26 research outputs found

    Hierarchical Multi-Objective Fuzzy Collaborative Optimization of Integrated Energy System under Off-Design Performance

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    In order to solve the frequently occurred nonlinear working characteristics problem of the devices in integrated energy system (IES), where this nonlinear problem causes the offset of operation characteristics and design points of those devices, in this paper, the hierarchical multi-objective fuzzy collaborative optimization model of IES under off-design performance is proposed. Firstly, the high-order nonlinear models of devices under off-design performance, including fuel cell (FC), gas turbine (GT), absorption lithium bromide chiller (ABS), etc., are presented considering renewable energy and diversified storage devices, which can more accurately describe the actual working condition of devices. Secondly, according to the needs of different engineering application modes, the lower level collaborative optimization model of energy hub (EH) with economic, eco-friendly, primary energy saving, and renewable energy accommodation rate as optimization objectives is proposed, which can well adapt to and reflect real world energy system. Thirdly, based on the relationship between master and slave dispatch centers, the upper level modeling and optimal scheduling model of IES consisting of coupling power system, natural gas system, and heat system is proposed. Then, a multi-objective fuzzy collaborative optimization model for EH and IES is developed, where continuous differentiable Sigmoid function is taken as the membership function. Finally, simulation results show that the proposed models and optimal dispatch method can effectively solve the frequently occurred non-linear working characteristics problem of the devices in IES. The optimal results are suitable for planning, calculation, operation, dispatch of IES, which can reasonably reflect the operation characteristics of IES

    Review on the research methods of the barrier and explosion-proof properties of porous materials

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    Barrier and explosion proof material can quickly transfer heat and block flame propagation, consequently prevent explosion accident. It is the essential safety technology to solve the problem of explosion or “secondary explosion” during the storage and transportation of flammable and explosive dangerous chemicals in liquid or gaseous state. Since the 1960s, the research at home and abroad on the barrier and explosion proof technology has been carried out mainly for the storage and transportation safety of fuel oil. It has been widely used in automobile fuel tank, fuel carrier, gas station, oil pipeline and aircraft fuel tank. In this paper, the research methods of barrier and explosion protection are reviewed, and the development of this technology in the future is prospected.Barrier and explosion proof material can quickly transfer heat and block flame propagation, consequently prevent explosion accident. It is the essential safety technology to solve the problem of explosion or “secondary explosion” during the storage and transportation of flammable and explosive dangerous chemicals in liquid or gaseous state. Since the 1960s, the research at home and abroad on the barrier and explosion proof technology has been carried out mainly for the storage and transportation safety of fuel oil. It has been widely used in automobile fuel tank, fuel carrier, gas station, oil pipeline and aircraft fuel tank. In this paper, the research methods of barrier and explosion protection are reviewed, and the development of this technology in the future is prospected

    Relations between the loop transposition of DNA G-quadruplex and the catalytic function of DNAzyme

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    The structures of DNA G-quadruplexes are essential for their functions in vivo and in vitro. Our present study revealed that sequential order of the three G-quadruplex loops, that is, loop transposition, could be a critical factor to determinate the G-quadruplex conformation and consequently improved the catalytic function of G-quadruplex based DNAzyme. In the presence, of 100 mM K+, loop transposition induced one of the G-quadruplex isomers which shared identical loops but differed in the sequential order of loops into a hybrid topology while the others into predominately parallel topologies. D-1 NMR spectroscopy and mutation analysis suggested that the hydrogen bonding from loops residues with nucleotides in flanking sequences may be responsible for the stabilization of the different conformations. A well-known DNAzyme consisting of G-quadruplex and hemin (Ferriprotoporphyrin IX chloride) was chosen to test the catalytic function. We found that the loop transposition could enhance the reaction rate obviously by increasing the hemin binding affinity to G-quadruplex. These findings disclose the relations between the loop transposition, G-quadruplex conformation and catalytic function of DNAzyme

    Quantitative analysis methods of source-to-sink systems in deep-time and their progress

