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Adding new dimension to non-directed C（sp3）–H functionalizations

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Science China Chemistry 2025年

作者： Konstantin P.Bryliakov Laboratory of Selective Oxidation Catalysis N.D.Zelinsky Institute of Organic Chemistry RAS

Aliphatic C–H groups are among the most abundant yet least reactive functional groups in organic molecules. nature has evolved metalloenzymes such as those of the cytochrome P450 superfamily that efficiently activate individual tertiary（3） and secondary （2） C（sp3）–H bonds in complex molecules with the highest level of regio-and stereoselectivity [1], thus encouraging studies aimed at engineering artificial metalloenzymes for synthetic applications [2].

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Multi-Step Clustering of Smart Meters time Series:Application to Demand Flexibility Characterization of SME Customers

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 869-907页

作者： Santiago Bañales Raquel Dormido natividad Duro Department of Computer Sciences and Automatic Control Universidad Nacional de Educación a Distancia(UNED)Madrid28040Spain Iberdrola Innovation Middle East Doha210177Qatar

Customer segmentation according to load-shape profiles using smart meter data is an increasingly important application to vital the planning and operation of energy systems and to enable citizens’participation in the energy *** study proposes an innovative multi-step clustering procedure to segment customers based on load-shape patterns at the daily and intra-daily time *** meter data is split between daily and hourly normalized time series to assess monthly,weekly,daily,and hourly seasonality patterns *** dimensionality reduction implicit in the splitting allows a direct approach to clustering raw daily energy time series *** intraday clustering procedure sequentially identifies representative hourly day-unit profiles for each customer and the entire *** the first time,a step function approach is applied to reduce time series *** attributes embedded in surveys are employed to build external clustering validation metrics using Cramer’s V correlation factors and to identify statistically significant determinants of load-shape in energy *** addition,a time series features engineering approach is used to extract 16 relevant demand flexibility indicators that characterize customers and corresponding clusters along four different axes:available Energy(E),temporal patterns(t),Consistency(C),and Variability(V).the methodology is implemented on a real-world electricity consumption dataset of 325 Small and Medium-sized Enterprise(SME)customers,identifying 4 daily and 6 hourly easy-to-interpret,well-defined *** application of the methodology includes selecting key parameters via grid search and a thorough comparison of clustering distances and methods to ensure the robustness of the *** research can test the scalability of the methodology to larger datasets from various customer segments(households and large commercial)and locations with different weather and socioeconomic conditio

关键词： Electric load clustering load profiling smart meters machine learning data mining demand flexibility demand response

DIRECt MEASUREMEnt OF WEAK DEPLEtIOn FORCE BEtWEEn tWO SURFACES

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Chinese Journal of Polymer Science 2011年第1期29卷 1-11页

作者： Xiang-jun Gong Xiao-chen Xing Xiao-ling Wei to ngai Department of Chemistry the Chinese University ofHong Kong Shatin N.T. Hong Kong China Department of Physics the Chinese University ofHong Kong Shatin N.T. Hong Kong China

In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive ＂depletion force＂ if the size of the polymer molecule is larger than the interparticle separation. this is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space, which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. this depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBt and beyond. We present here our results for applying total internal reflection microscopy （tIRM） to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles （ca. 150 nm） exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using tIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo^sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBt-scale depletion attraction as function of solution pH.

关键词： Depletion interaction total internal reflection microscopy (tIRM) nanobubbles Microgel particles

Recent Advances in the Unconventional Design of Electrochemical Energy Storage and Conversion Devices

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Electrochemical Energy Reviews 2022年第4期5卷 38-62页

作者： Senthil Velan Venkatesan Arpita nandy Kunal Karan Stephen R.Larter Venkataraman thangadurai Department of Chemistry University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada Department of Chemical&Petroleum Engineering University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada Department of Geoscience University of Calgary2500 University Drive NWCalgaryAB T2N1N4Canada

As the world works to move away from traditional energy sources,effective efficient energy storage devices have become a key factor for *** emergence of unconventional electrochemical energy storage devices,including hybrid batteries,hybrid redox flow cells and bacterial batteries,is part of the *** alternative electrochemical cell configurations provide materials and operating condition flexibility while offering high-energy conversion efficiency and modularity of design-to-design *** power of these diverse devices ranges from a few milliwatts to several ***-ing durable electronic and point-of-care devices is possible due to the development of all-solid-state batteries with efficient electrodes for long cycling and high energy *** batteries made of earth-abundant metal ions are approaching the capacity of lithium-ion *** are being reduced with the advent of flow batteries with engineered redox molecules for high energy density and membrane-free power generating electrochemical cells,which utilize liquid dynamics and interfaces(solid,liquid,and gaseous)for electrolyte *** batteries support electrode regeneration strategies for chemical and bio-batteries reducing battery energy *** batteries have different benefits,e.g.,carbon-neutral Li-CO_(2) batteries consume CO_(2) and generate power,offering dual-purpose energy storage and carbon *** work considers the recent technological advances of energy storage *** transition from conventional to unconventional battery designs is examined to identify operational flexibilities,overall energy storage/conversion efficiency and application ***,a list of facilities for large-scale deployment of major electrochemical energy storage routes is provided.

