氮缺乏条件下小球藻碳水化合物与脂肪酸的合成规律研究

以小球藻Chlorella zofingiensis为研究对象,分析其体内两个次级代谢产物(脂肪酸和碳水化合物)在氮缺乏条件下的合成规律。研究结果表明,氮缺乏时C. zofingiensis在2d内仍能继续生长,伴随着叶绿素含量的急剧下降。细胞的最初响应是在1 d内大量合成碳水化合物,含量从初始的48.4%增至66.9%,之后碳水化合物部分降解,而脂肪酸持续增长,含量从最初的6.2%增至24.5%。此外,研究还发现氮缺乏后饱和脂肪酸和单不饱和脂肪酸含量增大,而多不饱和脂肪酸含量有所减小。推测碳水化合物可能作为短期应急响应用于藻从逆境中快速恢复,而随着胁迫的延长,藻倾向于积累能量密度更高的脂肪作为长期储能物质

Hydrogen TransFer Hydrogenation of Acetophenone by Ruthenium Complexes Containing Polydentate Aminophosphine Ligand

利用C2-对称的双胺双膦钌（Ⅱ）配合物ruCl2（P2n2H4）为催化剂，研究了苯乙酮的氢转移还原反应.在苯乙酮、钌配合物和异丙氧基钾的摩尔比为200∶1∶12的条件下，于65℃反应2H后，苯乙酮的转化率高达99%.讨论了苯乙酮的氢转移氢化机理.The catalytic hydrogen transFer hydrogenation of acetophenone using C 2 symmetric diamine/diphosphine ruthenium(Ⅱ) complex has been studied.Complex RuCl 2(P 2N 2H 4) shows an excellent catalytic activity in hydrogen transFer hydrogenation of acetophenone in a molar ratio of substrate/Ru/ iso PrOK 200∶1∶12, leading to 2 phenylethanol in 99% yield aFter 2 h.A hydrogen transFer mechanism is also discussed.国家自然科学基金;中国石油化学工业总公司石油化工科学院资

不同地区北树鼩头骨几何形态特征差异分析

为了探讨不同地区北树鼩(Tupaia belangeri)头骨的形态特征,本研究选取12个采样地:三亚、大新、乐业、兴义、河口、昆明、西昌、勐腊、大理、片马、腾冲和禄劝,采用主成分分析、薄片样条分析和多维尺度分析研究各采样地北树鼩上颌骨的背面、侧面、腹面和下颌侧面的形态。结果表明:主成分分析显示采样地中北树鼩头骨背面、侧面、腹面和下颌侧面中8个地区(乐业、兴义、何口、昆明、西昌、大理、勐腊和禄劝)的头骨侧面聚集为一枝,三亚和大新各为一枝,片马和腾冲聚集为一枝。薄片样条分析显示不同地区北树鼩头骨背面中颧弓、鼻骨和眼眶为形变多发生的部位; 头骨侧面中眼眶、鼻骨、颧骨和前臼齿为形变多发生的部位; 头骨腹面中听泡、第一臼齿上颌骨外侧最内凹点和第一臼齿齿冠内侧缘点为形变多发生的部位; 下颌侧面中角突前最上凹点、下颌中部最低点和臼齿齿槽为形变多发生的部位。多维尺度分析显示12个地区北树鼩头骨有一定差异,这可能与分布、海拔和地理阻隔有关

Hydrogen transfer hydrogenation of acetophenone by ruthenium complexes containing polydentate aminophosphine ligand

The catalytic hydrogen transfer hydrogenation of acetophenone using C-2-symmetric diamine/diphosphine ruthenium(II) complex has been studied. Complex RuCl2(P2N2H4) shows an excellent catalytic activity in hydrogen transfer hydrogenation of acetophenone ina molar ratio-of substrate/Ru/iso-PrOK 200:1:12, leading to 2-phenylethanol in 99% yield after 2 h, A hydrogen transfer mechanism is also discussed

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel