CO2 Hydrogenation to Formate and Formic Acid by Bimetallic Palladium-Copper Hydride Clusters.

Mass spectrometric analysis of the anionic products of interaction between bimetallic palladium-copper tetrahydride anions, PdCuH4-, and carbon dioxide, CO2, in a reaction cell shows an efficient generation of the PdCuCO2H4- intermediate and formate/formic acid complexes. Multiple structures of PdCuH4- and PdCuCO2H4- are identified by a synergy between anion photoelectron spectroscopy and quantum chemical calculations. The higher energy PdCuH4- isomer is shown to drive the catalytic hydrogenation of CO2, emphasizing the importance of accounting for higher energy isomers for cluster catalytic activity. This study represents the first example of CO2 hydrogenation by bimetallic hydride clusters

Thermal properties of carbon black aqueous nanofluids for solar absorption

In this article, carbon black nanofluids were prepared by dispersing the pretreated carbon black powder into distilled water. The size and morphology of the nanoparticles were explored. The photothermal properties, optical properties, rheological behaviors, and thermal conductivities of the nanofluids were also investigated. The results showed that the nanofluids of high-volume fraction had better photothermal properties. Both carbon black powder and nanofluids had good absorption in the whole wavelength ranging from 200 to 2,500 nm. The nanofluids exhibited a shear thinning behavior. The shear viscosity increased with the increasing volume fraction and decreased with the increasing temperature at the same shear rate. The thermal conductivity of carbon black nanofluids increased with the increase of volume fraction and temperature. Carbon black nanofluids had good absorption ability of solar energy and can effectively enhance the solar absorption efficiency

Selection of reliable reference genes for gene expression studies in peach using real-time PCR

<p>Abstract</p> <p>Background</p> <p>RT-qPCR is a preferred method for rapid and reliable quantification of gene expression studies. Appropriate application of RT-qPCR in such studies requires the use of reference gene(s) as an internal control to normalize mRNA levels between different samples for an exact comparison of gene expression level. However, recent studies have shown that no single reference gene is universal for all experiments. Thus, the identification of high quality reference gene(s) is of paramount importance for the interpretation of data generated by RT-qPCR. Only a few studies on reference genes have been done in plants and none in peach <it>(Prunus persica </it>L. Batsch). Therefore, the present study was conducted to identify suitable reference gene(s) for normalization of gene expression in peach.</p> <p>Results</p> <p>In this work, eleven reference genes were investigated in different peach samples using RT-qPCR with SYBR green. These genes are: actin 2/7 (<it>ACT</it>), cyclophilin (<it>CYP2</it>), RNA polymerase II (<it>RP II</it>), phospholipase A2 (<it>PLA2</it>), ribosomal protein L13 (<it>RPL13</it>), glyceraldehyde-3-phosphate dehydrogenase (<it>GAPDH</it>), 18S ribosomal RNA (<it>18S rRNA</it>), tubblin beta (<it>TUB</it>), tubblin alpha (<it>TUA</it>), translation elongation factor 2 (<it>TEF2</it>) and ubiquitin 10 (<it>UBQ10</it>). All eleven reference genes displayed a wide range of C_qvalues in all samples, indicating that they expressed variably. The stability of these genes except for <it>RPL13 </it>was determined by three different descriptive statistics, geNorm, NormFinder and BestKeeper, which produced highly comparable results.</p> <p>Conclusion</p> <p>Our study demonstrates that expression stability varied greatly between genes studied in peach. Based on the results from geNorm, NormFinder and BestKeeper analyses, for all the sample pools analyzed, <it>TEF2</it>, <it>UBQ10 </it>and <it>RP II </it>were found to be the most suitable reference genes with a very high statistical reliability, and <it>TEF2 </it>and <it>RP II </it>for the other sample series, while <it>18S rRNA</it>, <it>RPL13 </it>and <it>PLA2 </it>were unsuitable as internal controls. <it>GAPDH </it>and <it>ACT </it>also performed poorly and were less stable in our analysis. To achieve accurate comparison of levels of gene expression, two or more reference genes must be used for data normalization. The combinations of <it>TEF2</it>/<it>UBQ10/RP II </it>and <it>TEF2/RP II </it>were suggested for use in all samples and subsets, respectively.</p

Review of Variable-Rate Sprayer Applications Based on Real- Time Sensor Technologies

Precision variable rate spray is one of the research hotspots in the field of modern agriculture spraying applications. Variable rate spraying of the canopy allows growers to apply adjusted volume rate of pesticides to the target, based on canopy size, and to apply plant protection products in an economical and environmentally sound manner. In the field of pesticide application, knowledge of the geometrical characteristics of plantations will guarantee a better adjustment of the dosage of the agrochemicals applied. This technology is integrated with intelligent real-time sensors, which have a high potential for agricultural precision spray applications. This book chapter presents the foundations and applications in agriculture of the primary systems used for real-time spray target detection of the geometrical characterization of tree plantations. Systems based on infrared, ultrasonic, light detection and ranging (LIDAR), and stereo vision sensors were discussed, respectively, on their performances to detect spray targets. Among them, laser scanners and stereo vision systems are probably the most promising and complementary techniques for achieving three-dimensional (3D) pictures and maps of plants and canopies. The advantages of data fusion applied in real-time target detection and its accuracy in density estimation of the plants were stressed

A traffic fundamental diagram calibrating methodology to avoid unbalanced speed–density observations

Traffic fundamental diagram is extremely important to analyse traffic flow and traffic capacity, and the central part of traffic fundamental diagram is to calibrate speed–density relationship. However, because of unbalanced speed–density observations, calibrating results using Least Square Method (LSM) with all speed–density points always lead to inaccurate effect, so this paper proposed a selecting data sample method and then LSM was used to calibrate four well-known single-regime models. Comparisons were made among the results using LSM with all speed–density points and the selecting data sample. Results indicated that the selecting data sample method proposed by this paper can calibrate the singleregime models well, and the method overcomes the inaccurate effect caused by unbalanced speed–density observations. Data from different highways validated the results. The contribution of this paper is that the proposed method can help researchers to determine more precise traffic fundamental diagram

Preparation and evaluation of PEGylated phospholipid membrane coated layered double hydroxide nanoparticles

AbstractThe aim of the present study was to develop layered double hydroxide (LDH) nanoparticles coated with PEGylated phospholipid membrane. By comparing the size distribution and zeta potential, the weight ratio of LDH to lipid materials which constitute the outside membrane was identified as 2:1. Transmission electron microscopy photographs confirmed the core-shell structure of PEGylated phospholipid membrane coated LDH (PEG-PLDH) nanoparticles, and cell cytotoxicity assay showed their good cell viability on Hela and BALB/C-3T3 cells over the concentration range from 0.5 to 50 μg/mL

Sustainable Layout Planning Methods for Taxi Service Centres: A Case Study of Jiangning District, Nanjing

Taxi fleet size has undergone a continuous rapid growth in Chinese cities, while the service facility layout planning has relatively lagged behind, causing a decrease in the service quality. Therefore, it is crucial to carry out taxi service centre layout planning. This study analyses the functional orientation and hierarchical layout mode of taxi service centres, and then proposes stepwise layout planning methods combining existing transportation facilities. Considering the demand for integrated service centres is relatively low and convenient service centres are highly flexible, their layout can be determined by qualitative analysis. The constrained layout model of functional service centres is established by optimizing the layout scheme among various alternative taxi service centres. The study finds the model is a mixed 0–1 integer programming problem, genetic algorithms are applied to solve it. Finally, the proposed methods are applied to a real case of Jiangning district, Nanjing. The results show that one integrated service centre, four functional service centres, and twenty-three convenient service centres could satisfy taxi drivers’ demand, which suggests that the proposed methods should effectively address the layout planning problem of taxi service centres, thus have important implications for other cities’ downtown areas in China and beyond

Shubnikov de Haas quantum oscillation of the surface states in the metallic Bismuth Telluride sheets

Metallic Bi2Te3 crystalline sheets with the room-temperature resistivity of above 10 m{\Omega} cm were prepared and their magnetoresistive transport was measured in a field of up to 9 Tesla. The Shubnikov de Haas oscillations were identified from the secondly-derived magnetoresistance curves. While changing the angle between the field and normal axis of the sheets, we find that the oscillation periods present a cosine dependence on the angle. This indicates a two-dimensional transport due to the surface state. The work reveals a resolvable surface contribution to the overall conduction even in a metallic topological insulator.Comment: accepted by EPJD, 201

Intense duskside lower band chorus waves observed by Van Allen Probes: Generation and potential acceleration effect on radiation belt electrons

Abstract Local acceleration driven by whistler mode chorus waves largely accounts for the enhancement of radiation belt relativistic electron fluxes, whose favored region is usually considered to be the plasmatrough with magnetic local time approximately from midnight through dawn to noon. On 2 October 2013, the Van Allen Probes recorded a rarely reported event of intense duskside lower band chorus waves (with power spectral density up to 10-3nT 2/Hz) in the low-latitude region outside of L=5. Such chorus waves are found to be generated by the substorm-injected anisotropic suprathermal electrons and have a potentially strong acceleration effect on the radiation belt energetic electrons. This event study demonstrates the possibility of broader spatial regions with effective electron acceleration by chorus waves than previously expected. For such intense duskside chorus waves, the occurrence probability, the preferential excitation conditions, the time duration, and the accurate contribution to the long-term evolution of radiation belt electron fluxes may need further investigations in future