In the current context of global climate change and threats to the ecological environment, ice and snow tourism destinations face significant challenges in ecological security protection. The urgent ...question of how to scientifically assess the ecological security status of ice and snow tourism destinations in order to formulate effective management and protection strategies needs to be addressed. The ecological security of ice and snow tourism destinations is not only related to the preservation of the natural environment but also directly affects the sustainable development and brand image of these destinations. Therefore, effectively communicating the brand of ice and snow tourism destinations while protecting the ecology has become an urgent issue. Emerging technologies like the Internet of Things (IoT) and deep learning hold great potential in remote sensing image processing and data analysis and can provide effective tools and methods to address the above-mentioned issues. Therefore, this study focuses on exploring the application of IoT and deep learning in the assessment of ecological security and brand communication in ice and snow tourism destinations, providing more scientifically grounded decision support for the management and development of these destinations. Taking an ice and snow tourism destination in Area C as a case study, this study first analyzes the applications of the IoT and DL in ecological safety assessment. Subsequently, by utilizing the DeeplabV3+ model for land type classification and combining the Drive-Pressure-State-Impact-Response (DPSIR) model and the Environment-Economy-Society (EES) model, the DPSIR-EES model is constructed to assess the ecological safety of ice and snow tourism destinations. The results indicate that, for remote sensing image classification, the overall accuracy of the DeeplabV3+ model reaches 91.56%, and the Kappa coefficient reaches 0.862, significantly surpassing traditional methods, thereby demonstrating its superiority in remote sensing image classification. The ecological safety assessment of the ice and snow tourism destination in Area C reveals that the overall ecological safety remains stable between 0.88 and 0.89. Tourism spatial density is one of the influencing factors on its ecological safety, with an obstacle factor of 0.31, indicating the significance of economic factors in ecological safety. Finally, based on the aforementioned analysis, approaches for shaping and communicating the brand of the ice and snow tourism destination in Area C are proposed. This study holds important practical significance for better environmental protection and enhancing brand value.
Scientific interest in carbon‐based materials (CBMs) has grown dramatically over the past few decades. Due to a variety of atomic orbital hybrid forms (sp, sp2 and sp3 hybridization), carbon can form ...a variety of materials with diverse structures and characteristics. CBMs used as efficient catalyst supports show extensive promise in organic reactions, which is attributed to their structural similarity with organics, large specific surface area, chemical stability, and photocatalytic properties. This review presents the synthesis of CBM‐supported palladium nanocatalysts based on impregnation, template methods, etc. The CBMs include activated carbon (AC), graphene, carbon nanotubes (CNTs), and their functionalized products, as supports for improving the activity and recyclability of simple Pd nanocatalysts. After surveying the literature where these catalysts have been utilized for carbon–carbon coupling reactions, there is a particular emphasis on Suzuki, Heck, and Sonogashira reactions. The catalytic mechanism of these Pd nanocatalysts (surface heterogeneous catalysis or homogeneous catalysis caused by Pd leaching) is discussed in detail, especially the effect of Pd leaching on the stability of the catalyst.
This review presents thesynthesis of carbon‐based materials (CBMs) supported palladium nanocatalysts based on impregnation, template methods, etc. After surveying the literature where these catalysts have been utilized for carbon‐carbon coupling reactions, there is a particular emphasis on Suzuki, Heck, and Sonogashira reactions. The catalytic mechanism ofthese Pd nanocatalysts (surface heterogeneous catalysis or homogeneous catalysis caused by Pd leaching) is discussed in detail, especially the effect of Pd leaching on the stability of the catalyst.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
COVID-19 is associated with 5.1% mortality. Although the virological, epidemiological, clinical, and management outcome features of COVID-19 patients have been defined rapidly, the inflammatory and ...immune profiles require definition as they influence pathogenesis and clinical expression of COVID-19. Here we show lymphopenia, selective loss of CD4+ T cells, CD8+ T cells and NK cells, excessive T-cell activation and high expression of T-cell inhibitory molecules are more prominent in severe cases than in those with mild disease. CD8+ T cells in patients with severe disease express high levels of cytotoxic molecules. Histochemical studies of lung tissue from one fatality show sub-anatomical distributions of SARS-CoV-2 RNA and massive infiltration of T cells and macrophages. Thus, aberrant activation and dysregulation of CD8+ T cells occur in patients with severe COVID-19 disease, an effect that might be for pathogenesis of SARS-CoV-2 infection and indicate that immune-based targets for therapeutic interventions constitute a promising treatment for severe COVID-19 patients.
