Search

This retrospective study aimed to evaluate the effect of intense pulsed light treatment (IPL) combined with meibomian gland expression (MGX) in treating meibomian gland dysfunction (MGD) related dry eye disease (DED) for the first time in Northeast China.Thirty-one MGD-related dry eye patients were managed by IPL-MGX from October to December 2019 in The First Hospital of Jilin University. Those patients had single IPL-MGX treatment with one follow-up visit, and no topical eye drops used were included in the study. General checkup and data collection helped in determining the age, sex, diagnosis, status of the MG, first noninvasive tear break-up time (1st NIBUT), average NIBUT, the height of tear film, and additional medical history.There was an improvement in the function of the meibomian gland (MG), with a significant decrease in the MG dropouts in the upper eyelid (Rt eye, p = 0.0047; Lt eye, p = 0.0158) and lower eyelid (Rt eye, p = 0.0017; Lt eye, p = 0.0027) plus the average NIBUT (Rt eye, p = 0.0264) also showed improvement after the IPL-MGX treatment. Though no significant difference was reached with the average NIBUT of the Lt eye (p = 0.5256) and the NIBUT grade (Rt eye, p = 0.0578; Lt eye, p = 0.0588), there was an increased duration of the average NIBUT and improved NIBUT grading. The negative results may be because of the maximum severity of DED and the limited treatment times.The result suggests that IPL-MGX was effective in treating MGD-related DED.Diese retrospektive Studie zielt darauf ab, die Wirkung einer Behandlung mit intensiv gepulstem Licht (IPL) in Kombination mit der Meibom-Drüsen-Expression (MGX) bei der Behandlung der Meibom-Drüsen-Dysfunktion (MGD) im Zusammenhang mit dem Trockenen Auge (DED) zum ersten Mal in Nordostchina zu bewerten.31 Patienten mit Trockenem Auge im Zusammenhang mit MGD wurden von Oktober bis Dezember 2019 im Ersten Krankenhaus der Jilin-Universität mit IPL-MGX behandelt. Diese Patienten erhielten eine einzige IPL-MGX-Behandlung mit einem Folgebesuch, und es wurden keine topischen Augentropfen in die Studie aufgenommen. Die allgemeine Untersuchung und Datenerfassung half bei der Bestimmung von Alter, Geschlecht, Diagnose, Status der MG, Zeit der ersten nicht invasiven Tränenfilmunterbrechung (1. NIBUT), durchschnittlicher NIBUT, Höhe des Tränenfilms und zusätzlicher Krankengeschichte.Es gab eine Verbesserung der Funktion der Meibom-Drüse (MG) mit einer signifikanten Abnahme der MG-Aussetzer im oberen Augenlid (rechtes Auge, p = 0,0047; linkes Auge, p = 0,0158) und im unteren Augenlid (rechtes Auge, p = 0,0017; linkes Auge, p = 0,0027) plus die durchschnittliche NIBUT (rechtes Auge, p = 0,0264) zeigte ebenfalls eine Verbesserung nach der IPL-MGX-Behandlung. Obwohl kein signifikanter Unterschied zwischen der durchschnittlichen NIBUT auf dem linken Auge (p = 0,5256) und dem NIBUT-Grad (rechtes Auge, p = 0,0578; linkes Auge, p = 0,0588) erreicht wurde, gibt es eine längere Dauer der durchschnittlichen NIBUT und eine verbesserte NIBUT-Einstufung. Die negativen Ergebnisse können auf den maximalen Schweregrad der KCS und die begrenzten Behandlungszeiten zurückzuführen sein.Das Ergebnis legt nahe, dass IPL-MGX bei der Behandlung von MGD-bedingter KCS wirksam war.

The integration of Li2 S6 within a poly(ethylene oxide) (PEO)-based polymer electrolyte is demonstrated to improve the polymer electrolyte's ionic conductivity because the strong interplay between O2- (PEO) and Li+ from Li2 S6 reduces the crystalline volume within the PEO. The Li/electrolyte interface is stabilized by the in situ formation of an ultra-thin Li2 S/Li2 S2 layer via the reaction between Li2 S6 and lithium metal, which increases the ionic transport at the interface and suppresses lithium dendrite growth. A symmetric Li/Li cell with the Li2 S6 -integrated composite electrolyte has excellent cyclability and a high critical current density of 0.9 mA cm-2 at 40 °C. Impressive electrochemical performance is demonstrated with all-solid-state Li/LiFePO4 and high-voltage Li/LiNi0.8 Mn0.1 Co0.1 O2 cells at 40 °C.

