夏玉米花丝生长发育动态的研究

以不同穗型的玉米品种为材料,对玉米花丝生长发育动态进行研究.结果表明,花丝的发生首先开始于果穗中下部,其次是基部和中部,顶部花丝出现最晚;花丝出现集中在开始出现后的最初两天.吐丝后第三天生长速率最大.中下部花丝最先抽出苞叶,其次是基部和中部,顶部最晚.前两天的吐丝总量超过50%,尤以第二天吐丝百分率最高.衰亡过程也开始于中下部,基部和中部其次,顶部最晚;每一根花丝从基部开始衰亡,然后向顶部逐渐推移.果穗短粗型的品种花丝发育比较集中、吐丝较快;果穗细长型的品种花丝发育较缓慢,吐丝期延长,发育较晚的顶部花丝不易吐出苞叶。     

群体密度对玉米茎秆农艺性状及抗倒伏性的影响

以抗倒伏性能不同的玉米品种为试验材料,研究密度对其农艺性状及茎秆抗倒伏性能的影响。结果表明,随着密度的增加,基部向上各节长和节粗变化不规律。节干重、单位茎长干重和茎秆抗折力均随着密度的增加先增加后降低,其中,单位茎长干物质重均在密度7万株/hm²时最大,各节干重和茎秆抗折力最大值出现时间因品种和节位而不同。相关分析结果表明,玉米倒伏率与第3、第4节所有指标均呈显著相关,与第5、第6节间单位茎长干物质重、节干重和茎秆抗折力均呈显著正相关,与株高、穗位高和穗位高系数的相关性因品种而异。     

环境因素对大豆化学品质及产量影响研究Ⅱ.遮光对大豆化学品质及产量的影响

研究表明,遮光对大豆的产量及品质有一定的影响作用.随着遮光时数的增多,也就是日照时数的减少,大豆子粒的蛋白质含量、脂肪含量、蛋脂总量及产量都有显著的变化.但品种的遗传特性对化学品质及产量的影响大于遮光的影响.光照长度的影响作用不仅涉及光合时间而且与光周期本身的机制有关.遮光对大豆子粒产量及品质影响大小顺序为:产量(F=5.93**)＞蛋白质(F=3.16*)＞脂肪(F=2.61)＞蛋脂总量(F=0.64).     

Air-gap spinning of cellulose/ionic liquid solution and its characterization

In order to study the effects of the spinning conditions on the structure and the properties of the regenerated fiber, cellulose was dissolved in ionic liquid and then spun into fiber using an air-gap spinning process. The solution concentration, the take-up speed and the fixation of the fiber ends during coagulation improved the crystallinity and the tensile strength at the same time. The fiber surface became smooth by addition of DMF (dimethylformamide). However, it decreased the crystallinity and the tensile strength of the fibers. We revealed that the developed structure during coagulation determined the morphology and the properties of the fibers. The co-solvent resulted in smooth surface of the fiber and also changed the mechanical properties.     

Controlling supermolecular structures and improving colorfastness in cotton fibers

A new discovery was made in which commercially available triethanolamine could reduce the lattice volume of the supermolecular structure of cotton from the periphery of the lattice by moving cellulose chains on the surface of the crystallites to the amorphous regions, thereby decreasing the close-packed crystallization volume and leading to an increased free volume of the amorphous regions. Subsequently, several supermolecular structures for cotton fibers were successfully controlled to improve the colorfastness in cotton fibers at the molecular level. With the decrease in the degree of crystallinity, more unfixed dyes could be removed by washing reagents, whereas the remaining dyes were mostly fixed to the cotton by covalent bonds, causing a stronger colorfastness, with the best wet rubbing fastness reaching a relatively permanent grade 4. Moreover, the effect mechanism revealed that the unfixed dyes were detached from the cotton fibers according to the reverse process of the adsorption models and that there were additional methods for the unfixed dyes in the fibers to be removed in the presence of triethanolamine than when using pure water. In addition, the binding forces of dye adsorption in the cotton fibers decreased, while the entropy of dye adsorption was higher than that measured when using pure water. Thus, the results suggested that controlling the supermolecular structures of the cotton fibers promoted the removal of unfixed dyes from the fibers and achieved improved colorfastness.     