Multiple Comparison Procedures Cao, Jing; Zhang, Song
JAMA : the journal of the American Medical Association,
08/2014, Volume:
312, Issue:
5
Journal Article
Peer reviewed
The article discusses how many a time the use of multiple comparison procedures in clinical trials can cause a number of significant problems. Some of the reasons as to why multiple comparison ...procedures are made use of are also highlighted.
In recent years, the study of oxidative stress (OS) has become increasingly popular. In particular, the role of OS on female fertility is very important and has been focused on closely. The ...occurrence of OS is due to the excessive production of reactive oxygen species (ROS). ROS are a double-edged sword; they not only play an important role as secondary messengers in many intracellular signaling cascades, but they also exert indispensable effects on pathological processes involving the female genital tract. ROS and antioxidants join in the regulation of reproductive processes in both animals and humans. Imbalances between pro-oxidants and antioxidants could lead to a number of female reproductive diseases. This review focuses on the mechanism of OS and a series of female reproductive processes, explaining the role of OS in female reproduction and female reproductive diseases caused by OS, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia and so on. Many signaling pathways involved in female reproduction, including the Keap1-Nrf2, NF-κB, FOXO and MAPK pathways, which are affected by OS, are described, providing new ideas for the mechanism of reproductive diseases.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Biomass gasification converts into syngas, then into other chemicals via Fischer-Tropsch (F-T) synthesis is promising for renewable energy utilization. Although gasification is a sustainable and ...environmental-friendly technology for value-added utilization of biomass, tar formation is the major problem during the biomass gasification. Tar could condense on the reactor then block and foul equipment. An optimized gasifier and highly active catalyst were proved to be effective for biomass tar elimination. Furthermore, tar formation mechanism and the decomposition pathway were also important to advance the optimization of gasification reactors and catalyst design. This paper summarized the fundamentals, such as gasifier types, Ni-based catalyst, and reaction and deactivation mechanism. This review also sheds light on other excellent catalysts, effective gasifiers and mathematical models of biomass catalytic gasification, and catalyst reaction mechanisms and mathematical models are also discussed in detail. At last, the paper ends with a conclusion and prospective discussion to the latter lab and industrial-scale research.
•It sheds light on excellent catalysts, gasifiers of biomass gasification.•In-depth discussion of mathematical models are provided.•Detailed description of deactivation and reaction mechanisms.•Prospects and disadvantages of gasification reactions are described.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
During the past two years, the introduction of DMSO has revolutionized the fabrication of high-quality pervoskite MAPbI3 (MA = CH3NH3) films for solar cell applications. In the developed DMSO ...process, the formation of (MA)2Pb3I8·2DMSO (shorted as Pb3I8) has well recognized as a critical factor to prepare high-quality pervoskite films and thus accomplish excellent performances in perovskite solar cells. However, Pb3I8 is an I-deficient intermediate and must further react with methylammonium iodide (MAI) to be fully converted into MAPbI3. By capturing and solving the molecular structures of several intermediates involved in the fabrication of perovskite films, we report in this work that the importance of DMSO is NOT due to the formation of Pb3I8. The use of different PbI2-DMSO ratios leads to two different structures of PbI2-DMSO precursors (PbI2·DMSO and PbI2·2DMSO), thus dramatically influencing the quality of fabricated perovskite films. However, such an influence can be minimized when the PbI2-DMSO precursor films are thermally treated to create mesoporous PbI2 films before reacting with MAI. Such a development makes the fabrication of high-quality pervoskite films highly reproducible without the need to precisely control the PbI2:DMSO ratio. Moreover, the formation of ionic compound (MA)4PbI6 is observed when excess MAI is used in the preparation of perovskite film. This I-rich phase heavily induces the hysteresis in PSCs, but is readily removed by isopropanol treatment. On the basis of all these findings, we develop a new effective protocol to fabricate high-performance PSCs. In the new protocol, high-quality perovskite films are prepared by simply treating the mesoporous PbI2 films (made from PbI2-DMSO precursors) with an isopropanol solution of MAI, followed by isopropanol washing. The best efficiency of fabricated MAPbI3 PSCs is up to 19.0%. As compared to the previously reported DMSO method, the devices fabricated by the method reported in this work display narrow efficiency distributions in both forward and reverse scans. And the efficiency difference between forward and reverse scans is much smaller.