Development of low-cost, high-efficiency, and environmentally benign adsorbents for mercury removal is of significant importance for environmental remediation. Herein, we report a novel porous puff...

The purpose of this paper is to develop an emission inventory and source profile database for volatile organic compounds (VOCs) in Sichuan Province. Based on the test data of the research literatures, the source profiles of species containing no oxygenated volatile organic compounds (OVOCs) were revised and reconstructed to obtain the normalized VOCs source profile. In addition, the source profile-based 1 km × 1 km speciated VOCs emission inventory was established in accordance with the 2015 Air Pollution Source Emission Inventory in Sichuan Province with the ozone formation potential (OFP) estimated to assess the impact on ozone formation. There were 45 profiles and 519 species included in the established VOCs source profile database. Since the profiles were established mainly based on domestic test data, foreign research results were employed to supplement the profiles of some sources that had not been actually tested or had been researched less in China. In addition, the profiles of some sources such as biomass burning and transportation with emissions containing rich OVOCS have been revised and reconstructed, and the profiles including redundant data of many tested sources were simplified accordingly as well. Therefore, the established source profile database is well applicable to the establishment of the speciated VOCs emission inventory and the source apportionment. The VOCs emission inventory showed that the anthropogenic emissions of alkanes, alkenes, alkynes, aromatics, OVOCs, halohydrocarbons and other VOCs in Sichuan Province were 167.1 kt, 77.4 kt, 13.2 kt, 216.7 kt, 202.7 kt, 32.5 kt and 64.2 kt respectively; the total OFP in Sichuan was 2584.9 kt, and the above-mentioned VOCs contributed 6.9%, 26.1%, 0.5%, 42.3%, 23.2%, 0.4% and 0.5% to the total OFP, respectively. Therefore, alkenes, aromatics and OVOCs were the major species for ozone formation among the VOCs emitted in Sichuan Province, and controlling the emissions of such species plays a key role in reducing ozone formation. The major VOCs species emitted in various cities of Sichuan Province were aromatics, OVOCs and alkanes; however, different cities have their own remarkable characteristics. VOCs emissions and major OFP contributing species in Sichuan Province were mainly distributed in the Sichuan Basin as well as some areas in Liangshan and Panzhihua, where the population was relatively dense and the industry was relatively developed. The main source of m-Xylene and toluene was solvent use; therefore, m-Xylene and toluene were more intensively distributed in urban built-up areas. Furthermore, since biomass burning contributed a lot to ethene and formaldehyde emissions, ethene and formaldehyde were substantially distributed in cultivated areas in eastern Sichuan and southern Sichuan.

KDP crystals were grown using rapid techniques and conventional temperature cooling methods. The nonlinear absorption of various growth sections in the crystals was explored using the z-scan technique. It was shown that the nonlinear absorption coefficient of the KDP crystals, grown using rapid techniques, is greater than that of conventional crystals. The largest nonlinear absorption response was discovered at the interface between the pyramid and prism sections; however, the nonlinear absorption of the prismatic sector was smaller than that of the pyramidal sector of the crystal. The nonlinear absorption of the crystals decreased with increase in supersaturation. The value of nonlinear absorption became larger when the conventional specimen was closer to the regenerated cap.

Uncertainty assessments of hydrological prediction results can reflect additional hydrological information and reveal important hydrological characteristics of river basins, which is of great significance to disaster prevention and reduction. The hydrological uncertainty processor (HUP), which is a key part of the Bayesian forecasting system (BFS), has derived a variety of methods for hydrological uncertainty forecasting. The HUP allows for any form of marginal distributions of hydrological data and does not require a unified estimation structure for the marginal distribution function. The Gaussian mixture model (GMM) is a probability distribution estimation model that can approximate any probability distribution with arbitrary precision. In this paper, the GMM was used to estimate the marginal distribution of observed and modelled data, and this method is called HUP-GMM. The uncertainty of river discharge at the Yichang hydrological station on the main stem of the Yangtze River in China is predicted by the HUP-GMM. The Weibull and Gamma distributions, which are commonly used hydrological probability distributions, are compared to analyse the performance of the GMM. In June, when the measured flow h3 is 13,850 m3/s and the GMM, Gamma and Weibull distributions are used, the prior probabilities are 1.63E-04, 1.05E-04 and 9.50E-05 and the posterior probabilities are 2.57E-04, 1.61E-04 and 1.38E-04, respectively. In September, when the measured flow h3 is 35,400 m3/s and the GMM, Gamma and Weibull distributions are used, the prior probabilities are 5.98E-05, 2.21E-05 and 2.18E-05 and the posterior probabilities are 1.64E-04, 9.15E-05 and 8.43E-05, respectively. The results show that the performance of the uncertainty estimation of the prior and posterior probability distributions in the HUP-GMM has been improved.

