带加载线 小型化 HFSS 谐振器
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基于禁忌搜索的含异形板件的板式家具码垛优化算法
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作者 季晏庆 赵诗奎 《济南大学学报(自然科学版)》 北大核心 2025年第1期143-150,共8页
为了减少含异形板件的板式家具打包的包裹个数,提出基于禁忌搜索的该类板式家具码垛优化算法;分析该类板式家具码垛问题的约束条件,并建立目标函数;采用可以有效确定订单中所有该类板式家具码垛顺序与旋转方向的编码方式,并利用启发式... 为了减少含异形板件的板式家具打包的包裹个数,提出基于禁忌搜索的该类板式家具码垛优化算法;分析该类板式家具码垛问题的约束条件,并建立目标函数;采用可以有效确定订单中所有该类板式家具码垛顺序与旋转方向的编码方式,并利用启发式算法生成实时监测包裹质量的较优初始解,以便利用禁忌搜索求解该类板式家具码垛问题;结合临界多边形和最低水平线法,设计将编码转换为对应码垛方案的解码方式,并给出所提出算法的适配值函数及邻域结构;利用禁忌搜索计算该类板式家具订单,确定并优化每个板件的码垛顺序、旋转方向与码垛位置,得到包裹个数较少的码垛方案;选取欧洲排样问题兴趣小组(ESICUP)提供的算例测试所提出的算法,并与已有研究中可复现的板件智能分包方法对比。结果表明,相对于对比方法,所提出算法所得该类板式家具打包的包裹个数减少38.46%,验证了所提出算法的可行性与有效性。 展开更多
关键词 家具打包 码垛优化 禁忌搜索 异形板件 临界多边形 最低水平线法 板式家具
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On-line Popularity Monitoring Method Based on Bloom Filters and Hash tables for Differentiated Traffic 被引量:4
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作者 ZHANG Guo ZHANG Jianhui +1 位作者 WANG Binqiang ZHANG Zhen 《China Communications》 SCIE CSCD 2016年第S1期72-86,共15页
Towards line speed and accurateness on-line content popularity monitoring on Content Centric Networking(CCN) routers, we propose a three-stage scheme based on Bloom filters and hash tables for differentiated traffic. ... Towards line speed and accurateness on-line content popularity monitoring on Content Centric Networking(CCN) routers, we propose a three-stage scheme based on Bloom filters and hash tables for differentiated traffic. At the first stage, we decide whether to deliver the content to the next stage depending on traffic types. The second stage consisting of Standard Bloom filters(SBF) and Counting Bloom filters(CBF) identifies the popular content. Meanwhile, a scalable sliding time window based monitoring scheme for different traffic types is proposed to implement frequent and real-time updates by the change of popularities. Hash tables according with sliding window are used to record the popularity at the third stage. Simulation results reveal that this method reaches a 40 Gbps processing speed at lower error probability with less memory, and it is more sensitive to the change of popularity. Additionally, the architecture which can be implemented in CCN router is flexible and scalable. 展开更多
关键词 CCN line speed TRAFFIC type BLOOM filters HASH tables POPULARITY monitoring
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Numerical simulation of the temperature field within new type of monolayer freezing-shaft lining 被引量:4
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作者 CHEN, Xiaoxiang YANG, Weihao 《Mining Science and Technology》 EI CAS 2010年第2期198-203,共6页
Numerical simulation was used to estimate the temperature field within a poured concrete,mono-layer freezing-shaft lining.The affects from various factors were investigated.The maximum temperature within the lining in... Numerical simulation was used to estimate the temperature field within a poured concrete,mono-layer freezing-shaft lining.The affects from various factors were investigated.The maximum temperature within the lining increases as the lining thickness increases,decreases as the soil-side wall temperature decreases,decreases as the air temperature inside the shaft decreases and decreases as the air velocity inside the shaft increases.The compression speed of an insulating foam layer affects the maximum temperature difference between the interior and the sidewalls.The maximum temperature difference between the interior and the sidewalls approaches or exceeds the maximum allowable for the curing of poured concrete structures.Attention should be paid to the question of the lining cracking during the curing period.The temperature gradient in the vertical direction may be minimized by preventing air contact against the steel connection board supporting the base of the freshly poured section. 展开更多
