水稻精确定量栽培技术对稻瘟病的控制作用

2009年至2010年在田间自然发病条件下,应用水稻精确定量栽培技术进行小区试验和多点对比试验,以当地常规栽培为对照,比较稻瘟病发病程度。结果表明,采用水稻精确定量栽培技术对叶瘟和穗瘟均有控制作用,在发病前期、中期较明显,并可推迟10 d左右发生叶瘟,其中在水肥调控的前提下,扩行处理(26.4 cm×9.9 cm、33 cm×16.5 cm、29.7 cm×13.2 cm、19.8 cm×19.8 cm)对穗瘟的控制率在36.04%～53.15%,与其他处理控制率差异显著;而到发病后期,尤其是在稻瘟病偏重发生年份和感病品种中,差异则不明显。生产上应用该技术作为控制稻瘟病的综合措施之一,对减少农药使用量、生产安全稻米、保护环境等具有积极作用。     

日本落叶松种子园花粉散发及其空间分布特征

对湖北省建始县长岭岗林场日本落叶松种子园内花粉散发和空间分布特征进行2年的研究.结果表明:日本落叶松花粉散发受气候因子的影响很大;整个散粉期间日本落叶松花粉散发量呈现低-高-低的节律,每天花粉散发量呈极显著差异;散粉期间出现一个散粉高峰期,一般持续3~5 d,散粉高峰期间每天不同时间段的散粉量也呈现低-高-低的节律,散粉高峰时间段出现在8∶00~16:00,具体时间段受当日天气的影响,每天不同时间段内花粉散发量呈极显著差异;种子园内不同样点花粉散发量中,八方位花粉散发量及树冠内、中、外部花粉散发量均未达到显著性差异,花粉分布都呈均匀分布型;种子园内不同垂直高度花粉散发量呈极显著差异,花粉分布呈集群分布型.     

Protective effect of pyrrolidine dithiocarbamate on kidneys in type 2 diabetic rats

AIM: To investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) on the kidneys in type 2 diabetic rats. METHODS: High-fat diet and a small dose (27 mg/kg) of streptozotocin-induced diabetic rats were treated with or without PDTC (50 mg穔g^-1穌^-1, ip) for 1 week, and age-matched nondiabetic animals were also used for comparison. The concentration of malondialdehyde (MDA)and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined by commercial kit. The ratio of urine microalbumin/creatinine was measured by an automatic biochemical analyzer. The morphological changes of renal glomerulus were observed by HE/Masson staining and transmission electron microscopy. The expression of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in the renal tissues was examined by the method of immunohistochemistry. RESULTS: PDTC-treated rats had lower blood glucose level and urine microalbumin/creatinine ratio than those in untreated diabetic rats. The levels of tissue MDA in diabetic rats were significantly higher, and the activity of SOD and GSH-Px was lower than those in normal control rats (P<0.05). The renal damage in diabetic rats was significantly improved after PDTC treatment. PDTC administration markedly attenuated the expression of iNOS and the production of NT in renal glomerulus and tubule in diabetic rats. CONCLUSION: PDTC not only reduces blood glucose level, but also protects the diabetic rats from diabetic nephropathy by diminishing the expression of iNOS and the production of NT.     

浅析初中生盒饭热能

中学生是国家的希望,一名初中生每天中午需要补充多少能量呢?学校的午餐盒饭又是否能够提供足够的能量呢?对DB 31/160—2005《盒饭卫生与营养要求》中初中生盒饭的营养要求部分进行了分析与研究,并提出建议,从而帮助初中生身体得到健康和良好的发展。     

Effect of H2O2 on voltage-gated potassium channels in rat pulmonary artery smooth muscle cells

AIM:To determine the effect of hydrogen peroxide (H₂O₂) on voltage-gated potassium channel currents (IKv) in pulmonary vascular smooth muscle cells (PASMCs). METHODS:Using whole cell patch-clamp technique, IKv was recorded in freshly isolated rat PASMCs with acute enzymatic digestion method. The effect of hydrogen peroxide on IKv in PASMCs was investigated in normoxia. RESULTS:IKv in PASMCs was increased significantly by H₂O₂ and the increase depended on the concentration in normoxia. Current-voltage relationship curve shifted to the left. CONCLUSION:Hydrogen peroxide is an important K+ channel opener.     

昆明地区梨煤污病发生规律与防治

梨煤污病由仁果粘壳孢[Gloeodes pomigena(Schw.)Collby.]引起,主要危害梨果实.在果皮表面形成一层水痕状黑灰色霉状物,菌丝着生于果实表面,少数菌丝侵入到果皮下层,严重影响梨外观品质[1].该病1998年来在昆明地区砀山酥梨上发生,危害严重,未防治果园病果率达100%.现将梨煤污病发生规律调查和药剂防治试验报道如下.     

不同改良措施对草原土壤理化性质的影响

为探索吉林省西部退化草地的治理修复技术,复壮退化草地,通过田间试验的方法,研究了不同措施对草原土壤理化性质的改良效果。结果表明,不同改良措施均对土壤理化性质的改善有较好的效果,其中施用秸秆处理对提高土壤水稳性团聚体含量效果最好,比对照提高了34.5%,土壤团聚体破坏率比对照降低了22.7%;各处理对降低土壤容重均有较好效果,围栏内土壤的碱化度比不围栏降低了31.7%,其它各改良措施降低碱化度的作用更明显;草原土壤磷、钾肥较为缺乏,而且单纯的施用化肥效果并不好,需要配合有机肥的施用才能有效提高土壤肥力。     

秸秆培肥土壤对优先流中养分淋失的影响

为了研究秸秆培肥土壤后对优先流中养分淋失的影响,采用原状土柱模拟养分淋溶的方法,对秸秆培肥后土壤中养分淋失的状况进行了研究。结果表明,土壤经秸秆培肥后,淋溶液中氮、磷和钾的累计含量降低,淋失速度和含量也都有不同程度的降低,但对不同养分降低的效果不同,对阳离子养分的保持效果更好一些,未施秸秆处理的NH4+-N累计含量为秸秆培肥处理的4.54倍;而对硝态氮的保持作用最差,未施秸秆处理的NO3--N累计含量为秸秆培肥处理的2.79倍。说明秸秆培肥土壤对减少养分淋失和降低地下水污染具有一定作用。     

植绿挡墙在叉仔河治理工程中的应用及设计优化

为了赋予技术成熟、安全可靠、应用广泛的传统混凝土挡墙生态特性,将其直立的墙面适当放缓后退,浇筑成阶梯形状,在阶梯边沿上设置矮墙,形成生态槽,充填种植土,栽培适宜的景观植物,即为植绿型挡墙。结合植绿型挡墙在叉仔河治理中的应用,优化了挡墙设计,临水侧墙面综合坡比为1∶0.8,生态槽净宽0.65~0.85 m,槽深0.4 m,槽壁厚0.15 m,相邻槽距1.0 m,同时,墙背调整为仰斜式,坡比为1∶0.25,墙趾处设格宾护脚防冲。植绿型挡墙用于河道治理中,既经久耐用,又可形成生态美景,还有利于不幸落水者攀爬上岸自救。     

作物根茬留田的保土培肥效应

论述了作物根茬留田可以增强土壤的生物活性,促进土壤中的生物化学过程,从而更新土壤中已渐老化的腐殖质,保持地力常新。这种培肥效应,改善了土壤的物理性状和增强土壤的保持水土和保肥供肥性能,增加了作物的产量。连续根茬留田还有迭加效应。