The establishment of the air pollutant emission inventory of urban motor vehicles is the key to control motor vehicle pollution; therefore, the purpose of this paper is to develop an air pollutant emission inventory of urban motor vehicles in Chengdu. The IVE model localization including the actual measurement correction was completed, the motor vehicle emission factors on various types of roads in Chengdu's different development areas were calculated, and the 1 km × 1 km on-road mobile source emission inventory for the year of 2016 was established in the bottom-up method based on the collected data on road network, traffic flow, vehicle driving cycle, the vehicle population in Chengdu, etc. The inventory showed that the CO, VOCs, NOx, SO2, PM10 and NH3 emissions of Chengdu's on-road mobile sources had reached 432.2 kt, 44.8 kt, 72.4 kt, 0.4 kt, 11.3 kt and 6.2 kt respectively in 2016. Light-duty vehicle, medium-duty vehicle, and heavy-duty vehicle were the major contributors to CO emissions, and their CO emissions accounted for 44%, 14% and 11% of the total CO emission respectively; VOCs mainly came from light-duty vehicle, motorcycle, and heavy-duty truck, the VOCs emissions of which accounted for 49%, 19% and 10% of the total VOCs emission respectively; NOx and SO2 mainly came from light-duty vehicle and heavy-duty truck, the NOx emissions of which accounted for 25% and 48% of the total NOx emission, and the SO2 emissions of which accounted for 70% and 14% of the total SO2 emission respectively; in addition, the heavy-duty truck caused PM10 emission accounting for 78% of the total PM10 emission, while the light-duty vehicle caused NH3 emission accounting for 81% of the total NH3 emission. The spatial distribution of on-road mobile source pollutant emissions showed that emissions were concentrated in the downtown with a decreasing trend from the downtown to the suburbs and the outer suburbs. Based on the 95% confidence intervals, the uncertainties of CO, VOCs and NOx emission estimations were relatively low with relative errors ranging from - 68% to 87%, 58%–84% and 97%–75%. Considering the uncertainties of the traffic flows and emission factors, the on-road mobile source emission inventory shall be further improved to provide important scientific research supporting for the prevention and control of air pollution in Chengdu.

The integration of Li

Joint operation of reservoir group is an important method for flood mitigation. Most of the existing flood control operation methods only focus on a single reservoir and a single object, which cannot take into account the coordination and complementarity of different reservoirs, and it is difficult to comprehensively consider the safety of multiple flood control objectives in the upstream and downstream of the basin. In this context, this paper proposed a multi-objective modeling and optimization method for flood control operation of large-scale reservoir groups based on different pre-set frameworks. 12 large reservoirs in the Yangtze River Basin were selected as a case. The results show that the proposed method can reasonably and effectively deal with the complex optimization problem of large-scale reservoir group operation scheme, and can further improve the intelligent level of multi-reservoir joint flood control operation.

Volatile organic compounds (VOCs) from anthropogenic sources are deleterious to air quality, climate, human health and vegetation. However, research on VOCs source profiles of the non-solvent use in some industries and the emission characteristics of motor vehicles under actual road conditions is limited in China. In this research, VOCs source profiles of industries (wood-based panel manufacturing and pharmacy) based on all product processes were constructed, and those of light and medium duty vehicles exhaust based on actual road conditions at different speeds were acquired in Chengdu, a megacity in southwest China. The results show that VOCs groups of various sources were dominated by oxygenated VOCs (OVOCs), which accounted for 27–84% of the total VOCs emission. Due to the great contribution of OVOCs to industrial source reactivity (SR), attention should be paid to the control over the emissions of the species with high reactivity, such as aromatics and alkenes, but also to the production processes with relatively large proportions of OVOCs species emission. VOCs emissions from gasoline and diesel vehicles running at a speed ranging from 0 to 40 km/h have approximately the same ozone formation potential (OFP), while the contribution of VOCs emission from diesel vehicles to the formation of urban ozone pollution deserves further attention. It is found that VOCs emission characteristics of some industries in China have changed as the upgrading of production processes in automobile manufacturing and other industries, such as the extensive use of water-based coatings instead of outdated solvent-based coatings, which increased the uncertainty of judgment parameters (B/T ratio, etc.) in source apportionment research. The ranges of B/T ratio of industrial process sources, solvent use sources and motor vehicles are 0.00–0.23, 0.01–0.75 and 0.35–0.92, respectively. Therefore, updating existing source profiles and further understanding the emission constitutions of characteristic species in these source profiles (such as BTEX ratio) will be conducive to further research on emission inventory, source apportionment for O3 pollution control effectively.

