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1.
为明确小麦开花至成熟期间锌在不同器官内的积累动态,探讨锌对小麦开花后农艺性状及籽粒蛋白质形成的调控作用,采用离体穗培养技术研究了不同浓度锌对新春8号和杜伦的影响。结果表明,开花后离体穗培养小麦各器官的含锌量变化趋势基本一致,不同器官含锌量关系为:穗>倒一节>倒二节。缺锌小麦生长受抑制,节间生长严重受阻,倒一节长度对锌的反应比倒二节敏感。开花期旗叶叶绿素含量受锌影响不大,花后两周叶绿素含量受锌离子浓度的影响较大。增加供锌量显著或极显著地增加小麦穗粒数,提高其结实率;低锌强烈抑制杜伦的小花分化,减少其穗粒数,高锌促进小花分化但是使结实率下降;缺锌阻碍籽粒灌浆,显著降低千粒重,高锌使小麦千粒重有小幅下降。锌对小麦籽粒总蛋白含量的影响不显著;小麦籽粒蛋白组分含量受锌离子浓度的影响显著,各蛋白组分与锌的相关性和相关度差异较大。 相似文献
2.
采用水培试验,研究了在两种供钾水平(K,0.5mmol L-1和5.0 mmol L-1)条件下4个不同籽粒苋品种植株体内矿质营养元素的含量及其变化.同时,还在低钾条件下,测定了不同籽粒苋品种根、茎、叶中矿质营养成分的含量和构成情况,结果表明(1)籽粒苋各品种氮、钾含量随着供钾水平降低而减少,一般基因型氮钾含量降幅大于富钾基因型;在相同供钾水平条件下,富钾基因型的氮钾含量均高于一般基因型,而相同基因型的不同品种间氮钾含量则相近.籽粒苋各品种氮主要分布在根和叶中,其次是茎;磷大量分布在根,其次是叶,再次是茎;钾主要存在于茎中,根和叶次之.(2)籽粒苋钙、镁、硫含量随着供钾水平的升高而降低,富钾基因型镁、硫含量低于一般基因型.籽粒苋不同品种的钙、镁主要分布在叶片中,其次是茎和根;硫在根中的分布最少,叶中最多.(3)不同品种B、Cu、Fe、Mn、Zn等微量元素含量随着供钾水平的降低而升高,灰分含量则降低.富钾基因型B、Fe、Zn及灰分含量都高于一般基因型,而Cu的含量则是一般基因型高于富钾基因型.4个籽粒苋品种的硼、铜主要存在于叶片中,其次是根,茎含量相对前两者要小;铁、锰、锌在根的含量最高,叶片次之,茎最低,根系中铁的含量分别是叶和茎的7倍左右和10倍以上. 相似文献
3.
以两种不同基因型玉米(唐玉10号、博丰12号)为材料,用溶液培养的方法研究了低锌、缺锌和正常供锌对玉米生长发育的影响,并对两品种的SOD同工酶谱和蛋白质表达进行了分析。结果表明:一定浓度的低锌比缺锌对玉米危害更大,但不同基因型玉米对此敏感性不同,博丰12号表现出这种现象相对迟缓,而唐玉10号表现得迅速。与正常供锌相比,低锌处理时唐玉10号和博丰12号的一些SOD同工酶的活性降低,但博丰12号的一个SOD同工酶的活性明显提高,而缺锌对两品种的SOD同工酶谱影响不大。SDS-PAGE分析表明,低锌或缺锌处理时两种不同基因型玉米都有一些蛋白质组分增加或缺失。 相似文献
4.
采用盆钵试验研究了菜园土高磷条件下对油菜磷、锌颉颃作用的影响。结果表明,随着土壤有效磷含量的升高,油菜植株体内的含磷量也在不断升高,但上升的趋势逐渐减缓,其中,茎叶的含磷量始终大于根中的含磷量。而植株的含锌量则有很大的不同,随着土壤有效磷含量的增加,植株根中的含锌量也在不断的增加,直到趋于平稳,而茎叶中锌的含量随土壤有效磷含量的升高而增加到一定程度后表现出下降的变化趋势。这说明油菜的磷、锌颉颃作用是发生在植株体内的一种生理机制。 相似文献
5.
