Superb VOCs capture engineering carbon adsorbent derived from shaddock peel owning uncompromising thermal-stability and adsorption property

High applied thermal-stability and superior structural property for activated carbon adsorbent are extremely promising,which also is the determining short slab in volatile organic compounds(VOCs)adsorption applications.Herein,we develop the outstanding engineering carbon adsorbents from waste shaddock peel which affords greatly-enhanced thermal-stability and super structural property(S_(Lang)=4962.6 m2·g^(-1),Vmicro=1.67 cm^(3)·g^(-1)).Such character endows the obtained adsorbent with ultrahigh adsorption capture performance of VOCs specific to benzene(16.58 mmol·g^(-1))and toluene(15.50 mmol·g^(-1),far beyond traditional zeolite and activated carbon even MOFs materials.The structural expression characters were accurately correlated with excellent adsorption efficiency of VOCs by studying synthetic factor-controlling comparative samples.Ulteriorly,adsorption selectivity prediction at different relative humidity was demonstrated through DIH(difference of the isosteric heats),exceedingly highlighting great superiority(nearly sixfold)in selective adsorption of toluene compared to volatile benzene.Our findings provide the possibility for practical industrial application and fabrication of waste biomass-derived outstanding biochar adsorbent in the environmental treatment of threatening VOCs pollutants.

Distribution Characteristics of Soil Salinity in Absorbing Carbon Forest

[Objective] The paper was to analyze the soil salinity characteristics in Xinjiang region, and develop salinization characteristic research, so as to provide reference for salinization research in arid region. [Method] With different land types of soil vertical profiles in Karamay absorbing carbon forest as research object, soil salinity and water soluble ions were determined and analyzed using statistical characteristic value and trend surface, and the distribution characteristic of soil salinity in the region was explored.[Result] The salinity in survey area of absorbing carbon forest mainly were sulfate-chloride type and chloride type, of which cations were mainly Na＋, K＋ and Ca2＋, anions were CO32-, Cl- and SO42-, the variation coefficient of CO32 - was as high as 292.91, while the variation coefficient of Cl- was 265.56. The variation of soil total soluble salts in the soil layer of 0-100 cm was not significant, indicating that the content in each soil layer was relatively stable. [Conclusion] The study provided basis for speeding up dynamic monitoring for soil salinization and finding the effective control approach against salinization

Q-switched ytterbium doped fiber laser using multi-walled carbon nanotubes saturable absorber

A Q-switched ytterbium-doped fiber laser （YDFL） is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide （MWCNTs-PEO） film as a passive saturable absorber （SA）. The saturable absorber is prepared by mixing the MWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The laser generates a stable pulse operating at wavelength of 1060.2 nm with a threshold pump power of 53.43 mW. The YDFL generates a stable pulse train with repetition rates ranging from 7.92 to 24.27 kHz by varying 980-nm pump power from 53.42 to 65.72 mW. At 59.55-mW pump power, the lowest pulse width and the highest pulse energy are obtained at 12.18 μs and 143.5 n J, respectively.

Q-switched fiber laser using carbon platinum saturable absorber on side-polished fiber

A 1550 nm Q-switched fiber laser using a carbon platinum saturable absorber deposited on side-polished fiber（SPF） is proposed and demonstrated. The SPF is approximately 2 mm with a polarization-dependent loss（PDL）of 0.4 dB and an insertion loss of 2.5 dB. A stable Q-switched output spectrum is obtained at 1559.34 nm with a peak power of ~6 mW, a pulse width of 1.02 μs, pulse energy of 5.8 nJ, average output power of 0.76 mW, and a repetition rate of 131.6 kHz taken at a pump power of 230.0 mW. A signal-to-noise ratio of 49.62 d B indicates that the Q-switched pulse is highly stable.

Mode-locked 2 μm fiber laser with a multi-walled carbon nanotube as a saturable absorber

We propose and demonstrate a passively mode-locked fiber laser operating at 1951.8 nm using a commercial thulium-doped fiber （TDF） laser, a homemade double-clad thulium-ytterbium co-doped fiber （TYDF） as the gain media, and a multi-walled carbon nanotube （MWCNT） based saturable absorber （SA）. We prepare the MWCNT composite by mixing a homogeneous solution of MWCNTs with a diluted polyvinyl alcohol （PVA） polymer solution and then drying it at room temperature to form a film. The film is placed between two fiber connectors as a SA before it is integrated into a laser ring cavity. The cavity consists of a 2 m long TDF pumped by a 800 nm laser diode and a 15 m long homemade TYDF pumped by a 905 nm multimode laser diode. A stable mode-locking pulse with a repetition rate of 34.6 MHz and a pulse width of 10.79 ps is obtained when the 905 nm multimode pump power reaches 1.8-2.2 W, while the single-mode 800 nm pump power is fixed at 141.5 mW at all times. To the best of our knowledge, this is the first reported mode-locked fiber laser using a MWCNT-based SA.

Self-starting harmonic mode-locked Tm-Bi co-doped germanate f iber laser with carbon nanotube-based saturable absorber

We report a ring cavity passively harmonic mode-locked fiber laser using a newly developed thulium- bismuth co-doped fiber （TBF） as a gain medium in conjunction with a carbon nanotube （CNT）-based saturable absorber. The TBF laser generates a third harmonic mode-locked soliton pulse train with a high repetition rate of 50 MHz and a pulse duration of 1.86 ps. The laser operates at 1 901.6 nm with an average power of 6.6 mW, corresponding to a pulse energy of 0.132 nJ, at a 1 552 nm pump power of 723.3 roW.

Degradation products of different water content sevoflurane in carbon dioxide absorbents by gas chromatography-mass spectrometry analysis

Background Sevoflurane is currently used as a volatile inhalation anesthetic with many clinical advantages. A representative degradation product, compound A, was quantitatively measured to investigate whether there are different reactions between two kinds of water content sevoflurane formulations with different carbon dioxide （CO2） absorbents.