关键词 new type MONOLAYER freezing shaft lining temperature field numerical simulation
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Study on a cold-cathode H^- PIG-type ion source 被引量:4
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作者 LONG Jidong YANG Zhen +2 位作者 DONG Pan HE Xiaozhong ZHANG Kaizhi 《Nuclear Science and Techniques》 SCIE CAS CSCD 2013年第4期1-4,共4页
A cold-cathode Penning Ion Gauge(PIG) type ion source as the internal ion source of an 11 MeV cyclotron is designed and tested at Institute of Fluid Physics.The design considerations and some testings are presented.Ex... A cold-cathode Penning Ion Gauge(PIG) type ion source as the internal ion source of an 11 MeV cyclotron is designed and tested at Institute of Fluid Physics.The design considerations and some testings are presented.Experimental results of Balmer-line-Emission show that the discharge characteristic,which is mainly determined by gas-flow rate,is not very sensitive to arc current and magnetic field in the operation ranges of the cyclotron.The arc power decreases and ascends while the gas-flow rate goes up from 0.5 SCCM to 20 SCCM.By improving the sealing design and reducing the machine tolerance of the source,the minimum power consumption reduces from 9 SCCM to 4 SCCM,thus having better energy efficiency and benefiting for the pumping system.Preliminary DC extractions show that H–microampere current ranges from several tens to hundreds under different operation conditions.Some problems during the experiments and future plan are discussed in the end. 展开更多
关键词 离子源 冷阴极 回旋加速器 G型 密封设计 实验过程 物理研究所 放电特性
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A New Type of Double-Lumen Catheter to Replace Current One in RCA 被引量:1
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作者 Yingfeng Xue Zhenguo Yu 《International Journal of Clinical Medicine》 2016年第9期620-627,共8页
Objective: To replace the peripheral venous puncture for blood sampling with taking blood samples extracorporally from arterial line before predilution during RCA-CRRT performed. Methods: A new type of double-lumen fe... Objective: To replace the peripheral venous puncture for blood sampling with taking blood samples extracorporally from arterial line before predilution during RCA-CRRT performed. Methods: A new type of double-lumen femoral catheter was used instead of the current tubes. The new type of double-lumen tube had a greater distance from the inner venous ports to the inner arterial ports than current tubes. The minimum distance from the venous port to the arterial port was greatly lengthened. Replacement solution contained citrate, zero Ca<sup>2+</sup>, zero bicarbonate, low Na<sup>+</sup>. Blood samples were synchronously collected from the arterial line before the infusion of citrate replacement fluid and from the peripheral vein. The iCa concentration data of two groups were analyzed to observe the difference between iCa concentration levels in the arterial line and in peripheral vein;the anticoagulant effect of RCA and possible complications were observed, such as bleeding, clottings and hypocalcaemia. Results: 28 times of RCA-CRRT were performed on17 AKI and CRF patients with active bleeding or at the high risk of bleeding;336 blood samples were collected. Statistics showed that the difference of iCa concentration between arterial line group and the peripheral vein group was not significant (P = 0.9), there is a high degree of similarity between the iCa concentration of arterial line blood and the peripheral venous blood. None of the patients developed citrate toxicity or metabolic alkalosis. None induced bleeding, or bleeding aggravated. No obvious clotting occurred. Systemic calcium concentration was achieved in the ideal range. Conclusion: In clinical practice, the data of iCa concentration from arterial line can be used to replace that from peripheral vein when the new type of double-lumen femoral catheter is placed in femoral vein. RCA-CRRT therapy is safe and effective. 展开更多
