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1.
J. P. Wilson 《Plant Breeding》1997,116(3):239-243
Quantitative disease resistance should be exploited to complement the use of genes for qualitative or hypersensitive resistance. The expression and inheritance of partial rust resistance of pearl millet inbreds 700481-21-8 and ‘ICMP 501’ crossed to moderately susceptible Tift 383’ were evaluated in seedling assays in the greenhouse and in generation mean and single-seed descent populations in the field. Uredinium sizes on seedling leaves of hybrids were generally intermediate to those of the parental inbreds and consistent differences could be discerned in uredinium lengths. Area under the disease progress curves (AUDPCs) of individual plants of the parents, F1, F2, and backcross F1S to each parent were determined from field trials. Broad-sense heritability estimates for both crosses were 43%. In generation mean analyses, additive genetic effects were significant in the cross of 700481–21–8 × Tift 383′, whereas additive, dominance, and dominance × dominance epistatic effects were significant for ‘ICMP 501’בTift 383’. The number of genes conferring partial resistance was estimated to be two for 700481–21–8 and 2.5 for ‘ICMP 501’. A hierarchical single-seed descent analysis revealed significant differences in AUDPC among F3-derived F4 progenies in the F6 generation. Selection for progenies with greater resistance should be possible among F4 families. Higher levels of resistance were observed in progeny derived from ‘ICMP 501’. Because segregation of resistance differed among progeny derived from 700481–21–8 and ‘ICMP 501’, the genetic basis for resistance probably differs between the two inbreds.  相似文献   

2.
To solve the frequency dispersive feature in powerline channel, the quthors analyzed the anti-interference performance of modulation schemes with different subcarrier bases, and use orthogonal wavelet packet as subcarrier base instead of sine base in OFDM to suppress multi-path effect and frequency selective fading by its orthogonality in powerline channel. Through experiment, performances of wavelet packet modulation with different wavelet packets and OFDM are analyzed. Experiment results indicate that when the SNR has reached a certain level, orthogonal wavelet packet modulation has better performance than bi-orthogonal wavelet packet and sine base.  相似文献   

3.
Numerous studies have shown that packet reordering is common,especially at wireless and Satellite networks where there are high degree of parallelism and different link speeds.Packets reordering decreases TC Pperformance,because it leads to over estimation of network congestion.The CETEN(Cumulative Explicit Transport Error Notification) has solved the overestimation caused by packet corruption.However,it does not consider the reordering at wireless network,which makes the LEAST(Loss Estimations AlgorithmS for TCP) loss rate value imprecise.The solution is based on explicit spurious retransmit notification at receiver side,and signals the sender packet loss caused by reordering packet.This mechanism can improve precision of LEAST and make the TC Pmore robust.The method is showed efficient in experiment.  相似文献   

4.
Through many tests and standard analysis,the effects of solution concentration and temperature on rate of concrete sulfate attack were investigated.The test results show that when solution concentration and temperature are lower than certain value,the speed of attack is accelerated with increasing concentration and temperature,however,higher temperature and concentration of solution may decrease the rate of attack.The speed of attack of sodium sulfate is faster than the one of attack of magnesium sulfate under various factors.It is suitable to adopt the coefficient of tensile as the accelerated assessing criterion for the attack of sodium sulfate.The coefficient of tensile and compressive strength should be considered together for the attack of magnesium sulfate.  相似文献   

5.
Through many tests and standard analysis, the effects of solution concentration and temperature on rate of concrete sulfate attack were investigated. The test results show that when solution concentration and temperature are lower than certain value, the speed of attack is accelerated with increasing concentration and temperature, however, higher temperature and concentration of solution may decrease the rate of attack. The speed of attack of sodium sulfate is faster than the one of attack of magnesium sulfate under various factors. It is suitable to adopt the coefficient of tensile as the accelerated assessing criterion for the attack of sodium sulfate. The coefficient of tensile and compressive strength should be considered together for the attack of magnesium sulfate.  相似文献   

