The urban heat island (UHI) effect is an important issue in urban planning. In this study, the framework of the land surface temperature (LST) and UHI
index
for urban development land (UDL) based on ...urban planning in China was proposed to examine the spatiotemporal evolution of the LST and the UHI
index
for the whole city as well as the LST and the UHI
index
of UDL at four node stages (1995, 2003, 2014 and 2019), reflecting the process of urbanization. The results demonstrate that the UHI
index
showed an overall trend of first decreasing and then increasing in the process of urbanization over 2 decades. The UHI is characterized by the evolution of spatial distribution from a local point-like aggregation (1995) to a linear expansion along the urban construction land (2003), then to patchy areas tending towards overall homogeneous coverage gradually expanding (2019). The LST increased yearly, but the UHI
index
first decreased and then increased, while the average UHI
index
and the LST of UDL in the overall relationship maintained good consistency each year. The industrial and logistics concentration area with railway marshalling yard as the core area is the most important patch to maintain the urban thermal pattern. The results provide a quantitative basis for the thermal environmental planning of UDL and a reference for research on UHI under different land planning and management systems in other countries and regions of the world.
The composition and microstructure of heterojunctions could remarkably affect the photo-induced charge separation of semiconductors, thus changing their photocatalytic activity. In this work, a ...simple solid-state chemical reaction route was developed to fabricate BiOCl/Bi2O2CO3 p-n heterojunctions hierarchical nanostructures self-assembled by thin nanoplates. The as-synthesized heterojunctions significantly enhanced photocatalytic activity in comparison with individual Bi2O2CO3 and BiOCl. In particularly, the 60% BiOCl/Bi2O2CO3 heterojunction exhibited the highest photocatalytic activity, which was around 188 times and 17 times higher than that of pristine Bi2O2CO3 under visible and ultraviolet light, respectively. The remarkable enhanced photodegradation performance of heterojunction is ascribed to its higher specific surface area and the efficient separation of photo-generated carriers. Combining with the theoretical and experimental results, the transition paths of electrons and holes between BiOCl and Bi2O2CO3 was investigated, therefore the self-photosensitized photocatalytic mechanism of BiOCl/Bi2O2CO3 composite has also been well explained.
•A simple and fast solid-state chemical method was firstly used to synthesize BiOCl/Bi2O2CO3 composites.•BiOCl/Bi2O2CO3 p-n heterojunction exhibited remarkable visible/UV light-driven photocatalytic activity.•A simple and direct photosensitization pathway of RhB over the composite is proposed.
The streamlined design of self-bending extrusion die Min, Fanlei; Liu, Huiping; Zhu, Guangming ...
International journal of advanced manufacturing technology,
09/2021, Letnik:
116, Številka:
1-2
Journal Article
Recenzirano
In this paper, the method of limit analysis is adopted, and three kinds of self-bending extrusion dies controlled by combined function are presented. They are the sin-atan self-bending extrusion die, ...the sin-erf self-bending extrusion die, and the sin-tanh self-bending extrusion die. Through numerical simulation, self-bending profiles can be obtained from all three kinds of dies. These dies can make the billet flow closer to the real billet flow path and maximize the billet utilization rate. They also can reduce the extrusion load and reduce the local damage of the die and then prolong the die life. It is very effective to predict the bending deformation of the billet by analyzing the central flow line of the billet. It provides a theoretical reference for the design of the actual streamlined self-bending die.
Inheriting excellent traditional Chinese culture is a prerequisite for ensuring the continuity of the cultural genes of the Chinese nation. However, with the historical mission of shaping the ...national character of the descendants of the Chinese nation, intangible cultural heritage martial arts face the problem of an unclear curriculum content construction mechanism in university inheritance and make it difficult for these martial arts to shoulder the responsibility of cultural inheritance in the era.
Educational ethnography as a research method is conducive to the in-depth exploration of the mechanism of curriculum content construction in the inheritance of intangible cultural heritage martial arts in universities.
