共查询到20条相似文献，搜索用时 15 毫秒
1.
[目的]为发展麻江大蒜产业提供科学参考依据。[方法]测定麻江红蒜3种不同种植方式下的产量、植株性状、根系分布范围和数量、叶面积大小和保绿期等指标。[结果]麻江红蒜实行稻草免耕种植比其他2种种植方式增产显著,产量达804.5 kg,比无覆盖物种植(对照)增产31.7%。[结论]稻草覆盖地面的栽培方式能够有效改善大蒜的生长环境。 相似文献
2.
In proteins homologous to the green fluorescent protein (GFP), formation of red fluorescence requires three autocatalytic steps, whereas only two are needed for green fluorescence. Multiple red/green color diversification events in the GFP superfamily may reflect convergent evolution of the more complex three-step pathway. In the great star coral Montastraea cavernosa, a recreated common ancestor of green and red proteins turned out to be green, indicating that in this case red proteins evolved their color independently from most other homologous red proteins. Furthermore, red color appears to have evolved gradually by small incremental transitions. 相似文献
3.
云南省烟蚜红绿2种体色生物型的差异 总被引：2，自引：0，他引：2
从形态学和生物学方面对云南省红绿2种体色生物型烟蚜进行了研究,并用类平均法对形态特征指标进行了聚类分析。结果表明：红色型有翅烟蚜和绿色型有翅烟蚜的体长、触角、额瘤、尾片及尾板等形态特征上存在显著性差异;红色型烟蚜的产仔量、寿命及生殖期均显著高于绿色型烟蚜;2种体色生物型烟蚜的种群增长曲线均为S型,红色型烟蚜的种群饱和时的密度较绿色烟蚜高,但自然反应时间较绿色烟蚜短。 相似文献
4.
Field experiments to evaluate four different colored sticky cards for trap-ping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yel ow, blue, green, and red... 相似文献
5.
王文生 《山西农业大学学报(自然科学版)》1993,13(3):233-236
采用“84·567”固体涂膜剂对甜椒做全果涂膜处理进行贮藏保鲜,试验结果表明:经过60天左右的贮藏,涂膜处理的果实平均好果率82.2%,商品率92.8%。与对照相比,自然损耗率、腐烂率平均降低5.7％和22.8%,腐烂指数、花萼枯萎指数及呼吸强度均显著降低,转红指数、转红率也有所下降。 相似文献
6.
Molecular genetics of human blue cone monochromacy 总被引：19，自引：0，他引：19
J Nathans C M Davenport I H Maumenee R A Lewis J F Hejtmancik M Litt E Lovrien R Weleber B Bachynski F Zwas 《Science (New York, N.Y.)》1989,245(4920):831-838
Blue cone monochromacy is a rare X-linked disorder of color vision characterized by the absence of both red and green cone sensitivities. In 12 of 12 families carrying this trait, alterations are observed in the red and green visual pigment gene cluster. The alterations fall into two classes. One class arose from the wild type by a two-step pathway consisting of unequal homologous recombination and point mutation. The second class arose by nonhomologous deletion of genomic DNA adjacent to the red and green pigment gene cluster. These deletions define a 579-base pair region that is located 4 kilobases upstream of the red pigment gene and 43 kilobases upstream of the nearest green pigment gene; this 579-base pair region is essential for the activity of both pigment genes. 相似文献
7.
绿盲蝽滞育与非滞育卵的形态学观察 总被引：4，自引：0，他引：4
在河南省新乡市采集绿盲蝽成虫的非滞育种群和自然越冬种群置于室内饲养,收集其所产的卵进行观察,并将越冬卵放入4℃冰箱经过低温处理后重新进行孵化.结果表明,越冬卵在温度26℃,相对湿度80%±10%,光照L:D=16:8的试验条件下不能像非滞育卵一样正常孵化,经低温处理60 d后能够正常孵化,说明了绿盲蝽以卵的滞育进行越冬的特性.非滞育卵在相同条件下孵化5 d以后出现红色复眼,随后卵变为黄绿色;而滞育卵同样条件下进行孵化并不出现红色复眼且颜色为黄色. 相似文献
8.
香椿苗期几个光合特性的研究 总被引：3，自引：0，他引：3
研究结果表明，香椿品系间的光合能力和光合特性存在差异。红芽品系和红叶品系的光合能力高于绿芽品系。红芽品系的光饱和点为３０ＫＬＸ，而绿芽品系为１０～４０ＫＬＸ。红芽品系的光合适温为２０～２２℃（春季），而绿芽品系为１６～２４℃。香椿苗期的光合能力和光合特性亦存在季节性差异。净光合速率（Ｐｎ）在春季出现高峰，夏初低谷，从仲夏至秋冬变化平缓且Ｐｎ值低于春季。秋季的光合适温比春季高２℃，为２２～２４℃。在晴天，香椿苗光合日变化呈双峰型，上午大峰，下午山峰，中午低谷。综合分析表明，小气候因子中强光、高温和低湿是造成中午Ｐｎ降低的主要原因。 相似文献
9.