Volatile organic compound (VOC) source profiles of Chengdu were established based on stack and fugitive emission source samples by field measurements. A total of 54 VOC samples collected fr...

The Yangtze River Economic Belt is one of the three national strategies of China, while flood risk is one of the most important concerns in the development of Yangtze River Economic Belt. In order to decrease the risks caused by floods, complete flood management system and adequate pre-arranged planning are desiderated to be researched in advance. This study considers two typical situations of flood risk, in which one is sluice-control situation in flood detention area and another is dike-break situation in flood-protected area, and proposes a framework for flood risk mapping. The results show that the losses caused by flood hazards are massive both in the two typical cases when extreme floods happen. The economic losses of different indicators are of great difference in flood detention area and flood-protected area, respectively. The framework effectively handles the complex boundaries in the Yangtze River Economic Belt and provides more accurate flood routing information. The evacuation plan module which has been incorporated in the framework also provides informative assistance for emergent action of evacuation under urgent condition.

This theoretical study conducted an X-ray fluorescence (XRF) analysis on specimen variation, with emphasis on variations on the thicknesses, density and particle sizes of specimens. The theoretical formula for X-ray fluorescence intensity was derived. These specimen variations were simulated using Monte Carlo Neutron-Particle Transport Code MCNP5. The Cu element X-ray characteristic peak counts were calculated. These variations made a conspicuous impact on the fluorescence intensity X-ray characteristic, in terms of theoretical formulas and calculations. There was a nonlinear relationship between thicknesses and count, except for thin specimens. As the density increased, the count increased in an exponential form for the saturated thick specimens. When the density reached 1 g.cm-3 , the count remained constant. The matrix materials (moisture) could increase the matrix effects. The higher the moisture was, the greater the matrix effect was. Specimen particle size also affects these measurement results. Hence, these specimens must be prepared before measurement. The calculations were consistent with the theoretical formulas.

A novel synthetic strategy has been successfully developed, which utilizes supercritical CO2 (SC-CO2) to fabricate sulfur-modified zeolites (zeolites@S) for Hg2+ removal from water. Owing to the low viscosity, high diffusivity and excellent dissolving capacity of SC-CO2 as well as the nontoxicity, noninflammability and being a low-cost solvent it exhibits the strong ability to expand the crystal structure of zeolite and the high-efficiency transfer of sulfur in zeolite matrices. Benefiting from this unique microstructure, zeolites@S adsorbents provide abundant pores and voids for absorbing Hg2+, and synchronously offer extra active sites for chemically trapping Hg2+ with sulfur. The pseudo-first-order kinetic/pseudo-second-order kinetic models and Langmuir/Freundlich isotherm models have been employed to study the adsorption behaviors and adsorption kinetic parameters. The results demonstrated that zeolites@S-15 (sulfur content = 15 wt%) exhibited the highest adsorption capacity and the best kinetic parameters for Hg2+ relative to other samples. This work will not only provide important reference for the rational design of zeolite based adsorbents for Hg2+ removal from aqueous solution, but also pave a new way to boost the commercialization of low-cost and high-efficiency functionalized adsorbents for purifying wastewater.

Lithium‑selenium (Li–Se) batteries are considered as promising candidates for the next generation battery technology due to their high volumetric energy density and low cost. Compared with Se cathode in Li–Se batteries, Li2Se cathode can not only alleviate the negative effect of volume expansion in the cycle process, but also avoid utilizing lithium foil as the anode. However, Li2Se has received little coverage due to its high cost and difficulty in production. Herein, two facile synthesis routes, including ball milling and direct heating, are successfully developed to produce pure Li2Se particles by reacting LiH powers with Se powers (2LiH + Se = Li2Se + H2↑). The microstructure of Li2Se particles is investigated by cryogenic transmission electron microscopy (cryo-TEM) technology for the first time. The Li2Se cathode with layer-by-layer structure exhibits superior electrochemical performance at high loading (698 mA h g−1@50 mA g−1@10.6 mg cm−2; 333 mA h g−1@1000 mA g−1@7.1 mg cm−2), attributed to the high polyselenides-trapping and reutilization capability of active layer as well as the excellent polyselenides-interception and high conductivity of barrier layers. This innovative synthesis strategy of Li2Se and the intriguing design of cathodic structure are highly expected to promote the practical implementation of the safer high energy-density Li–Se batteries.

