Zinc Porphyrins with a Pyridine‐Ring‐Anchoring Group for Dye‐Sensitized Solar Cells

Anchoring groups are extremely important in controlling the performance of dye‐sensitized solar cells (DSCs). The design and characterization of sensitizers with new anchoring groups, in particular non‐carboxylic acid groups, has become a recent focus of DSC research. Herein, new donor? π? acceptor zinc? porphyrin dyes with a pyridine ring as an anchoring group have been designed and synthesized for applications in DSCs. Photophysical and electrochemical investigations demonstrated that the pyridine ring worked effectively as an anchoring group for the porphyrin sensitizers. DSCs that were based on these new porphyrins showed an overall power‐conversion efficiency of about 4.0 % under full sunlight (AM 1.5G, 100 mW cm^?2).     

HMD-Net: A Vehicle Hazmat Marker Detection Benchmark

Vehicles carrying hazardous material (hazmat) are severe threats to the safety of highway transportation, and a model that can automatically recognize hazmat markers installed or attached on vehicles is essential for intelligent management systems. However, there is still no public dataset for benchmarking the task of hazmat marker detection. To this end, this paper releases a large-scale vehicle hazmat marker dataset named VisInt-VHM, which includes 10,000 images with a total of 20,023 hazmat markers captured under different environmental conditions from a real-world highway. Meanwhile, we provide an compact hazmat marker detection network named HMD-Net, which utilizes a revised lightweight backbone and is further compressed by channel pruning. As a consequence, the trained-model can be efficiently deployed on a resource-restricted edge device. Experimental results demonstrate that compared with some established methods such as YOLOv3, YOLOv4, their lightweight versions and popular lightweight models, HMD-Net can achieve a better trade-off between the detection accuracy and the inference speed.     

Production of Atosiban’s Key Intermediate Pentapeptide: Synthetic Approaches to the Development of a Peptide Synthesis with Less Racemization and Simplifier Purification Process

The key intermediate NH₂-Ile-Thr(Bzl)-Asn-Cys(Bzl)-Pro-COOH of Atosiban was prepared from N-Boc-S-Bzl-cysteine by the stepwise lengthening of the chain according to the repetitive N,O-bis(trimethylsilyl)acetamide/N-hydroxysuccinimide ester (BSA/NHS) strategy. This synthetic route required no chromatography purification and can be readily performed, yielding a highly pure pentapeptide compound.     

比浊法测定酸性镀铜液中微量氯离子

以乙二醇为增溶剂,硝酸银作沉淀剂,采用氯化银比浊法,在不分离硫酸铜的条件下,直接测定酸性镀铜液中微量氯离子。测定波长为440 nm,线形范围为0~50μg/25 mL,其表观摩尔吸光系数ε=1.3×105,方法检出限为0.035μg/mL,该法用于测定酸性镀铜液中微量氯离子在不同水平的加标回收率为95.4%~104.5%。结果表明,该法准确,快速,简便,其它的常见离子无干扰。     

Padé approximations of quantized-vortex solutions of the Gross–Pitaevskii equation

Quantized vortices are important topological excitations in Bose–Einstein condensates. The Gross–Pitaevskii equation is a widely accepted theoretical tool. High accuracy quantized-vortex solutions are desirable in many numerical and analytical studies. We successfully derive the Padéapproximate solutions for quantized vortices with winding numbers ω = 1, 2, 3, 4, 5, 6 in the context of the Gross–Pitaevskii equation for a uniform condensate. Compared with the numerical solutions, we find that(1) they approximate the entire solutions quite well from the core to infinity;(2) higher-order Padé approximate solutions have higher accuracy;(3) Padé approximate solutions for larger winding numbers have lower accuracy. The healing lengths of the quantized vortices are calculated and found to increase almost linearly with the winding number. Based on experiments performed with ~(87)Rb cold atoms, the healing lengths of quantized vortices and the number of particles within the healing lengths are calculated, and they may be checked by experiment. Our results show that the Gross–Pitaevskii equation is capable of describing the structure of quantized vortices and physics at length scales smaller than the healing length.     

Shape effect on the size and dimension dependent order-disorder transition temperatures of bimetallic alloys

Chemically ordered bimetallic nanocrystals may be promising candidates for the future magnetic-storage applications. In order to theoretically understand the order-disorder transition in nanoscale, a model based on the previous result for the size and dimension dependent melting temperature is developed to describe the effects of sizes, shapes and dimensions on order-disorder transition temperatures (T_OD) of bimetallic alloys. The results show that T_OD drops as size decreases, shape factor increases and dimension decreases. Also, the shape effect on T_OD cannot be neglected. Among these effects on T_OD, size is the strongest, while shape is the weakest. All these conclusions have been compared and confirmed by the recent simulations and experiments.     

INFINITE PERIODIC SOLUTIONS TO A CLASS OF SECOND-ORDER NEUTRAL DIFFERENTIAL EQUATIONS

By means of variational structure and Z2 group index theory, we obtain infinite periodic solutions to a class of second-order neutral differential equations.     

一类二阶常微分方程边值问题的无穷多个解

利用变分原理和Z2不变群指标研究了二阶常微分方程边值问题{u″(t)-u(t) f(t,u(t))=0,0＜t＜1,u′(0)=0,α1u(1) u′(1)=0,(其中α1＞-1/2).得出了这类方程存在无穷个解的充分条件.     

Interfacial Enhancement by γ‐Al2O3 of Electrochemical Oxidative Dehydrogenation of Ethane to Ethylene in Solid Oxide Electrolysis Cells

Oxidative dehydrogenation of ethane (ODE) is limited by the facile deep oxidation and potential safety hazards. Now, electrochemical ODE reaction is incorporated into the anode of a solid oxide electrolysis cell, utilizing the oxygen species generated at anode to catalytically convert ethane. By infiltrating γ‐Al₂O₃ onto the surface of La_0.6Sr_0.4Co_0.2Fe_0.8O_3‐δ‐Sm_0.2Ce_0.8O_2‐δ (LSCF‐SDC) anode, the ethylene selectivity reaches as high as 92.5 %, while the highest ethane conversion is up to 29.1 % at 600 °C with optimized current and ethane flow rate. Density functional theory calculations and in situ X‐ray photoelectron spectroscopy characterizations reveal that the Al₂O₃/LSCF interfaces effectively reduce the amount of adsorbed oxygen species, leading to improved ethylene selectivity and stability, and that the formation of Al‐O‐Fe alters the electronic structure of interfacial Fe center with increased density of state around Fermi level and downshift of the empty band, which enhances ethane adsorption and conversion.     

Total chemical and semisynthetic approaches for the preparation of ubiquitinated proteins and their applications

Protein ubiquitination is an important post-translational modification (PTM) in eukaryotic organisms that regulates a variety of cellular processes, such as protein degradation, signal transduction, apoptosis, and DNA damage tolerance. To decipher mechanistically the diverse biological functions of ubiquitination, homogeneous ubiquitinated proteins are greatly needed. Although direct isolation from cell source and in vitro enzymatic methods can be used to produce such proteins, these methods often suffer from problems of low yield or heterogeneous products. Comparably, total chemical and semisynthetic approaches offer good alternatives to produce the ubiquitinated proteins with high purity and selectivity. This review summarizes the recent developments of protein ubiquitination strategies and the use of the synthesized proteins to help garner structural and functional insight into the inner workings of the ubiquitin system.