关键词： Unconventional energy storage Redox flow battery Organic electrolytes Membrane-free flow cell All-solid-state batteries

Interference from HOnO in the measurement of ambient air nO2 via photolytic conversion and quantification of nO

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Journal of Environmental Sciences 2021年第9期33卷 184-193页

作者： nicholas J.Gingerysty Charles A.Odame-Ankrah nick Jordan Hans D.Osthoff Department of Chemistry University of CalgaryCalgary AB T2N 1N4Canada Global Analyzer Systems Ltd. Calgary AB T2E 7L6Canada

the reference method to quantify mixing ratios of the criteria air pollutant nitrogen dioxide(nO_(2)) is nO-O_(3) chemiluminescence(CL), in which mixing ratios of nitric oxide(nO) are measured by sampling ambient air directly, and mixing ratios of nO_(x)(= sum of nO and nO_(2))are measured by converting nO_(2) to nO using, for example, heated molybdenum catalyst or,more selectively, photolytic conversion(P-CL).In this work, the nitrous acid(HOnO) interference in the measurement of nO_(2) by P-CL was *** with two photolytic nO2 converters are *** first used radiation centered at 395 nm, a wavelength region commonly utilized in *** second used light at 415 nm, where the overlap with the HOnO absorption spectrum and hence its photolysis rate are *** ratios of nO_(2),nO_(x) and HOnO entering and exiting the converters were quantified by thermal Dissociation Cavity Ring-down Spectroscopy(tD-CRDS).Both converters exhibited high nO_(2) conversion efficiency(CF_(nO2);> 90%) and partial conversion of *** of CF against flow rate were consistent with photolysis frequencies of 4.2 s^(-1) and 2.9 s^(-1) for nO_(2) and 0.25 s^(-1) and 0.10 s^(-1) for HOnO at 395 nm and 415 nm, *** larger than predicted from the overlap of the emission and HOnO absorption *** results imply that measurements of nO2 by P-CL marginally but systematically overestimate true nO_(2) concentrations,and that this interference should be considered in environments with high HOnO:nO_(2) ratios such as the marine boundary layer or in biomass burning plumes.

关键词： Photolytic conversion of nO_(2) HOnO interference

MULtI-WORLD MECHAnISM FOR MODELInG EVOLUtIOnARY DESIGn PROCESS FROM COnCEPtUAL DESIGn tO DEtAILED DESIGn

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Chinese Journal of Mechanical Engineering 2007年第6期20卷 104-108页

作者： XUE Deyi YAnG Haoguang tU Yiliu Department of Mechanical and Manufacturing Engineering University of Calgary Calgary T2N 1N4 Canada

A multi-world mechanism is developed for modeling evolutionary design process from conceptual design to detailed design. In this mechanism, the evolutionary design database is represented by a sequence of worlds corresponding to the design descriptions at different design stages. In each world, only the differences with its ancestor world are recorded. When the design descriptions in one world are changed, these changes are then propagated to its descendant worlds automatically. Case study is conducted to show the effectiveness of this evolutionary design database model.

关键词： Design database Design process Design evolution

Data-driven model for predicting production periods in the SAGD process

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Petroleum 2022年第3期8卷 363-374页

作者： Ziteng Huang Min Yang Bo Yang Wei Liu Zhangxin Chen Department of Chemical and Petroleum Engineering University of Calgary2500 University Drive NWCalgaryT2N 1N4Canada

Many studies have analyzed the cumulative production performance in the SAGD(steam assisted gravity drainage)process by data-driven models but a study based on these models for a dynamic analysis of a SAGD production period is still *** is important for engineers to define the production period in a SAGD process as it has a stable and high oil production rate and engineers need to reset operational conditions after the production period *** this paper,a series of SAGD models were constructed with selected ranges of reservoir properties and operational *** SAGD production period parameters,including the start date,end date,and duration,are collected based on the simulated production *** neural network,extreme gradient boosting,light gradient boosting machine,and catboost were constructed to reveal the hidden relationships between twelve input parameters and three output *** data-driven models were trained,tested,and *** results showed that compared with the other output parameters,the R^(2) of the end date is the highest and it becomes higher with a larger training data *** extreme gradient boosting algorithm is a better choice to predict the Start date while the artificial neural network generates better prediction for the other two output *** study shows a significant potential in the use of data-driven models for the SAGD production dynamic *** results also serve to support the utilization of the datadriven models as efficient tools for predicting a SAGD production period.

