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1.
Samples of marine pleuston were collected from the sea-surface along considerable sections of the track of Eye of the Wind during its 2-year circumnavigational expedition 'Operation Drake' from November 1978 to October 1980. One hundred and eleven of the tow samples contained insects of the genus Halobates . They were assigned to four oceanic species: H. micans, H. sericeus, H. germanus and H. splendens; two coastal species: H. maculatus, H. princeps, and one undescribed species. Various development stages of the oceanic species were found. The locations, time of collection and surface temperatures where sea-skaters were collected are tabulated. Distributional boundaries and population densities of the oceanic species collected are discussed. 相似文献
2.
Xiao LiWei Xing Shuping Zhuo Jin ZhouFeng Li Shi-Zhang QiaoGao-Qing Lu 《Bioresource technology》2011,102(2):1118-1123
Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH. Electrochemical measurements show that the carbons made by impregnation-activation process have better capacitive behavior and higher capacitance retention ratio at high drain current than the carbons made by carbonization-activation process, which is due to that there are abundant macroscopic pores and less interior micropore surface in the texture of the former. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons and commercial wood-based active carbon, thus highlighting the success of preparing high performance electrode material for EDLC from SSS. 相似文献
3.
We tried to establish compatible carbon content models of individual trees for a Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantation from Fujian province in southeast China. In general, compatibility requires that the sum of components equal the whole tree, meaning that the sum of percentages calculated from component equations should equal 100%. Thus, we used multiple approaches to simulate carbon content in boles, branches, foliage leaves, roots and the whole individual trees. The approaches included (i) single optimal fitting (SOF), (ii) nonlinear adjustment in proportion (NAP) and (iii) nonlinear seemingly unrelated regression (NSUR). These approaches were used in combination with variables relating diameter at breast height (D) and tree height (H), such as D, D2H, DH and D&H (where D&H means two separate variables in bivariate model). Power, exponential and polynomial functions were tested as well as a new general function model was proposed by this study. Weighted least squares regression models were employed to eliminate heteroscedasticity. Model performances were evaluated by using mean residuals, residual variance, mean square error and the determination coefficient. The results indicated that models with two dimensional variables (DH, D2H and D&H) were always superior to those with a single variable (D). The D&H variable combination was found to be the most useful predictor. Of all the approaches, SOF could establish a single optimal model separately, but there were deviations in estimating results due to existing incompatibilities, while NAP and NSUR could ensure predictions compatibility. Simultaneously, we found that the new general model had better accuracy than others. In conclusion, we recommend that the new general model be used to estimate carbon content for Chinese fir and considered for other vegetation types as well. 相似文献
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5.
Yanji Qu Lin Zhuo Na Li Yiqing Hu Weihua Chen Yun Zhou Jinwei Wang Qingmei Tao Jing Hu Xiaolu Nie Siyan Zhan 《PloS one》2015,10(4)
International hospital-based studies have indicated a high risk of cognitive impairment after stroke, evidence from community-based studies in China is scarce. To determine the prevalence of post-stroke cognitive impairment (PSCI) and its subtypes in stroke survivors residing in selected rural and urban Chinese communities, we conducted a community-based, cross-sectional study in 599 patients accounting for 48% of all stroke survivors registered in the 4 communities, who had suffered confirmed strokes and had undergone cognitive assessments via the Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and Hachinski Ischemia Scale (HIS). Detection of PSCI was based on scores in these neuropsychological scales. Factors potentially impacting on occurrence of PSCI were explored by comparing demographic characteristics, stroke features, and cardiovascular risk factors between patients with and without PSCI. The overall prevalence of PSCI was 80.97% (95%CI: 77.82%-84.11%), while that of non-dementia PSCI (PSCI-ND) and post-stroke vascular dementia (PSD) was 48.91% (95%CI: 44.91%-52.92%) and 32.05% (95%CI: 28.32%-35.79%), respectively. Prior stroke and complications during the acute phase were independent risk factors for PSCI. The risk of recurrent stroke survivors having PSCI was 2.7 times higher than for first-episode survivors, and it was 3 times higher for those with complications during the acute phase than for those without. The higher prevalence of PSCI in this study compared with previous Chinese studies was possibly due to the combined effects of including rural stroke survivors, a longer period from stroke onset, and different assessment methods. There is an urgent need to recognize and prevent PSCI in stroke patients, especially those with recurrent stroke and complications during the acute phase. 相似文献
6.