本文采用温室水培的方法,研究了不同的钙素供应水平对烟草各种矿质养分的吸收与积累的影响。结果表明,在其它养分形态与浓度一致条件下,随着钙浓度从75mgL-1提高到900mgL-1,烟草生长量呈抛物线型变化。钙浓度为150mgL-1时烟株干物质量最大。超过150mgL-1,随钙的增加而下降,当钙素达900mgL-1(K/Ca为1/6)时,烟株生长严重受抑。随着供钙水平由低到高,烟株氮、磷、钾、锌、锰含量均呈抛物线型变化,含钙量呈直线上升关系,而镁和铜含量则随钙浓度提高而显著下降。烟株各养分积累量均随营养液钙浓度提高呈抛物线型变化,但不同养分出现最大积累量时的营养液钙浓度却不相同。不同供钙水平上烟叶中各元素含量的变化特征与全株的结果基本一致。在低钙浓度范围(75~300mgL-1),钙对钾有协合关系,增钙促进提钾,大于300mgL-1后有拮抗作用,提钙导致降钾。钙与镁、锌、铜、锰间也存在明显的交互作用。烟叶中各元素含量与积累量的变化趋势与整株基本一致。 相似文献
6.
本文通过长期定位施肥试验 ,分析了不同施肥结构对砂质潮土交换性钙、镁及有效硫、锌、锰、铜、铁等在 0~ 1 2 0cm土体中空间分布变化的影响 .结果表明 ,磷肥明显提高土壤交换性钙的含量 ,而有机肥与氮肥对土壤钙含量无明显影响 .但有机肥显著增加土壤交换性镁含量 ,各层镁含量与有机肥用量呈显著或极显著正相关 ,磷肥同样对土壤镁有提高作用 ,但氮肥无论是否与有机肥配施均降低了土壤各层交换性镁含量 .土壤 0~ 4 0cm有效锌、锰、铁均随有机肥增加而增加 ,并与有机肥用量呈极显著正相关 .而化肥无论是否与有机肥配施均降低土壤有效锌含量 ,但却增加了有效铁含量 .氮肥单施降低土壤有效锰含量 .在无有机肥情况下 ,施磷提高土壤有效铁含量 ,而在施有机肥条件下磷肥则降低耕层有效铁含量 .磷肥只在单施化肥时增加土壤有效锰含量 相似文献
7.
研究了江苏省邳州市港上镇银杏基地不同年限 (2~ 6年生 )叶用银杏园土壤的氮、磷、钾及有效铁、铜、锌等养分元素的含量和脲酶、磷酸酶的活性。结果表明随栽培银杏年限延长 ,土壤有机碳、全氮、碱解氮、有效锌的含量及碱性磷酸酶的活性均表现出降低的趋势 ,但土壤速效钾却出现增加。提出土壤碱性磷酸酶亦可作为表征叶用银杏园土壤肥力的一个敏感性指标 相似文献
8.
在河南省不同生态类型区典型地块采集大量土壤和烟叶样品进行分析化验 ,结果表明 :河南省主要植烟土壤的 pH介于中性—微碱性范围 ,有机质和有效氮含量中等偏高 ,大部分土壤有效磷含量偏低 ,有效钾含量较高 ;中量元素钙含量过高 ,最高含量达 4 0 66mg/kg,钾钙关系失调 ;微量元素中锌较缺乏 .烟叶品质突出表现为钾素中等偏低 ,氯离子含量偏高 .为此提出该区烟草施肥中应掌握“稳氮、增磷、补钾、控钙、降氯、配微”的施肥对策 相似文献
9.
对西藏高原大棚蔬菜土壤进行了分析研究。结果表明,与相邻露地土壤相比,其有机质、全磷、全氮、速效磷、碱解氮、硝态氮、铵态氮、全镁等含量均有增加,全钾、速效钾、全钙等含量均有减少;土壤pH值下降,有酸化的趋势;微量元素铁、硼、锌、钼等全量均有增加的趋势。塑料大棚土壤硝态氮发生了积累。土壤有机质、硝态氮、全铁、全硼、全锌、全镁、全钼等含量有随塑料大棚种植年限的延长而增加的趋势;土壤全钙量随塑料大棚种植年限的延长而减少,这是大棚土壤结构性变差的主要原因;土壤全锰量、全铜量无明显的变化规律;土壤pH值随塑料大棚种植年限的延长而下降,出现了土壤酸化现象。因此,西藏高原设施蔬菜土壤管理应注重有机肥的施用,控制氮肥的施用量和施肥时期,合理轮作倒茬,适当施用石灰,调节土壤酸度,根据蔬菜生长情况,适当施用钾肥,改变传统观念—西藏土壤不缺钾;注意灌水方法。 相似文献
10.
