11 research outputs found
Dataset 1.zip
1.This zip contains a folder, a python file and a readme file. The folder 'train_set' contains subfolders 'transmitted' and 'received', which are the original OAM intensity patterns and distorted patterns respectively.
2.The python file 'ccGAN' is our proposed network,which is based on pytorch.
3.the test sets are not included in this folder, readers can build their own according to their own needs.
3.If the readers have questions, find some better solutions to the issueïŒadditional requirements to data or more concise and elegant description of the code, please contact the author, the author would be grateful.
e-mail: [email protected]
Producing Pyridines via Thermocatalytic Conversion and Ammonization of Waste Polylactic Acid over Zeolites
In this study, polylactic acid served
as raw material to produce
fine chemicals (pyridines) via a thermocatalytic conversion and ammonization
(TCC-A) process. Ammonia was employed as not only carrier gas but
also a reactant in this process. The thermal decomposition behavior
of PLA under N<sub>2</sub> or NH<sub>3</sub> atmosphere was investigated.
Different catalysts, including MCM-41, ÎČ-zeolite, ZSM-5 (Si/Al
= 50) and HZSM-5 with different Si/Al ratios (Si/Al = 25, 50, 80)
were also screened. Reaction temperature and residence time, which
may affect the pyridines production, were investigated systematically.
It was verified that all the investigated factors, including catalyst
structure, catalyst acid amounts, reaction temperature, and residence
time, influenced the PLA conversion and the pyridines production.
The highest pyridines yield, 24.8%, was achieved by using HZSM-5 (Si/Al
= 25) at around 500 °C. The catalyst regeneration tests were
carried out. It demonstrated that the catalyst was stable after five
regenerations and the catalytic activity did not change significantly.
A possible reaction pathway from PLA to pyridines was also proposed.
PLA initially thermally decomposed to form lactic acid and some byproducts
such as acetaldehyde, acetone, etc., and then lactic acid, the mixture
of acetaldehyde and acetone, or other byproducts reacted with ammonia
to form imines and finally underwent complicated reactions to form
pyridines
Selective Conversion of Furfural to Cyclopentanone with CuZnAl Catalysts
A new
catalytic system was developed for the selective conversion
of biomass-derived furfural to cyclopentanone in aqueous solution.
CuZnAl catalysts with different Cu/Zn molar ratios (0.5, 1, 2, and
3) and calcination temperatures (350, 500, and 700 °C) were investigated,
and the CuZnAl-500â0.5 catalyst (Cu/Zn = 0.5, calcined at 500
°C) showed a remarkable catalytic performance in the reaction.
A 62% yield of cyclopentanone was obtained at the optimized conditions
(150 °C, 4 MPa H<sub>2</sub>, 6 h), and the TOF was 9.4 h<sup>â1</sup>. The catalysts were characterized by nitrogen adsorption,
XRD, TEM, N<sub>2</sub>O titration, ICP, XPS, and a carbonâsulfur
analyzer. The factors that influenced the activity of catalysts were
also investigated. Additionally, the CuZnAl-500â0.5 was recycled
five times and maintained good activity and stability. Hence, the
current work presents a new and efficient catalytic system for the
conversion of furfural to cyclopentanone. The low-cost nature of the
CuZnAl makes it a potential catalyst for the production of cyclopentanone
in industry
Synthesis and Assessment of Peptide GdâDOTA Conjugates Targeting Extradomain B Fibronectin for Magnetic Resonance Molecular Imaging of Prostate Cancer
Contrast
enhanced MRI is commonly used in imaging and treatment
planning of prostate cancer. However, no tumor targeting contrast
agent is commercially available for accurate detection and characterization
of prostate cancer with MRI. Extradomain B fibronectin (EDB-FN), an
oncoprotein present in aggressive tumors, is a promising molecular
target for detection and stratification of high-risk prostate cancer.
In this work, we have identified four small peptides (GVK, IGK, SGV,
and ZD2) specific to EDB-FN for tumor targeting. <i>In silico</i> simulations of the binding patterns and affinities of peptides to
the EDB protein fragment revealed different binding site to different
peptide in the ligandâreceptor interactions. Tumor specificity
and organ distribution of the peptides were assessed using fluorescence
imaging in male mice bearing PC-3 human prostate cancer xenografts.
Targeted contrast agents were synthesized by conjugating tetraazacyclododecane-1,4,7,10-tetraacetic
acid (DOTA) to the peptides in the solid phase, followed by complexation
with GdCl<sub>3</sub>. The contrast agents were characterized by MALDI-TOF
mass spectrometry and relaxivity measurements. All four peptide GdâDOTA
conjugates resulted in robust tumor contrast enhancement in MR imaging
of the PC3 mouse prostate cancer model. The peptide GdâDOTA
conjugates specific to EDB-FN are promising targeted small molecular
macrocyclic contrast agents for MR molecular imaging of prostate cancer
Multianalysis of 35 Mycotoxins in Traditional Chinese Medicines by Ultra-High-Performance Liquid ChromatographyâTandem Mass Spectrometry Coupled with Accelerated Solvent Extraction
A generic procedure, which involved accelerated solvent
extraction
and homemade cleanup cartridges, has been developed for the extraction
and purification of 35 mycotoxins in various traditional Chinese medicine
(TCM) matrixes, i.e., rhizomes and roots, seeds, flowers, and grasses
and leaves, for subsequent analysis by ultra-high-performance liquid
chromatographyâtandem mass spectrometry (UHPLCâMS/MS).