临时收储政策改革背景下玉米盈利能力与生产率

基于2000-2018年“东北三省一区”的投入产出面板数据和O’ Donnell提出的加总价格-数量框架,采用Färe-Primont生产率指数分析临储政策的实施及改革对玉米盈利能力及其组成部分的影响,探究玉米盈利能力变化的动力源泉。研究发现,临储政策实施后,临储地区玉米盈利能力降低,其原因是产出-投入相对价格(TT)大幅下降,全要素生产率(TFP)则增长缓慢。临储政策虽大幅提高了玉米价格,但同时也造成了土地租金的大幅增长,再加上劳动力价格的上涨,共同导致了TT的大幅下降。临储政策改革后,临储地区玉米盈利能力持续降低,由TT和TFP的下降共同驱动。临储政策改革还表现出较强的时间异质性,价补分离政策能够有效缓解临储政策取消对农民利益的冲击。     

马铃薯高淀粉生理基础的研究——块茎组织结构与淀粉积累的关系

马铃薯块茎以皮层区的淀粉含量最高,环髓次之,内髓最少,但环髓区的淀粉在整个块茎中所占的比重最大,淀粉含量指数也最高;内髓区的淀粉在块茎中占的比重最小,淀粉含量指数也最低.皮层区的淀粉含量高低、皮层的厚度、环髓区的淀粉含量指数与块茎淀粉含量呈显著的正相关、皮层区、环髓区、内髓区的细胞大小、输导系统的筛管和导管面积,随块茎的增大和淀粉的积累而增大,其中除皮层区细胞大小与块茎淀粉含量呈负相关之外,其余各组织的细胞大小与块茎淀粉含量没有明显的相关性.     

Correlation of Nitrogen Concentration with Dry-Matter Partitioning to Spikelets and Total Husk Volume on the Panicle in Japonica Rice

Summary

A rice husk restricts the grain development physically. We examined the correlation of the total husk volume on a panicle, a parameter of yield capacity, with the nitrogen concentration (per dry weight) and the dry weight of the above-ground part of the plant, using single-stem-trained japonica rice (cv. Nipponbare) plants. The growth of rice plants was regulated by shading at two levels and nitrogen application at three levels from about 40 days before the heading (about 10 days before the panicle initiation). The number of spikelets per dry weight of the above-ground part of the plant at the end of the spikelet differentiation stage was linearly correlated with the nitrogen concentration at that time. The ratio of the spikelet dry weight at heading to the dry weight of the above-ground part of the plant at the end of the spikelet differentiation stage increased as the nitrogen concentration increased at a low nitrogen concentration, but the increase of the ratio slowed down at a nitrogen concentration of 2%. Decrease in dry weight of the spikelet resulted in a decrease of lemma size. Therefore, the ratio of the total husk volume on a panicle to the plant dry weight at the end of spikelet differentiation stage also increased as the nitrogen concentration increased at a low nitrogen concentration, but the increase stopped at a nitrogen concentration of 2% in contrast to the ratio of the spikelet number to the dry weight of the plant. These results suggest that, to increase the total husk volume on a panicle by nitrogen application, dry-matter production must be increased by the nitrogen application.     

The price elasticity of transferring agricultural water to industrial water during non-drought period in Taiwan

In this study, the demand function for the transferring agricultural water to industrial water during non-drought period covering from January 1998 to December 2008 in Taiwan was estimated, and the water usage statistics derived from the short-term water charge agreements, regarding the charging of water management fees and water usage fees from the irrigation associations, were applied to the estimation in the empirical model. The results of the research are presented as follows: (a) the demand for transferring agricultural water into industrial water is non-elastic; the price elasticity is −0.368; (b) the transferred water volume decreases when the water price rises; (c) the transferred water volume also decreases when the wholesale price index of domestic products rises; (d) the buyer’s industry classification was the significant factor influencing the transfer water demand; (e) the different title of transferred water including: “building utilization cost” or that in “costs for enhanced irrigation management” was the significant factor influencing the transfer water demand; (f) type of repository of irrigation association for transferred water was the significant factor influencing the transfer water demand; (g) whether irrigation association enhances irrigation management was the significant factor influencing the transfer water demand; (h) the source of transferred water was the significant factor influencing the transfer water demand; (i) the method for water transfer was the significant factor influencing the transfer water demand; (j) more water transferred by the industry when the total population of Taiwan increases; (k) the transferred water volume rises when the groundwater level of the water transferred area rises; and (l) the areas for water transferred was the significant factor influencing the transfer water demand.     

Effects of material parameters and process conditions on the roll-drafting dynamics

Roll drafting, a mechanical operation attenuating fiber bundles to an appropriate thickness, is an important operation unit for manufacturing staple yarns. It influences not only the linear density regularity of the slivers or staple yarns that are produced, but also the quality of the textile product and the efficiency of the thereafter processes. In this research, the dynamic states of the fiber bundle in the roll drafting zone were analyzed by simulation, based on the mathematical model that describes the dynamic behavior of the flowing bundle. The state variables are the linear density and velocity of the fiber bundles and we simulated the dynamics states of the bundle flow, e.g., the profiles of the linear density and velocity in the draft zone for various values of the model parameters and boundary conditions, including the initial conditions to obtain their influence on the dynamic state. Results showed that the mean velocity profile of the fiber bundle was strongly influenced by draft ratio and process speed, while the input sliver linear density has hardly affected the process dynamics. Velocity variance of individual fibers that could be supposed to be a disturbing factor in drafting was also influenced by the process speed. But the major disturbance occurred due to the velocity slope discontinuity at the front roll, which was strongly influenced by the process speed. Thickness of input sliver didn’t play any important role in the process dynamics.     

