排序方式: 共有73条查询结果,搜索用时 15 毫秒
11.
12.
沈阳城市森林主要绿化树种——丁香的光合特性研究 总被引:20,自引:4,他引:16
应用LI-6400红外气体分析仪对城市森林典型树种丁香不同季节光合作用的日变化规律进行研究,采用相关分析和多元逐步回归统计分析方法,得出净光合速率与光合有效辐射、气温、大气湿度、气孔导度等生理生态因子间的相关关系.结果表明,丁香春季和夏季光合速率呈双峰曲线,秋季呈单峰曲线.春季影响光合速率的主要因子为光合有效辐射和气孔导度;夏季影响光合速率的主要因子为气孔导度和光合有效辐射;秋季为气孔导度和胞间CO2浓度,建立了相应的影响因子回归方程。 相似文献
13.
Zhi Li Yu Zhang Kang Zhou Taoyi Kong Xing Zhou Yaming Hao Xin Huang Jie Xu Yuwen Cheng Haimei Liu Ziyang Guo Yonggang Wang 《Liver Transplantation》2024,14(15):2303786
Sodium-ion batteries (SIBs), based on hard carbon anodes and Na+-intercalation compound cathodes, have gained significant attention. Nonetheless, hard carbon anodes involve the storage of Na+ at a low potential, typically below 0.1 V (vs Na/Na+), which increases the risk of dendritic Na growth on the anode surface during overcharging. Herein, a safe organic/inorganic composite anode containing tetrasodium 3,4,9,10-perylenetetracarboxylate (Na4PTC) and Metallic bismuth (Bi) with a weight ratio of 7:2, which exhibits an average potential of 0.7 V (vs Na+/Na) and a capacity of 150 mAh g−1 is proposed. The electrode reaction involves a reversible coordination reaction within the organic host and alloying reactions within the metallic Bi component. Importantly, the organic component efficiently buffers the volume changes in Bi during the alloying reaction, while the metallic Bi enhances the electronic conductivity of the organic material. As a result, this composite anode shows high cycle stability and rate performance, even under high mass loadings ranging from 10 to 50 mg cm−2. Furthermore, it is demonstrated that the Na-ion full cell, consisting of the composite anode and the Na3V2O2(PO4)2F cathode, exhibits minimal capacity degradation over 100 cycles while maintaining a high areal capacity of 1.1 mA cm−2. 相似文献
14.
Fang Dong Shu Yang Haimei Sun Jihong Yan Xiaoxia Guo Dandan Li 《Journal of receptor and signal transduction research》2017,37(2):141-148
Gastrointestinal (GI) distention is a common pathological characteristic in most GI motility disorders (GMDs), however, their detail mechanism remains unknown. In this study, we focused on Ca2+ overload of smooth muscle, which is an early intracellular reaction to stretch, and its downstream MAPK signaling and also reduction of SCF in vivo and in vitro. We successfully established colonic dilation mouse model by keeping incomplete colon obstruction for 8 days. The results showed that persistent colonic dilation clearly induced Ca2+ overload and activated all the three MAPK family members including JNK, ERK and p38 in smooth muscle tissues. Similar results were obtained from dilated colon of patients with Hirschsprung's disease and stretched primary mouse colonic smooth muscle cells (SMCs). Furthermore, we demonstrated that persistent stretch-induced Ca2+ overload was originated from extracellular Ca2+ influx and endoplasmic reticulum (ER) Ca2+ release identified by treating with different Ca2+ channel blockers, and was responsible for the persistent activation of MAPK signaling and SCF reduction in colonic SMCs. Our results suggested that Ca2+ overload caused by smooth muscle stretch led to persistent activation of MAPK signaling which might contribute to the decrease of SCF and development of the GMDs. 相似文献
15.
锡林郭勒盟气候干燥度的时空变化规律 总被引:6,自引:0,他引:6
以锡林郭勒盟15个气象站点1981—2007年的月平均气温、月累积降水量数据为基础,在Arcgis软件的支持下,得到DeMartonne干燥度的空间数据。研究结果表明,锡林郭勒盟27a平均干燥程度自东向西递增;1981—2007年,锡林郭勒盟整体上表现出干燥度数值下降、干旱程度上升的趋势;从干燥度的年代,20世纪80年代和90年代是锡林郭勒盟气候相对湿润时期,21世纪初期,锡林郭勒盟大部分地区的气候呈现干燥度值减小、干燥程度加大的趋势,干性干旱区在空间分布上占据了主导地位,结果也打乱了原有的气候带状交替格局。21世纪初与20世纪80年代相比,各干燥度等值线的位置均发生了明显的东移现象。 相似文献
16.