同钾素浓度处理的砂培试验表明,150mgkg-1的钾素浓度处理其及以下的浓度处理烤烟都出现不同程度的缺素症状。烟叶干物质有随着钾素浓度的增加而增加的趋势。烟叶在不同生育期内对钾素的吸收和累积都是与钾素的供应呈正相关。磷的吸收与钾的供应呈一定的正相关。全氮在烟株体内分布趋势是根>叶>茎,全钾分布趋势是叶>茎>根,磷多集中在根部,叶内含量较少。烟草钾与钙、镁的吸收存在颉颃作用。 相似文献
11.
The use of artificial neural networks (ANNs) as a tool for simultaneous determination of Zn(II), Cd(II) and Hg(II) in water has been investigated, by employing an optode based on the 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) complex immobilised on Amberlite XAD-4 resin. Studies were performed with binary and ternary mixtures of Zn(II), Cd(II) and Hg(II) ions in the 0–3.0 mg l−1 range (prepared in pH 8.0 NH4Cl solution), in order to avoid sensing phase saturation. A 0.1 mol l−1 HCl solution was employed to regenerate the optode after each measurement. Reflectance measurements were recorded in the 400–800 nm region after pumping metal ion solution for 1, 1.5, 2.0, 2.5 and 3.0 min. Spectra were smoothed by employing a weighted sliding average of three reflectance intensities (weights of 1:3:1) and normalised to the reflectance intensities of the immobilised reagent in the NH4Cl solution. A feed-forward ANN with error back-propagation training algorithm was employed for data treatment. The ANN was initially fed through seven inputs neurons, corresponding to reflectance intensities at 558, 568, 583, 590, 605, 615 and 623 nm, and optimised with respect to the number of hidden neurons, momentum and learning rate. Binary mixtures of Zn(II) and Cd(II), and Hg(II) and Cd(II) were employed to evaluate the capability of prediction by the ANN. Measurements were carried out in triplicate leading to standard deviations (expressed in mg l−1) better than 0.29 for Cd(II), 0.38 for Hg(II) and 0.35 for Zn(II) and absolute errors better than 0.14 for Cd(II), 0.31 for Hg(II) and 0.36 for Zn(II). Similar results were obtained when solution mixtures containing all three metal ions were employed in the studies. These results indicate that ANN can be employed for simultaneous determination of metal ions in water. However, attention must be given to the leaching and to the saturation of the sensing phase, which limit the lifetime and analytical range of the sensor, respectively. 相似文献
12.
The EVA (espacios virtuales de aprendizaje, or virtual learning spaces) project applies artificial intelligence tools to teleteaching methods, in a way that eliminates or mitigates the need for synchronous and in situ education. (A) A taxonomy of the space of knowledge (also called ‘Learning Space'; currently our prototype teaches M.Sc. courses in Computer Science) is formed and discretized. (B) EVA finds each student's initial knowledge state (through a computer examination) and final (desired) knowledge state, and from these, a particular learning trajectory is designed for that student. (C) Personalized books (called polybooks, because they are formed by modules (chapters) written in a variety of media) are armed by concatenating — along the learning trajectory — modules from a large pool, and sent to the student through the net in a store-and-forward fashion. (D) EVA searches the net for teaching material which has not been indexed in the discretized learning space, using a tool (Clasitex) inside an agent that finds the main themes or topics that an article (written in natural language) covers. (E) EVA also schedules for each student synchronous activities (lectures in TV, teleconferences, on-line question and answering sessions, chats). (F) EVA suggests for each student suitable ‘classmates' (students having similar learning trajectories) in her town, as well as possible advisers (students or alumni having knowledge that the student is acquiring). The present status, problems, models and tools of EVA are presented. 相似文献
13.
