Ground-based solar absorption studies for the Carbon Cycle science by Fourier Transform Spectroscopy (CC-FTS) mission

Carbon cycle science by Fourier transform spectroscopy (CC-FTS) is an advanced study for a future satellite mission. The goal of the mission is to obtain a better understanding of the carbon cycle in the Earth's atmosphere by monitoring total and partial columns of CO₂, CH₄, N₂O, and CO in the near infrared. CO₂, CH₄, and N₂O are important greenhouse gases, and CO is produced by incomplete combustion. The molecular O₂ column is also needed to obtain the effective optical path of the reflected sunlight and is used to normalize the column densities of the other gases. As part of this advanced study, ground-based Fourier transform spectra are used to evaluate the spectral region and resolution needed. Spectra in the 3950–7140 cm^?1 region with a spectral resolution of 0.0042 cm^?1 recorded at Kiruna (67.84°N, 20.41°E, and 419 m above sea level), Sweden, on 1 April 1998, were degraded to the resolutions of 0.01, 0.1, and 0.3 cm^?1. The effect of spectral resolution on the retrievals has been investigated with these four Kiruna spectra. To obtain further information on the spectral resolution, optical components and spectroscopic parameters required by the future mission, high-resolution solar absorption spectra between 2000 and 15000 cm^?1 were recorded using Fourier transform spectrometers at Kitt Peak (31.9°N, 111.6°W, and 2.1 km above sea level), Arizona, on 25 July 2005 and Waterloo (43.5°N, 80.6°W, and 0.3 km above sea level), Ontario, on 22 November 2006 with spectral resolutions of 0.01 and 0.1 cm^?1, respectively. Dry air volume mixing ratios (VMRs) of CO₂ and CH₄ were retrieved from these ground-based observations. The HITRAN 2004 spectroscopic parameters are used with the SFIT2 package for the spectral analysis. The measurement precisions for CO₂ and CH₄ total columns are better than 1.07% and 1.13%, respectively, for our observations. Based on these results, a Fourier transform spectrometer (maximum spectral resolution of 0.1 cm^?1 or 5 cm maximum optical path difference (MOPD)) operating between 2000 and 15000 cm^?1 is suggested as the primary instrument for the mission. Further progress in improving the atmospheric retrievals for CO₂, CH₄, and O₂ requires new laboratory measurements of the spectroscopic line parameters.     

Influence of different initial distributions on robust cooperation in scale-free networks: A comparative study

We study the evolutionary Prisoner's dilemma game on scale-free networks, focusing on the influence of different initial distributions for cooperators and defectors on the evolution of cooperation. To address this issue, we consider three types of initial distributions for defectors: uniform distribution at random, occupying the most connected nodes, and occupying the lowest-degree nodes, respectively. It is shown that initial configurations for defectors can crucially influence the cooperation level and the evolution speed of cooperation. Interestingly, the situation where defectors initially occupy the lowest-degree vertices can exhibit the most robust cooperation, compared with two other distributions. That is, the cooperation level is least affected by the initial percentage of defectors. Moreover, in this situation, the whole system evolves fastest to the prevalent cooperation. Besides, we obtain the critical values of initial frequency of defectors above which the extinction of cooperators occurs for the respective initial distributions. Our results might be helpful in explaining the maintenance of high cooperation in scale-free networks.     

Enhancement of the electrocatalytic oxidation of dyeing wastewater (reactive brilliant blue KN-R) over the Ce-modified Ti-PbO2 electrode with surface hydrophobicity

Journal of Solid State Electrochemistry - Rational hydrophobic anode has been considered as a promising approach for water pollution remediation. However, the construction method of the hydrophobic...     

A quantitatively controllable mesoscopic reliability model of an interdependent public transit network considering congestion,time-delay interaction and self-organization effects

Nonlinear Dynamics - This paper establishes a multi-parameter controlling cascading failures (CFs) model for measuring interdependent public transit network (PTN) reliability under mesoscopic...     

