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A comparison between high temperature catalytic and persulfate oxidation for the determination of total dissolved nitrogen in natural waters

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Acta Oceanologica Sinica 2023年第4期42卷 41-49页

作者： Tiantian ge xue Yang Shan Jiang Liju Tan College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of ChinaQingdao 266100China

Total dissolved nitrogen(TDN) is an important parameter for assessing the nutrient cycling and status of natural *** accurate determination of TDN in natural waters is essential for assessing its contents and distinguishing different forms of nitrogen in the *** TDN in various systems has been largely documented,and the concentrations of TDN are usually obtained using high-temperature catalytic(HTC) or persulfate oxidation(PO).However,the accuracy of these methods and their suitability for all types of natural waters are still *** explore both methods in-depth,assorted samples were tested,including eight solutions composed of nitrogen-containing compounds(3 dissolved inorganic nitrogen fractions:NO_(3)^(-),NO_(2)^(-)and NH_(4)^(+);5 organic compounds:EDTA-2Na,vitamin B1,vitamin B12,amino acids,and urea) and 105 natural waters which were collected from an open ocean(Northwest Pacific Ocean,28),a marginal sea(Yellow Sea,34),an estuary(Huanghe River mouth,31),rivers(Huanghe River,4;Licun River,4),and precipitations(4 samples).The results showed that heterocycles and molecular dimensions had certain effects on the oxidation efficiency of the PO method but had little effect on *** was no significant difference between the two methods for natural waters,but HTC was more suitable for deep-sea samples with low TDN concentrations(less than 10 μmol/L) and low organic ***,HTC has a relatively simple measurement process,a high degree of automation,and low ***,HTC can be recommended to determine the TDN of samples in freshwater and seawater.

关键词： total dissolved nitrogen high-temperature catalytic persulfate oxidation natural waters

Glaucoma drainage device implantation and cyclophotocoagulation in the management of refractory glaucoma after Descemet-stripping automated endothelial keratoplasty

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International Journal of Ophthalmology(English edition) 2024年第2期17卷 257-264页

作者： Min-Shu Wang xue-Chuan Dong Mi-Yun Zheng Xiang Fan ge-ge Xiao Jing Hong Ling-Ling wu Department of Ophthalmology Peking University Third HospitalBeijing 100191China Key Laboratory of Restoration of Damaged Ocular Nerve Beijing 100191China NIMO Ophthalmology Research Institute Beijing 100176China Department of Ophthalmology the First Hospital of PutianTeaching HospitalFujian Medical UniversityPutian 351100Fujian ProvinceChina

AIM:To compare the surgical outcomes of glaucoma drainage device implantation(GDI)and trans-scleral neodymium:YAG cyclophotocoagulation(CPC)in the management of refractory glaucoma after Descemetstripping automated endothelial keratoplasty(DSAEK).METHODS:This retrospective study on observational case series enrolled 29 patients who underwent DSAEK and posterior anti-glaucoma surgery(15 with GDI and 14 with CPC).The main outcome measures were intraocular pressure(IOP),glaucoma surgery success rate(defined as IOP of 6–21 mm Hg without additional anti-glaucoma operation),number of glaucoma medications,endothelial graft status,and best-corrected visual acuity(BCVA).RESULTS:The mean follow-up time was 34.1 and 21.0mo for DSAEK or glaucoma surgeries,both for the GDI and CPC *** groups showed significant IOP reduction after glaucoma *** GDI group presented a significantly higher success rate in IOP control than the CPC group(60%vs 21.4%,P=0.03).Both procedures significantly decreased the number of glaucoma medications(P=0.03).Forty percent and 57%of cases in the GDI and the CPC group,respectively,experienced endothelial graft failure during follow-up(P=0.36).Significantly worse BCVA after surgery was observed in the CPC group but not in the GDI ***:Both GDI and CPC significantly decrease IOP in eyes with glaucoma after *** is preferable to CPC in refractory glaucoma cases after DSAEK,as it manifests a significantly higher success rate for IOP control,similar endothelial graft failure rate,and relatively preserves BCVA than CPC.

