检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

滇重楼组织培养初代培养体系初探

农业与技术 2023年第3期43卷 18-21页

作者：李金月陈志怡毕节职业技术学院贵州毕节551700

本文以滇重楼为试验材料,研究了初代诱导培养基中添加不同浓度6-BA、2,4-d和盐酸特比萘芬对外植体生长的影响。结果表明,初代诱导培养基中添加2.5mg·L^(-1)6-BA、1.0mg·L^(-1)2,4-d和150mg·L^(-1)盐酸特比萘芬,可以诱导滇重楼根状茎... 详细信息

本文以滇重楼为试验材料,研究了初代诱导培养基中添加不同浓度6-BA、2,4-d和盐酸特比萘芬对外植体生长的影响。结果表明,初代诱导培养基中添加2.5mg·L^(-1)6-BA、1.0mg·L^(-1)2,4-d和150mg·L^(-1)盐酸特比萘芬,可以诱导滇重楼根状茎的第1节间形成较多、质量较好的丛生芽,并对控制外植体的真菌类污染起到一定作用。

关键词：滇重楼培养基诱导 6-BA 2 4-d

In-Vitro Production of Anthocyanin in Sesbania grandiflora (Red Katuray) as Influenced by Varying Concentrations of 2,4-d and BA Added on MS Medium

在线全文

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2016年第15期7卷 2297-2306页

作者： donata A. Largado-Valler College of Agriculture Dr. Emilio B. Espinosa Sr. Memorial State College of Agriculture and Technology Mandaon Philippines

The study aimed to determine the anthocyanin content in callus cultures of Sesbania grandiflora L. (Red Katuray) using petal explants as influenced by 2,4-d and BA. The specific objective of this study is to determine the effect of plant growth regulators specifically auxin (2,4-d) and BA (Benzyladenine) on Murashige and Skoog’s (MS) medium in anthocyanin production. Earliest callus initiation was noted in 2.5 ppm to 5.0 ppm 2,4-d without BA and 2.5 ppm 2,4-d with 2.5 ppm BA. Same treatment combination had the highest degree of callus formation and obtained the greatest percentage of callus formation 2.5 ppm 2,4-d without BA and 2.5 ppm 2,4-d with 2.5 ppm BA. The heaviest weight of callus was registered at 2.5 ppm 2,4-d without BA. Significantly higher anthocyanin content was noted in 2.5 ppm to 5.0 ppm 2,4-d without or with 2.5 ppm BA, with 2.5 and 5.0 ppm BA and with 5.0 ppm 2,4-d and 2.5 ppm BA. There is a positive relationship between callus formation and anthocyanin production. Results showed that treatments that promoted significantly greater callus formation e.g. 2.5 ppm 2,4-d alone or in combination with 2.5 ppm BA also produced the highest anthocyanin content.

关键词： Anthocyanin In Vitro 2 4-d BA

“探究2,4-d对插枝生根的作用”实验中因变量的确定

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

生物学教学 2023年第6期48卷 55-56页

作者：王维浙江省平阳县鳌江中学温州325401

“探究2,4-d对插枝生根的作用”是浙科版高中生物学教材选择性必修1教材中的重要实验,实践中一些师生对该实验中的因变量常有疑惑,本文选择常见的碰碰香作为实验材料展开探究。发现2,4-d浓度在2.5×10-4—2.5×10-14g/L浓度范围内,对根... 详细信息

“探究2,4-d对插枝生根的作用”是浙科版高中生物学教材选择性必修1教材中的重要实验,实践中一些师生对该实验中的因变量常有疑惑,本文选择常见的碰碰香作为实验材料展开探究。发现2,4-d浓度在2.5×10-4—2.5×10-14g/L浓度范围内,对根的平均长度和根的总长度作用差异不明显,但是对根的数量有显著的差异。该探究可为师生提供一定的参考。

关键词：因变量2 4-d 碰碰香总根长平均根长生根数

Modeling the Interior of Black Holes Utilizing a 4-d Spatial Blackbody Radiation Model with an Exponential distribution