水稻开花期冠层温度与土壤水分及产量结构的关系

在开花期对水稻进行不同梯度水分胁迫处理,研究了水稻开花期冠层温度与土壤水分状况及产量结构之间的关系。 水稻开花期冠层温度一般低于气温,但土壤含水量对冠层温度有显著影响,土壤含水量越低,水稻冠层温度越高,冠气温差绝对值越小,并且在13：00时冠气温差与对照差别最大,认为13：00可以作为测定冠气温差的最适时间。通过对开花时间进行观察,发现土壤含水量最低的处理,植株开花高峰提前,开花时间集中在花期的最初3 d,其平均穗长较小,穗重较轻;而土壤含水量较高的处理与对照一致,开花时间主要集中在花期中间时段,平均穗长较大,穗重较重。土壤含水量越低,每穗饱粒数越少。     

黑茶香气化学研究进展

黑茶是我国独有的茶类,独特的渥堆工艺形成了其陈纯的香气特征。本文详尽综述了近年来黑茶香气化学研究的进展,从黑茶香气成分的化学特性方面归纳出甲氧基苯类和烯醛类化合物是黑茶独特香型的特征成分,分析了渥堆、干燥、贮藏等主要加工工艺对黑茶香气品质的影响,讨论了微生物对黑茶香气形成的影响,并指出了原料、香气提取方式等对黑茶香气分析的影响;最终提出黑茶特征性香气成分的鉴定与表征,香气骨架分子官能团的转化机理,以及微生物对香气形成的参与机制应是今后黑茶香气研究的难点。     

福建省财政收入与三大产业GDP的协整分析与误差修正模型研究

文章利用协整理论,根据福建省1978～2007年度数据,对福建省财政收入与三大产业GDP之间的关系进行实证研究,研究结果表明：(1)福建省财政收入与三次产业GDP之间存在着长期均衡的协整关系和短期动态调整机制;(2)福建省财政收入对第一产业GDP的弹性大于1,而对第二产业GDP和第三产业GDP的弹性小于1;(3)根据Granger因果关系检验,第一产业GDP和第二产业GDP不是财政收入的Granger因,财政收入也不是第一产业GDP和第二产业GDP的Granger因。在滞后期为1的情况下,第三产业GDP是财政收入的Granger因,但财政收入不是第三产业GDP的Granger因。     

Stab-resistant property of the fabrics woven with the aramid/cotton core-spun yarns

Aramid fibers are mainly used for industrial applications and human body protection against ballistic threats. But they are used mostly in forms of composites. And fabrics woven with a high yarn count offer a moderate protection performance against the knife stabbing due to the low shear strength. This research is focused on investigating the effect of the aramid core-spun yarns on the stab resistance of the woven fabrics. With the aramid core-spun yarns with core to sheath weight ratio of 1 to 2.5 the armor specimens having different fabric densities were prepared and the knife edge impact test was conducted. On the impact energy of the knife at the level 1 according to the NIJ standard, the drop tower test results demonstrated that fabric density of the armor specimens affected the stab resistance significantly. The penetration depth of the impactor through the armor specimens was associated with the thickness and mass of the armor sample in different ways. Being the stab resistance introduced by considering the penetration depth of the impactor via thickness and weight per surface area, the effects of the fabric conditions on the anti-stabbing property could be systematically analyzed and turned out that there was an optimal level of the fabric density, showing the most effective stab resistance.     

Effect of time between soil infestation with Pochonia chlamidosporia and planting on the efficacy of the fungus in managing Meloidogyne javanica

The fungus Pochonia chlamydosporia acts on populations of the root-knot nematode by parasitizing their eggs before they hatch, preventing the release of juveniles. In this study, the effect of the time at which the fungus is applied to soil infested with the nematode, before transplanting tomato and lettuce seedlings, was evaluated. The reduction of symptoms and the nematode population in the host plant was also evaluated, as well as the fluctuation of the fungus population during the studied period. The seedlings were transplanted at 0, 5, 10, 15 or 20 days after incorporation of the inocula of the fungus and the nematode into the soil. The population of P. chlamydosporia, without the presence of plants, increased and reached its maximum 10 days after its incorporation into the soil. At the end of the experiments, the number of colony forming units (CFU) of the fungus in the soil remained high enough to act on the next cycle of crops. For both cultures, the greatest effect on reducing the number of galls and eggs of Meloidogyne javanica was obtained by increasing the contact time of the fungus with the nematode in the soil before transplanting seedlings. In the second run, for both cultures, there was an increase in shoot weight with increasing of incubation time before the transplantation of seedlings.     

