313 research outputs found
Preparation of ordered TiO2 macroporous membrane using PBMA colloid crystal as template
Poly(butyl methacrylate) (PBMA) colloidal crystal templates were assembled orderly on the clean substrates of monocrystalline silicon by dip-drawing technique and titanium dioxide (TiO2) macroporous membranes were prepared by using sol-dipping template method to fill the interstices among the PBMA templates, followed by calcination to remove the templates at 550℃. Calcination of the PBMA templates was carried out according to the following procedure: the rate of rising temperature was 5℃/min from room temperature to 150℃, 2℃/min from 150℃ to 270℃, 1℃ /min from 270℃ to 430℃, 2℃/min from 430℃ to 550℃ and maintained it at 550℃ for 2h. X-ray diffraction (XRD) spectra indicated the macroporous materials were anatase structure. The polymerization mechanism of BMA with Fenton reagent as a new initiator was discussed, and the removal process of the PBMA templates and the formation of TiO2 pore size were investigated, respectively. The results showed that the new method of polymerization overcomes many problems associated with the conventional emulsion polymerization techniques such as long reaction time, necessary deoxygenation, and complicated operation
Mixed Eucalyptus plantations in subtropical China enhance phosphorus accumulation and transformation in soil aggregates
IntroductionThe production of Eucalyptus, a principal economic tree genus in China, is faced with challenges related to soil phosphorus (P) limitations. In this study, we explore variations in phosphorus content, storage, and transformation in Eucalyptus forests. We hypothesize that mixed forests augment soil aggregate stability and P content and that microaggregates are pivotal in determining P differences between mixed and pure forests. Additionally, we posit that mixed forests foster P transformation, enhancing its efficacy in the soil. Current research on the distribution and transformation of soil total P (TP) and P fractions at the soil aggregate level is limited.MethodsIn this study, we selected soil from a Eucalyptus-Mytilaria laosensis Lecomte mixed forest, Eucalyptus-Erythrophleum fordii Oliv mixed forest, and pure Eucalyptus forest in Chongzuo County, Guangxi, China, as the research objects. Using a dry-sieving method, we divided the soil collected in situ from the 0–40 cm layer into aggregates of >2, 1–2, 0.25–1, and <0.25 mm particle sizes, measured the TP and P fractions (resin-extractable inorganic P, bicarbonate-extractable inorganic P, bicarbonate-extractable organic P, sodium hydroxide-extractable inorganic P, sodium hydroxide-extractable organic P, dilute hydrochloric acid-extractable P, concentrated hydrochloric acid extractable inorganic P, concentrated hydrochloric acid-extractable organic P and residue-P) in different aggregates, and used redundancy analysis and PLS SEM to reveal key factors affecting soil P accumulation and transformation.ResultsThe results showed that compared to pure Eucalyptus forests, mixed Eucalyptus forests significantly enhanced the stability of soil aggregates and the content and storage of phosphorus, especially the Eucalyptus-Mytilaria laosensis mixed forest. The content of total soil phosphorus and its fractions decreased with increasing aggregate particle size, while the opposite trend was observed for stored P, with aggregates <0.25 mm being the main fraction influencing soil phosphorus accumulation. The transformation process of P fractions was primarily constrained by dissolution rates, mineralization rates, biological activity, including the action of microbes, fungi, and plant–root interactions, and other factors.DiscussionMixed forests increased the transformation of phosphorus in soil aggregates, effectivel enhancing the availability of soil phosphorus. In summary, this study provides important evidence for the systematic management of subtropical artificia Eucalyptus forests and the sustainable utilization of soil resources
TiEV: The Tongji Intelligent Electric Vehicle in the Intelligent Vehicle Future Challenge of China
TiEV is an autonomous driving platform implemented by Tongji University of
China. The vehicle is drive-by-wire and is fully powered by electricity. We
devised the software system of TiEV from scratch, which is capable of driving
the vehicle autonomously in urban paths as well as on fast express roads. We
describe our whole system, especially novel modules of probabilistic perception
fusion, incremental mapping, the 1st and the 2nd planning and the overall
safety concern. TiEV finished 2016 and 2017 Intelligent Vehicle Future
Challenge of China held at Changshu. We show our experiences on the development
of autonomous vehicles and future trends
A practical overview of image classification with variational tensor-network quantum circuits
Circuit design for quantum machine learning remains a formidable challenge.
Inspired by the applications of tensor networks across different fields and
their novel presence in the classical machine learning context, one proposed
method to design variational circuits is to base the circuit architecture on
tensor networks. Here, we comprehensively describe tensor-network quantum
circuits and how to implement them in simulations. This includes leveraging
circuit cutting, a technique used to evaluate circuits with more qubits than
those available on current quantum devices. We then illustrate the
computational requirements and possible applications by simulating various
tensor-network quantum circuits with PennyLane, an open-source python library
for differential programming of quantum computers. Finally, we demonstrate how
to apply these circuits to increasingly complex image processing tasks,
completing this overview of a flexible method to design circuits that can be
applied to industrially-relevant machine learning tasks
Different water and nitrogen level effects on soil microbial properties of spinach
Understanding the interactions of plant soil environment and rhizosphere microbial changes are necessary to develop
new strategies for the sustainable agriculture. A field experiment with combination of three water levels and three
nitrogen rates was conducted to investigate the effect of water and nitrogen management on the changes of soil
microbial properties in non-rhizosphere and rhizosphere soils of spinach. Non-Rhizosphere and rhizosphere microbial
diversities were affected by water and nitrogen applications. Evenness index in the no-nitrogen treatment was more
than that of 85 and 170 kg ha–1 nitrogen treatments in the non-rhizosphere or rhizosphere soil. Microbial biomass
carbon in non-rhizosphere soil or rhizosphere soil decreased with the increase of nitrogen application, but showed
the highest value in 16.5% of soil water content, followed by 12.5% and 20.5% of soil water content. Soil microbial
biomass phosphorus content of 85 kg ha–1 nitrogen treatment in the non-rhizosphere soil or rhizosphere soil was
significantly different for 0 and 170 kg ha–1 nitrogen treatments. Nitrification rate increased with the increase of soil
water content in 0 and 170 kg ha–1
treatments. Our results demonstrated that water and nitrogen could impact the
soil fertility and microbial activity of spinach
Observation of Active Sites for Oxygen Reduction Reaction on Nitrogen-doped Multilayer Graphene
Active sites and catalytic mechanism of nitrogen-doped graphene in oxygen
reduction reaction (ORR) have been extensively studied but are still
inconclusive, partly due to the lack of an experimental method that can detect
the active sites. It is proposed in this report that the active sites on
nitrogen-doped graphene can be determined via the examination of its chemical
composition change before and after ORR. Synchrotron-based X-ray photoelectron
spectroscopy analyses of three nitrogen-doped multilayer graphene samples
reveal that oxygen reduction intermediate OH(ads) which should chemically
attach to the active sites remains on the carbon atoms neighboring pyridinic
nitrogen after ORR. In addition, a high amount of the OH(ads) attachment after
ORR corresponds to a high catalytic efficiency and vice versa. These pinpoint
that the carbon atoms close to pyridinic nitrogen are the main active sites
among the different nitrogen doping configurations
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