在线全文

学校读者我要写书评

暂无评论

Journal of High Energy Physics, Gravitation and Cosmology 2019年第3期5卷 953-983页

作者： Christopher Pilot Physics department Gonzaga University Spokane WA USA

This is a second follow up paper on a model, which treats the black hole as a 4-d spatial ball filled with blackbody radiation. For the interior radiative mass distribution, we employ a new type of truncated probability distribution function, the exponential distribution. We find that this distribution comes closest to reproducing a singularity at the center, and yet it is finite at 4-d radius, . This distribution will give a constant gravitational acceleration for a test particle throughout the black hole, irrespective of radius. The 4-d gravitational acceleration is given by the expression, , where R is the radius of the black hole, MR is its mass, and is the exponential shape parameter, which depends only on the mass, or radius, of the black hole. We calculate the gravitational force, and the entropy within the black hole interior, as well as on its surface, identified as the event horizon, which separates 3-d from 4-d space. Similar to a truncated Gaussian distribution, the gravitational force increases discontinuously, and dramatically, upon entry into the 4-d black hole from the 3-d side. It is also radius dependent within the 4-d black hole. Moreover, the total entropy is shown to be much less than the Bekenstein result, similar to the truncated Gaussian. For the gravitational force, we obtain, , where Mr is the radiative mass enclosed within a 4-d volume of radius r. This unusual force law indicates that the gravitational force acting upon a layer of blackbody photons at radius r is strictly proportional to the enclosed radiative energy, MrC2, contained within that radius, with 0.1λ being the constant of proportionality. For the entropy at radius, r, and on the surface, we obtain an expression which is order of magnitude comparable to the truncated Normal distribution. Tables are presented for three black holes, one having a mass equal to that of the sun. The other two have masses, which are ten times that of the sun, and 106 solar masses. The corresponding parameters are found to equal, , respectively. W

关键词： Black Holes 4-d Spatial Blackbody Radiation Model Exponential distribution

Evaluation of 2,4-d-Choline Based Herbicide Systems in 2,4-d Tolerant Soybean (<i>Glycine max</i>L.)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2017年第5期8卷 385-396页

作者： dwayne d. Joseph Colton H. Sanders Michael W. Marshall department of Plant and Environmental Sciences Clemson University Clemson SC USA Edisto Research and Education Center Clemson University Blackville SC USA

Weeds are the most limiting factor in soybean production in South Carolina. With early emergence and rapid growth, weeds effectlively compete for water, nutrients, and light resources. The recent evolution of herbicide resistant weeds has made it increasingly difficult for growers to effectively control weeds in soybean. Glyphosate and ALS-resistant Palmer amaranth biotypes have spread rapidly throughout South Carolina, especially in areas where resistance management is lacking. Soybean varieties have been recently developed with tolerance to 2,4-d. Field experiments were conducted at the Clemson University Edisto Research and Education Center located near Blackville, SC in 2012 and 2013 to evaluate selected 2,4-d choline based herbicide programs for weed management in 2,4-d tolerant soybean. Overall, all herbicide treatments were effective in controlling weeds at the POST2 timing. Palmer amaranth control was excellent;however, pitted morningglory was the most difficult. The 2,4-d plus glyphosate pre-mixture provided excellent control for all three weed species with >95% control at POST2 timing. In these treatments, the rate of 2,4-d choline plus glyphosate (1.09 kg ae ha-1 or 1.64 kg ae ha-1) did not have a significant effect on weed control (P = 0.3772). There was a decrease in pitted morningglory control 3 WAP in 2012 vs 2013 in plots treated with S-metolachlor + fomesafen because of a lack of activating soil moisture in 2012. Results from this study showed that all treatments evaluated provided good to excellent control of all 3 weed species. Based on the herbicide programs evaluated in the study, herbicide resistant weeds, such as Palmer amaranth, can be effectively controlled when treated at the correct growth stage.