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    Significane The analysis of source-to-sink system is a comprehensive study of tectonic geology, sedimentology, and sequence stratigraphy. Because of its integral, dynamic, and semiquantitative-quantitative characteristics, it has attracted widespread attention. Progress This review first introduces the key issues of the deep-time source-to-sink systems (pre-Quaternary systems), which include the quantitative characterization of sediment mass balance and the control of the transport process on the sediment. Due to the lack of stratigraphic records and the difficulty in obtaining parameters, the research is still challenging.Second, it reviews the quantitation methods of deep-time source-to-sink systems that can be classified into three categories, namely, geochronology, uniformitarianism, and sedimentology. By obtaining information such as geomorphological parameters, hydraulic parameters, erosion rates, and sediment flux, various methods establish the quantitative relationships between "sources" and "sinks" and then rebuild the sedimentary basin infilling history. This article introduces the principles and related parameters of different methods and then compares the advantages and limitations to provide a reference for future research. It is believed that geochronology is widely used, and the core lies in provenance analysis. The key to uniformitarianism is the analogy of geological background and the selection of geological parameters. The sedimentology is controlled by multiple variables, and the tectonic-climate background and research scale need to be considered comprehensively. Conclusions and Prospects Finally, this review states the development of quantitative analysis of deep-time source-to-sink systems. Under the guidance of the important idea of "the present is the key to the past", the research needs to focus on the provenance systems, sediment routing systems, sediment dispersal, and redistributive process, and coupling relationship between various parameters. Research also needs to pay attention to quantitative analysis at multiple timescales and multidisciplinary dynamic analysis. Compared with continental margin source-to-sink systems, continental lacustrine source-to-sink system patterns and prediction models need to be further improved

    Size, Morphology and Crystallinity Control Strategy of Ultrafine HMX by Microfluidic Platform

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    The crystal structure has a great influence on mechanical sensitivity and detonation performance of energetic materials. An efficient microfluidic platform was applied for size, morphology, and crystallinity controllable preparation of ultrafine HMX. The microfluidic platform has good mixing performance, quick response, and less reagent consumption. The ultrafine γ-HMX was first prepared at room temperature by microfluidic strategy, and the crystal type can be controlled accurately by adjusting the process parameters. With the increase in flow ratio, the particle size decreases gradually, and the crystal type changed from β-HMX to γ-HMX. Thermal behavior of ultrafine HMX shows that γ→δ is easier than β→δ, and the phase stability of HMX is β > γ > δ. Furthermore, the ultrafine β-HMX has higher thermal stability and energy release efficiency than that of raw HMX. The ultrafine HMX prepared by microfluidic not only has uniform morphology and narrow particle size distribution, but also exhibits high density and low sensitivity. This study provides a safe, facile, and efficient way of controlling particle size, morphology, and crystallinity of ultrafine HMX

    The Evolution of Permian Source-to-Sink Systems and Tectonics Implications in the NW Junggar Basin, China: Evidence from Detrital Zircon Geochronology

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    The basin type of the Junggar Basin changed during the Permian, but the time constraint of the tectonic evolution remains unclear. Besides, the fan deltas developed in the Permian in the Mahu Sag in the northwestern of the oil-rich basin. However, the provenances of the sedimentary systems remain unclear. Based on petrology and detrital zircon U-Pb ages, this study investigates the source-to-sink systems evolution and tectonics implications. Abundant lithic clasts in sandstones with low compositional and textural maturity imply proximal sources. The dating results showed a dominant peak (310–330 Ma) and a secondary peak (400–440 Ma) in the northern Mahu Sag, only one peak at 295–325 Ma in the central Mahu Sag, several peaks at 270–350 Ma in the southern Mahu Sag, and multiple peaks at 370–450 Ma in the Zhongguai Uplift. Thus, the north-western Junggar Basin was divided into four major source-to-sink systems, with adjacent central West Junggar as the main provenance and northern and southern West Junggar as the secondary provenance. The proportion of sediment supply from the southern and northern West Junggar is higher during the Middle-Late Permian. It suggests that the source-to-sink systems show inheritance and evolve from a single provenance into a complex provenance, indicating the uplift of West Junggar. The tectonic inversion may occur early in the Middle Permian and the response to tectonic activity is stronger in the southern West Junggar than in the northern West Junggar

    Size, Morphology and Crystallinity Control Strategy of Ultrafine HMX by Microfluidic Platform

