Boron Nitride Membranes with a Distinct Nanoconfinement Effect for Efficient Ethylene/Ethane Separation

A BN membrane with a distinct nanoconfinement effect toward efficient ethylene/ethane separation is presented. The horizontal and inclined self‐assembly of 2D BN nanosheets endow the BN membrane with abundant percolating nanochannels, and these nanochannels are further decorated by reactive ionic liquids (RILs) to tailor their sizes as well as to achieve nanoconfinement effect. The noncovalent interactions between RIL and BN nanosheets favor the ordered alignment of the cations and anions of RIL within BN nanochannels, which contributes to a fast and selective ethylene transport. The resultant membranes exhibit an unprecedented separation performance with superhigh C₂H₄ permeance of 138 GPU and C₂H₄/C₂H₆ selectivity of 128 as well as remarkably improved long‐term stability for 180 h, outperforming reported state‐of‐the‐art membranes.     

A fluorescent sensor based on quinazoline ketone derivatives for selectivity of Fe3+

In this work, we provided a fluorescent sensor based on a compound containing fluorophore quinazoline ketone for detecting metal ions. 2-Methyl-4(3 H)-quinazoline thione was synthesised as a fluorescent probe for tervalent ferric ion (Fe³⁺) detection. Fluorescent determination of 2-methyl-4(3 H)-quinazoline thione indicated its maximum emission wavelength of 306.5 nm. The fluorescence interference and titration experiments have shown that the compound has a high selective fluorescence response to Fe³⁺. With an increase in the Fe³⁺ ion concentration, the fluorescence emission strength gradually weakened, and a slight red shift appeared. With Job’s method, 2-methyl-4(3 H)-quinazoline thione was proved to form a 1:2 complex with Fe³⁺. The results revealed that 2-methyl-4(3 H)-quinazoline thione could be used as a fluorescent probe for the recognition of Fe³⁺ with high selectivity.     

Optical readout method for microcantilever array sensing and its sensitivity analysis

An optical readout platform using a knife-edge filter for detecting the bending of a bimaterial microcantilever array is established, and the influence of stress-induced micromirror deformation on the optical detection sensitivity is discussed. The influence of deformation is modeled theoretically and validated experimentally. Analysis shows that the optical detection sensitivity will decrease by 50% when the mirror has a deformation of lambda/5 (lambda is the wavelength of readout light). Finally, an infrared image is obtained by the platform.     

Lifetime Measurements of the States Around the Backbend in 126Ba

The high spin states in ¹²⁶Ba were populated by means of the reaction ¹¹⁶Sn (¹⁶O,2p4n)¹²⁶Ba at the beam energy of 73MeV. Lifetimes of the states around the backbend in the yeast band were measured by using the Doppler shift attenuation method. The corresponding normalized B(E2) values are pronouncedly reduced for the 10⁺ and 12⁺ states. The experimental results are compared with the theoretical predictions of the particle-rotor model.     

南四湖水中多环芳烃的分析及分布研究

采用固相萃取结合气相色谱-质谱(GC-MS)方法对南四湖水中13种多环芳烃进行了分析。南四湖水中检出的多环芳烃以二环、三环为主,检出的6种多环芳烃中相对含量较高的是菲、芴和苊,多环芳烃总浓度范围为0.004~3.53μg/L。入湖河口各点浓度比湖内点位低,上级湖的入湖河口含量高于下级湖的入湖河口,且湖内各点位多环芳烃的含量按湖水流向逐渐降低。     

ASK1-ER stress pathway-mediated fibrotic-EV release contributes to the interaction of alveolar epithelial cells and lung fibroblasts to promote mechanical ventilation-induced pulmonary fibrosis

