棕絮棉18个性状的杂种优势研究

本文利用3个亲本配制的6个杂交组合。研究了棕絮棉的生育期、株高、果技数、总果节数、木技数、木技铃、总铃数、单铃重、衣分、亩籽棉、株皮棉、2．5％跨长、整齐度、比强度、伸长率、麦克隆值等18个性状的中索优势、超亲优势和竞争优势。并据此初步选育出产量、纤维品质较为优良的杂种棉一个。     

微米木纤维JGD型木橡胶减震器的建模理论研究

选用可再生资源---红松木材的加工剩余物和边角碎料切削而成的木纤维为原料,用数学建模方法构造JGD型木橡胶减震器的外部造型,通过MATLAB验证JGD型木橡胶减震器仿真模型的通用性和精确性。动态输入模型参数,得到不同模型所需的加工尺寸,制作与模型相对应的模具。在模具上完成微米木纤维JGD型木橡胶减震器的整个模压加工过程,既能保证木橡胶减震器外形尺寸,又降低其生产成本,可为微米木纤维JGD型木橡胶减震器的加工系统实际生产提供理论依据。     

菠萝叶纤维与其它植物纤维的吸湿性能对比测试及分析

利用扫描电镜、X射线衍射等测试方法对菠萝叶纤维、亚麻纤维、苎麻纤维和棉花纤维的微观形态结构进行了分析。分析认为:菠萝叶纤维的形态结构有区别于其它三种植物纤维,有较大的比表面积;菠萝叶纤维的结晶度与亚麻纤维和苎麻纤维接近,高于棉花纤维。在热带标准状态下,采用烘箱干燥法和回归模型分析法,对测试的四种进行了吸湿、放湿测试与分析。结果表明:在吸湿性能方面,菠萝叶纤维表现最佳,棉花纤维最差;在纤维吸湿平衡回潮率和吸湿速率方面,菠萝叶纤维与亚麻纤维和苎麻纤维相近,且高于棉花纤维;在纤维放湿平衡回潮率和放湿速率方面,菠萝叶纤维高于亚麻纤维、苎麻纤维和棉花纤维。     

Sesbania aegyptiaca as promising biomass for manufacturing of MDF

Sesbania fiber is a fast-growing wood species that has been investigated for medium-density fiberboard (MDF) production. To assess the possibility of applying the local industrial defibration parameters of sugar-cane bagasse (SCB) on defibration of sesbania, the chemical constituents of unfibrated and defibrated sesbania, as well as their thermal stability and scanning electron micrographs, were estimated. Different preparation variables of MDF, such as density, level of urea-formaldehyde (UF) resin (with 0.19% free-formaldehyde [HCHO]), and pressing time were studied, in comparison with that produced by using SCB fibers. The results showed that most of the tested sesbania-based MDFs have mechanical properties that fulfill the minimum requirements of MDF ANSI standard. Additionally, applying 12% UF and pressing for 240 sec provided sesbania-based MDF with optimum reduction in thickness swelling (reached ～7%). It is important to note that the sesbania-based MDF produced under these conditions is characterized by a lower TS property, than that obtained from SCB, or that reported in standards. The preliminary feasibility study revealed that using sesbania fibers will be an added economical potential for MDF production.     

主成分回归法对亚麻纤维产量的综合评价

研究通过对亚麻12个农艺性状的相关性分析,确定亚麻纤维产量相关显著的农艺性状,利用主成分分析原理进行相关性状的降维处理,消除亚麻纤维产量综合评价中存在的性状间多重共线性影响,对亚麻纤维产量进行综合评价。结果表明,主成分回归法可以有效消除亚麻纤维产量综合评价中出现的性状间多重相关性问题,该法可对亚麻纤维产量进行综合评价,为作物产量的综合评价提供新思路。     

青海加什科羊与青海毛肉兼用半细毛羊被毛纤维物理性能比较

青海加什科羊和青海高原毛肉兼用半细毛羊(以下简称半细毛羊)毛纤维细度周岁:公羊50支分别占18.00%、31.17%,母羊分别占20.40%、26.25%;56~58支公羊分别占53.57%、68.82%,母羊分别占53.47%、36.50%,差异极显著(P0.01);成年:公羊50支分别占20.00%、42.26%,母羊分别占20.22%、43.56%;56~58支公羊分别占51.25%、57.76%,母羊分别占51.44%、56.44%,差异极显著(P0.01)。     