稻叶瘟对水稻光谱特性的影响研究 总被引：33，自引：0，他引：33
本文通过对4个感染不同等级稻叶瘟的水稻冠层反射光谱进行测试，并对光谱反射曲线进行微分分析，研究了绿光区、红光区和近红外区反射光谱的变异特征。结果表明：绿光区、红光区和近外区的水稻冠层光谱反射率随病情程度的加重分别呈现下降、上升和下降的趋势；绿光吸收边缘的特征波长值发生红移，红光吸收边缘和近红外吸收边缘的特征波长值发生蓝移。受害轻时近红外区反射率变化幅度大，受害重时绿光区和红光区反射率变化幅度大。本研究为应用遥感技术早期探测稻叶瘟的发生提供了实验依据。 相似文献
10.
Direct excitatory interactions between cones of different spectral types in the turtle retina 总被引：2，自引：0，他引：2
Cone linear sensitivities to red and green stimuli were measured intracellularly in the dark- and light-adapted turtle retina. Test flashes of small diameter were used to minimize horizontal cell feedback. Light adaptation was achieved with either green or red background illumination. The ratio of cone sensitivities to red and green light depended on the color of the background light and differed from the ratio measured in the dark. Electron microscope studies of Golgi-stained turtle cones revealed direct synaptic connections between red and green cones mediated by cone telodendria. These data indicate that the red cone photoresponse is not univariant as has been previously supposed and suggest that mixing of signals from different spectral classes of cones can occur via direct excitatory connections between cones. 相似文献
11.
[目的]明确共生菌对不同体色型麦长管蚜的影响。[方法]用利福平处理得到不同体色型脱共生麦长管蚜,对脱共生及共生麦长管蚜的总蛋白含量和转氨酶活力进行分析。[结果]与共生蚜虫相比,绿色型和红色型麦长管蚜的营养状况均明显恶化,且红色型麦长管蚜的营养状况恶化程度要比绿色型麦长管蚜高;经抗生素脱共生处理后麦长管蚜虫体内氨基酸之间的转换遭到干扰,且红色型麦长管蚜受到干扰较大;经抗生素脱共生处理后麦长管蚜体内氨的转运受到干扰,且红色型麦长管蚜受到干扰较大。[结论]共生菌对2种体色型麦长管蚜均有着重要的影响。 相似文献
12.
以遵义市长岗镇为例,分析其红色旅游与绿色生态发展双轮驱动的优势和存在问题,优势主要体现在红色文化资源丰富,绿色生态产业基础好,生态环境良好;问题主要体现在地处山区,交通不便,红色文化资源保护欠佳,配套基础设施滞后,旅游人才严重缺乏。结合长岗镇的生态、经济、社会发展现状,提出红色旅游与绿色生态发展双轮驱动的具体路径,即深挖红色资源的文化内涵、探索市场化的红色旅游开发模式、提高红色旅游从业人员的整体素质、提升红色资源的旅游价值、加快绿色生态产业优化升级、推动红色旅游与生态旅游协同发展。 相似文献
13.
[目的]明确红色型和绿色型豌豆蚜(Acyrthosiphon pisum)的种群数量变化机制,探索2种色型豌豆蚜的种内密度效应对其种群增长的影响。[方法]在温室内设置不同的密度梯度,单种色型豌豆蚜密度设置为8、16、24、32头/株,2种色型共存时红色型和绿色型密度分别设置为4∶4、8∶8、16∶16头/株。[结果]单种色型豌豆蚜从密度8头/株增至32头/株时,随着密度的升高,2种色型豌豆蚜的产蚜期和寿命显著缩短,产蚜量显著降低,说明2种色型豌豆蚜种群密度效应均存在一定的负效应。在总密度为8和16头/株时,2种色型豌豆蚜混合饲养的产蚜期、寿命与单种色型饲养相比无显著差异;在单种色型饲养的密度与混合饲养的同一色型密度相同时,由于混合饲养的总密度高于单种色型饲养,混合饲养的产蚜期、寿命显著短于单种色型饲养,产蚜量显著低于单种色型饲养;在密度为32头/株时,单种群饲养的产蚜期、寿命、单头产蚜量与混合饲养时无显著差异。在单种色型饲养条件下,同一密度下(16头/株除外)红色型豌豆蚜的发育历期显著长于绿色型豌豆蚜,在相同密度条件下,红色型豌豆蚜的产蚜期、寿命、产蚜量与绿色型豌豆蚜相比无显著差异;混合饲养中,在同一密度条件下,红色型豌豆蚜的产蚜期、寿命、产蚜量与绿色型豌豆蚜相比无显著差异。[结论]红色型豌豆蚜在该环境条件下的竞争力与绿色型豌豆蚜相当,红色型豌豆蚜与绿色型豌豆蚜共存对环境表现了一定的适生性。 相似文献
14.