关键词： Glyphosate Resistance 2 4-d Choline Weeds Soybean

Are Black Holes 4-d Spatial Balls Filled with Black Body Radiation? Generalization of the Stefan-Boltzmann Law and Young-Laplace Relation for Spatial Radiative Transfers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of High Energy Physics, Gravitation and Cosmology 2019年第3期5卷 638-682页

作者： Christopher Pilot Physics department Gonzaga University Spokane WA USA

This is the first paper in a two part series on black holes. In this work, we concern ourselves with the event horizon. A second follow-up paper will deal with its internal structure. We hypothesize that black holes are 4-dimensional spatial, steady state, self-contained spheres filled with black-body radiation. As such, the event horizon marks the boundary between two adjacent spaces, 4-d and 3-d, and there, we consider the radiative transfers involving black- body photons. We generalize the Stefan-Boltzmann law assuming that photons can transition between different dimensional spaces, and we can show how for a 3-d/4-d interface, one can only have zero, or net positive, transfer of radiative energy into the black hole. We find that we can predict the temperature just inside the event horizon, on the 4-d side, given the mass, or radius, of the black hole. For an isolated black hole with no radiative heat inflow, we will assume that the temperature, on the outside, is the CMB temperature, T2 = 2.725 K. We take into account the full complement of radiative energy, which for a black body will consist of internal energy density, radiative pressure, and entropy density. It is specifically the entropy density which is responsible for the heat flowing in. We also generalize the Young- Laplace equation for a 4-d/3-d interface. We derive an expression for the surface tension, and prove that it is necessarily positive, and finite, for a 4-d/3-d membrane. This is important as it will lead to an inherently positively curved object, which a black hole is. With this surface tension, we can determine the work needed to expand the black hole. We give two formulations, one involving the surface tension directly, and the other involving the coefficient of surface tension. Because two surfaces are expanding, the 4-d and the 3-d surfaces, there are two radiative contributions to the work done, one positive, which assists expansion. The other is negative, which will resist an increase in volume. The 4-d side promotes expansion wherea

关键词： Black Holes 4-d Spatial Balls Black Body Radiation Stefan-Boltzmann Law Young-Laplace Relation

Efficacy of 2,4-d, dicamba, Glufosinate and Glyphosate Combinations on Selected Broadleaf Weed Heights

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2018年第6期9卷 1321-1333页

作者： dwayne d. Joseph Michael W. Marshall Colton H. Sanders department of Plant and Environmental Sciences Clemson University Clemson SC USA Edisto Research and Education Center Clemson University Blackville SC USA

Palmer amaranth, sicklepod and pitted morningglory are the three most common and troublesome weeds in soybean in South Carolina. They exhibit very aggressive growth capabilities and if left uncontrolled in fields will cause significant reductions in soybean yields. dicamba and 2,4-d herbicides are currently having a resurgence in usage due to the recent commercialization of soybean trait technologies with tolerance to these herbicides. dicamba and 2,4-d when tank mixed with glufosinate and glyphosate may offer additional weed control to resistant weeds through the process of herbicide synergism. Greenhouse experiments were conducted in 2013 at Edisto Research and Education Center near Blackville, SC to evaluate the efficacy of glyphosate, glufosinate, dicamba and 2,4-d treatments alone and in combination on Palmer amaranth, sicklepod, and pitted morningglory at selected heights. Results suggested that glufosinate alone provided the overall best control for all 3 weed species. Glyphosate alone provided the lowest control of all 3 species at all heights. Synergism or improved sicklepod control was observed when glufosinate was tank mixed with dicamba. However, as sicklepod increased in height, glufosinate + 2,4-d or dicamba combination offered the best control compared to glufosinate alone (90% versus 86% in 20 cm plants and 87% versus 85% in 30 cm plant). In the 5 cm Palmer amaranth, decreased control was observed when glyphosate or glufosinate was tank mixed with 2,4-d. These experiments showed that glufosinate alone and/or in combination with 2,4-d or dicamba was the overall best treatment on the three broadleaf weed species.