Research suggests that the construction of curriculum content for the inheritance of intangible cultural heritage martial arts in universities relies on the form of cooperation between universities and inheritors, and form three models of curriculum content construction: off campus, on campus, and on-campus cooperation. The construction of curriculum content for off-campus inheritors belongs to the "attachment style" model, which is based on the actual needs of the inheritors and the selection of boxing types. The construction of curriculum content for inheritors on campus belongs to the "reshaping" model, which is the inheritor's "simplification and reorganization" based on traditional routines and subjective and objective conditions of inheritance. The construction of course content in school local cooperation belongs to the "integrated" model, which is the reintegration of course content by universities based on their own development characteristics and the characteristics of various martial arts.
In the inheritance of intangible cultural heritage martial arts in universities, emphasis is placed on local knowledge, core skills, cultural traditions, and other characteristics, highlighting the excellence of its cultural inheritance. In the future, the focus of the inheritance of these martial arts in universities should be to cultivate innovative talents who are familiar with both traditional and modern martial arts.
Urban heat islands (UHI) are important environmental issue in cities where urban spatial structure has been proven to play an important role in alleviating UHI effects. The relationship between land ...surface temperature and urban spatial structures has been explored, providing strong support for their cooling effects. Urban roads are the skeleton of urban spatial structures, with obvious spatial structure characteristics; however, research on the relationship between roads and the thermal environment has been mostly focused at the micro and meso level, lacking exploration at the macro spatial structure scale. Xuzhou—a typical average-sized city in China—was selected as the research object and the road system as the carrier. The thermal environmental effects of road elements such as their structural attributes, geometric attributes and unique construction attributes were quantitatively analyzed using geographically weighted regression analysis. The results revealed that 1) the contribution of roads in the study area to the UHI effect is relatively stable; therefore, this area should become an important cooling space to decompose UHI patch connectivity and thus decrease the UHI effect. 2) the self-organizing structural characteristics of urban roads affect their thermal environments where in the straightness of the road structure and road thermal environment showed a clear overall negative correlation And 3) the length and width of the road segments had negative and positive effects on the thermal environment, respectively. The green coverage of the roads has a global negative effect on the thermal environment, but shows obvious spatial non-stationarity. Therefore, green measures must be implemented in different regions. The results here provide a quantitative basis for urban road system planning and urban form management and control that incorporates thermal environment improvements, as well as a reference for the study of urban thermal environments under different spatial forms and planning control systems in other countries and regions.
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•Quantify the evolution character and impact on thermal environment of road structure.•Explore the spatial non-stationarity of the thermal environment based on the MGWR.•Design a framework for synergizing thermal environment with road spatial structure.
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•U-Pb age of zircons from Zhongyuku pluton yields 149.6±2.4Ma.•Metallogenic events is Late Jurassic-Early Cretaceous.•Petrology, mineral, and geochronology were used for mineral ...exploration.
The Luanchuan ore fields form part of the East Qinling metallogenic belt in central China. In this study, we compare two ore-bearing intrusions, the Shibaogou granitic pluton (SBG) and the Zhongyuku granitic pluton (ZYK), with the ore-barren Laojunshan intrusion (LJS) from the Luanchuan ore field. Geochemically, all the three intrusions are characterized by high-Si, high-K, and alkalis, together with moderate-ASI, exhibiting I-type granite features. The rocks, especially the ore-related plutons also show enrichment in LREEs. Mineral chemistry of biotite from the intrusions exhibits similar features of high Si and Mg, and low Al and Fe. Zircon grains from the ZYK intrusion yielded a U-Pb age of 149.6±2.4Ma. The zircon grains show εHf (t) values and two stage model ages (TDM2) in the range of −16.8 to −19.7 and 1998–2156Ma respectively. The biotite composition and Hf isotopic data indicate that the magma was derived by re-melting of deep crustal material with minor input of mantle components. We evaluate the results to understand the physico-chemical conditions, petrogenesis, and tectonic setting, and their implications for mineral exploration. The ore-bearing plutons show wide ranges of temperature and oxygen fugacity, favoring Mo-W mineralization. In addition, estimates on pressure and depth of emplacement suggest that lower solidification pressure in a decompressional setting contributed to the evolution of magmatic hydrothermal deposits. Our data suggest that the ZYK has the highest potential for Mo-W mineralization. The ore-bearing plutons of ZYK and SBG were formed in a transitional tectonic setting from compression to extension, with the large-scale metallogeny triggered by slab melts at ca. 145Ma. However, the ore-barren LJS batholith formed in an extension-related geodynamic setting at ∼115Ma. Our study shows that different tectonic settings and consequent physico-chemical conditions dictated the ore potential of the intrusions in the Luanchuan ore district.