[目的]为控制和延缓采后果蔬抗坏血酸（ASA）含量的下降提供理论支持。[方法]以采后红提和青椒为试材,研究热激和储藏温度对其ASA含量及代谢相关酶活性变化的影响。[结果]15℃下青椒和红提的ASA含量下降比25℃下慢。经过10 min热激处理后,红提的ASA含量瞬间上升,随后迅速下降;青椒中ASA含量有部分损失。说明热激处理不能有效延缓红提ASA含量的下降,可以延缓青椒ASA含量的下降,提高青椒贮藏品质。不同温度下抗坏血酸过氧化物酶（APX）和抗坏血酸氧化酶（AAO）活性均呈下降趋势。经过10 min热激处理后,红提的APX和AAO以及青椒的AAO活性瞬间下降明显,红提和青椒中脱氢抗坏血酸还原酶（DHAR）活性瞬间提高,随后迅速降低;而红提中单脱氢抗坏血酸还原酶（MDAR）活性提高,青椒中MDAR活性降低。[结论]在储藏过程中,DHAR的活性可能是影响ASA含量变化的重要因素。 相似文献
15.
In this study, we established a dynamic morphological model using the accumulated thermal effectiveness and photosynthetic active radiation(PAR)(A-TEP), aiming to explore the relationship between muskmelon(Cucumis melo L.) fruit attributes and environmental factors. Muskmelon surface color was described by parameters of red, green, blue, hue, saturation and brightness(HSI). Three characteristic parameters, gray level co-occurrence matrix(GLCM), angular second moment(ASM), entropy, contrast, and the coverage rate were used to describe the process of muskmelon fruit netting formation. ASM was not significant difference during muskmelon fruit growth. The number and deep of netting stripes gradually increased with fruit growth. Coverage rate increased rapidly for 15–30 d after pollination. The vertical and horizontal diameters of muskmelon fruit were followed a logistic curve. And root mean squared errors(RMSE) between the simulated and measured vertical and horizontal diameters were 3.527 and 4.696 mm, respectively. RMSE of red, green, blue, saturation and brightness were 0.999, 2.690, 2.992, 0.033 and 5.51, respectively, and the RMSE for entropy, contrast and coverage rates were 0.077, 0.063 and 0.015, respectively, indicating a well consistent between measured and simulated values. 相似文献
16.
从陕西省清涧红枣绿色食品产业的执行标准、红枣无公害田间栽培管理技术、绿色食品标志认证及加工生产等方面提出标准化指标体系。 相似文献
17.
The united efforts of assemblies of neurons in the brain's primary visual cortex translate incoming visual signals into action potentials. These action potentials encode, for example, the contrast and orientation of different parts of the image. Some neurons are sensitive to one particular orientation, other are sensitive to other orientations, but all neurons respond equally well to the image contrast. In a Perspective, Volgushev and Eysel explain the finding (Anderson et al.) that neurons are able to maintain this sensitivity to the orientation of a stimulus regardless of the contrast by adding noise to the membrane potential, such that action potentials can also be generated in response to weak signals at low contrast. 相似文献
18.
Four color names-red, yellow, green, and blue-can be used singly or combined in pairs to describe all other colors. Orange, for example, can be described as a reddish yellow, cyan as a bluish green, and purple as a reddish blue. Some dyadic color names (such as reddish green and bluish yellow) describe colors that are not normally realizable. By stabilizing the retinal image of the boundary between a pair of red and green stripes (or a pair of yellow and blue stripes) but not their outer edges, however, the entire region can be perceived simultaneously as both red and green (or yellow and blue). 相似文献
19.
北京城市居住区绿地的滞尘效益 总被引：78，自引：2，他引：78
该文比较分析北京城市居住区３种不同结构类型的绿地（乔灌草型、灌草型和草坪型）的滞尘效益，并且定量估算北京城近郊８区居住区绿地滞尘量．同时认为由乔、灌、草构成合理的绿化结构，能充分利用空间，最大可能地提高绿地上的绿量，具有较好的滞尘效益． 相似文献
20.
When observers who watched repeated alternations of a red contracting spiral and green expanding spiral were later shown stationary spirals, red and a green the red stationary spiral appeared to be expanding and the green stationary spiral appeared to be contracting. These color-contingent motion after effects complement reports of motion-contingent color aftereffects and suggest that both may reflect adaptation of detectors specific to color and motion. 相似文献