17.
18.
Sishen Li Jizeng Jia Xianyun Wei Xiaocun Zhang Linzhi Li Haimei Chen Yuding Fan Haiyan Sun Xinhua Zhao Tiandong Lei Yunfong Xu Fangshan Jiang Honggang Wang Lihui Li 《Molecular breeding : new strategies in plant improvement》2007,20(2):167-178
A new genetic linkage map was constructed based on recombinant inbred lines (RILs) derived from the cross between the Chinese
winter wheat (Triticum aestivum L.) varieties, Chuang 35050 and Shannong 483 (ChSh). The map included 381 loci on all the wheat chromosomes, which were composed
of 167 SSR, 94 EST-SSR, 76 ISSR, 26 SRAP, 15 TRAP, and 3 Glu loci. This map covered 3636.7 cM with 1327.7 cM (36.5%), 1485.5 cM (40.9%), and 823.5 cM (22.6%) for A, B, and D genome,
respectively, and contained 13 linkage gaps. Using the RILs and the map, we detected 46 putative QTLs on 12 chromosomes for
grain yield (GY) per m2, thousand-kernel weight (TKW), spike number (SN) per m2, kernel number per spike (KNS), sterile spikelet number per spike (SSS), fertile spikelet number per spike (FSS), and total
spikelet number per spike (TSS) in four environments. Each QTL explained 4.42–70.25% phenotypic variation. Four QTL cluster
regions were detected on chromosomes 1D, 2A, 6B, and 7D. The most important QTL cluster was located on chromosome 7D near
the markers of Xwmc31, Xgdm67, and Xgwm428, in which 8 QTLs for TKW, SN, SSS and FSS were observed with very high contributions (27.53–67.63%). 相似文献
19.
Mon-Juan Lee Liu Chien-Liang Ju-Ying Tsai Wae-Ting Sue Wan-Shun Hsia Haimei Huang 《Archives of microbiology》2010,192(9):739-746
Uridine monophosphate (UMP) kinase converts UMP to the corresponding UDP in the presence of metal ions and ATP and is allosterically
regulated by nucleotides such as UTP and GTP. Although the UMP kinase reported to date is Mg2+-dependent, we found in this study that the UMP kinase of Helicobacter pylori had a preference for Mn2+ over Mg2+, which may be related to a conformational difference between the Mn2+-bound and Mg2+-bound UMP kinase. Similar to previous findings, the UMP kinase activity of H. pylori UMP kinase was inhibited by UTP and activated by GTP. However, a relatively low GTP concentration (0.125 mM) was required
to activate H. pylori UMP kinase to a level similar to other bacterial UMP kinases using a higher GTP concentration (0.5 mM). In addition, depending
on the presence of either Mg2+ or Mn2+, a significant difference in the level of GTP activation was observed. It is therefore hypothesized that the Mg2+-bound and Mn2+-bound H. pylori UMP kinase may be activated by GTP through different mechanisms. 相似文献
20.
沈阳市城市森林结构与效益分析 总被引:55,自引:10,他引:45
采用样方调查方法对沈阳市243km^2范围的树木进行每木实地调查,在地理信息系统应用软件Arc View3.2平台上建立了基于CITYgreen模型的城市森林信息管理系统,应用该信息系统分析了沈阳市土地利用及树木分布的格局、树种构成、树木密度、树高、胸径、健康状况等反映城市森林结构特征的指标结果表明,2001年沈阳市有树136种,1 914 500株树木,森林覆盖率为9.77%,25种主要树木占树木总数的84.78%,胸径小于0.25m(一类胸径)和大于0.5m(三类胸径)的树木占82.8%;幼龄树27%、中龄树58%、老龄树15%;84%的树木健康状况为中等以上,城市森林信息管理系统计算表明,沈阳市城市森林每年生态效益折合经济价值为2.65千万美元。 相似文献