A prediction&ndash, correction solver is presented here for rapid simulation of free-surface flows in dendritic and looped river networks. Rather than solving a large global algebraic system over the entire domain of river networks, the model solves subsystems for subdomains of branches in two steps: prediction and correction. With the help of the prediction&ndash, correction method (PCM), the partial linearization technique, the semi-implicit method, and the Eulerian&ndash, Lagrangian method (ELM), the model only needs to solve tridiagonal linear systems for branches and is free of any iteration. The new model was tested using a hypothetical looped river network with regular cross sections, the Three Gorges Reservoir (TGR) dendritic river network, and the Jing-south looped river system (with seasonally flooding branches). In the first test, a time-step sensitivity study was conducted and the model was revealed to produce accurate simulations at large time steps when the condition for application of the PCM to river networks was satisfied. In the TGR test, the PCM model provided almost the same histories of water levels and discharges as those simulated by the HEC-RAS model. In the Jing-south test, the mean absolute error in simulated water levels was 0.07&ndash, 0.24 m, and the relative error in simulated cross-section water flux was 0.5&ndash, 4.9% compared with field data, the conservation error was generally 2 &times, 10&minus, 4 to 3 &times, 4. The PCM model was revealed to be 2&ndash, 4 times as fast as a reported model, which solves local nonlinear subsystems using two-layer iterations, and 1.2&ndash, 1.4 times as fast as the HEC-RAS. Using a time step of 1200 s, it took the sequential code 26.8 and 23.1 s to complete a simulation of a one-year unsteady flow process, respectively, in the TGR river networks (with 588 cells) and the Jing-south river system (with 662 cells).

Monoclinic Li3V2(PO4)3 (LVP) fulfills safety requirements including superior chemical and thermal stabilities since the oxygen atoms are firmly anchored in PO43− units, however the low intrinsic electronic conductivity strictly limits its electrochemical performance. Herein, to overcome this problem, a rationally designed passion fruit-like LVP@C/CNT composite constructed with LVP grains as seeds, carbon matrix as pulp, and carbon nanotubes (CNTs) as filaments, has been prepared via a facile spray pyrolysis method. In such unique biomimetic structure, carbon matrix encases LVP to reduce its particle size, which is beneficial to shorten ion pathways; Porous structure scattered around carbon matrix facilitates the rapid penetration of electrolyte; 3D CNT networks afford high-speed electron conduction and remarkable structural stability by forming the bridges between LVP grains. Owing to the multiple merits of this biomimetic structure, the rationally designed LVP@C/CNT composite with 3 wt% CNT exhibits high reversible capacity, superior cyclic stability and remarkable rate capability.

Uveal melanoma is the most common intraocular malignant tumor in adults. Chrysin is a flavonoid present in honey, propolis, various plants and herbs. In the present study, the cytotoxic effects of chrysin were investigated on human uveal melanoma cell lines (M17 and SP6.5) and associated signaling pathways, and a comparison to the effects on normal ocular cells [scleral fibroblasts and retinal pigment epithelial (RPE) cells] was performed. The effects of chrysin on cell viability were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was determined by using terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling assay. Mitochondrial permeability was determined by JC-1 fluorescein analysis. Cytosol cytochrome c levels, and the activities of caspase-3, −8 and −9 were measured by enzyme-linked immunosorbent assay or colorimetric assay. Chrysin reduced the viability of cultured human melanoma cells in a dose-dependent manner (0, 10, 30 and 100 µM) with IC50 at 28.3 and 35.8 µM in SP6.5 and M17 cell lines, respectively. Chrysin at 30–100 µM levels selectively reduced the viability of melanoma cells without affecting the viability of scleral fibroblasts and RPE cells. Chrysin increased mitochondrial permeability, the levels of cytosol cytochrome c, and caspase-9 and −3 activities, but not capase-8 activity in uveal melanoma cells. The results of the present study indicate that chrysin induces apoptosis of human uveal melanoma cells via the mitochondrial signaling pathway and suggest that chrysin may be a promising agent in the treatment of uveal melanoma.

