Topology optimization of unsteady incompressible Navier–Stokes flows

This paper discusses the topology optimization of unsteady incompressible Navier–Stokes flows. An optimization problem is formulated by adding the artificial Darcy frictional force into the incompressible Navier–Stokes equations. The optimization procedure is implemented using the continuous adjoint method and the finite element method. The effects of dynamic inflow, Reynolds number and target flux on specified boundaries for the optimal topology of unsteady Navier–Stokes flows are presented. Numerical examples demonstrate the feasibility and necessity of this topology optimization method for unsteady Navier–Stokes flows.     

Certain Sufficient Conditions for Starlikeness and Convexity of Meromorphically Multivalent Functions

In this paper we derive certain sufficient conditions for starlikeness and convexity of order α of meromorphically multivalent functions in the punctured unit disk.     

Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic‐Polymer‐Based Iridium Catalysts

As a new energy source that could replace petroleum, the global reserves of methane hydrate (combustible ice) are estimated to be approximately 20 000 trillion cubic meters. A large amount of methane hydrate has been found under the seabed, but the transportation and storage of methane gas far from coastlines are technically unfeasible and expensive. The direct conversion of methane into value‐added chemicals and liquid fuels is highly desirable but remains challenging. Herein, we prepare a series of iridium complexes based on porous polycarbazoles with high specific areas and good thermochemical stabilities. Through structure tuning we optimized their catalytic activities for the selective monoborylation of methane. One of these catalysts (CAL‐3‐Ir) can produce methyl boronic acid pinacol ester (CH₃Bpin) in 29 % yield in 9 h with a turnover frequency (TOF) of approximately 14 h^?1. Because its pore sizes favor monoborylated products, it has a high chemoselectivity for monoborylation (CH₃Bpin:CH₂(Bpin)₂=16:1).     

Defect mitigation using d-penicillamine for efficient methylammonium-free perovskite solar cells with high operational stability

Trap-dominated non-radiative charge recombination is one of the key factors that limit the performance of perovskite solar cells (PSCs), which was widely studied in methylammonium (MA) containing PSCs. However, there is a need to elucidate the defect chemistry of thermally stable, MA-free, cesium/formamidinium (Cs/FA)-based perovskites. Herein, we show that d-penicillamine (PA), an edible antidote for treating heavy metal ions, not only effectively passivates the iodine vacancies (Pb²⁺ defects) through coordination with the –SH and –COOH groups in PA, but also finely tunes the crystallinity of Cs/FA-based perovskite film. Benefiting from these merits, a reduction of non-radiative recombination and an increase in photoluminescence lifetime have been achieved. As a result, the champion MA-free device exhibits an impressive power conversion efficiency (PCE) of 22.4%, an open-circuit voltage of 1.163 V, a notable fill factor of 82%, and excellent long-term operational stability. Moreover, the defect passivation strategy can be further extended to a mini module (substrate: 4 × 4 cm², active area: 7.2 cm²) as well as a wide-bandgap (∼1.73 eV) Cs/FA perovskite system by delivering PCEs of 16.3% and 20.2%, respectively, demonstrating its universality in defect passivation for efficient PSCs.

Iodine vacancy defects in MA-free perovskite are effectively passivated through the interaction between Pb²⁺ and the functional groups in d-penicillamine, resulting in an impressive efficiency of 22.4% along with excellent operational stability.     

Synthesis,cytotoxicity and anti‐metastatic properties of new pyridyl–thiazole arene ruthenium(II) complexes

A series of novel ruthenium(II)–cymene complexes ( 1 – 8 ) containing substituted pyridyl–thiazole ligands, [Ru(η⁶‐p‐cymene)(L)Cl]Cl (L = N,N‐chelating derivatives), have been synthesized and characterized using elemental analysis, infrared, ¹H NMR and ¹³C NMR spectroscopies and mass spectrometry. All these complexes not only display marked cytotoxicity in vitro against three different human cancer cell lines (HeLa, A549 and MDA‐MB‐231), but also exhibit promising anti‐metastatic activity at sub‐cytotoxic concentrations. Cell cycle analysis shows that the ruthenium(II) complex‐induced growth inhibition was mainly caused by S‐phase cell cycle arrest. Further protein level analysis suggests that compound 5 may exert antitumor activity via a p53‐independent mechanism.     