关键词 RCA-CRRT Ionized Calcium Arterial line Peripheral Vein New type of Double-Lumen Femoral Catheter
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STUDY ON THE LOG PRODUCTION LINE IN LOG YARD
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作者 Pan Delu Wang Jingxin Northeast Forestry University 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1991年第2期77-82,共6页
The article deals with the prduction lines in log yard by investigating the utilizationof machines in forest areas,presents the methods and rules of differentiating the log productionlines and also summarizes the form... The article deals with the prduction lines in log yard by investigating the utilizationof machines in forest areas,presents the methods and rules of differentiating the log productionlines and also summarizes the formation and development of three kinds of log production lines innortbeast forest areas of China.It gives different combination types of log production lines andtheir applications, so it is significant for us to evaluate and standardize the log Production lines. 展开更多
关键词 LOG production line The machines combining types LOG YARD FOREST LOGGING operations
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Properties and Stability of a Meso-Scale Line-Form Disturbance 被引量:1
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作者 沈新勇 丁一汇 赵南 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第2期282-290,共9页
By using the 3D dynamic equations for small- and meso-scale disturbances, an investigation is performed on the heterotropic instability (including symmetric instability and traversal-type instability) of a zonal lin... By using the 3D dynamic equations for small- and meso-scale disturbances, an investigation is performed on the heterotropic instability (including symmetric instability and traversal-type instability) of a zonal line-like disturbance moving at any angle with respect to basic flow, arriving at the following results: (1) with linear shear available, the heterotropic instability of the disturbance will occur only when flow shearing happens in the direction of the line-like disturbance movement or in the direction perpendicular to the disturbance movement, with the heterotropic instability showing the instability of the internal inertial gravity wave; (2) in the presence of second-order non-linear shear, the disturbance of the heterotropic instability includes internal inertial gravity and vortex Rossby waves. For the zonal line-form disturbance under study, the vortex Rossby wave has its source in the second-order shear of meridional basic wind speed in the flow and propagates unidirectionally with respect to the meridional basic flow. As a mesoscale heterotropic instable disturbance, the vortex Rossby wave has its origin from the second shear of the flow in the direction perpendicular to the line-form disturbance and is independent of the condition in the direction parallel to the flow; (3) for general zonal line-like disturbances, if the second-order shear happens in the meridional wind speed, i.e., the second shear of the flow in the direction perpendicular to the line-form disturbance, then the heterotropic instability of the disturbance is likely to be the instability of a mixed Rossby-internal inertial gravity wave; (4) the symmetric instability is actually the instability of the internal inertial gravity wave. The second-order shear in the flow represents an instable factor for a symmetric-type disturbance; (5) the instability of a traversal-type disturbance is the instability of the internal inertial gravity wave when the basic flow is constant or only linearly sheared. With a second or nonlinear vertical shear of the basic flow taken into account, the instability of a traversal-type disturbance may be the instability of a mixed vortex Rossby - gravity wave. 展开更多
