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1.
滩地杨树生长立地因子的多变量分析   总被引:3,自引:0,他引:3  
应用多元统计分析方法,对长江中下游滩地杨树人工林生长与立地条件诸因子的关系进行研究.结果表明:影响滩地杨树人工林生长的立地因子为土壤质地、土壤容重、滩面高程、土壤湿度、淹水时间,其中前三项为主要影响因子.结果为今后滩地杨树大面积造林及经营管理提供了重要理论依据和参考.  相似文献   

2.
从生态学角度看蜜蜂病虫害致病因子─—综合生态效应   总被引:1,自引:0,他引:1  
从生态学角度看蜜蜂病虫害致病因子─—综合生态效应肖锡红(江西省养蜂研究所,南昌330201)ComprehensiveEcologicalEffectofinfectingFactorsonHoneybeeDisease.¥XiaoXihong(Ji...  相似文献   

3.
本文报道点刻跳小蜂属2新种,即从甘肃古浪采集的禾蜡蚧点刻跳小蜂DiscodeseriopeltisXuetHe,sp.n.和从辽宁沈阳采集的沈阳点刻跳小蜂DiscodesshenyangensisXuetHe,sp.n.。对新种进行了详细描述,并附特征图和检索表。点刻跳小蜂属在我国的分布为首次记录。模式标本存浙江农业大学植物保护系。  相似文献   

4.
本文对碧蝉属HeaDistant做了研究,并记述该属1新种──云南碧蝉Heayunnanensis,sp.nov.,模式标本保存在中国科学院动物研究所。  相似文献   

5.
微量元素锗对四种微藻光合色素的影响   总被引:3,自引:0,他引:3  
采用溶液培养方法,以锗作为胁迫因子,研究了锗对4种微藻“钝顶螺旋藻(Spirulina platensis)、盐生杜氏藻(Dunaliella salina)、淇江叉鞭金藻(Dicrateria zhanjiangensis)和微绿藻(Nannochloropsis.sp)光合色素的影响。实验结果表明,经10mg/dm^3锗处理后,四种藻类细胞中的光合色素都发生了较大变化,有些色素发生明显的增加或  相似文献   

6.
腔孢纲真菌的三个新种   总被引:4,自引:0,他引:4  
习平根  戚佩坤 《菌物系统》2000,19(4):466-469
在调查香龙血树Dracaena fragrans(L.)Ker-Ganl.的病害中,发现了腔孢纲真菌的3个新种,即:Phlmopsis dracaenicolaZ.D.Jiang,P.G.Xi et P.K.Chi,Bartalinia dracaenae P.G.Xi,Z.D.Jiang et P.K.Chi及Sphaeropsis dracaenae P.G.Xi et P.K.Chi,模式标  相似文献   

7.
哀牢山木果石栎群落优势种的生态位宽度与重叠   总被引:24,自引:0,他引:24  
通过多种方法比较研究了哀牢山木果石栎(Lithocarpus xylocarpus)群落8个优势种的生态位宽度和重叠,结果表明,该群落是以木果石栎、腾冲栲(Castanopsis wattii)、滇木荷(Schima noronhae)和景东石栎(Lithocarpus chintungensis)为优势种的共优群落,它们的生态位宽度值分别为0.8732,0.7856,0.6742和0.5798。  相似文献   

8.
河南伏牛山缘脊叶蝉亚科种类记述:同翅目:叶蝉科   总被引:3,自引:0,他引:3  
本文论述河南省伏牛山缘脊叶蝉亚科3属5种,其中包括1新属:管茎叶蝉属Fistulatus gen.nov.和3新种:中华管茎叶蝉Fistulatus sinensis sp.nov.河南胫槽叶蝉Drabescus henanensis sp.nov.细茎胫槽叶蝉Drabescus minipenis sp.nov。此外还厘订新异2个。新种模式标本分别保存在中国农业大学,中国科学院动物研究所,中山大  相似文献   

9.
王伴月 《古脊椎动物学报》2001,39(1):24-42,T004,T006
根据新材料修订了Dianomys属及其两个种(D. obscuratus和D. qujingensis)的鉴定特 征。原定为D、obscuratus的P4应为dP4,原定的M1/2和m1/2分别被确认为M1和m2,原属 D.obscuratus的p4,实属D.qujingensis。D.qujingensis与D.obscuratus的区别除个体较大 外,还在于其上颊齿具分叉的后脊,m1具下中脊和p4具较发育的附加刺。另建立了一新属 (杨氏鼠Youngomys),包括二新种(云南杨氏鼠Y .yunnanensis、小杨氏鼠Y pisinnus)和一未 定种(Youngomys?sp.)。youngomys的主要特征为:颊齿比例上较窄长,齿冠较低,主尖钝,脊 较细而低;上臼齿长大于宽,后脊向原尖斜伸,内脊较低;下臼齿下原尖后臂较向后伸,无明显 的舌部,下内尖臂很弱,横向,不与下外脊连等。 Y pisinnuS与 Y yunnanensis的区别在于个体 较小,齿冠较低,脊更细弱,较显丘形,上臼齿次尖位置向舌侧移,具较明显的后小尖,和后脊 不与原尖连等。 用PAUP 3.1.1对亚洲古近纪的梳齿鼠类进行了系统分析,表明第四前臼齿的  相似文献   

10.
湖岸滩地梳齿式生态农业发展模式的探讨   总被引:1,自引:0,他引:1  
湖岸滩地梳齿式生态农业发展模式的探讨沈显生(安徽教育学院生物系,合肥230061)StudyofAgroecologyDevelopingPaternintheComb_TechformonaLakesideLand.ShenXiansheng(D...  相似文献   

11.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

12.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

13.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

14.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

15.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

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18.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

19.
Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.  相似文献   

20.
In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.  相似文献   

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