大棚不同地膜栽培对蔬菜生长及产量的影响

通过在大棚内进行不同地膜,研究了大棚内麻地膜覆盖对辣椒、黄瓜生长及产量的影响。试验结果表明,大棚内麻地膜覆盖栽培促进蔬菜生长,提高辣椒、黄瓜产量。麻地膜覆盖栽培辣椒、黄瓜比聚乙烯农用黑膜增产5．2％、14．5％,比CK（不覆盖）增产24．7％、23．0％,与对照相比均达到显著差异。     

Effects of different sources of carbohydrates on intake,digestibility, chewing,and performance of Holstein dairy cows

To investigate the effects of different sources of carbohydrates on intake, digestibility, chewing, and performance, nine lactating Holstein dairy cows (day in milk= 100±21 d; body weight=645.7 ± 26.5 kg) were allotted to a 3 × 3 Latin square design at three 23-d periods. The three treatments included 34.91% (B), 18.87% (BC), and 18.86% (BB) barley that in treatment B was partially replaced with only corn or corn plus beet pulp in treatments BC and BB, respectively. The concentration of starch and neutral detergent soluble carbohydrate varied (22.2, 20.2, and 14.5; 13.6, 15.9, and 20.1% of DM in treatments B, BC, and BB, respectively). Cows in treatment BB showed a higher DMI and improved digestibility of DM, NDF, and EE compared with treatments B or BC. Ruminal pH was higher in cows fed on BB (6.83) compared with those that received B or BC treatments (6.62 and 6.73, respectively). A lower proportion of propionate accompanied the higher pH in the BB group; however, a greater proportion of acetate and acetate: propionate ratio was observed compared with cows fed either on the B or BC diet. Moreover, cows fed on the BB diet showed the lowest ruminal passage rate and longest ruminal and total retention time. Eating time did not differ among treatments, rumination time was greater among cows fed on the BB diet compared with the others, whereas total chewing activity was greater than those fed on BC, but similar to those fed on B. The treatments showed no effect on milk yield. Partially replacing barley with corn or beet pulp resulted in an increase in milk fat and a lower protein concentration. Changing dietary NFC with that of a different degradability thus altered intake, chewing activity, ruminal environment, retention time or passage rate, and lactation performance. The results of this study showed that beet pulp with a higher NDF and a detergent-soluble carbohydrate or pectin established a more consistent ruminal mat than barley and corn, thus resulting in higher mean retention time and chewing activity, whereas no changes in 3.5% FCM and milk fat were observed.     

Comparison of 5′-inosine monophosphate and p-nitrophenyl phosphate degrading activities among red,pink, and white muscle fibers of cultured carp

ABSTRACT:   As part of a study to clarify the differences in the temporal change in K -value among fish species, the temporal change in K -value and the 5'-inosine monophosphate (5'-IMP) and p-nitrophenol phosphate (p-NPP) degrading activities in the red, pink, and white muscle fibers in the dorsal muscle of the carp were compared. The temporal change in K -value was fastest in red, followed by pink, and white muscle fibers, at both 0°C and 32°C. Moreover, the 5'-IMP and p-NPP degrading activities were highest in red, followed by pink, and white muscle fibers at near optimum pH concentrations. The 5'-IMP degrading activity at pH 7.0 had a positive correlation with the increasing rate of K -value at 32°C for all types of muscle fibers. These results suggest that differences in increasing rates of K -values between red, pink, and white muscle fibers corresponded to the 5'-IMP degrading activities.     

不同贮藏条件对槟榔品质的影响

以新鲜槟榔为试材,研究不同包装方式与气体成分的保鲜效果。通过测定不同时间段果实的失重率、腐烂率及粗纤维含量,得出CA处理组优于MA处理组,即通过调节环境中的02与CO2含量可以延长槟榔的保鲜期,而由腐烂率及切分后槟榔的表观可以看出,CA2-2,即网兜装槟榔,置于023％、CO220％的气调瓶贮藏,效果最佳,贮藏30d较好保持槟榔果实原有品质。