Recent clinical research has revealed that mechanical ventilation (MV) can initiate pulmonary fibrosis and induce mechanical ventilation-induced pulmonary fibrosis (MVPF). However, the underlying mechanism remains largely uncharacterized. Based on a mouse model of MVPF and an alveolar epithelial cell cyclic strain model, the present study explores the possible mechanism of MVPF. Single-cell RNA-sequencing and EV RNA-sequencing analysis revealed that MV promoted apoptosis signal-regulating kinase 1 (ASK1)-mediated endoplasmic reticulum (ER) stress pathway activation and extracellular vesicle (EV) release from alveolar epithelial cells. Furthermore, the ASK1-ER stress pathway was shown to mediate mechanical stretch (MS)- or MV-induced EV release and lung fibroblast activation in vivo and in vitro. These processes were suppressed by ER stress inhibitors or by silencing ASK1 with ASK1- short hairpin RNA (shRNA). In addition, MVPF was suppressed by inhibiting ASK1 and ER stress in vivo. Therefore, the present study demonstrates that ASK1-ER stress pathway-mediated fibrotic-EV release from alveolar epithelial cells contributes to fibroblast activation and the initiation of pulmonary fibrosis during MV. The inhibited release of EVs targeting the ASK1-ER stress pathway might be a promising treatment strategy for MVPF.Subject terms: Diseases, Molecular biology     

十二醇聚乙二醇醚分子量分布与其溶液界面性能的关系

利用高纯单一十二醇聚乙二醇醚C₁₂E_n摸似配制Gauss分布型混合物,测定其水溶液的表面张力、增溶量及去污率。实验结果表明,聚乙二醇链长不同分布的醇醚混合物属于理想混合。混合溶液的Γ_∞、Πcmc 随分布宽度增加而增大。形成表面吸附膜及胶束时,短 EO 链分子占先。胶束溶液对乙苯的增溶量随分子中EO数增多而增大。宽分布C₁₂E_n的去污率优于窄分布,但在一定分布范围内,其影响不显著。     

A relative Kuznietsov trace formula on G2

In this paper, we set up the general formulation to study distinguished residual representations of a reductive group G by the relative trace formula approach. This approach simplifies the argument of [JR], which deals with this type of relative trace formula for a special symmetric pair (GL(2n), Sp(2n)) and also works for non-symmetric, spherical pairs. To illustrate our idea and method, we complete our relative trace formula (both the geometric side identity and the spectral side identity) for the case (G ₂, SL(3)). Received: 6 February 1999     

丙酮酸分子结构与振动光谱的密度泛函理论研究

用密度泛函方法BLYP、B3LYP和从头算Hartree-Fock(HF)方法在6-31G*基组水平上对丙酮酸分子的几何结构（甲基的重叠式和交错式两种构象）和振动光谱分别进行了优化和计算,并给出了各种频率所对应的红外强度及拉曼活性,对光谱进行了指认。结果表明：在丙酮酸分子的两种构象中,重叠式比较稳定*B3LYP计算得到的构型参数与实验结果比较一致;在振动频率的计算中,BLYP未标度力场所计算的非CH3伸缩振动基频预测值和实验值的平均绝对偏差为10.4cm-1;而HF标度力场的平均绝对偏差为17.9cm-1。说明两者的结果与实验观测频率比较吻合,但B3LYP的频率计算值偏差（38.3cm-1）较大。根据振动频率的势能分布和红外光谱强度对此分子的振动基频进行了理论归属。     

光学窗口凹腔流场的光学传输效应研究

当带有光学成像探测制导系统的高速飞行器在大气层内飞行时,光学窗口与来流之间会形成复杂的凹腔绕流流场,产生气动光学效应。建立了求解超声速流场的高精度LES/RANS混合算法模型,研究了超声速流动条件下的Settles三维凹腔流动;在计算得到精确流场数据的基础上,研究了凹腔剪切层区域的光学传输效应。结果表明,凹腔流动的剪切层结构将引起光线抖动,导致严重的波面畸变,明显降低光强斯特雷尔(Strehl)比,严重影响光学传输性能,进而大大降低光学制导精度。