稀有（鱼句）鲫卵黄蛋白原电泳表征

鱼类卵黄蛋白原是检测环境内分泌干扰化合物雌激素效应的敏感生物标志物.稀有(鲍)鲫是我国目前最具发展潜力的用于生态毒理学研究的实验室模型物种.本文采用强效人工合成的雌激素乙炔基雌二醇对成熟雄性稀有(鲍)鲫和未成年稀有(鲍)鲫进行诱导,然后用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳对血清中的蛋白进行了表征,发现雌激素诱导的特异性蛋白由两个亚单位组成,分子量分别为170和147kDa,该蛋白与成熟雌鱼所具有的特异性蛋白完全一致,而且分子量在其它硬骨鱼类卵黄蛋白原分子量范围之内,确定该蛋白为稀有(鲍)鲫的卵黄蛋白原

稀有（鱼句）鲫卵黄蛋白原电泳表征

鱼类卵黄蛋白原是检测环境内分泌干扰化合物雌激素效应的敏感生物标志物.稀有(鲍)鲫是我国目前最具发展潜力的用于生态毒理学研究的实验室模型物种.本文采用强效人工合成的雌激素乙炔基雌二醇对成熟雄性稀有(鲍)鲫和未成年稀有(鲍)鲫进行诱导,然后用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳对血清中的蛋白进行了表征,发现雌激素诱导的特异性蛋白由两个亚单位组成,分子量分别为170和147kDa,该蛋白与成熟雌鱼所具有的特异性蛋白完全一致,而且分子量在其它硬骨鱼类卵黄蛋白原分子量范围之内,确定该蛋白为稀有(鲍)鲫的卵黄蛋白原

Effects of livestock exclusion and climate change on aboveground biomass accumulation in alpine pastures across the Northern Tibetan Plateau

National Natural Science Foundation of China 41171044：Chinese Academy of Sciences XDB03030401 KZCXZ-XB3-08；China Postdoctoral Science Foundation 2013M530716<p class="FR_field"> To better understand the ecological and economic benefits of short-term grazing exclusion on the aboveground net primary productivity (ANPP) of alpine pastures, we conducted annual multi-site transect surveys in the summers from 2009 to 2011 and calculated the aboveground biomass discrepancy (ABD) between grazed and ungrazed pastures at plant community and economic group levels for three zonal alpine grassland types-meadow, steppe, and desert-steppe-across the northern Tibetan Plateau. Our results indicated that aboveground biomass (AGB) significantly differed among grassland types and declined northwesterly from 64.07 to 11.44 g m(-2) with decreasing precipitation and increasing temperature. The mean ABD exhibited considerable community dependency, with meadow (12.47 g m(-2)) &gt; steppe (6.91 g m(-2)) &gt; desert steppe (2.54 g m(-2)), and it declined from 25.42 to 1.29 g m(-2) with decreasing precipitation and increasing temperature. &#39;Good forage&#39;, i.e. grasses and sedges, benefited most from grazing exclusion, followed by edible forbs. With longer grazing exclusion durations (GEDs), the aboveground biomass of poisonous locoweeds initially decreased and then increased compared with the adjacent grazed sites. In the nested analysis of co-variances with a general linear model, growing season precipitation (GSP; from May to September) accounted for 52.67% of the observed variation in AGB, followed by AGT (9.77 %) and pasture management systems (PMSs; grazing or grazing-excluded, 5.31 %). The variation in ABD was explained primarily by AGT (16.52 %), GED (20.25 %), and the interaction of AGT x GED (19.58 %). Our results confirm that precipitation is the primary factor controlling the ANPP of alpine grasslands on the Northern Tibetan Plateau and that the ecological benefits arising from grazing exclusion are also partly dependent on grassland type and exclusion duration. Therefore, spatial and temporal variations in growing season precipitation and plant functional traits or economic group composition should be jointly considered when developing policies concerning the management and spatial layouts of grazing exclosures in this region.</p

Tensile Behaviors and Strain Hardening Mechanisms in a High-Mn Steel with Heterogeneous Microstructure

Heterogeneous structures with both heterogeneous grain structure and dual phases have been designed and obtained in a high-Mn microband-induced plasticity (MBIP) steel. The heterogeneous structures show better synergy of strength and ductility as compared to the homogeneous structures. Higher contribution of hetero-deformation induced hardening to the overall strain hardening was observed and higher density of geometrically necessary dislocations were found to be induced at various domain boundaries in the heterogeneous structures, resulting in higher extra strain hardening for the observed better tensile properties as compared to the homogeneous structures. MBIP effect is found to be still effective in the coarse austenite grains of heterogeneous structures, while the typical Taylor lattice structure and the formation of microband are not observed in the ultra-fine austenite grains of heterogeneous structures, indicating that decreasing grain size might inhibit the occurrence of microbands. High density of dislocation is also observed in the interiors of BCC grains, indicating that both phases are deformable and can accommodate plastic deformation. It is interesting to note that the deformation mechanisms are highly dependent on the phase and grain size for the present MBIP steel with heterogeneous structures

不同处理对藏北地区退化人工草地垂穗披碱草种群克隆表型的影响

以不同退化程度和采用不同恢复措施的垂穗披碱草人工草地为对象,通过野外调查和室内分析相结合的方法研究了各类草地垂穗披碱草克隆种群相关表型特征的差异,结果表明,随着人工草地建植年限的延长,草地退化渐趋严重,垂穗披碱草克隆种群相关表型参数显著降低。相比较而言,封育可以提高种群的有性繁殖能力,但施肥和补播措施可以显著提高垂穗披碱草种群的克隆生长,其株高、分株数以及株丛数显著增加,而有性繁殖能力相对降低。因此,针对藏北高原以垂穗披碱草为最主要建群种或单优种群的退化草地恢复,施肥和补播应为最有效措施

<p>Designing structures with combined gradients of grain size and precipitation in high entropy alloys for simultaneous improvement of strength and ductility & nbsp;</p>

Suppressing the early strain localization at the nanostructured topmost layer is crucial for achieving better tensile ductility in the gradient structure. Thus, structures with combined gradient distributions along the depth for both grain size and volume fraction of precipitates were designed and introduced in a high entropy alloy by surface mechanical attrition treatment and aging. Yield strength and uniform elongation were observed to be simultaneously improved in the structures with combined gradients as compared to the corresponding structures with only grain size gradient. More severe strain gradients and higher density of geometrically necessary dislocations were observed to be produced at various domain boundaries in the structures with combined gradients, resulting in stronger hetero-deformation-induced (HDI) extra hardening for better tensile properties. Shearing and bowing hardening mechanisms were observed for L1( 2) and B2 precipitates, respectively. Higher volume fractions of B2 and L1( 2) phases at the topmost layer induce stronger precipitation hardening, which compensates the diminished strain hardening due to the reduced grain size at the topmost layer for better tensile ductility in the structures with combined gradients. The observed higher yield strength in the structures with combined gradients have been discussed based on mechanisms of dislocation strengthening, precipitation strengthening and HDI strengthening. (C)& nbsp;2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.& nbsp

藏北高原高寒草甸地上生物量与气候因子的关系

采用收获法测量了藏北不同海拔高度(4300~4700m)2010年(6~8月)嵩草草甸群落地上总生物量,通过相关分析和多重回归分析法探讨了地上生物量与土壤温度、土壤含水量、空气温度、相对湿度、饱和水汽压亏缺以及比湿的关系。结果表明:总体而言,随着海拔高度的升高地上生物量逐渐增加,地上生物量与相对湿度、比湿以及土壤含水量分别呈极显著的正相关关系,与饱和水汽压亏缺呈极显著的负相关关系,而与土壤温度、空气温度呈不显著的负相关关系;相对湿度和饱和水汽压亏缺共同解释了地上生物量94%的变异,其中相对湿度的贡献较大。相对湿度是决定高寒嵩草草甸沿海拔分布的主导因子

高粱总DNA导入春小麦新品系高分子量麦谷蛋白亚基的变化

通过花粉管通道法将高粱总DNA导入春麦甘麦8号、陇春13号和陇春10号,经过多代选择获 得了5个稳定遗传新品系．在高分子量麦谷蛋白亚基分析中,甘麦8号后代89144的高分子量麦谷蛋白 亚基发生突变,较其受体多了5+10亚基,而少了2+12亚基;其他几个转基因后代与其受体比较,高分 子量麦谷蛋白亚基组成未发生变化;但是各亚基的相对质量分数有较大变化．高分子量麦谷蛋白亚基 的组成和各亚基质量分数的变化直接影响小麦品质．本研究对外源总DNA花粉管通道法导入小麦在 改良小麦品质方面的作用进行了讨论