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Chip-based ion chromatography (chip-IC) with a sensitive five-electrode conductivity detector for the simultaneous detection of multiple ions in drinking water

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Microsystems & Nanoengineering 2020年第1期6卷 530-537页

作者： xiaoping li Honglong Chang Ministry of Education Key Laboratory of Micro/Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University710072 Xi’anP.R.China

The emerging need for accurate,efficient,inexpensive,and multiparameter monitoring of water quality has led to interest in the miniaturization of benchtop chromatography *** paper reports a chip-based ion chromatography(chip-IC)system in which the microvalves,sample channel,packed column,and conductivity detector are all integrated on a polymethylmethacrylate(PMMA)chip.A laser-based bonding technique was developed to guarantee simultaneous robust sealing between the homogeneous and heterogeneous interfaces.A five-electrode-based conductivity detector was presented to improve the sensitivity for nonsuppressed anion *** anions(F^(−),Cl^(−),NO_(3)^(−),and SO _(4)^(2−))were separated in less than 8 min,and a detection limit(LOD)of 0.6 mg L^(−1) was achieved for SO_(4)^(2−).Tap water was also analyzed using the proposed chip-IC system,and the relative deviations of the quantified concentration were less than 10%when compared with that a commercial IC system.

关键词： conductivity electrode chromatography

Superhydrophilic–superhydrophobic patterned surfaces:From simplified fabrication to emerging applications

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Nanotechnology and Precision Engineering 2022年第3期5卷 55-79页

作者： Hao Chen xiaoping li Dachao li State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise *** surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental *** review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned ***,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are ***,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are ***,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.

关键词： Superhydrophobicity Superhydrophilicity Wettability patterns Droplet array Biosensor

Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 712-724页

作者： Dajun Zhai xiaoping li Jun Shen College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)

Product oriented oxidative bromination of methane over Rh/SiO_2 catalysts

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Journal of Natural Gas Chemistry 2010年第5期19卷 522-529页

作者： Zhen liu Wensheng li xiaoping Zhou Department of Chemical Engineering Hunan University Changsha 410082 Hunan China

Rh/SiO2 was prepared for the oxidative bromination of methane. The catalyst was prepared by calcination at different temperatures and for different times to obtain catalysts with different specific surface areas for the purposes of producing either CH3Br or CH3Br and CO. It was found that the catalyst having a low specific surface area （calcined at relatively high temperature） favors the selective oxidation of methane to prepare CH3Br, while the catalyst having a high specific surface area favors the deeper partial oxidation of methane, which is good for CH3Br and CO preparation, The 650 h on stream life-time test revealed that the catalytic performance of the 0.4Rh/SiO2-900-10 catalyst was excellent. Both methane conversion and CH3Br selectivity kept increasing trends during the life-time test. No matter how serious was the Rh leaching during the reaction, the 0.4Rh/SiO2-900-10 catalyst did not deactivate at all.

关键词： oxidative bromination of methane methyl bromide Rh/SiO2

Temperature Control System with Multi-closed Loops for lithography Projection Lens

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 207-213页

作者： NIE Hongfei li xiaoping HE Yan State Key Laboratory of Digital Manufacturing Equipment ＆ Technology Huazhong University of Science and Technology Wuhan 430074 China Tianhua College Shanghai Normal University Shanghai 201815 China

Image quality is one of the most important specifications of optical lithography tool and is affected notably by temperature, vibration, and contamination of projection lens（PL）. Traditional method of local temperature control is easier to introduce vibration and contamination, so temperature control system with multi-closed loops is developed to control the temperature inside the PL, and to isolate the influence of vibration and contamination. A new remote indirect-temperature-control（RITC） method is proposed in which cooling water is circulated to perform indirect-temperature-control of the PL. Heater and cooler embedded temperature control unit（TCU） is used to condition the temperature of the cooling water, and the TCU must be kept away from the PL so that the influence of vibration and contamination can be avoided. A new multi-closed loops control structure incorporating an internal cascade control structure（CCS） and an external parallel cascade control structure（PCCS） is designed to prevent large inertia, multi-delay, and multi-disturbance of the RITC system. A nonlinear proportional-integral（PI） algorithm is applied to further enhance the convergence rate and precision of the control process. Contrast experiments of different control loops and algorithms were implemented to verify the impact on the control performance. It is shown that the temperature control system with multi-closed loops reaches a precision specification at ±0.006 ℃ with fast convergence rate, strong robustness, and self-adaptability. This method has been successfully used in an optical lithography tool which produces a pattern of 100 nm critical dimension（CD）, and its performances are satisfactory.