关键词： Steam assisted gravity drainage Data-driven model Artificial neural network Extreme gradient boosting Light gradient boosting machine CatBoost

Geomorphological responses of rivers to active tectonics along the Karahay?t Fault, Western türkiye

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Journal of Mountain Science 2024年第5期21卷 1464-1474页

作者： Savaş tOPAL Pamukkale University Department of Geological EngineeringKınıklıCampusDenizli 20160Türkiye

Understanding the topography in active tectonic areas and assessing the rates and models of active deformation in the upper crust are primary objectives in tectonic geomorphology studies. the drainage pattern of river systems is highly sensitive to tectonically induced changes, and it often preserves the records of the formation and progression of most tectono-geomorphic processes within its boundaries. therefore, the evolution of landforms is a consequence of the evolution of individual drainage basins in which they are formed. Assessing the rates of tectonic deformation using geomorphic data is a traditionally adopted method to characterize the nature of active faults. Globally, the Digital Elevation Model(DEM) is widely used as a crucial tool to analyze the morphotectonic features of drainage basins. In this study, some geomorphic indices were applied to investigate the impact of tectonism on landscape along the Karahay?t Fault and its associated drainage areas. these geomorphic indices are mountain front sinuosity(Smf values between 1.17-1.52), valley floor width-to-height ratio(Vf values between 0.25-1.46), basin asymmetry factor(AF values between 15-72), drainage basin shape(Bs values between 3.18-6.01), hypsometric integral and curve(HI values between 0.32-047), channel sinuosity(S values between 1-1.6), normalized steepness index(Ksn values between 1-390) and Chi integral(χ values between 200-4400). the development of drainage areas on the hanging wall and footwall block of the Karahayit Fault differs depending on the uplift. the drainage areas developed on the hanging wall present different patterns depending on the regional uplift caused by the fault. this reveals that the fault contributed significantly to the development of drainage areas and regional uplift in the region. In addition, the maximum earthquake magnitude that may occur in the future on the Karahayit Fault, whose activity is supported by geomorphic indices, is calculated as 6.23. Since an ea

关键词： Drainage basins Geomorphic indices normalized steepness index(Ksn) Chi integral(χ) Morphotectonic features Karahayıt Fault

Cryogenic wedges on the nE Qinghai-tibet and Ordos Plateaus:their characteristics,origin and OSL dating

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Research in Cold and Arid Regions 2021年第6期13卷 463-473页

作者： Stuart A.Harris Department of Geography University of CalgaryCalgaryAlbertaT2N 1N4Canada

Cryogenic wedges developed due to very cold,rather arid conditions during the maximum of the last cold event when the drying up of the neighboring China Sea resulted in the failure of the East Asian *** the climate ameliorated and the Monsoon rains reappeared,ice-wedges *** warming permitted thawing of the ice infillings accompanied by replacement of the ice by sediments partly from the host ground as well as from the surface by wind or sheet *** cases of extreme surface water flow on slopes after 10 ka B.P.,small baydjarakhs typically c.50 cm high developed,only to have the resulting hollows infilled by sediments carried by wind and/or sheet *** shallow structures form a network on top of many of the cryogenic *** complex history makes dating the ages of the wedges difficult using OSL ***,past field work ignored the problem of the angle of the cut face to the direction of the wedge infilling when sampling the contents of the narrow wedges,resulting in potential contamination of the samples with the host *** of the larger deposits should be alright,but the likelihood of contamination makes the interpretation of the resulting OSL dates from the narrow wedges *** wedges consisting of primary mineral infillings should still have similar OSL dates with depth for a given wedge,but the distinction between ice-wedge infillings and soil wedges is difficult since both can exhibit older dates of the infillings with *** available data suggests that ice-wedges were significantly more common than sediment-filled primary wedges.A protocol to avoid having to obtain large numbers of OSL dates by more careful field sampling and the use of grain size determinations is provided in the Appendix.

关键词： cryogenic wedges OSL dating nE Qinghai-tibet Plateau differentiation of primary and secondary wedges baydjarakhs in arid climates