关键词： glaucoma drainage device implantation cyclophotocoagulation refractory glaucoma Descemetstripping automated endothelial keratoplasty

Review of Service Restoration for Distribution Networks

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Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 1-14页

作者： Feifan Shen Qiuwei wu Yusheng xue Center for Electric Power and Energy Department of Electrical EngineeringTechnical University of DenmarkLyngbyDenmark State Grid Electric Power Research Institute NanjingChina

With the rapid deployment of the advanced metering infrastructure(AMI)and distribution automation(DA),selfhealing has become a key factor to enhance the resilience of distribution *** a permanent fault occurrence,the distribution network operator(DNO)implements the selfhealing scheme to locate and isolate the fault and to restore power supply to out-of-service *** an essential component of self-healing,service restoration has attracted considerable *** paper mainly reviews the service restoration approaches of distribution networks,which requires communication *** service restoration approaches can be classified as centralized,distributed,and hierarchical approaches according to the communication *** these approaches,different techniques are used to obtain service restoration solutions,including heuristic rules,expert systems,metaheuristic algorithms,graph theory,mathematical programming,and multi-agent ***,future research areas of service restoration for distribution networks are discussed.

关键词： Distribution networks fault detection fault isolation service restoration self-healing scheme

Study on the flow field uniformity of hydro-floating ship lift combined type hydraulic-driven system based on the residual energy theory

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Journal of Hydrodynamics 2022年第6期34卷 1156-1161页

作者： Bo wu Ya-an Hu Shu xue State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing210029China Key Laboratory of Transport Technology in Navigation Building Construction Nanjing Hydraulic Research InstituteNanjing210029China

The hydro-floating ship lift originally invented in China is a major innovation in the field of navigation *** shaft water levels synchronization of its unique hydraulic-driven system plays a crucial role in reducing the torque of the synchronous shafts and ensuring the safety and stability operation of the ship *** study aims to investigate the muti-shaft water level synchronization and the flow velocity uniformity of the combined type hydraulic-driven *** on the theory of residual energy,a new index m2 proposed in this study is more suitable for evaluating the flow velocity uniformity of the combined hydraulic-driven ***,the critical value of m2=75 is calculated via the results of the scaled physical mode test as the threshold of water flow uniformity,and it provides a basis for determining the reasonable height of the pressure stabilizing chamber.

关键词： Hydro-floating ship lift water levels synchronism residual energy velocity distribution uniformity coefficient

Isoconversional kinetic analysis of decomposition of bastnaesite concentrates with calcium hydroxide

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Journal of Rare Earths 2020年第12期38卷 1361-1371页

作者： Peng Cen xue Bian Wenyuan wu School of Metallurgy Northeastern UniversityShenyang 110819China

Isoconversional methods combined with thermogravimetry were applied to investigate the decomposition kinetics of bastnaesite concentrates with different amounts of calcium hydroxide *** apparent activation energy was calculated,and the results indicate that the overall reaction involves more than one single *** reaction with a lower content(15 wt%)involves another step which denotes the decomposition of newly formed calcium carbonate during *** activation energy increases with increasing amount of calcium hydroxide in the lower range(0-15 wt%).This is due to the resistance of calcium hydroxide to heat and mass transport,However,more calcium can promote the decomposition reaction more effectively and thus reduce the activation *** fitting was performed by fitting the experimental data to Avrami-Erofeev model to determine the reaction model and pre-exponential *** theoretical models were proven to be reliable for kinetic prediction.

关键词： Bastnaesite Thermal analysis kinetics Isoconversional method Calcium hydroxide Rare earths

Order Timing for Manufacturers with Spot Purchasing Price Uncertainty and Demand Information Updating

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Journal of Systems Science and Systems Engineering 2020年第6期29卷 631-654页

作者： Mengchu wu Lijun Ma Weili xue School of Economics and Management Southeast UniversityNanjing 211189China College of Management and Institute of Big Data Intelligent Management and DecisionShenzhen UniversityShenzhen 518060China

In this paper we study the competitive order timing decisions of two manufacturers with demand forecasting updating and uncertain raw material *** can order the raw materials early when the market is highly uncertain with a fixed wholesale price(Contract procurement)or late when the market is less uncertain with an uncertain raw material price(Spot trading).Different from most existing literature,we assume the spot price and the market demand is *** find that in the monopoly setting the manufacturer prefers the contract procurement to the spot trading when the unit wholesale price for the contract procurement is not greater than the expected unit spot price of the raw *** the duopoly setting,we characterize the equilibria of a strategic order timing game in which manufacturers choose when to buy the raw *** find that when the demand during the contract procurement stage and the spot price uncertainty is small both manufacturers prefer the contract procurement strategy and when the demand during the contract procurement stage and the spot price uncertainty is large both manufacturers prefer the spot *** the demand during the contract procurement stage and the spot price uncertainty is high and purchase costs do not decline too severely over time,the unique equilibrium of this game is that one manufacturer chooses contract procurement to order early and the other chooses spot trading to order ***,we find that the correlation of spot purchasing price and the market demand signal during the contract procurement stage will weaken the advantages of spot trading *** the spot purchasing price and the market demand signal during the contract procurement stage are not correlated,manufacturers prefer spot trading under the highly volatile spot trading price,fluctuating demand,and high information precision.

