Rapid growth and sterility of growth hormone gene transgenic triploid carp

Triploid carp (100%) with 150 (3n=150) chromosomes were obtained by crossing the females of improved tetraploid hybrids (♀, 4n=200) of red crucian carp (♀)×common carp (♂) with the males of diploid yellow river carp (♂, 2n=100). The crosses yielded transgenic triploid carp (positive triploid fish, 44.2% of the progeny) and non-transgenic triploid carp (negative triploid fish). Histological examination of the gonads of 24-month-old positive triploid fish suggested they were sterile and the fish were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of barbells. Most of the quantifiable traits of the triploid carp were intermediate between those of the two parents. The positive and negative triploid fish were raised in the same pond for 2 years. The mean body weight of the positive triploid fish was 2.3 times higher than the negative triploid fish. The weight of the largest positive triploid fish was 2.91 times higher than that of the largest negative triploid fish. Thus, we produced fast-growing transgenic triploid carp that have a reduced ecological risk because of their inability to mate and produce progeny.     

Premixed jet flame characteristics of syngas using OH planar laser induced fluorescence

Lean premixed flame characteristics of several typical low calorific value (LCV) syngases (basis CO/H2/CH4/CO2/N2),including bituminous coal,wood residue,corn core,and wheat straw gasification syngas,were investigated using OH planar laser induced fluorescence (PLIF) technology.OH radical distributions within the turbulent flame were measured for different turbulence intensities.Flame structures of syngases were analyzed and characterized with respect to burnt and unburnt regions,flame curvature (sharp cusp),local extinction (holes and penetration),OH reaction layer thickness,wrinkling,and other features,with OH-PLIF instantaneous images and statistical analysis.Results show that H2 content,LCV,and turbulence intensity are the most effective factors influencing the OH radical intensity and thickness of OH radical layers.The bituminous coal gasification syngas with relatively higher LCV and H2 content tends to burn out easily.Through changes in thickness of the OH radical layers and signal intensities,the reaction layer can be compressed by intensifying turbulence and thereby the combustion processes of syngas.     

Characteristics of strontium isotopes and their implications in the Qixing Cave of Guizhou,China

The strontium isotopic compositions (87Sr/86Sr) of samples including soils, bedrock, soil waters, drip waters and their corresponding speleothems in the Qixing Cave (QXC), Guizhou Province, China, were systemically measured and analyzed. The results indicate that there are significant Sr isotopic differences among samples. The mean 87Sr/86Sr ratios in drip water for the samples 1#, 4# and 9# were 0.709568, 0.709139 and 0.708761, respectively, which possibly result from different flow paths, residence times, and other hydrogeological processes in the unsaturated zone overlying QXC. Meanwhile, levels of 40.8%, 57.6% and 72.4% of Sr in drip waters for 1#, 4# and 9#, respectively, were derived from bedrock dissolution, which was calculated by the mixture model of the two end-members (soil and bedrock). There is, however, no positive correlation between the relative proportion from bedrock dissolution (δ13C value is 1.8‰) and drip water δ13CDIC values. The mean drip water δ13CDIC value in 1# is the heaviest (–4.5‰) with the lowest contribution rate of bedrock dissolution, whereas the value in 9# is the lightest (–9.3‰) with the highest contribution rate of bedrock dissolution. The proportion from host rock dissolution in 4# is higher than that in 1# and lower than that in 9#, while its mean drip water δ13CDIC value (–8.6‰) is higher than that of 9# and lower than that for 1#. This suggests that the prior calcite precipitation (PCP) processes in the unsaturated zone overlying the cave are responsible for the δ13CDIC value differences between different drip waters, and not bedrock dissolution. Furthermore, this study also demonstrates that the 87Sr/86Sr ratios of speleothems in the 1# and 4# mainly reflect the variation in the relative proportions from the soil system (soil water) and bedrock dissolution overlying the cave. It is, therefore, feasible to use the strontium isotopic signals of speleothems as an indicator for soil chemical weathering intensity, and consequently as a monsoon proxy in the study area.     

Carbon and hydrogen isotopic compositions and their evolutions of gases generated by herbaceous swamp peat at different thermal maturity stages

Coalbed methane (CBM) accumulation models include continuous gas accumulation and staged gas accumulation.However,studied on the geochemical characteristics and indices to evaluate staged accumulation CBM are lacking.This study for the first time obtained the carbon and hydrogen isotopic compositions of methane and ethane generated at different evolution stages using thermal simulation of samples prepared by treating an herbaceous swamp peat at different temperatures.The results showed that the carbon isotopic compositions of methane and ethane were obviously affected by the thermal evolution level of the starting sample,while the hydrogen isotopic compositions were closely related to the maturity of gases.The carbon and hydrogen isotopic compositions of gases generated by coal-forming organic matter with Ro values from 1.2%,1.7%,2.4%,3.2% and 3.7% to 5.2% were determinated.The relationship between Ro values and the carbon and hydrogen isotopic compositions of gases generated by coal-forming organic matter at different evolution stages as well as the carbon or hydrogen isotopic relationships between methane and ethane were established.The results provide a scientific basis for studying the genesis of CBM generated at different maturity intervals and understanding the geochemical characteristics of staged accumulation CBM.These results were applied to a case study on CBM from the southern Qinshui basin,and it was found that the CBM accumulated after the Middle Jurassic and was characteristic of staged gas accumulation.This is consistent with the result of geological studies,and further showed that the results of thermal simulation experiments are very important for evaluating the genesis of natural CBM.     