关键词： Palmer Amaranth Pitted Morningglory Sicklepod Synergism Antagonism Glufosinate dicamba 2 4-d Glyphosate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

外源2,4-d对大豆再生过程的影响

基因组学与应用生物学 2015年第6期34卷 1324-1332页

作者：李思楠张超马彦龙姜成涛王玲爽王传奇于以成李文滨苏安玉武小霞大豆生物学教育部重点实验室东北农业大学农学院哈尔滨150030 东北农业大学资源与环境学院哈尔滨150030

为了寻找与大豆再生直接相关的基因,提高大豆转化率,解决大豆再生和转化困难的问题,以再生较好的东农50、再生较差绥农14两个大豆品种为材料,设计不同2,4-d浓度处理及不同取材时间,测定与大豆再生相关的IAA、SOd、PAL以及再生率指标。... 详细信息

为了寻找与大豆再生直接相关的基因,提高大豆转化率,解决大豆再生和转化困难的问题,以再生较好的东农50、再生较差绥农14两个大豆品种为材料,设计不同2,4-d浓度处理及不同取材时间,测定与大豆再生相关的IAA、SOd、PAL以及再生率指标。结果表明:东农50在2,4-d浓度为8 mg/L、12 h处理下IAA浓度最大,比对照增加了76.9%,在2,4-d浓度为4 mg/L、4 h处理下SOd酶活性增幅最高,比对照增加了50.9%,在2,4-d浓度为4 m/L、8 h处理下PAL酶活性最高,比对照增加了76.4%;绥农14在2,4-d浓度为8 mg/L、2 h处理下IAA浓度最大,比对照增加97.1%,在2,4-d浓度为4 mg/L、12 h处理下SOd酶活性最高,比对照增加23.8%,在2,4-d浓度为2 mg/L、4 h处理下PAL酶活性最高,比对照增加53.9%。东农50和绥农14均在2,4-d浓度为4 mg/L时再生率最高,分别为87.6%和79.5%。依照该实验结果进行取材,应用转录组测序技术挖掘与大豆再生直接相关的基因,解释再生作用机理,解决大豆再生和转化受基因型限制的难题,为大豆基因功能研究及转化率的提高提供了理论和技术支持。

关键词：大豆再生 2 4-d IAA SOd PAL

苯磺隆和2,4-d对盆栽小麦土壤微生物量碳、氮的影响

在线全文

学校读者我要写书评

暂无评论

核农学报 2012年第4期26卷 705-709页

作者：李咏玲张天宝王惟帅王丽玲杜慧玲山西农业大学文理学院山西太谷030801

通过盆栽小麦试验,研究了除草剂苯磺隆和2,4-d对小麦生长过程中土壤微生物量碳、氮以及碳/氮比(Cmic/Nmic)的影响。结果表明,苯磺隆、2,4-d对土壤微生物量碳、氮的影响主要表现为先抑制后激活,抑制作用随着时间的延长和浓度的增大而增强... 详细信息

通过盆栽小麦试验,研究了除草剂苯磺隆和2,4-d对小麦生长过程中土壤微生物量碳、氮以及碳/氮比(Cmic/Nmic)的影响。结果表明,苯磺隆、2,4-d对土壤微生物量碳、氮的影响主要表现为先抑制后激活,抑制作用随着时间的延长和浓度的增大而增强,与对照相比达极显著差异水平。苯磺隆、2,4-d对微生物量碳的抑制作用第14天和第7天分别达到最大,为54.9%和45.2%;对微生物量氮的抑制作用均为第7天最大,分别为51.0%和65.4%。2种除草剂处理均在第28天微生物量碳、氮达到最大,为对照的1.09和1.33倍,呈极显著的激活作用,且激活作用随着浓度的增大而增强;对土壤微生物量碳/氮的影响主要呈增加-降低-增加的变化趋势。研究表明苯磺隆、2,4-d对土壤微生物量碳、氮的影响主要与处理的浓度和时间有关,与除草剂的种类无关。

关键词：苯磺隆 2 4-d 土壤微生物量碳土壤微生物量氮