作业次序对深松旋耕联合作业机作业质量及功耗的影响

该文选用华北平原壤土区常用的深松旋耕联合作业机作为试验设备,分析深松、旋耕作业次序对其作业质量及功耗的影响。运用离散元仿真分析结果表明,旋耕深松作业次序比深松旋耕作业次序的工作紧凑、刀辊受力均匀。随着作业深度的增加,深松旋耕作业次序作用的深层土壤较多。建立以旋耕深度、深松深度为因素,以2种作业次序功耗为指标的回归方程综合分析得出,作业深度较浅时,深松旋耕作业次序功耗、地表平整度、植被覆盖率优于旋耕深松作业次序;作业深度较大时,旋耕深松作业次序功耗明显小于深松旋耕作业次序,且两者作业质量差异不显著。田间试验表明,离散元仿真建立的2种作业次序作业深度与作业功耗的回归方程及测量的地表平整度、土壤膨松度及植被埋覆率基本能真实反映田间作业情况。     

基于EDEM的双螺旋奶牛饲喂装置给料性能分析与试验

奶牛精确饲喂技术的实施不仅能够促进奶牛业健康发展,而且还能够提高牛场经济效益。基于牛场现状,该文在设计的等径双螺旋精确给料的奶牛饲喂装置基础上,理论分析了物料输送速度与给料时间,通过Solidworks对双螺旋给料装置进行了三维建模,并利用EDEM软件分别对40 mm搅龙和70 mm搅龙不同转速(80、100及120 r/min)的给料过程进行了离散元仿真,分析了装置给料稳定性,结果表明,40 mm搅龙在转速为120 r/min时变异系数为0.052 2,70 mm搅龙在转速为100 r/min时变异系数为0.105 2,给料稳定性最优。为进一步验证仿真结果,在搭建的双螺旋给料饲喂装置上,对40 mm搅龙和70 mm搅龙进行了给料试验,试验结果显示,40 mm螺距搅龙转速120 r/min和70 mm搅龙转速100 r/min时给料稳定性最优,试验结果与仿真结果吻合。在验证装置给料稳定性基础上,对给料精度进行了试验,结果显示:40 mm搅龙和70 mm搅龙在80、100、120 r/min等不同工作转速组合下,给料精度均大于95%,当40 mm搅龙转速为120 r/min,70 mm搅龙转速为100 r/min时,给料时间为14.1 s,给料量为6.009 kg,装置给料精度不低于99.835%,符合奶牛精确饲喂效率与精度要求。     

A study of the effectiveness of post-treatment after hair straightening process

In order to minimise the hair damage due to hair straightening process, post-treatment is recommended to protect the damaged hair from further depreciation and breakage. However, few reported quantitatively about the effectiveness of post-treatment after hair straightening process. Therefore, the aim of this paper will investigate the effectiveness of post-treatment methods for chemically straightened hairs. The effectiveness will be evaluated through different analytical methods such as scanning electron microscopy (SEM), diffuse reflectance spectrophotometry, tensile strength test and urea bisulphite solubility test for the properties related to morphological structure, hair colour change, tensile strength as well as chemical damage respectively. From the findings of the instrumental results, it was obvious that the application of post-treatments would improve the lustre of the damaged hair by giving higher value in lightness when compared with the raw hair control sample. Furthermore, the strength property of the post-treated hair increased when compared with the chemically straightened hair. This was due to the fact that the film-forming agents of conditioning products formed a protective layer and smooth surface on the fibre surface.     

A mixture neural methodology for computing rice consumptive water requirements in Fada N’Gourma Region, Eastern Burkina Faso

Crop consumptive water requirement (Crop-ET) is a key variable for developing management plans to optimize the efficiency of water use for crop production particularly in semiarid zone. In Burkina Faso, the unfavorable climatic conditions characterized by the low and unevenly distribution of rainfall have pushed water resources management to the forefront of the crop production issue. Crop-ET is extremely required in rainwater effective management for mitigating the impact of water deficit on the crops. Basically, Crop-ET determination involves reference evapotranspiration (ETo) and crop coefficient (Kc) which required complete climatic data and specific site crop information, respectively. ETo estimation with the recommended FAO56 Penman–Monteith (PM) equation is limited in Burkina Faso due to the numerous meteorological data required which are not always available in many production sites. In such circumstances, research to compute directly Crop-ET as an alternative to the two-step approach of calculating ETo and determining site specific Kc, seems desirable. Therefore, this study aims to evaluate the performance of a mixture principal component analysis neural network (PCANN) model for computing rice Crop-ET directly from temperatures data in Fada N’Gourma region located in Eastern Burkina Faso, Africa. From the statistical results, rice Crop-ET can be successfully computed by using PCANN methodology, when only temperatures data are available in this African semiarid environment. Thus, in poor data situation, Crop-ET direct computation can be rapidly addressed through PCANN model for agricultural water management in African semiarid regions.     