All target analytes could be simultaneously quantitated in less than
17 min per run, showing narrow symmetrical peaks. The developed method
was also successfully applied in routine monitoring programs, which
implied a significant reduction of both effort and time, to investigate
the contamination of TCMs. Among 60 commercial TCMs analyzed, 50 were
positive. The achieved data underpin the practical application of
the UHPLCâMS/MS method as a valuable tool for the trace analysis
of multiple mycotoxins in TCMs
Renewable NâHeterocycles Production by Thermocatalytic Conversion and Ammonization of Biomass over ZSMâ5
Chemical conversion of biomass to
value-added products provides
a sustainable alternative to the current chemical industry that is
predominantly dependent on fossil fuels. N-Heterocycles, including
pyrroles, pyridines, and indoles, etc., are the most abundant and
important classes of heterocycles in nature and widely applied as
pharmaceuticals, agrochemicals, dyes, and other functional materials.
However, all starting materials for the synthesis of N-heterocycles
currently are derived from crude oil through complex multistep-processes
and sometimes result in environmental problems. In this study, we
show that N-heterocycles can be directly produced from biomass (including
cellulose, lignocelluloses, sugars, starch, and chitosan) over commercial
zeolites via a thermocatalytic conversion and ammonization process
(TCC-A). All desired reactions occur in one single-step reactor within
seconds. The production of pyrroles, pyridines, or indoles can be
simply tuned by changing the reaction conditions. Meanwhile, N-containing
biochar can be obtained as a valuable coproduct. We also outline the
chemistry for the conversion of biomass into heterocycle molecules
by the addition of ammonia into pyrolysis reactors demonstrating how
industrial chemicals could be produced from renewable biomass resources.
Only minimal biomass pretreatment is required for the TCC-A approach
Antiresonances in the Mid-Infrared Vibrational Spectrum of Functionalized Graphene
We
report anomalous antiresonances in the infrared spectra of doped
and disordered single layer graphene. Measurements in both reflection
microscopy and transmission configurations of samples grafted with
halogenophenyl moieties are presented. Asymmetric transparency windows
at energies corresponding to phonon modes near the Î and K points
are observed, in contrast to the featureless spectrum of pristine
graphene. These asymmetric antiresonances are demonstrated to vary
as a function of the chemical potential and defect density. We propose
a model that involves coherent intraband scattering with defects and
phonons, thus relaxing the optical selection rule forbidding access
to <b>q</b> â Î phonons. This interpretation of
the new phenomenon is supported by our numerical simulations that
reproduce the experimental features
Electrical Switch to the Resonant Magneto-Phonon Effect in Graphene
We report a comprehensive study of
the tuning with electric fields
of the resonant magneto-exciton optical phonon coupling in gated graphene.
For magnetic fields around <i>B</i> ⌠25 T that correspond
to the range of the fundamental magneto-phonon resonance, the electronâphonon
coupling can be switched on and off by tuning the position of the
Fermi level in order to Pauli block the two fundamental inter-Landau
level excitations. The effects of such a profound change in the electronic
excitation spectrum are traced through investigations of the optical
phonon response in polarization resolved magneto-Raman scattering
experiments. We report on the observation of a splitting of the phonon
feature with satellite peaks developing at particular values of the
Landau level filling factor on the low or on the high energy side
of the phonon, depending on the relative energy of the discrete electronic
excitation and of the optical phonon. Shifts of the phonon energy
as large as ±60 cm<sup>â1</sup> are observed close to
the resonance. The intraband electronic excitation, the cyclotron
resonance, is shown to play a relevant role in the observed spectral
evolution of the phonon response
Controllable Phase Transition for Layered ÎČâFeSe Superconductor Synthesized by Solution Chemistry
Low-temperature synthesis of ÎČ-FeSe
superconductor from soluble
precursors is a great challenge in the chemical solution approaches.
Here, we develop a new and facile solution-based synthetic route to
first fabricate narrow-phased ÎČ-FeSe superconductor with soluble
iron and selenium sources as starting materials. The growth mechanism
of ÎČ-FeSe superconductors is discussed by kinetically controllable
syntheses in various reaction conditions. Chemically engineering the
stoichiometry of ÎČ-FeSe products by selenium-diffusion process
gives rise to a transition of antiferromagnetic-superconducting-antiferromagnetic
(AFM-SC-AFM) order. Once the AFM order is suppressed, SC ÎČ-FeSe
nanosheets show a tunable initial superconducting transition temperature
(<i>T</i><sub>C</sub>) from 3.2 to 10 K in the superconducting
regime. Electrical measurements on superconducting ÎČ-FeSe exhibit
an upper critical magnetic field higher than 14 T, showing potential
application of ÎČ-FeSe nanosheet for superconducting device.
This method provides guidance for future applications in such chemical
solutions for diffusion-controlled synthesis of narrow-phased functional
materials, which are enriched of abundant fundamental physics and
potentials for future applications
Strain Superlattices and Macroscale Suspension of Graphene Induced by Corrugated Substrates
We investigate the organized formation
of strain, ripples, and
suspended features in macroscopic graphene sheets transferred onto
corrugated substrates made of an ordered array of silica pillars with
variable geometries. Depending on the pitch and sharpness of the corrugated
array, graphene can conformally coat the surface, partially collapse,
or lie fully suspended between pillars in a fakir-like fashion over
tens of micrometers. With increasing pillar density, ripples in collapsed
films display a transition from random oriented pleats emerging from
pillars to organized domains of parallel ripples linking pillars,
eventually leading to suspended tent-like features. Spatially resolved
Raman spectroscopy, atomic force microscopy, and electronic microscopy
reveal uniaxial strain domains in the transferred graphene, which
are induced and controlled by the geometry. We propose a simple theoretical
model to explain the structural transition between fully suspended
and collapsed graphene. For the arrays of high density pillars, graphene
membranes stay suspended over macroscopic distances with minimal interaction
with the pillarsâ apexes. It offers a platform to tailor stress
in graphene layers and opens perspectives for electron transport and
nanomechanical applications