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IJS, KILJ, NUK, PNG, UL, UM
Traditional fossil fuel overuse could lead to global warming and environmental pollution. As a renewable energy, biomass energy is a sustainable and low pollution carbon energy, which has a wide ...range of sources. Syngas production from biomass thermochemical conversion is a promising technology to realize effective utilization of the renewable energy. Syngas produced from gasification could be further converted into value-added chemicals via the method of Fischer-Tropsch synthesis. Syngas and CO2 methanation could transform renewable energy into feasible transport and high-density energy. However, tar formation and catalyst deactivation are the main problem during the biomass gasification and methanation. This review sheds light on the development of biomass gasification and syngas methanation. Firstly, we presented the common reactors and some other factors during gasification. Secondly, we provide a comprehensive introduction of the advanced active catalyst for gasification and syngas methanation. Finally, some representative large-scale and commercial plants and companies for biomass gasification were compared and discussed in details. Then the prospective developments in combination of gasification and methanation were concluded to give an outlook for biomass gasification and its downstream development.
•Detailed review of gasification and methanation development.•Discussion of high active catalyst for gasification and methanation.•It sheds light on effective reactors for biomass gasification.•Large-scale commercial development of gasification and methanation are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Compared with the traditional fuel aircraft tractor, the electric tractor using the four-wheel hub motor independent drive mode has the advantages of environmental protection, low costs, ...flexibility, high controllability, and convenience for later maintenance. The paper uses a four-wheel hub motor tractor and a linear vehicle model to propose a hierarchical steering control strategy. The upper layer control adopts the improved integrated sliding mode control algorithm with the yaw angular speed as the control goal to obtain the additional yaw torque. The additional yaw torque obtained is reasonably distributed to each wheel by the use of the rule distribution algorithm of the lower layer control, to obtain the optimal driving torque of each wheel. Finally, the steering stability of the electric aircraft tractor at different speeds is verified based on Simulink. The results show that the control strategy can better control the speed and stability of steering control of electric vehicles.
This work is aimed to study in situ upgrading of Shengli lignite pyrolysis vapors over different metal-loaded HZSM-5 in a drop tube reactor. Co/HZSM-5, Mo/HZSM-5 and Ni/HZSM-5 (5.0wt%) were prepared ...by wet impregnation and characterized by N2 adsorption-desorption analyzer, X-ray diffraction, transmission electron microscope, Fourier transform infrared spectrometer and temperature programmed desorption of ammonia. The effects of temperature and catalyst on product yields and tar properties were investigated. The results show that the optimal temperature for liquid product was 600°C and aromatics can be directly produced from solid lignite by catalytic fast pyrolysis over metal-loaded HZSM-5 under such mild condition. Due to the participation of metal and acid sites, the bifunctional metal-loaded HZSM-5 showed comparable catalytic activity for deoxygenation reaction in the valorization of oxygen content below 7.1%. The introduction of metal causes the increase of aromatics and the decrease of organic oxygen species in upgraded tar remarkably. Among the catalysts, Ni/HZSM-5 exhibited the best performance for production of high quality tars with highest aromatics content of 94.2% (area%), which can be used as a potential candidate for catalytic upgrading of pyrolysis oil.
•Metal-loaded HZSM-5 was prepared for conversion of lignite to light aromatics.•The BTEXN formation was enhanced by metal-loaded HZSM-5.•Oxygen content in pyrolysis tar is remarkably decreased by metal-loaded HZSM-5.•Ni-loaded HZSM-5 is a potential candidate in catalytic upgrading of pyrolysis oil.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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