共查询到20条相似文献，搜索用时 78 毫秒
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土壤微团聚体与土壤的能量变化郭素萍（河北林学院林经系保定０７１０００）关键词土壤微团聚体，土壤肥力，土壤粘粒，腐殖质，能量中图分类号Ｓ７１４．１ＳＯＩＬＭＩＣＲＯ－ＡＧＧＲＥＧＡＴＥＡＮＤＳＯＩＬＥＮＥＲＧＹＧｕｏＳｕｐｉｎｇ（ＨｅｂｅｉＦｏｒｅｓｔ... 相似文献
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主干大扒皮对红星苹果幼树生长与成花的影响朱梅玲，乔进春（河北保定林学院经济林系保定０７１０００）关键词“红星”苹果，主干大扒皮，新梢，花芽形成分类号Ｓ６６１．１ＥＦＦＥＣＴＳＯＦＢＡＲＫＳＬＩＰＰＩＮＧＯＮＧＲＯＷＴＨＡＮＤＦＬＯＷＥＲＦＯＲＭＡＴＩ... 相似文献
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桦木次生林经营效果分析及对策姚庆玉（崇礼县国营和平林场０７６３５０）关键词桦木次生林，经营效果，对策中图分类号Ｓ７９２．１５ＡＮＡＬＹＳＩＳＯＦＭＡＮＡＧＩＮＧＥＦＦＥＣＴＡＮＤＣＯＵＮＴＥＲＭＥＡＳＵＲＥＳＦＯＲＳＥＣＯＮＤＡＲＹＢＩＲＣＨＦＯＲＥ... 相似文献
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高校图书馆科技期刊目录之我见李淑芬（河北林学院图书馆，保定０７１０００）关键词高校，图书馆，科技期刊目录中图分类号Ｇ２５４．３ＳＵＧＧＥＳＴＩＯＮＳＯＮＴＨＥＣＡＴＡＬＯＧＵＥＳＯＦＳＣＩＥＮＴＩＦＩＣＡＮＤＴＥＣＨＮＩＣＡＬＰＥＲＩＯＤＩＣＡＬＳＩ... 相似文献
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建立科研和生产相结合新机制的几点体会常子江（河北林学院科研处保定０７１０００）关键词科研，生产，结合，机制中图分类号Ｇ３１１ＫＮＯＷＬＥＤＧＥＳＯＦＴＨＥＮＥＷＳＹＳＴＥＭＦＯＲＴＨＥＣＯＮＮＥＣＴＩＯＮＯＦＳＣＩＥＮＴＩＦＩＣＲＥＳＥＡＲＣＨＷＩＴ... 相似文献
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天女花生物学特性观察初报王志杰（河北省青龙满族自治县老岭林场，青龙县０６６５０１）关键词生物学特性，天女花，青龙县中图分类号Ｓ６８５．９９ＯＢＳＥＲＶＡＴＩＯＮＳＯＮＢＩＯＬＯＧＩＣＡＬＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＭＡＧＮＯＬＩＡＳＩＥＢＯＬＤ... 相似文献
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《中国林学(英文版)》1997,(1)
ＴｈｅＣｈｉｎａ’ｓＮａｔｕｒｅＲｅｓｅｒｖｅｓＭａｎａｇｅｍｅｎｔＰｒｏｊｅｃｔＦｉｎａｎｃｅｄｂｙｔｈｅＧｌｏｂａｌＥｎｖｉｒｏｎｍｅｎｔＦａｃｉｌｉｔｙ（ＧＥＦＮＲＭＰ）ＧａｏＳｈｅｎｑｉＴｈｅＯｆｆｉｃｅｏｆＷｏｒｌｄＢａｎｋＬｏａｎＦｏｒ... 相似文献
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Augmented endothelial nitric oxide (NO) synthase (eNOS) signaling has been reported to be associated with improvements in cardiac remodeling, and NO levels have been shown to be related to cardiac hypertrophy and heart failure. Imperatorin, a dietary furanocoumarin, has been shown to prevent cardiac hypertrophy in the spontaneous hypertension rats (SHR). Thus, we aimed to clarify whether imperatorin attenuates both cardiac hypertrophy and heart failure via the NO-signaling pathway. In neonatal mouse cardiac myocytes, imperatorin inhibited protein synthesis stimulated by either isoproterenol or phenylephrine, which was unchanged by NG-nitro-L-arginine methyl ester (L-NAME). Four weeks after transverse aortic constriction (TAC) on Kunming (KM) male mice, the ratio of heart weight to body weight was lower after imperatorin treatment than in controls (6.60 ± 0.35 mg/g in TAC, 4.54 ± 0.29 mg/g with imperatorin 15 mg kg−1 d−1, ig, P < 0.01); similar changes in the ratio of lung weight to body weight (7.30 ± 0.85 mg/g in TAC, 5.42 ± 0.51 mg/g with imperatorin 15 mg kg− 1 d− 1, ig) and the myocardial fibrosis. All of these improvements were blunted by L-NAME. Imperatorin treatment significantly activated phosphorylation of eNOS. Myocardial mRNA levels of natriuretic peptide precursor type B and protein inhibitor of NO synthase, which were increased in the TAC mice, were decreased in the imperatorin-treated ones. Imperatorin can attenuate cardiac hypertrophy both in vivo and in vitro, and halt the process leading from hypertrophy to heart failure by a NO-mediated pathway. 相似文献
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以花楸树成熟合子胚胎为材料,利用室内培养皿发芽法研究外源NO供体(SNP)、NO合成抑制剂(PTIO)、脱落酸(ABA)以及乙烯受体抑制剂(NBD)对花楸树胚胎萌发和幼苗发育初期活性氧(ROS)积累的影响.结果表明:光照条件下SNP预处理可减弱PTIO或ABA对胚胎萌发的抑制作用,但不能减弱NBD处理对胚胎萌发的抑制作用.SNP预处理显著增加幼苗叶片中叶绿素含量,但这种增加效应不能被PTIO解除.PTIO抑制SNP预处理引起的幼苗叶片中过氧化氢(H2O2)含量和超氧阴离子含量的增加.SNP预处理解除PTIO对根部超氧阴离子含量的抑制作用.研究结果为阐明胚胎萌发过程中反应氮调节的(NO依赖型)休眠解除和ROS积累的关系奠定基础. 相似文献