关键词： Procurement order timing competition uncertainty game theory

generalized Thermal Instability Criterion of Black Hole Accretion Disks

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Chinese Physics Letters 1998年第7期15卷 542-544页

作者： wu xue-bing Beijing Astronomical Observatory Chinese Academy of SciencesBeijing 100012 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

The conventional thermal instability criterion cannot be applied to the advection-dominated accretion disks around black holes where the radiative cooling is insufficient to balance the viscous *** surface density change associated with the temperature perturbations,which was usually neglected in deriving the conventional criterion,was recently shown to be much significant in the advection-dominated *** both advection and surface density change,a generalized thermal instability criterion is *** applying it to the optically thin and optically thick advection-dominated disks,it is found that the former one is thermally stable and the latter one is thermally unstable against short wavelength perturbations,which agrees well to those found recently by both analytic and quantitative stability analyses.

关键词： criterion perturbations Criterion

Hot-cracking susceptibility and shear fracture behavior of dissimilar Ti6Al4V/AA6060 alloys in pulsed Nd:YAG laser welding

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Chinese Journal of Aeronautics 2021年第4期34卷 375-386页

作者： Xin xue Xinyong wu Juan LIAO School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350116China Fujian Nebula Electronics Co. Ltd.Fuzhou 350015China

Laser welding of dissimilar titanium/aluminum alloys has been employed at an increasing rate,particularly in the aerospace industry,owing to its advantages in terms of current design flexibility and fuel/cost *** major problem with dissimilar Ti/Al welds arises from the difference in the thermal expansion and contraction of the two metals,which leads to hot-cracking susceptibility and the mitigation of the mechanical property after *** the present study,pulsed Nd:YAG laser welding of Ti6 Al4 V and AA6060 has been ***-cracking susceptibility in the heat affected zone and the shear fracture behavior of the lap joints were investigated through microstructural characterization and mechanical *** results indicate that the hot cracking tendency can be reduced by increasing the pulse peak power(7.5–8.5 kW)and the laser point diameter(0.8–1.0 mm)with specific pulse duration and *** alternative control strategy for less hot cracks in the Ti/Al lap joint can be to increase the weld width and decrease the cooling rate during *** shear fracture of the Ti/Al lap joint is likely to occur along the lower side path of the weld interface with decreasing weld surface collapsed amount and increasing aluminum base metal melt depth.

关键词： Aluminum alloy Hot-cracking susceptibility Pulsed Nd:YAG laser welding Shear fracture behavior Titanium alloy

A lipophilic prodrug of Danshensu:preparation,characterization,and in vitro and in vivo evaluation

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Chinese Journal of Natural Medicines 2017年第5期15卷 355-362页

作者： GUO xue-Jiao FAN xue-Jiao QIAO Bin ge Zhi-Qiang Department of Pharmaceutical Engineering School of Chemical Engineering and Technology Tianjin University Education Ministry Key Laboratory of Systems Bioengineering Tianjin 300072 China

Danshensu [3-(3, 4-dihydroxyphenyl) lactic acid, DSS], one of the significant cardioprotective components, is extracted from the root of Salvia miltiorrhiza. In the present study, an ester prodrug of Danshensu(DSS), palmitoyl Danshensu(PDSS), was synthesized with the aim to improve its oral bioavailability and prolong its half-life. The in vitro experiments were carried out to evaluate the physicochemical properties and stability of PDSS. Although the solubility of PDSS in water was only 0.055 mg·mL^(-1), its solubility in Fa SSIF and Fe SSIF reached 4.68 and 9.08 mg·mL^(-1), respectively. Octanol-water partition coefficient(log P) was increased from-2.48 of DSS to 1.90 of PDSS. PDSS was relatively stable in the aqueous solution in pH range from 5.6 to 7.4. Furthermore, the pharmacokinetics in rats was evaluated after oral administration of PDSS and DSS. AUC and t1/2 of PDSS were enhanced up to 9.8-fold and 2.2-fold, respectively, compared to that of DSS. Cmax was 1.67 ± 0.11 μg·mL^(-1) for PDSS and 0.81 ± 0.06 μg·m L-1 for DSS. Thus, these results demonstrated that PDSS had much higher oral bioavailability and longer circulation time than its parent drug.

关键词： Danshensu Prodrug Oral bioavailability Circulation time