6.
以青麦仁为主要原料,对青麦仁预制菜肴的配方和加工工艺进行研究。结果表明,原料包最佳工艺为:熟制时间2 min,熟制温度95℃,炒制时间2 min,炒制油量4%,炒制温度165℃;以400 g青麦仁为基准,酱包的最佳配方为:蔗糖14 g,食盐1.5 g,酱油10 g,色拉油15 g,淀粉1 g,黄原胶0.05 g,单硬脂酸甘油酯0.24 g;原料包和酱包的储藏试验结果表明:经过灭菌后的酱包和原料包在储藏第30天时的菌落总数分别为1.9 lg(CFU/g)和3.0 lg(CFU/g),符合食品标准规定。  相似文献   

7.
Since there exists multi-protocol attack when several security protocols are co-executed in a computer network, an automatic detection system for multi-protocol attack (ADMA) is proposed. The system is composed of two parts named protocol search subsystem and attack verification subsystem. According to the consistency condition of the type of encrypted messages between the target protocol and the secondary protocol, the protocol search subsystem can automatically search for the candidate secondary protocols, which may be used to attack the target protocol. By improving the SAT-based model checking, attack verification subsystem can automatically verify whether multi-protocol attack exists between the target protocol and the candidate secondary protocols or not. The experiment results show that ADMA system can implement automatic detection for multi-protocol attack, and some new multi-protocol attacks are found in the detection.  相似文献   

8.
There are background noises and interferences in the signal acquired,due to partial discharge(PD) detection system covers a broad frequency band.To suppress periodic narrowband signal which is a quite serious interference in PD measurement,the existing suppression method is introduced,the new method of wavelet packet transform is mainly studied to de-noise the periodic narrowband in XLPE cable PD detection system,which is based on the db4 basic wavelet using soft threshold.The results of the experiment show that wavelet packet transform is effective in restraining the periodic narrowband interferences to extract the PD pulses in XLPE cable PD monitoring system.  相似文献   

9.
In this paper,six reinforced concrete beams dismounted from their worksites under long-term sulphate attack are studied.The authors analyzed the working properties and cracking moment of the reinforced concrete beams under long-term sulphate attack,suggesting that the reinforced concrete beams under long-term sulphate attack may have more favorable cracking-resistant behavior in some circumstances.  相似文献   

10.
‘BJ 104’ was the most widely grown pearl millet hybrid in India until it became susceptible to downy mildew (DM) in 1984—85. Residual variability for resistance was found in both parental lines, 5141 B (maintainer of 5141 A) and J 104, and through four generations of pedigree selection under intense disease pressure in the DM nursery, two lines, IC-MA841 (from 5141 B) and ICMP 84814 (from J 104), were selected resulting in a reconstituted DM resistant hybrid (‘ICMH 84814’) which was equal in yield to the original ‘BJ 104’. The reconstituted hybrid, though phenotypically similar, can be distinguished from “BJ 104” being slightly taller, flowers later, has heavier heads, and 1000-seed weight, but tillers less. A similar exercise was attempted on Tifton 23 B, the female parent of the first widely grown hybrid (‘HB 3’— the male parent was also J 104), but no variability for resistance to DM was found.  相似文献   

11.
In order to improve the alerts quality and prediction capability of traditional intrusion detection systems (IDS), the advanced alerts correlation algorithms are proposed, which is based on attack scenarios modeling using colored petri net (CPN). The current analysis approach information filtering is updated to messages logic deduction by reasoning under the model. The alert and the attack are converted to two different parameters for computation. By means of transforming CPN model and calculating the minimal covering set, the algorithms for multi-step attack and cooperative attack are designed. The experimental alerts correlation analysis system (ACAS) is programmed. That experiment results indicate that these algorithms could be applied to improve the alerts quality and prediction ability of IDS effectively.  相似文献   

12.
The influence of three kinds of additives: silica fume,slag and fly ash on the sulphate attack resistance of concrete were studied.The experiment results show that these three kinds of additives can improve sulphate attack resistance of the concrete and the order of their efficiency from high to low is silica fume,slag and fly ash;the development of mortar expansion value is closely related to the degree of sulphate attack resistance of the concrete;integrated assessing two concrete properties: mortar expansion value and compressive strength ratio can more exactly assess the sulphate attack resistance of the concrete.  相似文献   