Generation and Propagation of Optical Superoscillatory Vortex Arrays

Superoscillation is an intriguing wave phenomenon which enables subwavelength features propagating into far field and hence has potential applications in super‐resolution microscopy as well as particle trapping and manipulation. While previous demonstrations mostly concentrate on designing complicated nanostructures for generating uncontrollable superoscillatory functions, here a new technique which allows for creating polynomially shaped superoscillatory functions that contain phase singularity arrays is demonstrated both theoretically and experimentally. Such a technique is implemented in optical experiments for the first time and controllable superoscillatory lobes with feature much below the diffraction limit is achieved. More importantly, a general theoretical framework, which, to our knowledge, has not been reported before, is developed to show how the created superoscillations propagate to a distance of many Rayleigh ranges and eventually disappear when the distance is sufficiently larger. The validity of the model is confirmed by the experiments. The results may trigger further studies in light field shaping and manipulations in subwavelength scale.     

Addition-elimination of nitroalkanes to 3-phenacylideneoxindoles—direct method for the synthesis of 3-alkenylphenacylidene-oxindoles

The first addition-elimination of nitroalkanes to 3-phenacylideneoxindoles was developed, affording the corresponding 3-alkenylphenacylidene-oxindoles with high yields.The addition-elimination mechanism of 3-phenacylideneoxindoles with nitroalkanes and removable NO₂ group in concert guarantees the high regioselectivity.     

Precise measurement and control of the pressure-driven flows for microfluidic systems

The pressure-driven device is designed and the flow rates of the microfluidic systems can be supplied by the pressure-driven flows, which can significantly reduce the flow-rate fluctuations coming from the pump source. For pressure-driven flows, the flow rates of the fluids can be predicted by measuring the pressure drop along a polytetrafluoroethylene (PTFE) tubing. Especially, by varying the geometrical parameters of the PTFE tubing, the predicted flow rates of the fluids are compared with the experimental measurements, and the testing precision of the pressure-driven flows can be obtained. Meanwhile, the dynamic characteristics of the open-loop and closed-loop control pressure-driven device are comparatively studied. Particularly, a proportional and integral (PI) controller is integrated with the closed-loop control pressure-driven device, and the effects of the parameters of the PI controller on the dynamic characteristics of the pressure-driven devices are mainly discussed. Most importantly, by improving the dynamic characteristics of the pressure-driven devices, precise measurement and control of the pressure-driven flows can be achieved for microfluidic systems.     

Recent Advances in Iodine-Promoted C−S/N−S Bonds Formation

Sulfur-containing scaffold, as a ubiquitous structural motif, has been frequently used in natural products, bioactive chemicals and pharmaceuticals, particularly C−S/N−S bonds are indispensable in many biological important compounds and pharmaceuticals. Development of mild and general methods for C−S/N−S bonds formation has great significance in modern research. Iodine and its derivatives have been recognized as inexpensive, environmentally benign and easy-handled catalysts or reagents to promote the construction of C−S/N−S bonds under mild reaction conditions, with good regioselectivities and broad substrate scope. Especially based on this, several new strategies, such as oxidation relay strategy, have been greatly developed and accelerated the advancement of this field. This review focuses on recent advances in iodine and its derivatives promoted hybridized C−S/N−S bonds formation. The features and mechanisms of corresponding reactions are summarized and the results of some cases are compared with those of previous reports. In addition, the future of this domain is discussed.     

Affibody‐Conjugated RALA Polymers Delivering Oligomeric 5‐Fluorodeoxyuridine for Targeted Therapy of HER2 Overexpressing Gastric Cancer

Affibody‐conjugated RALA (affi‐RA) are designed for delivering oligomeric 5‐fluorodeoxyuridine (FUdR, metabolite of 5‐FU) strand to raise the selectivity of 5‐fluorouracil (5‐FU), decrease its toxicity and improve its suboptimal therapeutic efficacy. The nanodrugs, FUdR@affi‐RA, are spontaneously assembled by electrostatic interaction between positively charged affi‐RA and negatively charged FUdR₁₅‐strands (15 consecutive FUdR). FUdR@affi‐RA exhibits excellent stability under simulated physiological conditions. Compared with free FUdR, FUdR@affi‐RA shows excellent targeting and higher cytotoxicity in human epidermal growth factor receptor 2 (HER2) overexpressing gastric cancer N87 cells. Moreover, the anticancer mechanism studies reveal that FUdR@affi‐RA enhances the expression and activity of apoptosis‐associated proteins in the Bcl‐2/Bax‐caspase 8,9‐caspase 3 apoptotic pathway induced by FUdR. This study indicates that the fusion vector, affi‐RA, presents a promising delivery system platform for nucleoside analogue drugs and provides a new strategy for the development of therapeutics of cancer treatment.