Influence of the core-sheath weight ratio and twist on the tensile strength of the ring core yarns with high tenacity filaments

Core spun yarns are applied for various purposes that especially require the multi-functional performance. This research reports on the core spinning effect on the yarn strength. We prepared various core yarns by combining different kinds of high tenacity filaments in core with cotton staples in sheath with various twist levels in the ring spin system. And the tensile strength was tested to investigate the contribution of the core-sheath structure to the core yarn strength. The influence of the twist level was also checked up on the relationship between the core-sheath structure and the yarn strength. Results turned out that the core-sheath weight ratio had influence on the tensile properties of the ring core-spun yarns in different ways according to the core filaments used for the yarn. Increasing the twists yielded a monotone decreasing strength for the aramid and the basalt core yarns, while the PET core yarns showed almost unchanged strength, which could be ascribed to the extensional property of the filaments.     

水稻不同栽培模式叶龄跟踪调查分析

运用叶龄诊断技术,研究水稻不同栽培模式的植株生长发育进程和产量性状。结果表明,叶龄进程前期与秧苗素质呈正相关,后期与气象条件呈正相关,而与栽培模式关系不大。而栽培模式与分蘖进程、成穗质量、产量性状关系极大。在本试验区内,几种栽培模式各具特点,但钵育摆栽秧苗素质好,水稻产量最高,比常规栽培提高12.6%。     

茶树害虫防治的新途径--化学生态防治

本文介绍了应用化学生态学原理进行茶树害虫防治的目前进展和发展前景。重点介绍了应用昆虫性信息素和茶树挥发性互利素在害虫防治中的应用。在昆虫性信息素的应用上,主要利用人工模拟的雌性害虫的性信息素来引诱同种害虫的雄性害虫以达到预测和迷向防治的目的。在茶树挥发性互利素的应用上,当害虫危害茶树后,害虫的口腔分泌物中的酶类会由叶片的伤口进入茶树组织内而使茶树体内代谢途径发生变化,形成新的挥发性化合物。这种新的挥发性化合物对这些害虫的天敌有很强的引诱作用,而对害虫却没有或只有很弱的引诱活性,通过这类化合物可以使天敌很容易找到它扑食或寄生的害虫的位置,为天敌寻觅到害虫提供了线索,同时为被害的茶树提供了保护．应用化学生态学进行害虫的防治尽管还没有在生产上达到应用的程度,但前景辉煌。     

Prediction of the fabric’s crease recovery property with Taguchi design of experiment

The creasing characteristic of fabrics is affected by many factors like yarn twist, fabric density, fabric constructions, fabric thickness apart from the fiber type. In the first part of this study, the effect of yarn fineness, yarn twist, fabric tightness and weave construction factors on crease recovery was studied. In the second part of the study, in order to improve the creasing recovery of the fabrics, shape memory alloy (SMA) wires were used and the effect of shape memory alloy (SMA) wire on the crease recovery of cotton fabrics produced with different types of weave constructions were determined. Due to the high cost of SMA wire and the weaving operation adversity the two experimental plans were designed according to Taguchi design of experiment (TDOE). From the analysis of the first part, it was found that the yarn linear density had the greatest effect on fabric crease recovery compare to others. Twist coefficient was the second, weft density was third and the weave construction had the least significant effect on the crease recovery. The fabrics produced with coarser and low twisted yarns with high tightness and longer floats in the weave construction have higher crease recovery property. In the second part of the study, the application of the SMA wire significantly increased the crease recovery angle of the fabrics. The thickness of the SMA wire is very important and the effect depends on the wire thickness. The increase of the SMA wire thickness increases the crease recovery significantly. However it must be appropriate with the yarn and fabric properties. The distance between the SMA wire distances was expected to increase the crease recovery however the effect was found not significant. The fabrics produced with coarser yarns with longer floats in the weave construction have higher crease recovery property. However, statistically the effects of these parameters were found not significant due to the dominant effect of the wire thickness.     

棉花雄性不育系的研究现状与利用前景

本文从四个方面对棉花雄性不育系的研究现状与利用前景进行综述：(1)棉花雄性不育系的研究进展情况；(2)棉花雄性不育系的形态特征及其与外界环境因素之间的关系；(3)棉花雄性不育系在棉花的杂交制种中的利用；(4)棉花雄性不育系在生产应用中应解决的几个问题及其应用前景：