魔芋叶片中4种总RNA提取方法的比较

本研究分别利用TRIzol法、异硫氰酸胍法、改良的CTAB法及试剂盒这4种方法提取魔芋叶片的总RNA,并用紫外光谱和琼脂糖凝胶电泳对各个提取效果进行鉴定。反复试验的结果表明:TRIzol法难以提取魔芋叶片总RNA,异硫氰酸胍法提取的总RNA浓度低、杂质较多且有部分降解,这两种方法不适宜用于魔芋叶片总RNA提取;试剂盒方法提取的总RNA产率和纯度较高,但稳定性差、成功率低且成本较高;改良的CTAB法利用PVP和β-巯基乙醇去除酚类物质,水饱和酚-氯仿去除蛋白质,醋酸钾去除多糖,该方法提取得到的总RNA的纯度较高,OD260/OD280值为1.893,而且效果稳定,有良好的可重复性。因此,我们认为改良的CTAB法是一种简便、快速且经济的提取魔芋叶片总RNA的方法。     

浅谈国家森林公园生态旅游开发

随着城市化进程的日益加快,人们渴望自然的热情也日益增长,一种以“人与自然和谐”为中心,提倡环保的森林生态旅游成为国际生态旅游的新时尚。但由于经济技术、专业设施及民众环保意识较差等因素,我国在森林生态旅游开发中存在着一系列问题。本文就此以方正龙山国家森林公园为例,指出其现存问题,并提出相应的解决对策。     

腾冲红花油茶籽油主要理化成分分析

对云南9个代表性种群的腾冲红花油茶籽油的主要理化成分进行分析。结果表明：比重、折光指数、酸值和过氧化值的变化幅度依次为0.903 2～0.915 9 d40/40、1.470 0～1.473 6 n40、0.345 0～0.750 5 mg/g、11.905 1～33.629 9 meq/kg;通过气相色谱法分析,腾冲红花油茶籽油富含不饱和脂肪酸,含量为82.11%～84.04%;并且富含钙、磷、钾等矿质元素。     

施用蔗渣对土壤镉赋存形态和生物有效性的影响研究

采用化学反应的合成方法向蔗渣中引入巯基官能团,并进行电镜扫描和红外光谱分析。在此基础上,通过土壤培养试验和生物盆栽试验,研究了蔗渣和改性蔗渣对模拟镉(Cd)污染农田土壤中镉的赋存形态和生物有效性的影响。结果表明,采用该合成方法,成功地向蔗渣中引入了巯基官能团。在土壤培养试验中,有机物对土壤Cd赋存形态的转化与土壤pH的相关性不明显,但与土壤中胡敏酸(HA)和富里酸(FA)含量的变化具有一定的相关性:土壤中HA含量随培养时间的延长而逐渐升高,各处理土壤弱酸提取态Cd含量相应减少,而土壤残余态Cd含量则逐渐增加,且巯基蔗渣的作用效果均强于未改性蔗渣。在生物盆栽试验研究中,外加5 mg·kg-1Cd显著降低了小白菜的生物量,而施用有机物料对小白菜均有显著的增产效果,研究结果同时表明蔗渣和巯基蔗渣都不同程度降低了土壤有效态Cd的含量以及小白菜地上部分的镉含量,且巯基蔗渣的作用效果较为显著。另外,小白菜地上部分镉含量与小白菜生物量呈现显著负相关,与土壤有效镉含量呈显著正相关。     

玉溪烟区烤烟主要大田生长期紫外辐射分析与模拟

选取云南省玉溪市红塔区和通海县两个不同海拔烟区连续3a(2008-2010年)烤烟主要大田生长期(5-8月),利用逐日正午(11:30-12:30)紫外辐射强度和同期光照度、部分气候要素值的观测资料,分析紫外辐射强度变化与气候要素之间的关系,并选取光照度和云量两个要素对紫外辐射强度进行模拟预测。结果表明,烤烟大田生长期紫外辐射强度均值的年际变化不显著,同时期气象条件中,云量是影响烤烟生长期紫外辐射强度均值的主要因子。光照度、云量与紫外辐射强度变化的关系较密切,紫外辐射强度与光照度的比值较恒定,紫外辐射强度随云量的增加而降低。统计回归模型模拟表明,可用光照度和云量对紫外辐射强度进行估算,模拟值较准确。