In this paper; the surface plasmon resonance (SPR) sensor with a porous silica film was studied. The effect of the thickness and porosity of the porous silica film on the performance of the sensor ...was analyzed. The results indicated that the figure of merit (FOM) of an SPR sensor can be enhanced by using a porous silica film with a low-refractive-index. Particularly; the FOM of an SPR sensor with 40 nm thick 90% porosity porous silica film; whose refractive index is 1.04 was improved by 311% when compared with that of a traditional SPR sensor. Furthermore; it was found that the decrease in the refractive index or the increase in the thickness of the low-refractive-index porous silica film can enlarge the FOM enhancement. It is believed that the proposed SPR sensor with a low-refractive-index porous silica film will be helpful for high-performance SPR sensors development.
Embelin exhibits the broad bioactivities such as antitumor, antifertility, antidiabetic, anti-inflammatory, antioxidant, anticonvulsant, anxiolytic, antimicrobial, and hepatoprotective activity. In ...order to further understand the pharmacokinetic characteristics and oral bioavailability of embelin in vivo, the concentration of embelin in rat plasma was determined by a sensitive high-performance liquid chromatography with diode array detector (HPLC-DAD). The preparation of samples was accomplished by a simple precipitating protein with methanol. Emodin was selected as the internal standard (IS). Embelin and IS were completely separated on an analytical column (Extend-C18, 4.6 × 250 mm, 5 μm) using 0.1% phosphoric acid in methanol and 0.1% phosphoric acid in aqueous solution (90:10, v/v) as the mobile phase. The lower limit of quantification was 0.15 μg/mL. Oral bioavailability of embelin was 30.2 ± 11.9%. This study could provide the information about pharmacokinetics and oral bioavailability of embelin, which was useful to assess the clinic efficacy and safety and promote further development of embelin.
Poly(amic acid)s (PAAs) alignment agents have been prepared from the alicyclic dianhydrides, including 1,2,3,4‐cyclobutanetetracarboxylic dianhydride (CBDA, I), ...1,3‐dimethyl‐1,2,3,4‐cyclobutanetetracarboxylic dianhydride (DMCBDA, II), and ester‐linked aromatic diamines, including 4‐aminophenyl‐4′‐aminobenzoate (APAB, a) and bis(4‐aminophenyl)terephthalate (BPTP, b), respectively. The derived PAAs, including PAA‐Ia (CBDA‐APAB), PAA‐Ib (CBDA‐BPTP), and PAA‐IIa (DMCBDA‐APAB) exhibited the preferable molecular weights, while the PAA‐IIb (DMCBDA‐BPTP) showed the low one due to the low polymerization reactivity both for the DMCBDA dianhydride and the BPTP diamine. All the PAA solutions except PAA‐IIb were adopted as the alignment components to fabricate liquid crystal (LC) minicells with a mode of in‐plane switching (IPS). The polyimides (PI) alignment layers derived from the thermal dehydration reaction of the PAA precursors at 230°C for 30 min showed good alignments effects to the LC molecules, which exhibited the pretilt angles (θp) from 0.09 to 0.15° after being exposed by the linear polarized ultraviolet light sources with the wavelength of 254 nm. In addition, the PI alignment layers afforded good optoelectronic features to the minicells, including the voltage holding ratio values over 97% at room temperature, and the residual direct circuit voltages lower than 1.0 V. The anchoring energy results indicated that the PI‐IIa (DMCBDA‐APAB) alignment layer showed the highest interaction with the LC molecules, and thus exhibited the highest threshold voltage (Vth) in the voltage‐transmittance (V‐T) measurements for the minicells.