    No full text
    The crystal structure has a great influence on mechanical sensitivity and detonation performance of energetic materials. An efficient microfluidic platform was applied for size, morphology, and crystallinity controllable preparation of ultrafine HMX. The microfluidic platform has good mixing performance, quick response, and less reagent consumption. The ultrafine γ-HMX was first prepared at room temperature by microfluidic strategy, and the crystal type can be controlled accurately by adjusting the process parameters. With the increase in flow ratio, the particle size decreases gradually, and the crystal type changed from β-HMX to γ-HMX. Thermal behavior of ultrafine HMX shows that γ→δ is easier than β→δ, and the phase stability of HMX is β > γ > δ. Furthermore, the ultrafine β-HMX has higher thermal stability and energy release efficiency than that of raw HMX. The ultrafine HMX prepared by microfluidic not only has uniform morphology and narrow particle size distribution, but also exhibits high density and low sensitivity. This study provides a safe, facile, and efficient way of controlling particle size, morphology, and crystallinity of ultrafine HMX

    Alkaline-lacustrine deposition and paleoenvironmental evolution in Permian Fengcheng Formation at the Mahu sag, Junggar Basin, NW China

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    Alkaline-lacustrine deposition and its evolution model in Permian Fengcheng Formation at the Mahu sag, Junggar Basin were investigated through core and thin-section observation, geochemical and elemental analysis, logging response and lithofacies identification. Six lithofacies are developed in the Fengcheng Formation. The Feng 2 Member (P1f2) is dominated by lithofacies with alkaline minerals, while the upper part of the Feng 1 Member (P1f1) and the lower part of the Feng 3 Member (P1f3) are primarily organic-rich mudstones that are interbedded with dolomite and dolomitic rock. Paleoenvironment evolution of Fengcheng Formation can be divided into 5 stages, which was controlled by volcanic activity and paleoclimate. The first stage (the early phase of P1f1) was characterized by intensive volcanic activity and arid climate, developing pyroclastics and sedimentary volcaniclastic rocks. The secondary stage (the later phase of P1f1) had weak volcanic activity and humid climate that contributed to the development of organic-rich mudstone, forming primary source rock in the Fengcheng Formation. The increasing arid climate at the third stage (the early phase of P1f2) resulted in shrinking of lake basin and increasing of salinity, giving rise to dolomite and dolomitic rocks. The continuous aird climate, low lake level and high salinity at the fourth stage (the later phase of P1f2) generated special alkaline minerals, e.g., trona, indicating the formation of alkaline-lacustrine. The humid climate made lake level rise and desalted lake water, therefore, the fifth stage (P1f3) dominated by the deposition of terrigenous clastic rocks and dolomitic rocks. Key words: Junggar Basin, Permian Fengcheng Formation, depositional characteristics, paleoenvironment reconstruction, alkaline-lacustrine deposition, lithofacies, Mahu sa

    Sequence structure, sedimentary evolution and their controlling factors of the Jurassic Lianggaoshan Formation in the East Sichuan Basin, SW China

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    Based on the data of outcrops, seismic sections, thin sections, heavy mineral assemblages and detrital zircon U-Pb dating, the sedimentary characteristics, lake level fluctuation and provenance characteristics of the Middle Jurassic Lianggaoshan Formation (J2l) in eastern Sichuan Basin, SW China, were investigated to reveal the control of tectonic movements of the surrounding orogenic belts on the sedimentary systems. The J2l mainly developed a delta—lake sedimentary system, which contained a complete third-order sequence that was subdivided into four lake level up-down cycles (fourth-order sequence). The lake basins of cycles I and II were mainly distributed in eastern Sichuan Basin, while the lake basins of cycles III and IV migrated to central Sichuan Basin, resulting in the significant difference in sedimentary characteristics between the north and the south of eastern Sichuan Basin. The provenance analysis shows that there were three types of provenances for J2l. Specifically, the parent rocks of Type I were mainly acidic igneous rocks and from the proximal northern margin of the Yangtze Plate; the parent rocks of Type II were intermediate-acid igneous rocks and metamorphic rocks and from the central parts of the southern and northern Qinling orogenic belts; the parent rocks of Type III were mainly metamorphic rocks followed by intermediate—acid igneous rocks, and from the North Daba Mountain area. It is recognized from the changes of sedimentary system and provenance characteristics that the sedimentary evolution of J2l in eastern Sichuan Basin was controlled by the tectonic compression of the Qinling orogenic belt. In the early stage, the lake basin was restricted to the east of the study area, and Type I provenance was dominant. With the intensifying north-south compression of the Qinling orogenic belt, the lake basin expanded rapidly and migrated northward, and the supply of Type II provenance increased. In the middle and late stages, the uplift of the North Daba Mountain led to the lake basin migration and the gradual increase in the supply of Type III provenance
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