关键词： projection lens remote indirect-temperature-control cascade control structure parallel cascade control structure nonlinear proportional-integral(PI) algorithm

Using quantile regression to analyze the stressor–response relationships between nutrient levels and algal biomass in three shallow lakes of the Lake Taihu Basin, China

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Chinese Science Bulletin 2014年第28期59卷 3621-3629页

作者： Xiaohua Chen xiaoping li State Key Laboratory of Estuarine and Coastal Research East China Normal University Water Environmental Research Institute Shanghai Academy of Environmental Sciences

Understanding the stressor–response relationship between nutrient levels and algal biomass is a prerequisite for the management of eutrophication in lakes. In this study, a quantile regression(QR) approach was used to interpret the stressor–response relationships between nutrient(e.g., phosphorus, nitrogen) concentrations and algal biomass as measured by chlorophyll-a(Chl-a) levels. QR results indicated that Lake Dianshan and Lake Changdang,which are both heavily eutrophicated, were P-limited *** contrast, Lake Kuilei, which has significantly lower nutrient levels and algal biomass than the other two lakes,was P- and N-limited. Moreover, in Lake Kuilei, N and P levels had significant interaction effects on the algal biomass at the upper quantiles(s [ 0.68). The degree to which the lakes were P-limited increased with rises in the mean total P concentration in the lakes. QR has many advantages over ordinary least squares regression for discriminating limiting factors and, in particular, allows us to estimate changes near the upper extremes of distributions associated with limiting factors. QR is adapted to more specialized risk management problems, such as early warnings of the risk of algal *** probable value-at-risk of harmful algal blooms for Lake Kuilei, Lake Dianshan and Lake Changdang is s = 0.76(Chl-a = 9 mg/m3), s = 0.87(Chl-a = 24 mg/m3) and s = 0.72(Chl-a = 35 mg/m3), respectively. Given the results of the stressor–response relationship analysis, we conclude that reductions in P input represent the most feasible and least costly approach for managing eutrophication in the shallow lakes of the Lake Taihu Basin. To control the magnitude and duration of algal blooms in shallow lakes,reductions in P and N inputs are required. The 95 % CI bounds of slopes indicated that the interactions of nonnutrient factors with nutrients had strong impacts on the algal biomass in lightly eutrophicated Lake Kuilei. It is suggested that, in addition to reductions in n

关键词：富营养化湖泊藻类生物量分位数回归营养水平应激反应太湖流域回归分析中国

Volatile metabolites of willows determining host discrimination by adult Plagiodera versicolora

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Journal of Forestry Research 2022年第2期33卷 679-687页

作者： Jiahao ling xiaoping li Guo Yang Tongming Yin The Key Laboratory for Tree Genetics and Biotechnology of Jiangsu Province and Educational Department of China College of ForestryNanjing Forestry UniversityNanjing 200137People’s Republic of China

Plagiodera versicolora Laicharting is a highly damaging leaf beetle foraging on willow *** willow germplasm collections,observation has shown that Salix suchowensis Cheng was severely foraged by this leaf beetle while Salix triandra *** damage free or only slightly *** of olfactometer bioassays show that the headspace volatiles from leaves of *** significantly repelled adult beetles,suggesting that this species produces volatile repellents against *** had no effect on the *** chromatography-mass spec-trometry was carried out to profile the headspace volatile organic compounds and 23 compounds from leaves of the alternate species in significantly different concentrations were *** effects of 20 chemical analogs on host discrimination were *** response to these chemicals showed that o-cymene,a *** specific constituent,significantly attracted adult *** contrast,cis-3-hexenyl acetate,a constituent concentrated more in *** than in ***,significantly repelled *** o-cymene and cis-3-hexenyl acetate in comparable concentrations as in the volatiles of *** demonstrated that the latter could mask the attracting effect of the former,causing a neutral response by adult beetles to leaves of *** against clean *** addition,chemical analogs have the same effect as plants when resembling volatile organic compounds in real *** volatile metabolites were detected triggering host discrimination by one of the most damaging insect pests to host and non-host *** two metabolites are of considerable potential for use as olfactory signs in manag-ing the beetles.