A survey of ergonomics in the German Democratic Republic (GDR) was conducted over approximately a two-month period starting in mid-May 1982. This study was sponsored by the International Research and Exchanges Board (IREX) located in New York City. IREX maintains scientific exchange agreements with Eastern European countries and the USSR. This survey is one of a series of similar studies conducted in Eastern Europe. Earlier countries surveyed were Romania (Seminara, 1975), Bulgaria (Seminara, 1976a, 1976b, 1982), the USSR (Seminara, 1977, 1979/80), Poland (Seminara, 1979a), Czechoslovakia (Seminara, 1979b), Hungary (Seminara, 1980), and Yugoslavia (Seminara, 1983). 相似文献
14.
This work presents a pulsatile Zone Model Predictive Control (pZMPC) for the control of blood glucose concentration (BGC) in patients with Type 1 Diabetes Mellitus (T1DM). The main novelties of the algorithm – in contrast to other existing strategies – are: (i) it controls the patient glycemia by injecting short duration insulin boluses for both, the basal and bolus infusions, in an unified manner, (ii) it performs the predictions and estimations (critical to anticipate both, hypo and hyperglycemia) based on a physiological individualized long-term model, (iii) it employs disturbance observers to compensate plant-model mismatches, (iv) it ensures, under standard assumptions, closed-loop stability, and (v) it can be used – under minor modifications – as an optimal basal–bolus calculator to emulate conventional therapies. Because of the latter characteristic, a significantly better performance is achieved, not only in terms of classical indexes (time in the normoglycemia zone, avoidance of hypoglycemia in the short term, avoidance of hyperglycemia in the long term) but also in terms of its applicability (use of the pump or injections). Such a performance is tested in a cohort of in-silico patients from the FDA-accepted UVA/Padova simulation platform, considering the most challenging scenarios. 相似文献
15.
针对RSA算法中Z*φ(n)的代数结构问题,提出了一种在强素数条件下应用二次剩余理论进行研究的方法。给出了Z*φ(n)中元素阶的计算公式和元素的最大阶表达式,计算了Z*φ(n)中二次剩余的个数和二次非剩余的个数,同时估计出Z*φ(n)中元素的最大阶上限为φ(φ(n))/4并得到了Z*φ(n)中元素的最大阶达到φ(φ(n))/4的一个充要条件。另外还给出了全部二次剩余构成的子群A1成为循环子群的充分条件及Z*φ(n)的一种分解方法。最后证明了Z*φ(n)可由7个二次非剩余元素生成,商群Z*φ(n)/A1是一个Klein八元群。 相似文献
16.
A new dynamometer was developed for the measurement of specific movement power (SMP) exerted by mono- or multi-articular movements. To determine the reproducibility of SMP, two identical test protocols were carried out on separate days for six movement types on seven adult males. The movement types were arm pull (AP), leg rise (LR), knee extension (KE), elbow flexion (EF), hip extension (HE) and squat movement (SQ). Variations in peak power obtained in two tests ranged from 0.7% (AP) to 9.6% (SQ). Coefficients of the test- re-test correlation in peak power ranged from 0.805 (SQ) to 0.961 (AP) and standard errors ranged from 4 W (EF) to 14 W (SQ). SMP in upper extremities increased from 166 W (EF) to 307 W (AP) resulting from the increase in velocity. However, in the movements of lower extremities, SMP increased from 506 W (KE) to 1351 W (SQ) as a result of the increase in force. To evaluate the validity of the SMP, a pull movement in weightlifting was tested and related to the athletic performance on weightlifters. Positive linear correlation ( r = 0.862, p < 0.001) was observed between SMP and the total weight best records. It is concluded that this newly developed dynamometer has enough reproducibility and validity for evaluating the SMP, which is developed by various joint movement patterns related to the sport. The feasibility of applying this measuring protocol to the testing and training programmes for improving the daily living activities and athletic performances should now be assessed. 相似文献
17.
Chance discovery is to become aware of a chance and to explain its significance, especially if the chance is rare and its
significance is unnoticed. This direction matches with various real requirements in human life. This paper presents the significance,
viewpoints, theories, methods, and future work of chance discovery. Three keys for the progress are extracted from fundamental
discussions on how to realize chance discovery: (1) communication, (2) imagination, and (3) data mining. As an approach to
chance discovery, visualized data mining methods are formalized as tools aiding chance discoveries on the basis of these keys.
