Some Hardy type integral inequalities

We present new kinds of Hardy integral inequalities involving some generalization and improvement.     

Microfiber Mach-Zehnder interferometer embedded in low index polymer

Microfiber Mach Zehnder Interferometer (MMZI) is demonstrated by micromanipulating an optical microfiber drawn from a single mode fiber (SMF) using a flame brushing technique. The MMZI shows good interference fringes with an extinction ratio of 13 dB and a free spectral range (FSR) of 0.52 nm at 1530 nm. The MMZI is then embedded in a polymer with the refractive index of 1.36 to increase the stability and robustnes of the device. It is found that the transmission spectrum of the packaged MMZI is changed by the polymer, which increases the FSR to 0.83 nm. The degradation in transmission loss and extinction ratio are attributed to the disturbance at the coupling area during the packaging. Compared with waveguide based mach zehnder interferometer, the proposed MMZI is favoured due to easy fabrication, compact size, and easy integration with the fiber system.     

GC-MS,LC-MS/MS,Docking and Molecular Dynamics Approaches to Identify Potential SARS-CoV-2 3-Chymotrypsin-Like Protease Inhibitors from Zingiber officinale Roscoe

This study aims to identify and isolate the secondary metabolites of Zingiber officinale using GC-MS, preparative TLC, and LC-MS/MS methods, to evaluate the inhibitory potency on SARS-CoV-2 3 chymotrypsin-like protease enzyme, as well as to study the molecular interaction and stability by using docking and molecular dynamics simulations. GC-MS analysis suggested for the isolation of terpenoids compounds as major compounds on methanol extract of pseudostems and rhizomes. Isolation and LC-MS/MS analysis identified 5-hydro-7, 8, 2′-trimethoxyflavanone (9), (E)-hexadecyl-ferulate (1), isocyperol (2), N-isobutyl-(2E,4E)-octadecadienamide (3), and nootkatone (4) from the rhizome extract, as well as from the leaves extract with the absence of 9. Three known steroid compounds, i.e., spinasterone (7), spinasterol (8), and 24-methylcholesta-7-en-3β-on (6), were further identified from the pseudostem extract. Molecular docking showed that steroids compounds 7, 8, and 6 have lower predictive binding energies (MMGBSA) than other metabolites with binding energy of −87.91, −78.11, and −68.80 kcal/mole, respectively. Further characterization on the single isolated compound by NMR showed that 6 was identified and possessed 75% inhibitory activity on SARS-CoV-2 3CL protease enzyme that was slightly different with the positive control GC376 (77%). MD simulations showed the complex stability with compound 6 during 100 ns simulation time.     

Preparation and characterization of PEPPSI-palladium N-heterocyclic carbene complexes using benzimidazolium salts catalyzed Suzuki–Miyaura cross coupling reaction and their antitumor and antimicrobial activities

New palladium complexes were efficiently synthesized from the reaction of benzimidazolium salts 2a–e, potassium carbonate (K₂CO₃) and palladium chloride (PdCl₂) in pyridine (for 3a–e). The catalytic activity of these complexes in a catalytic system including palladium complexes and K₂CO₃ in DMF-H₂O was evaluated in Suzuki–Miyaura cross-coupling reactions of aryl bromides and chlorides with phenylboronic acid. Our novel complexes show excellent catalytic activities with high turnover numbers (TON) and high turnover frequencies (TOF) (e.g. for the Suzuki–Miyaura reaction: TON up to 370 and TOF up to 123.3?h^?1). Both benzimidazolium salts 2a–e and complexes 3 have been characterized using spectroscopic data and elemental analysis. The antimicrobial activity of the N-heterocyclic carbene palladium complexes 3a–e varies with the nature of the ligands. Also, the IC₅₀ values of both, complexes (3a–e) and benzimidazoles 2a–e, have been determined. In addition, the new palladium complexes were screened for their antitumor activity. Complexes 3e and 3d exhibited the highest antitumor effect with IC₅₀ values 6.85?μg/mL against MCF-7 and 10.75?μg/mL against T47D, respectively.     

Novel pressure and displacement sensors based on carbon nanotubes

We report newly designed pressure and displacement capacitive sensors based on a flexible paper–CNT structure.The carbon nanotube(CNT)powder was deposited on a thin paper substrate and was pressed at an elevated temperature.The sheet resistance of the paper–CNT films was in the range of 2–4 kΩ/cm2.The paper–CNT films were used to fabricate pressure and displacement sensors.The sensitivities of the pressure and the displacement sensors were found to be17.3 p F·m2/k N and 0.93 10-3p F/μm,respectively.The experimental results were compared with the simulated data and they found good agreement with each other.     

援疆效果满意度的公因子分析:综合评价和政策取向——以南疆三地州数据为例

以居民对援疆政策满意度为出发点,前学者的研究基础上确定援疆政策效果的满意度的衡量指标,选取6个大方向31个指标来测量援疆效果满意度.通过南疆三地州进行实地问卷调查获得数据为样本,采用因子分析方法确定二级指标及三级指标的权重,进行对援疆政策效果满意度综合评价.研究结论是南疆居民对援疆效果的满意度总得分接近70分,说明总体满意度较高,其中满意度最高的为收入及补贴,排在第一位,排在末尾的就是教育领域,排在第二位的是住房建设,而基层服务的满意度仅仅高于教育领域,排在第五位.排在第三位的就是医疗,第四位才是居民出行为核心内容的基础设施建设.从而为援疆政策效果满意度优化,解决存在的问题,全面改善援疆政策效果提出政策建议.     

Tunable laser generation with erbium-doped microfiber knot resonator

A tunable laser is demonstrated using a microfiber knot resonator structure made by erbiumdoped fiber (EDF). The laser is made of a 2 m long EDF where 30 mm of its end section is tapered to construct a microfiber knot resonator (MKR). The combination of the EDF and MKR generates a stable single wavelength laser at 1555 nm wavelength with a signal to noise ratio (SNR) of 33.7 dB using a 63 mW of 980 nm pump power. The peak wavelength of the laser can be tuned by 340 pm as the MKR diameter reduces from 5.0 to 0.5 mm with an acceptable penalty in output power.     

A note on ∣A∣k summability factors of infinite series

In this note we give an improvement to a recent result obtained by Savas and Rhoade concerning ∣A∣_k summability of infinite series.     

Effects of silver nanoparticles towards the efficiency of organic solar cells

We report an alternative approach to enhance the optical and electrical performance of a vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine:poly(3hexylthiophene) (VOPcPhO:P3HT) blending system by integrating plasmonic spherical silver into an active layer of organic solar cells. Studies of the influence of the size distribution and optical properties of the silver nanoparticles were carried out using UV–Vis spectroscopy and field emission scanning electron microscopy, respectively. Electrical characteristics with and without the presence of metallic nanostructures were analyzed using J–V characteristics to observe the plasmonic effects on the performance in the VOPcPhO:P3HT organic solar cells.