关键词： Herbivore insect Olfactory response Volatile organic compounds Cis-3-hexenyl acetate O-cymene

Thermal evolution characteristics of Triassic coal in Chuxiong Basin and its geological significance

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International Journal of Mining Science and Technology 2016年第5期26卷 937-945页

作者： Wang Meng li xiaoping Dai Xuguang School of Resources and Earth Science China University of Mining & Technology Key Laboratory of Coalbed Methane Resource & Reservoir Formation Process China University of Mining & Technology

Chuxiong Basin in Yunnan is a typical Mesozoic foreland basin which is enriched in widely distributed Triassic coal resources with thick deposits and of important strategic significance. By applying vitrinite reflectance measurement, inclusion thermometry, fission track dating and EASY% Ro numerical simulation, the Triassic coal thermal evolution history of the Chuxiong Basin was analyzed, and the results were concluded. The vitrinite reflectance of Chuxiong Basin is higher in the west and south in ***, in the east, west, and north of the basin, the vitrinite reflectance increases with increasing depth, and in the northern part, exceptionally high values occur, and there is no significant regularity in the east. The formation of inclusions inside quartz veins in Chuxiong Basin Triassic coal are unrelated with magmatic hydrothermal fluid, and there are multi-phase inclusions formed in three or four sections of tectonic movements. The main heating period(apparent age) of the Triassic coal is concentrated in the late Cenozoic, during which the coal was subjected to repeated thermal disturbance, resulting in a multimodal distribution of the fission track data, which reveals mild burial features of the early stages of the Late Cenozoic. The Triassic coal of Chuxiong Basin has experienced two major temperature increasing processes, which occurred in the early-mid Yanshan and the early Himalayan, respectively. The first hydrocarbon generation period of coal organic matter occurred in the formation stage of the foreland basin, during which the south and west of the basin generated large amounts of hydrocarbon, but little was preserved. The second generation stage in the Early Himalayan had conditions suitable for high gas accumulation, especially in the western and southern regions. The upper Triassic coal is of moderate burial depth and is less affected by the strike-slip effect. There are key areas of Chuxiong Basin oil and gas exploration, such as the Yanf

关键词： Chuxiong Basin Thermal evolution Triassic Coal

A fast pulse phase estimation method for X-ray pulsar signals based on epoch folding

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Chinese Journal of Aeronautics 2016年第3期29卷 746-753页

作者： Xue Mengfan li xiaoping Sun Haifeng Fang Haiyan School of Aerospace Science and Technology Xidian University

X-ray pulsar-based navigation （XPNAV） is an attractive method for autonomous deep- space navigation in the future. The pulse phase estimation is a key task in XPNAV and its accuracy directly determines the navigation accuracy. State-of-the-art pulse phase estimation techniques either suffer from poor estimation accuracy, or involve tile maximization of generally non- convex object function, thus resulting in a large computational cost. In this paper, a fasl pulse phase estimation method based on epoch folding is presented. The statistical properties of the observed profle obtained through epoch folding are developed. Based on this, we recognize the joint prob- ability distribution of the observed profile as the likelihood function and utilize a fast Fourier transform-based procedure to estimate the pulse phase. Computational complexity of the proposed estimator is analyzed as well. Experimental results show that the proposed estimator significantly outperforms the currently used cross-correlation （CC） and nonlinear least squares （NLS） estima- tors, while significantly reduces the computational complexity compared with NLS and maxinmm likelihood （ML） estimators.

关键词： Epoch folding Maximum likelihoodPhase estimation X-ray pulsar X-ray pulsar-basednavigation (XPNAV)