989 resultados para Cao


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The establishment and optimization of in vitro primmorph formation from a Chinese sponge, Stylotella agminata (Ridley), collected from the South China Sea, were investigated. Our aims were to identify the key factors affecting primmorph formation in this species and to optimize the technique for developing an in vitro primmorph culture system. The size of dissociated cells from S. agminata is relatively small, in the range between 5 and 10 mum. Round-shaped primmorphs of less than 100 gm were formed 3 days after transferring the dissociated cells into seawater containing Ca2+ and Mg2+. The effect of various cell dissociation conditions, inoculum. cell density, concentration of antibiotics, pH, and temperature was further investigated upon the formation of primmorphs. The time required for primmorph formation, primmorph size distribution, and the proliferating capability were microscopically documented. Healthy sponge S. agminata, inoculum. cell density and culture temperature play a critical role for the successful formation of primmorphs and that the microbial contamination will have to be controlled. (C) 2002 Elsevier Science B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Experimental data are presented to show the influence of the enhanced oil recovery system's components, alkali, surfactant, and polymer, on the demulsification and light transmittance of the water separated from the emulsions. Among which, the effects of surfactants, polyoxyethylene (10) alkylphenol ether (OP-10) and sodium petroleum sulfonate (CY-1) on emulsion stability, are the strongest of any component, the effects of polymer, hydrolytic polyacrylamide (HPAM) 3530S, on emulsion stability are the weakest. This research also suggests a possible emulsion minimization approach, which could be implemented in refineries utilizing microwave radiation. Compared with conventional heating, microwave radiation can effectively enhance the demulsification rate by an order of magnitude and increase the light transmittance of the water separated from the emulsions. The demulsification efficiency may reach 100% in a very short. time under microwave radiation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Catechol reacted with beta-methallyl chloride in the presence of base and phase transfer catalyst under microwave irradiation and gave 2-methallyloxyphenol within 1 similar to 2 minutes. The yield of 2-methallyloxyphenol varied from 64%similar to 68%.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

报道了中国四川苔类植物一新种———拟褐色合叶苔 (ScapaniaferrugineaoidesT .Cao ,C .GaoetJSun)。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

描述了采自中国西藏的苔类植物新种片毛合叶苔ScapaniamacroparaphylliaT .Cao ,C .Gao&J.Sun。新种与腋毛合叶苔S .bolanderiAust.相近 ,区别特征为 :植物体小 ,叶腋内假鳞毛状附属物大 ,呈长片状 ;叶缘齿细胞单列 ,通常 1 - 3个细胞长 ;叶表面角质层粗糙 ,具圆密疣 ,疣大 ,直径达 6- 7μm。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

描述了采自中国浙江九龙山的苔类植物一新种——毛茎合叶苔Scapania paraphyllia T.Cao,C.Gao,J.Sun & B.R.Zuo。该新种与腋毛合叶苔S.bolanderi Aust.相近,两种皆具带齿叶片和假鳞毛,但新种具如下特征可与腋毛合叶苔区别:(1)植物体小,通常红色;(2)假鳞毛多数,不分枝,不仅生于叶腋,茎上也有着生;(3)背脊为腹瓣长的1/4–1/3,背瓣为腹瓣大小的1/2–1/3;(4)叶角质层表面粗糙,具粗瘤,直径达6–8μm。与另一个相似种S.ampliata Steph.相比,因新种具有粗糙的叶表面和假鳞毛等特征,也易于区别。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Software Engineering Society of Korean; Institute for Information Scientists and Engineers; IEEE Reliability Society; KAIST (Korea Advanced Institute of Science and Technology); Korea Information Promotion Agency; Samsung SDS

Relevância:

10.00% 10.00%

Publicador:

Resumo:

National Key Research and Development Program [2010CB833500]; National Natural Science Foundation of China [30590381]; Chinese Academy of Sciences [KZCX2-YW-432]

Relevância:

10.00% 10.00%

Publicador:

Resumo:

National Key Research and Development Program [2010CB833500]; Natural Science Foundation of China [30590381]; Knowledge Innovation Project of Chinese Academy of Sciences [KZCX2-YW-432]

Relevância:

10.00% 10.00%

Publicador:

Resumo:

National Key Research and Development Program [2010CB833502]; National Natural Science Foundation of China [30600071, 40601097, 30590381, 30721140307]; Knowledge Innovation Project of the Chinese Academy of Sciences [KZCX2-YW-432, O7V70080SZ, LENOM07LS-01

Relevância:

10.00% 10.00%

Publicador:

Resumo:

China's cultivated land has been undergoing dramatic changes along with its rapidly growing economy and population. The impacts of land use transformation on food production at the national scale, however, have been poorly understood due to the lack of detailed spatially explicit agricultural productivity information on cropland change and crop productivity. This study evaluates the effect of the cropland transformation on agricultural productivity by combining the land use data of China for the period of 1990-2000 from TM images and a satellite-based NPP (net primary production) model driven with NOAH/AVHRR data. The cropland area of China has a net increase of 2.79 Mha in the study period, which causes a slightly increased agricultural productivity (6.96 Mt C) at the national level. Although the newly cultivated lands compensated for the loss from urban expansion, but the contribution to production is insignificant because of the low productivity. The decrease in crop production resulting from urban expansion is about twice of that from abandonment of arable lands to forests and grasslands. The productivity of arable lands occupied by urban expansion was 80% higher than that of the newly cultivated lands in the regions with unfavorable natural conditions. Significance of cropland transformation impacts is spatially diverse with the differences in land use change intensity and land productivity across China. The increase in arable land area and yet decline in land quality may reduce the production potential and sustainability of China's agro-ecosystems. (C) 2008 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Due to its inert reaction in soil system and distinctive vertical distribution in soil profile, caesium-137 (Cs-137) has been used as a tracer to assess wind erosion. In this study, 62 soil samples were collected from 4 sampling sites in Taipusi County, Inner Mongolia; Caesium-137 activities for those soil samples were measured using a gamma-ray spectrometry in Sichuan University, Chengdu. Distribution pattern of Cs-137 in vertical soil profile was different for different land use and land cover types. Caesium-137 was distributed homogeneously in plow layer of cropland, and negatively exponential in low to medium cover grassland. Distribution pattern in high covered grassland was represented by a peak at 2-4 cm soil depth followed by a negative exponential curve. Based on those findings, simplified mass balance model was chosen to estimate the rate of wind erosion for cropland, while profile distribution model was used for grassland. Estimated wind erosion rates were 7990, 4270 and 1808 Mg(.)km(-2.)a(-1) for cropland, low cover grassland and medium cover grassland, respectively. Wind erosion intensity correlated negatively with plant cover.