Determination of D-penicillamine and tiopronin in human urine and serum by HPLC-FLD and CE-LIF with 1,3,5,7-tetramethyl-8-bromomethyl-difluoroboradiaza-s-indacene

Two rapid and sensitive analytical methods are developed for the determination of D-penicillamine (D-PEN) and tiopronin (TP) through high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). A boron-dipyrrolemethene (BODIPY) fluorescence labeling reagent, 1,3,5,7-tetramethyl-8-bromomethyl-difluoroboradiaza-s-indacene (TMMB-Br) was successfully applied to derivatize these two thiol drugs. Fluorescein was used as the internal standard (IS) for the quantification of D-PEN and TP in CE-LIF. The derivatization and separation conditions were optimized carefully. Under the optimum conditions, the HPLC and CE separation of D-PEN and TP could be achieved within 12?min. The limits of detection were as low as 2.0 nmol/L for HPLC-FLD and 0.47 nmol/L for CE-LIF. The drugs in human urine and serum samples were determined successfully, and the recoveries were 95.0–06.7% and 95.2–104.3%, respectively.     

Synthesis and spectroscopic characterization of photo-affinity peptide ligands to study rhodopsin-G protein interaction

G protein-coupled receptors (GPCRs) are involved in the control of virtually all aspects of our behavior and physiology. Activated receptors catalyze nucleotide exchange in heterotrimeric G proteins (composed of alpha.GDP, beta and gamma subunits) on the inner surface of the cell membrane. The GPCR rhodopsin and the G protein transducin (G(t)) are key proteins in the early steps of the visual cascade. The main receptor interaction sites on G(t) are the C-terminal tail of the G(t)alpha-subunit and the farnesylated C-terminal tail of the G(t)gamma-subunit. Synthetic peptides derived from these C-termini specifically bind and stabilize the active rhodopsin conformation (R*). Here we report the synthesis of R*-interacting peptides containing photo-reactive groups with a specific isotope pattern, which can facilitate detection of cross-linked products by mass spectrometry. In a preliminary set of experiments, we characterized such peptides derived from the farnesylated G(t)gamma C-terminus (G(t)gamma(60-71)far) in terms of their capability to bind R*. Here, we describe novel peptides with photo-affinity labels that bind R* with affinities similar to that of the native G(t)gamma(60-71)far peptide. Such peptides will enable an improved experimental strategy to probe rhodopsin-G(t) interaction and to map so far unknown interaction sites between both proteins.     

Dynamic Hydrogen-Bond Network as a Modulator of Bismuth–Antimony Complex Anodes for Self-Healable and Wider Temperature Adaptive Potassium Ion Batteries

Antimony (Sb)-based anodes are attractive candidates in potassium-ion batteries (PIBs) due to their superior capacities and rational potassium inserting voltages. However, the sluggish kinetics and poor interface compatibility severely hinder practical application. Herein, Bi_0.67Sb_1.33S₃ nanospheres embedded into in situ formed poly(3,4-ethylenedioxythiophene) crosslinked with polythioctic acid (PET@PTA) (Bi_0.67Sb_1.33S₃/PET@PTA) were elaborately conceptualized with hydrogen bonds exchangeable binding (HBEB) sites. Bi_0.67Sb_1.33S₃/PET@PTA exhibits notable self-healing ability and wider temperature adaptability. Bi_0.67Sb_1.33S₃/PET@PTA displays an impressive capacity of 819 mAh g⁻¹ at 0.05 A g⁻¹, prominent cycle ability with a 73 % capacity conservation after 500 cycles at 2 A g⁻¹, and high capacity retention of 66 % and 84 % at −40 and 70 °C to that case at room temperature, respectively, for potassium storage. This work provides a new perspective for HBEB sites in maximizing the desirable K⁺ storage performance.     

彩色变焦照明系统设计

针对基于RGB混色技术在小角度、近距离空间内较难实现彩色LED,且有关彩色变焦照明相关文献也较少的问题,设计了一款彩色变焦照明系统。系统主要由LED光源、TIR透镜、微结构透镜组成,可在650mm处实现良好混色照明,变焦范围为4.2°~9.1°(半光强角),且变焦照明过程中,在光强下降为20%的角度内能量利用率达85%以上,半光强角内的能量利用率始终在75%以上,满足设计要求。     

THE MEASUREING AND PROCESSING OF STREAK CAMERA

狭缝摄影胶片图象运动参量测量和处理采用了胶片扫描仪对狭缝摄影胶片图象进行数字化,利用软件进行图象处理.文章介绍了对胶片扫描仪进行检验和标定方法;对由于狭缝摄影机的胶片速度和目标的实际影象速度不一致产生的畸变进行了分析和修正,实现了数据的精确测量和处理.