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为研究一氧化氮(NO)在打破百合鳞茎休眠中的作用,用硝普钠(SNP)处理休眠的"哥德琳娜"百合(Lilium brownii var. viridulum 'Gondelina')鳞茎后,在25 ℃下进行培养,观测其萌发生长和测定不同解除休眠生长时期GA(赤霉素)、IAA(吲哚乙酸)、ZR(玉米素核苷)、ABA(脱落酸)4种内源激素的质量摩尔浓度变化.结果表明,NO能够促进"哥德琳娜"百合鳞茎休眠的解除,随处理体积摩尔浓度的增加,鳞茎发芽率呈先增大后减小趋势,其中10 mmol/L SNP体积摩尔浓度浸泡处理对休眠"哥德琳娜"百合鳞茎的解除效果最好,发芽率达58.2%,比对照增大37.9个百分点,且与对照差异显著(P<0.05);鳞茎质量和根生长量呈先增大后减小趋势,10 mmol/L SNP体积摩尔浓度浸泡处理下增加最大,分别比对照增大41.74%和102.03%,且与对照差异显著(P<0.05);用10 mmol/L SNP体积摩尔浓度浸泡处理下,鳞茎内源激素GA、IAA和ZR质量摩尔浓度随处理天数增加呈增大趋势,且均与对照差异显著(P<0.05),而ABA质量摩尔浓度随处理天数增加呈减小趋势,与对照之间差异不显著.NO能够促进生长素的快速生成,加速"哥德琳娜"百合鳞茎休眠解除的进程. 相似文献
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北京低山区两种人工林土壤中N2O排放通量的研究 总被引：12，自引：0，他引：12
N2 O是一种重要的温室气体 ,其主要的排放源是土壤。本研究采用静态封闭箱式技术在 1997～1998年对北京西山低山区元宝枫和油松人工林地土壤中N2 O的排放通量进行了原位测定。研究结果表明该地区森林土壤为大气N2 O气体的一个重要的源 ,年平均排放通量为 3 16 μg·m- 2 h- 1 ,变动范围为 - 1 2～ 7 92μg·m- 2 h- 1 。林地土壤N2 O的排放有较明显的季节变化趋势 ;夏季最高 ,春秋季次之 ,冬季最低甚至出现负值。排放通量的大小主要决定于土壤温度、土壤湿度及测定时前 5d内降水量等因子。研究还表明N2 O的排放通量有一定的日变化趋势 ;6 :0 0出现最低点 ,9:0 0和 18:0 0出现最高点 相似文献
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Sesquiterpenes from Vladimiria souliei and their inhibitory effects on NO production 总被引：1，自引：0，他引：1
As a part of our ongoing search for plant-derived compounds that inhibit nitric oxide production, the methanol extract of the roots of Vladimiria souliei was found to show significant inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells. Bioactivity-guided isolation of the extract yielded two most active sesquiterpenes, including a new compound, named souliene A (1) and alismol (2). Their structures were elucidated by spectroscopic methods (IR, ESIMS, HRESIMS, 1D and 2D NMR). Two isolates showed promising inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells. 相似文献
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Two new (1 and 2) and one known (3) β-dihydroagarofuran sesquiterpenes were isolated from the fruits of Celastrus orbicultus Thunb. Their structures were elucidated as 1β,13-diacetoxy-8β,9β-dibenzoyloxy-β-dihydroagarofuran (1), 1β,13-diacetoxy-8α-hydroxy-9β-benzoyloxy-β-dihydroagarofuran (2), and 1β,6α,13-triacetoxy-9α-benzoyloxy-β-dihydroagarofuran (3), on the basis of spectroscopic data analyses. All the compounds exhibited inhibitory effects on LPS-induced nitric oxide production in murine microglial BV-2 cells. 相似文献
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A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography
was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue
got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0
mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base
solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution,
Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative
standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with
the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations
in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %. 相似文献
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本文对乌鞘岭地区天然分布的中国沙棘和西藏沙棘果实生长与成熟期间维生素C,PP,E等含量的动态变化进行了系统的调查和分析测定。结果表明:V_C主要存在于果肉中,且随果实发育而增加,果实变色期(花后107—110天)达到最高值,随后急速下降。但完熟后果肉中V_C减少时种子内V_C却有所增加。中国沙棘V_C水平远较西藏沙棘为高(5倍以上)。果实发育前期果肉中V_(PP)含量很高,以后逐渐下降,完熟期中国沙棘果实内V_(PP)再度升高,其变化与呼吸速率的变化表现出相同的消长规律。V_E主要存在于种子里,总趋势是随成熟而增加。种子变色期V_E上升至第一高峰值,随后下降,果实完熟后达到第二高峰值。西藏沙棘V_E含量高于中国沙棘。本文对不同维生素可能起的生理作用也进行了讨论。 相似文献