Angular dependent NEXAFS study of the molecular orientation of PTCDA multilayers on Au （111） surface

The molecular orientation of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) multilayers adsorbed on Au (111) surface has been investigated using angular dependent O K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The significant angular dependence of important resonant structures (π* and σ*) reveals that PTCDA molecules adopt an ordered geometry on the substrate surface. The average tilt angle of the PTCDA molecular planes is 27°±10° from the Au (111) surface.     

Role of locust <Emphasis Type="Italic">Locusta migratoria manilensis</Emphasis> claws and pads in attaching to substrates

The present study attempts to investigate the role of rigid claws and smooth adhesive pads in the locust Locusta migratoria manilensis,when attaching to various substrates.We measured the attachment forces on sandpaper and silicate glass plate of locusts with intact attachment system,and those with either the pretarsal claws or the tarsal pads having been entirely destroyed,to explore the role of pads and claws when a locust is walking on various substrates.To obtain information about morphological characteristics and material properties of the claws,we examined the intact and fractured claws by scanning electron microscopy,and tested the fractural force in a fracture experiment.We proposed a mechanical model for locust climbing on a slanting surface to analyze the conduction and final result of the attachment forces generated by the attachment organs on the fore-,mid-and hindlegs.Attachment forces generated by locusts with destroyed pads were similar to those generated by locusts with intact attachment system on both substrates,which presumably indicated that the claws have a significantly important role when attaching to various substrates.The result of the fracture experiment demonstrated that the claws are made of relatively stiff material,and their shear strength ranged between 39-45 MPa.Mechanical analysis of locust climbing on slanting surface showed that the force generated by the hindlegs suspended the whole body of locust up from the surface and pushed the body forward,while the midlegs steadily suspended the centre of gravity and the forelegs pulled the suspended body forward.The results obtained contribute to the further interpretation of the interaction mechanisms between insect attachment system and substrates,and supply information for designing and manufacturing slippery plates for trapping plague locusts.     

Potential influence of water level changes on energy flows in a lake food web

Large seasonal water-level fluctuations may influence isotopic signatures of primary producers and the types and amounts of these potential food sources accessible to aquatic fauna of Poyang Lake,the largest freshwater lake in China.In this study,the isotopic signatures of primary producers and consumers were determined,stable carbon and nitrogen isotope analysis and mixing models were combined to investigate the influence of water levels on the diet and isotopic composition of Poyang Lake fish and inverteb...     

A high-resolution environmental change record since 19 cal ka BP in Pumoyum Co,southern Tibet

A 380-cm-long sediment core was acquired from the deep water area of Pumoyum Co, southern Tibet. Twenty-five plant residue samples were selected, and organic carbon stable isotopes were obtained using the AMS ¹⁴C chronological method. The ¹⁴C age and carbon reservoir effect were calibrated with surface sedimentation rate measurements using ²¹⁰Pb dating. Results showed that the core sediment deposited over 19 cal ka BP. Based on a multi-proxy analysis of TOC and IC contents, grain size and pollen assemblage data, the palaeoclimatic evolution of Pumoyum Co was reconstructed since the last glacial. Pumoyum Co was a shallow lake prior to 16.2 cal ka BP; although the glacier around the lake began to melt due to increasing temperatures, climate was still cold and dry. In the interval of 16.2–11.8 cal ka BP, the sedimentary environment fluctuated drastically and frequently. Two cold-events occurred at 14.2 and 11.8 cal ka BP, and these may correspond to the Older Dryas and the Younger Dryas events, respectively. After 11.8 cal ka BP, Pumoyun Co developed into the deep lake as it is now. The lake water temperature was relatively lower at that time because of influx of cold water from glacial meltwater entering the lake. As a result, the multi-proxy indicators showed no sign of warm conditions. Comparisons between the sedimentary record of Pumoyum Co with that of other lakes of the same age in southern Tibet indicate a warmer climate following the last deglaciation influenced the southeastern Tibetan Plateau. These results imply that the southwest Asian monsoon gradually became stronger since the deglaciation during its expansion to the inner plateau. The glacial-supplied water of the lake responded sensitively to cold-events. The entire southern Tibet region was dominantly influenced climatically by the southwest Asian monsoon during the Holocene.     

高清晰度电视系统三维色域研究

根据相加混色原理,建立了常规色域的三维数学模型,在CIE1976LUV三维色度系统与Pointer物体真实表面色色域作了色度学比较.结果表明,常规HDTV传输系统之所以不能传输或重显全部Pointer色域,并不单纯因为色域范围小,两个色域涵盖的颜色范围有差别也是重要原因.这对需要从三维和颜色覆盖范围方面研究色域问题具有...     

非双倍测度下多线性Calderón-Zygmund算子及其交换子在Herz型空间上的有界性

本文引入非齐型空间上的Herz空间,并证明了多线性Calderon-Zygmund算子及其交换子在这些空间上的有界性.