13.
为探究大攻角及桥面粗糙度对扁平钢箱梁涡振性能的影响,对寸滩长江大桥主梁进行了风洞试验。应用Matlab软件模拟桥面粗糙度变化范围,根据模拟结果选取对应的砂纸在试验中模拟桥面粗糙度,分析了攻角及桥面粗糙度对扁平钢箱梁涡振区间及幅值的影响。试验研究表明:在大攻角下扁平钢箱梁的涡振振幅和范围明显增大,对桥址位于山区等容易发生大风攻角的地区的桥梁应进行大攻角试验。扁平钢箱梁的涡振响应随着桥面粗糙度增大而减小。正攻角范围内,桥面粗糙度对涡振响应的影响随着攻角减小而增大。桥面粗糙度发生变化时,扭转涡振响应更加敏感,变化幅度大于竖向涡振响应变化幅度。  相似文献   

14.
The paper proposes a reliable multicast protocol which is appropriate for real-time and interactive collaborative environment. The control tree and grouping mechanism are introduced to make error recovery localized, which can efficiently decrease the amount of packet stream on the backbone of network and the workload of host. Analysis shows that the protocol has perfect throughput and can be extended to very wide applications.  相似文献   

15.
大豆抗源抗SCN过程中POD酶动态分析   总被引:4,自引:0,他引:4  
能动地大豆抗源抗孢囊线虫(SCN)过程中过的氧化物酶(POD)活性和酶谱的变化研究,探讨了大豆抗源在抗病过程中是通过提高体内POD酶活性来抵御SCN的侵染,抗源品种POD活性和酶谱呈动态变化。在侵染高峰期(30 ̄35d),高抗抗原体内POD酶活性最强,酶谱着色较深;而感病品种在侵染高峰期POD酶活性降至最低值,且一些酶带受损以至消失。另外,证实了POD酶在抗病过程中参与木质素的合成。抗病过程中酶活  相似文献   

16.
Summary Orobanche attack on twelve broad bean cultivars was measured in connection with vegetative growth by means of two pot tests with different innoculum densities. Orobanche attack appeared to be related to the growth vigour of the host. The higher the root and shoot biomass of a cultivar, the higher the number and the more advanced the development of the tubercles was, independent of innoculum density. Therefore, in spite of the observed variation for Orobanche attack, the tested cultivars were considered to have the same level of susceptibility, however with exception of BPL 2210. This cultivar showed a lower attack than was expected of its growth vigour.Hollandseweg 2, 6706 KP Wageningen, the Netherlands.  相似文献   

17.
The traditional routing protocol for wireless mobile ad hoc networks is unable to achieve balanced energy consumption and could not adapt to the dynamic topology changes well.A novel on-demand rooting algorithm is proposed based on load balancing and mobility prediction.The proposed rooting algorithm excludes the unstable links in routing discovery,and allows the node with more energy forward the routing request packet preferentially.In addition,it adopts the active local routing recovery strategy by predicting the link connection time,and finishes the repair work before the link being actually failure.The simulation experiments demonstrate that,comparing with the traditional AODV protocol,with slight increase of the rooting control overhead,the proposed algorithm increases the average packet delivery ratio,decreases the average end-to-end delay of the data packets,and achieves load balancing in the network and prolong the life-span of the network,which shows the proposed algorithm is highly practical.  相似文献   

18.
为了实时监测‘富士’苹果的贮藏环境,维持冷库内苹果的高品质。在Zigbee技术和GPRS数据传输技术应用的基础上,结合温湿度、CO2乙烯传感器等模块,设计了一组数据采集节点,构建了冷库环境中的无线传感网络,同时利用J2EE技术开发了‘富士’苹果贮藏期品质安全预警远动系统,解决了数据采集和冷库实时环境监测及远程数据预警问题。在温度分别为0℃、相对湿度为90%及CO2浓度为1%的环境下对冷库进行了数据传输包收发率测试。测试结果表明,收包率可达80%以上。通过使用本系统,可以有效的对冷库内的‘富士’苹果品质安全进行实时远程监控。  相似文献   

19.
20.
The durability of concrete is always a problem of great importance while the high performance concrete raise higher requirement for durability. The authors of this paper carried out a study on resistance to chemical attack of the high performance concrete prepared with Portland cement, silica fume and superplasticizer ,which has proved that the high performance concrete offers excellent resistance to chemical attack.  相似文献   

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