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51.
黄瓜种质资源单性结实性评价 总被引:4,自引:1,他引:3
在春季日光温室条件下,对75份黄瓜种质资源的单性结实性进行了评价。结果表明:75份材料的单性结实率在0~100%呈连续分布。其中强单性结实材料40份,占53.3%,中等单性结实材料24份, 占32%,弱单性结实材料11份,占14.7%。其中的24份品种资源中,强单性结实品种20个,占83.3%,其余为中等单性结实。单性结实性强弱表现为坐果率的差异,不同种质资源无籽果实与有籽果实的单瓜重和瓜形指数基本相似。单性结实性一般随着节位升高而增强,其评价工作可侧重于20节内的低节位。 相似文献
52.
53.
基于ADAMS的拖拉机参数化实用模型的初步研究 总被引:1,自引:1,他引:0
提出研究拖拉机虚拟样机模型的重要性。通过应用ADAMS软件,建立拖拉机整车的虚拟样机模型,介绍前后桥系统、转向系统、车身和传动系统模型的创建过程,仿真分析给出了拖拉机行驶速度、运动轨迹和转弯半径的变化曲线,为拖拉机设计和性能分析提供了研究平台。 相似文献
54.
AIM: To investigate the regulation of ‘Tiao Gan Fang Yao’(TGFY) on neuroendocrine-immuno-function of bandage-stressed rat . METHODS:The stressed rat model was made by bandage. RIA was adopted to measure the function of hypothalamus-pitutary-adrenal gland axis (HPAA) of stressed rat. Meanwhile, the immunity of stressed rat and the regulation of TGFY were observed.RESULTS:Bandage stress increased the contents of serum corticosterone(CORT), and ACTH, and hypothalamus corticotropin releasing hormone (P<0.01 or 0.05), which suggested that the excitability of HPAA was enhanced. In addition, bandage stress reduced spleen lymphocyte proliferation (P<0.01) and decreased H2O2 releasing from the macrophages significantly (P<0.01). While TGFY could decrease HPAA excitability of bandage-stressed rat and strengthen its immunity. CONCLUSION:TGFY could regulate disorder of neuroendocrine-immuno-function of bandage-stressed rat. 相似文献
55.
QIAN Wei LOU Guo-qiang ZHOU Zhuo-lin WANG Jia LIU Xiu-jie HAO Mao-lin WANG Wan-tie 《园艺学报》2000,36(11):2056-2061
AIM To investigate the role of curcumin (CUR) in lung ischemia/reperfusion (I/R) injury (LIRI) and its relationship with autophagy. METHODS 40 SD rats were randomly divided into sham operation (sham) group, I/R group, solvent (DMSO) group, CUR group and CUR+rapamycin (CUR-Rap) group. The rats were intraperitoneally injected with normal saline, DMSO, CUR or CUR+Rap before operation. After the rat LIRI model was established, the lung tissues were taken to measure W/D, TLW, IAR, and the contents of SOD and MDA were also measured to indicate the oxidative stress level. Light and electron microscopes were used to observed the morphology and ultrastrucure of lung tissues. The expression levels of autophagy-related proteins were determined by Western blot to evaluate autophagy levels. RESULTS Compared with sham group, wet weight/dry weight (W/D), total lung water (TLW), injured alveoli rate(IAR) and malondialdehyde (MDA) content in all other groups were increased, superoxide dismutase (SOD) activity was decreased, the levels of autophagy were increased (P <0.05), and lung tissue injury and cell ultrastructural damage were aggravated in CUR group. Compared with DMSO group, W/D, TLW and IAR and MDA content were decreased, SOD activity was decreased, autophagy levels were also decreased (P <0.05), and lung tissue and cell ultrastructural damage were attenuated. Compared with CUR group, W/D, TLW, IAR and MDA content were increased, SOD activity declined, the autophagy levels were increased (P <0.05), and damage of lung tissues and cells were more serious in CUR-Rap group. CONCLUSION Curcumin attenuates the lung I/R injury in rats, and its mechanism may be related to the reduction of oxidative stress and the inhibition of autophagy. 相似文献
56.
SUN Kai CHEN Wen-hua ZHANG Ying LI Yan AN Meng-yao PAN Ying-ying WU Yan-na KANG Yi GAO Wei-zhen LOU Jian-shi 《园艺学报》2017,33(1):116-122
AIM: To study the effects of noninvasive delayed limb ischemia preconditioning (NDLIP) on animal cardiac function, myocardial morphology and myocardial apoptosis after myocardial infarction (MI). METHODS: Healthy SD male rats[n=45, weighing (250±10) g] were randomly divided into 3 groups:MI group:the animal model of MI was established by surgical ligation of left anterior descending artery (LAD) after 2 weeks; NDLIP group:after the success of the MI animal model, NDLIP was carried out every other day until the 4th, 6th and 8th weeks; sham group:as the negative control group, the animals were taken heart LAD threading but no ligation. All rats were fed conventionally. At the end of the 4th, 6th and 8th weeks, all rats were made ventricular intubation, and then the hemodynamic parameters were recorded. The blood samples were withdrawn from the abdominal aorta and the serum was separated via centrifugation. The serum contents of Bcl-2 and Bax were measured by ELISA. Left ventricular anterior wall was homogenized. The mitochondrial respiratory chain complexes Ⅰ, Ⅱ, Ⅲ and Ⅳ in the myocardial tissues were detected by ELISA. RESULTS: At the end of the 4th, 6th and 8th weeks, compared with MI group, left ventricular systolic pressure in NDLIP group was significantly increased, while left ventricular end-diastolic pressure in NDLIP group was significantly decreased (both P<0.05). Mitochondrial respiratory chain complexesⅠ, Ⅱ, Ⅲ and Ⅳ in NDLIP group were significantly increased (P<0.05). The serum level of Bcl-2 in NDLIP group was significantly increased and Bax level was reduced remarkably (both P<0.01). CONCLUSION: NDLIP improves the hemodynamic indexes, promotes the mitochondrial respiratory function and inhibits cell apoptosis, thus improving the prognosis of MI. 相似文献
57.