Simulations of solar radiation have become increasingly common in recent years because of the rapid global development and deployment of solar energy technologies. The effect of air pollution on solar radiation is well known. However, few studies have attempting to evaluate the potential of the air pollution index in estimating solar radiation. In this study, meteorological data, solar radiation, and air pollution index data from three sites having different air pollution index conditions are used to develop random forest models. We propose different random forest models with and without considering air pollution index data, and then compare their respective performance with that of empirical methodologies. In addition, a variable importance approach based on random forest is applied in order to assess input variables. The results show that the performance of random forest models with air pollution index data is better than that of the empirical methodologies, generating 9.1–17.0% lower values of root-mean-square error in a fitted period and 2.0–17.4% lower values of root-mean-square error in a predicted period. Both the comparative results of different random forest models and variance importance indicate that applying air pollution index data is improves estimation of solar radiation. Also, although the air pollution index values varied largely from season to season, the random forest models appear more robust performances in different seasons than different models. The findings can act as a guide in selecting used variables to estimate daily solar radiation and improve the accuracy of solar radiation estimation.

One-dimensional hydrodynamic modeling approaches are useful for flood simulations, however, most studies often neglect intermediate discharges due to difficulties in obtaining the associated data. Herein, we produced the XAJ-H1DM model by coupling the Xinanjiang (XAJ) model, without the Muskingum module, with a one-dimensional hydrodynamic (H1DM) model, using regionalization approaches to test their practicality. Another model, named H1DM-XAJ, was also produced by orderly calibrating the H1DM and XAJ models to achieve improved flood simulations in poorly gauged catchments. The flood simulation capabilities of the four models (including the single XAJ and H1DM models) were investigated and compared at a daily time scale in the Three Gorges Reservoir Region, China. The results show that the regionalization approaches can be successfully used in the application of the integrated hydrologic and hydrodynamic model in ungauged intermediate catchments. Further, the coupled models produced markedly improved estimates of peak discharge and runoff volume compared to the single models. Moreover, the ability of the coupled models to simulate the peak water level and hydrograph, which hydrological models lack, is significantly better than that of the single H1DM model. The framework presented can be applied in other data-scarce catchments worldwide for better understanding of the hydrodynamic processes.

Exploring of high specific capacity, long cycling stability and high rate capability anode materials with low cost and environmentally benign is closely bound up with the breakthrough of high energy density lithium ion batteries. Inspired by uniform geometries and elaborate morphologies of natural rose pollens, a series of porous SiOC microellipsoids are fabricated by a novel supercritical CO2 fluid assisted carbonization method using rose pollen as biotemplate and carbon source. The high permeability, superior diffusivity and excellent dissolving capability of supercritical CO2 fluid guarantees the efficient mass transfer, leading to the homogeneous elemental distributions in precursor and final product of SiOC. Interestingly, the content of free carbon phase, SiO2C2, SiO3C and SiO4 units in SiOC can be adjusted by varying the calcination temperature. The relationship between mixed SiCxO4-x units and electrochemical performance is systematically investigated. The results demonstrate that SiOC-600 with high content of SiO2C2 and SiO3C units delivers a satisfactory reversible capacity (415.1 mA h g−1 at 0.1 A g−1), a prolonged cycling life (351.3 mA h g−1 after 200 cycles) and enhanced rate capability (175.2 mA h g−1 at 2 A g−1).

In this work, a C18 composite solid-phase microextraction (SPME) fiber was prepared with a new method and applied to the analysis of organochlorine pesticides (OCPs) in water sample. A stainless steel wire (o.d. 127 μm) was used as the substrate, and a mixture of the C18 particle (3.5 μm) and the 184 silicone was used as the coating material. During the process of fiber preparation, a section of capillary column was used to fix the mixture onto the stainless steel wire and to ensure the constant of coating thickness. The prepared fiber showed excellent thermal stability and solvent resistance. By coupling with gas chromatography–mass spectrometry (GC–MS), the fiber exhibited wide linearity (2–500 ng L −1 ) and good sensitivity for the determination of six OCPs in water samples, the OCPs tested included hexachlorobezene, trans -chlordane, cis -chlordane, o , p -DDT, p , p -DDT and mirex. Not only the extraction performance of the newly prepared fiber was more than seven times higher than those of commercial fibers, the limits of detections (LODs) (0.059–0.151 ng L −1 ) for OCPs achieved under optimized conditions were also lower than those of reported SPME methods. The fiber was successfully applied to the determination of OCPs in real water samples by using developed SPME–GC–MS method.