Yukio Ohsawa, Ph.D.: He received Bechelor of Engineering (1990) from Faculty of Engineering, Master of Engineering (1992) and Ph.D. (1995) from
Graduate School of Engineering, respectively of The University of Tokyo. In the doctoral course he began artificial intelligence
research, especially of abductive inference. He was a research associate (1995–1999) in Osaka University on studies of text
mining and related issues, and moved to the current position, associate professor in the University of Tsukuba in 1999. From
2001, he is also a researcher of TRESTO (changed to PRESTO) in Japan Science and Technology Corporation. He received best
paper awards in two Annual Conferences of Japasese Society of AI (1994 and 1998), and a Journal Paper Award from JSAI in 1998.
His social activities are committees of conferences e.g., International Conference of Multi-Agent Systems (ICMAS) since 1998
and Discovery Science (DS) since 2001, program chair of MultiAgent and Cooporative Computations (MACC, in Japan) in 1999,
and committes of meetings including ones on Chance Discovery. 相似文献
18.
This systematic review study synthesizes research findings pertaining to the use of augmented reality (AR) in language learning. Published research from 2014 to 2019 has been explored and specific inclusion and exclusion criteria have been applied resulting in 54 relevant publications. Our findings determined: (a) devices and software employed for mastering AR; languages and contexts in which AR had been applied; theoretical perspectives adopted for guiding the use of AR; the number of participants in AR activities and benefits from using AR as an educational tool in the language classroom; (b) alignment of the affordances of Augmented Reality with the KSAVE (Knowledge, Skills, Attitudes, Values, Ethics) 21st-century skills framework; (c) future directions in AR research and practice. The main findings from this review demonstrate the popularity of mobile-based AR for supporting vocabulary (23.9%), reading (12.7%), speaking (9.9%) writing (8.5%) or generic language skills (9.9%). Our findings also uncovered areas that merit future attention in the application of AR in language learning – for instance learning theories were not often considered in the implementation of AR. The study concludes with suggestions for future research especially in the areas of instructional design and user experience. 相似文献
19.
The effects of a concurrent simulated driving task on performance in a working memory task was investigated in 20 subjects (10 females, 10 males, median age = 33 years). The working memory task consisted of (1) judging whether simple sentences, presented in series of four, were meaningful, and (2) recalling the first words of each sentence in the series. The concurrent task had three levels of difficulty: (a) no driving, (b) easy driving, and (c) difficult driving. Being involved in the driving task (levels b and c) was found to be associated with significant deterioration of both recall and judgement, but whether the driving task was easy or difficult (level b or c) had no discernible effect on either recall or judgement. The results are discussed with reference to models of working memory and attention. 相似文献
20.
This paper presents the development of a decision support system for run-time safety management in Smart Work Environments (SWEs). Our approach consists of four main phases: (i) definition of the basic steps of a methodology for run-time safety management; (ii) development of an ontological knowledge-base of safety in work environments; (iii) definition of constraints on the ontology based on organizations’ safety protocols; (iv) communication of relevant information to each actor in the safety management team. We propose a generic ontological model of safety expertise, based on Occupational Safety and Health Regulations (OSHA), that is employed as Knowledge required in our safety management methodology based on the MAPE-K (Monitor–Analyze–Plan–Execute and Knowledge) loop. We present the RAMIRES (Risk-Adaptive Management in Resilient Environments with Security) tool, implementing this methodology. RAMIRES is developed as a dashboard, supporting the safety management team in understanding the risk and its consequences, and to support decision making in risk treatment. RAMIRES interacts with the SWE and the safety management team (actors) in order to: (i) communicate the risks and preventive strategies to actors; (ii) obtain more data about the observed areas to understand the risk and its consequences; and (iii) execute the automatic preventive strategies and support actors in the execution of human-operated preventive strategies. In this paper, we show the details on concepts designed in the safety ontology and illustrate how these concepts can be extended to provide an abstract model of a specific use case. Furthermore, we propose the definition of constraints on the ontology using logic-based rules. Finally, we discuss the advantages and limitations of the proposed methodology regarding the resilience of the environment. 相似文献
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