为了探明不同氮钾肥用量对番茄根际土壤细菌群落及土壤养分和盐分的影响,以番茄为研究对象,设置不同氮肥和钾肥用量,通过土培盆栽模拟试验,利用高通量测序技术测定根际土壤微生物及土壤养分的变化。结果表明:1)施肥使主要的优势菌群发生明显改变,过量施肥显著降低根际土壤的细菌数量,根际土壤中肠杆菌科(Enterobacteriaceae)细菌的相对丰度明显下降,但鞘脂单胞菌科(Sphingomonadaceae)和黄单胞菌科(Xanthomonadaceae)相对丰度略有增加,细菌种群分布趋于单一化。2)过量施肥导致的土壤电导率(EC)增加、C/N下降,是土壤根际细菌群落发生改变的主要原因。3)过量施肥显著降低番茄株高、茎粗,但叶片叶绿素SPAD相对含量却呈现增加趋势,叶片光合作用受到抑制,从而产量明显下降。研究表明,施肥过量是导致设施土壤次生盐渍化的主要因素,次生盐渍化导致土壤中细菌群落发生改变,植株生长受到抑制,从而产量下降。 相似文献
58.
新疆吐鲁番地区‘无核白’葡萄水分和矿质元素周年吸收规律研究 总被引:3,自引:0,他引:3
为探究新疆吐鲁番地区‘无核白’葡萄水分和矿质元素的周年吸收规律,以4年生‘无核白’葡萄为试材,采用密闭式营养液循环供给系统栽培,避免了水分和矿质元素的流失,并设置低、中、高浓度(0.5、1.0和1.5倍标准配方浓度)的Hoagland营养液处理。在葡萄植株的生长发育过程中持续测定营养生长(新梢长度、新梢粗度、叶片面积)和生殖生长(果粒横径、果粒纵径、单果质量、可溶性固形物、可滴定酸)指标,检测和计算了不同发育阶段葡萄植株对水分和矿质元素的吸收量,并测定葡萄叶片和果实中矿质元素的含量变化。结果表明,中浓度营养液栽培的‘无核白’葡萄长势中庸,果实品质最佳,作为吐鲁番地区葡萄水分和矿质营养吸收量的参考依据,其生理需水量为每年4 149.5m~3·hm~(-2),矿质元素每公顷的吸收量分别为N 227.9 kg,P 22.9 kg,K 325.9 kg,Ca 341.8 kg,Mg 117.8 kg,Fe 1.9 kg,Mn 460.6 g,Cu 182.3 g,Zn 198.1 g,B 728.3 g。花后47~75 d,‘无核白’葡萄植株的水分和矿质元素吸收速率最大。叶片和果实中的矿质元素含量总体呈高浓度营养液处理中浓度营养液处理低浓度营养液处理的趋势。 相似文献
59.
为了解决新疆棉花秋收作业后的残膜回收难题,设计了适用于新疆棉花种植模式的立秆式搂膜机。介绍了整机的基本结构和工作原理,运用相关理论对关键部件搂膜齿进行受力分析,并利用ANSYS对3种不同形式的搂膜齿在作业过程中的总变形和等效应力进行有限元分析。结果表明:单个搂膜齿在搂膜作业时承受水平方向的土壤阻力约为28.8~43.2N,竖直方向的土壤支持力约为47.4N;弯齿形式的搂膜齿作业过程中的最大总变形和等效应力最小,分别为34.61mm和340.29MPa;直齿与斜齿形式的搂膜齿作业过程中的最大总变形和等效应力值相接近,分别为65.67、68.28mm和462.06、472.28MPa。研究结果可为搂膜式残膜回收机的设计与改进提供参考。 相似文献
60.
为解决红枣收获后的除杂分级作业问题,设计了一种振动筛式红枣多层除杂分级机。运用Auto CAD和Solid Works对整机及关键部件进行设计,利用正交试验确定该型红枣除杂分级机的各项结构参数。试验结果表明:在作业效率为142kg/h、风选除杂装置的风速为14m/s、振动式除杂分级装置的倾斜角度为11°、振动筛的振动频率为20Hz时,除杂分级作业后的红枣含杂率为1.53%、分级合格率为94.8%、损伤率为3.1%。该机工作效率高,作业质量稳定,可同时完成收获后红枣杂质的去除与红枣尺寸的分级作业。 相似文献