Optically transparent polymer films with excellent thermal and ultraviolet (UV) resistance have been highly desired in advanced optoelectronic fields, such as flexible substrates for photovoltaic ...devices. Colorless and transparent polyimide (CPI) films simultaneously possess the good thermal stability and optical transparency. However, conventional CPI films usually suffered from the UV exposure and have to face the deterioration of optical properties during the long-term service in UV environments. In the current work, the commercially available hindered amine light stabilizers (HALS) were tried to be incorporated into the semi-alicyclic CPI matrix with the aim of enhancing the UV exposure stability. For this target, a CPI-0 film was first prepared from hydrogenated pyromellitic dianhydride (HPMDA) and 2,2'-dimethylbenzidine (DMBZ) via a one-step polycondensation procedure. Then, the commercially available HALS were incorporated into the CPI-0 (HPMDA-DMBZ) film matrix to afford four series of CPI/HALS composite films. Experimental results indicated that the Tinuvin
791 HALS showed the best miscibility with the CPI-0 film matrix and the derived CPI-D series of composite films exhibited the best optical transmittances. The CPI-D nanocomposite films showed apparently enhanced UV exposure stability via incorporation of the 791 additives. For the pristine CPI-0 film, after the UV exposure for 6 h, the optical properties, including the transmittance at the wavelength of 350 nm (
), lightness (
*), yellow indices (
*), and haze obviously deteriorated with the
values from 55.7% to 17.5%, the
* values from 95.12 to 91.38, the
* values from 3.38 to 21.95, and the haze values from 1.46% to 9.33%. However, for the CPI-D-10 film (791: CPI-0 = 1.0 wt%, weight percent), the optical parameters were highly maintained with the
values from 61.4% to 53.8%, the
* values from 95.46 to 95.36, the
* values from 1.84 to 1.51, and the haze values from 0.69% to 3.34% under the same UV aging conditions.
Large inactive component mass ratio and internal resistance are two critical challenges in further realizing high energy and power density lithium-ion batteries. Herein, lightweight copper coated ...polyimide (PI@Cu) current collectors with a high electrical conductivity (2.25 × 105 S cm−1) and low area density (1.99 mg cm−2) are fabricated via a facile electroless copper deposition method. Compared with the commercial Cu foil current collector, lithium titanate anodes equipped with PI@Cu current collectors decrease the inactive component mass ratio and improve the gravimetric capacity based on the whole mass of the electrode. Meanwhile, the rough surface morphology of deposited Cu layers reduces the electrode layer/current collector interfacial resistance, resulting in a lower internal resistance and better rate capability. PI@Cu composite films are promising alternatives to the traditional copper foil current collectors for high energy density and power density lithium-ion batteries.
•A polyimide/copper composite current collector is prepared by a facile method.•The current collector possesses a high electrical conductivity and low area density.•The rough surface morphology of Cu layers reduces the interfacial resistance.
•A vortex-forced matrix solid phase dispersion method was established and developed.•The chistosan solution was applied as elution reagent.•The Celite AZO was employed as dispersant.•Simultaneous ...determination of four compounds from Ligustri Lucidi Fructus.
A simple and efficient sample preparation method to extract four bioactive compounds (echinacoside, specnuezhenide, oleuropein and nuezhenoside G13) from Ligustri Lucidi Fructus was established by vortex-forced matrix solid phase dispersion (VFMSPD) method. Chitosan solution was applied as green eluent in this procedure and Celite AZO was employed as dispersant. High performance liquid chromatography (HPLC) equipped with ultraviolet (UV) detector was used to analyze the target analytes. The best result of the investigation was obtained with Celite AZO as dispersant, sample/ dispersant ratio as 1:1, grinding for 2 min, 1 mL high-viscosity chitosan solution (0.5 mg mL−1) used as the elution reagent and vortex mixing for 1.5 min. The method exhibit a good linearity for the analytes (r2 > 0.999). The absolute recoveries of the four target compounds in Ligustri Lucidi Fructus ranged from 90.7% to 98.8% and the relative recoveries of the target compounds ranged from 99.2% to 102% (RSD ≤ 3.4%), which were obtained by the final optimization method. Consequently, the newly developed chitosan solution-based vortex-forced matrix solid phase dispersion (MSPD) combined with HPLC could be efficiently applied to extract and analyze the target compounds in Ligustri Lucidi Fructus samples.
The extraordinary optical transmission (EOT) phenomenon is usually more outstanding in optical and near-infrared frequency band than that in mid-infrared and other lower frequency range. In order to ...expand the high-quality EOT to a lower frequency, this paper proposes an effective redshift method which can cause the resonant frequencies of the EOT redshift greatly. Using this method, an EOT in mid-infrared frequency is achieved and the transmission of which is compared with that achieved via a conventional method. It is found that the peak transmission of the red-shifted EOT is enhanced greatly and can be as high as 90%, at the same time the resonance quality is preserved very well. The reason of the enhanced transmission is analyzed using the effective medium theory.
Apple replant disease（ARD） causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was ...remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured： yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed： hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components,（E）-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits： hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components（hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate） and two characteristic aldehyde aroma components（（E）-2-hexenal and hexanal） in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.
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