关键词 line-form disturbance symmetric instability traversal-type instability heterotropic instability vortex Rossby wave wave property
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ECMWF降水相态预报产品(PTYPE)应用和检验 被引量:9
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作者 董全 胡宁 宗志平 《气象》 CSCD 北大核心 2020年第9期1210-1221,共12页
运用我国2016-2018年三个冬半年(10月至次年3月)地面2515个站的天气现象观测资料,对ECMWF(European Centre for Medium-Range Weather Forecasts)的降水相态预报产品(PTYPE)(分为雨、雨夹雪、雪和冻雨四类)进行了系统性的检验评估,包括... 运用我国2016-2018年三个冬半年(10月至次年3月)地面2515个站的天气现象观测资料,对ECMWF(European Centre for Medium-Range Weather Forecasts)的降水相态预报产品(PTYPE)(分为雨、雨夹雪、雪和冻雨四类)进行了系统性的检验评估,包括细网格确定性模式预报产品和集合预报系统概率预报产品。结果显示,ECMWF的确定性预报产品对四类降水相态的正确率普遍达到90%以上,对降雨和降雪的TS评分也较高,冻雨次之,雨夹雪的TS评分较低,预报能力有限。确定性模式对我国雨雪分界线的预报,普遍存在短期位置略偏南、中期随时效延长越来越偏北的误差特点,且对雨夹雪的预报范围明显偏小,对冻雨的预报范围明显偏大。集合预报系统从概率的角度一定程度上弥补了确定性模式的上述误差。对概率预报的检验结果显示,集合预报系统降雨概率普遍偏低,降雪概率短期偏高、中期偏低,而雨夹雪和冻雨概率普遍偏低,但是都有一定的预报技巧。集合预报系统相对于确定性模式的优势,降雨体现在较小花费损失比事件的预报上,降雪体现在较大花费损失比事件的预报上。对雨夹雪和冻雨,相对于确定性模式,集合预报系统体现出了显著的优势,尤其是冻雨,集合预报系统的优势更加明显。 展开更多
关键词 ECMWF 降水相态预报产品(Ptype) 雨雪分界线 检验
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Experimental Study on the Flow Characteristics of ¬-Type Groyne
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作者 Joongu Kang Hongkoo Yeo 《Engineering(科研)》 2011年第10期1002-1011,共10页
A hydraulic model test for ¬-type groynes (with “¬” shape) was conducted to analyze the flow characteristics around these groynes. The results of the model tests are expected to be used as fundamental information ... A hydraulic model test for ¬-type groynes (with “¬” shape) was conducted to analyze the flow characteristics around these groynes. The results of the model tests are expected to be used as fundamental information in designing the ¬-type groyne constructed in the field. Main hydraulic factors such as velocity and thalweg line changes in the main channel and separation area were analyzed in this study. The thalweg line is a stream line where the maximum velocity occurs, whereas the separation area is the boundary between the main flow and the recirculation zone. Model tests with 5 different arm lengths of the ¬-type groynes were conducted by changing the velocity. The LSPIV (Large-Scale Particle Image Velocimetry) technique was used to measure and analyze flow variation around the ¬-type groynes. The velocity in the main channel measured to be increased by 1.5 times. The velocity variation on groyne arm length is little. The width of the thalweg lines (TCL) was changed to 55 - 57% of the channel width. The Froude number did not affect the thalweg line (TCL) and separation line (Sh) changes, however. 展开更多
关键词 ¬-type type Groyne THALWEG line SEPARATION line Recirculation ZONE LSPIV
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蓖麻Lm型雌性系及其杂交组合的杂种优势分析
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作者 周伟 余忠浩 +1 位作者 刘慧 周亚星 《西北农业学报》 CAS CSCD 北大核心 2024年第7期1274-1281,共8页
为了解Lm型雌性系蓖麻的配合力遗传基础,以5个蓖麻Lm型雌性系为母本,3个蓖麻两性系为父本,根据NC-Ⅱ不完全双列杂交组配15个杂交组合,对蓖麻杂交组合的配合力、遗传力以及杂种优势进行分析。结果表明:雌性系A1和两性系B2的GCA和杂交组合... 为了解Lm型雌性系蓖麻的配合力遗传基础,以5个蓖麻Lm型雌性系为母本,3个蓖麻两性系为父本,根据NC-Ⅱ不完全双列杂交组配15个杂交组合,对蓖麻杂交组合的配合力、遗传力以及杂种优势进行分析。结果表明:雌性系A1和两性系B2的GCA和杂交组合SCA在蓖麻大部分农艺性状中均表现优秀,可在提高蓖麻产量的亲本选育中作为优异亲本进行杂交组合的构建。对亲本杂种优势研究发现,两性系B2参与组配的杂交组合在多个农艺性状上表现为强杂种优势,而Lm型雌性系则表现为在单个性状上具有较强的杂种优势。从遗传力分析结果来看,蓖麻的主茎蒴果数、一级分枝蒴果数、主茎穗长、主茎节数、一级分枝百粒质量和产量受加性效应和非加性效应共同影响,且受环境影响较小,适宜在早代进行选择。 展开更多
关键词 蓖麻 Lm型雌性系 杂种优势 配合力 遗传力
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