E A Ceccarelli J G Verburg S Q Zhuo W S Allison 《Archives of biochemistry and biophysics》1989,272(2):400-411
The characteristics and specificity of inactivation of the chloroplast F1-ATPase (CF1) with 7-chloro-4-nitrobenzofurazan (Nbf-Cl) have been investigated. Inactivation of the octylglucoside-dependent Mg2+-ATPase activity of latent CF1 by Nbf-Cl can be correlated with the formation of about 1.2 mol of Nbf-O-Tyr per mole of enzyme. Following inactivation of CF1 with [14C]Nbf-Cl, polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate revealed that the majority of the radioactive reagent incorporated is present in the beta subunit. Treatment of the enzyme with [14C]Nbf-Cl following dithiothreitol heat activation, led to similar labeling of the beta subunit and substantial incorporation of 14C into the gamma subunit. On complete inactivation, about 4 mol of Nbf-S-Cys is formed per mole of dithiothreitol-heat-activated CF1. Incorporation of 14C into the gamma subunit is prevented by prior treatment of the latent CF1 or of the dithiothreitol-heat-activated CF1 with iodoacetamide. Following incubation of the dithiothreitol-heat-activated CF1 with iodoacetamide, complete inactivation of the octylglucoside-dependent Mg2+-ATPase activity by Nbf-Cl can be correlated with the formation of about 1.2 mol of Nbf-O-Tyr per mole of enzyme. After stabilization of the [14C]Nbf-O-Tyr derivative by treatment with sodium dithionite, a labeled peptide was purified. Automatic Edman degradation of this peptide revealed the sequence V-X-V-P-A-D-(D). The majority of the radioactivity was cleaved in the second cycle, the position occupied in CF1 by Tyr-beta-328, which is homologous to Tyr-beta-311, the residue reactive with Nbf-Cl in the beef heart mitochondrial F1-ATPase. When CF1, modified at Tyr-beta-328 with Nbf-Cl, is incubated at pH 9.0, the Nbf-O-Tyr adduct is hydrolyzed, leading to concomitant recovery of the ATPase activity. In double labeling experiments, two-dimensional isoelectric focusing in the presence of urea followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate indicates that 2-azido-ADP, covalently bound at the tight ADP binding site, and the tyrosine modified by [14C]Nbf-Cl are located in different beta subunits. 相似文献
7.
Restructured beef steaks, formulated with different beef particle sizes, fat content and binder levels, were evaluated with selected marketing factors by 30 consumers. Conjoint analysis was applied to consumers’hedonic scores and statement of purchase intent for raw and cooked steaks. Product preference, packaging and brand had significant (P < 0.05) impacts on hedonic scores for raw products. Price was an additional important factor in purchase intent. Parcooked products, only product preference was important for both hedonic rating and purchase intent. When products were not present, conjoint measurement indicated that nutritional information, price and brand influenced (P < 0.05) hedonic responses. 相似文献
8.
取食雄蜂蛹粉对龟纹瓢虫和异色瓢虫卵黄发生的影响 总被引:1,自引:1,他引:0
本文比较了龟纹瓢虫Proylea japonica和异色瓢虫Harmonia axyridis取食蚜虫和取食雄蜂蛹粉时的卵黄发生情况.当取食雄蜂蛹粉时,体内卵黄蛋白出现迟,积累速度慢,产卵前期长.但用保幼激素类似物ZR512点滴处理后则能达到与食蚜对照相当的水平.ZR512对取食雄蜂蛹粉瓢虫的作用显著大于取食岈虫者.进一步的研究表明,ZR512能促进这两种瓢虫取食雄蜂蛹粉,但对成虫的体重没有明显的影响.因此推论,雄蜂蛹粉基本能够满足这两种瓢虫生殖的营养需要,但对其内分泌有一定的影响,使瓢虫处于类似生殖滞育的状态.本文根据不同食物条件对卵黄蛋白发生的影响不同,建议用卵黄蛋白的量作为生理指标,以快速初步筛选和评估人工饲料. 相似文献
9.
10.
The long-distance migration of Nilaparvata lugens (Stål) (Delphacidae) in China: radar observations of mass return flight in the autumn 总被引:1,自引:0,他引:1
J. R. RILEY CHENG XIA-NIAN ZHANG XIAO-XI D. R. REYNOLDS XU GUO-MIN A. D. SMITH CHENG JI-YI BAO AI-DONG ZHAI BAO-PING 《Ecological Entomology》1991,16(4):471-489
Abstract.
- 1 A case study is presented of the autumn migration of the brown planthopper, Nilaparvata lugens (Stål), in the area of Nanjing in the People's Republic of China. The study was made using a high frequency (8 mm wavelength) radar and a net suspended from a kytoon.
- 2 The observations confirmed that long-distance return migrations occur in China in mid and late September, with N.lugens being carried on the prevailing north-easterly wind towards the autumn infestation and overwintering areas of the species.
- 3 After mass take-off in the late afternoon or at dusk, the migrants flew for several hours during the evening, often in a dense layer which formed at heights between about 400 and 1000m above ground. These layers often had well-defined ceilings corresponding to an air temperature of about 16°C. The migration height was above the top of the surface temperature inversion, i.e. the migrants did not fly at the height of the warmest air.
- 4 The dense layer concentrations overflying the radar were backtracked to source areas up to 240 km away in the north-east of Jiangsu Province. Planthoppers observed emigrating from the Nanjing area would reach areas in south Anhui Province or north Jiangxi Province if they flew for 12 h.
- 5 There was a second period of mass take-off at dawn. Insect layers sometimes formed but did not last longer than 1–2h.
- 6 The present results were strikingly different from those previously observed in the dry season in the Philippines, where migratory flight durations were largely confined to periods of about 30min at dusk and dawn.
- 7 Our observations are discussed in relation to the equator-wards return migrations undertaken in autumn by other insect species, and the importance of these migrations for the maintenance of long-flying genotypes in the overwintering populations is considered.