This case report details a rare instance of gallbladder diverticulum, highlighting the diagnostic and therapeutic challenges associated with this condition. Gallbladder diverticulum is an uncommon ...anomaly that often mimics the symptoms of more prevalent gallbladder diseases, making an accurate diagnosis challenging. The patient, a 55-year-old female, presented with atypical abdominal pain and was initially suspected to have chronic cholecystitis. Ultrasound examinations and subsequent enhanced computed tomography imaging revealed a gallbladder diverticulum without the presence of gallstones or polyps. Given the rarity of this condition and the potential for complications, a laparoscopic cholecystectomy was performed. The surgery was successful, and the patient's symptoms were completely resolved postoperatively, confirming the diagnosis. This report underscores the importance of considering gallbladder diverticulum in the differential diagnosis for atypical gallbladder symptoms and advocates for prompt surgical intervention to prevent complications. Our findings contribute to the limited literature on this rare condition and emphasize the need for awareness among clinicians to achieve optimal patient outcomes.
The micro-grooves with special structure and size have the special function of reducing surface flow resistance. Placing the micro-grooves over a larger area on the aircraft surface can achieve ...effective drag reduction, that is, a decrease in the resistance experienced during operation. Rolling method can be used to form micro-grooves on metal surface efficiently. However, the micro-grooves formed by this plastic forming method may have some defects, which in turn could cause serious negative impact on the drag reduction and mechanical properties of the micro-grooves. Therefore, optimization of the multi-pass rolling process to avoid the micro-groove defects is of great significance. This paper includes a series of analysis on the microstructure, strain, and material displacement of micro-grooves, which were carried out to explain the causes of micro-groove defects. Micro-grooves were formed on the surface of the sheet, and the plate also underwent both thickness reduction and extension in the
Y
-direction, under the pressure exerted by the roller. It was found that the extension of the plate had an adverse effect on the formation of micro-grooves; thus, the hole types of the roller were optimized accordingly. The simulation and experimental results showed that the optimized roller could produce the desired micro-grooves, which perfectly eliminated the generation of micro defects.
A twisted channel self-bending shunting die, a vertical shunting die, and a symmetrical streamlined shunting die were designed. The plate extrusions of these dies were simulated and experimented ...with. The experimental results show that the actual metal flow is consistent with it in the simulation. The results of the simulation show that the leftward bending plate is extruded out by the twisted channel self-bending shunting die, and the straight plate is extruded out by the other dies. The data for the welding path in the extrusion process of the three shunting dies were extracted, and the
J
values of the welding criterion were calculated. The longer the weld stability height distance above the
J
value, the wider the stable weld formation interval, the better the weld quality. The order of weld quality among the three dies is that vertical shunting die < symmetrical streamlined shunting die < twisted channel self-bending shunting die. The symmetrical streamlined shunting die and the twisted channel self-bending shunting die were simulated at different extrusion speeds, the results show that the greater the extrusion speed, the shorter the distance of the stable weld height above the junction value
J
, and the worse the weld quality of the shunting dies.
•The hypothesis that propofol alters gut microbes was tested in a rat model with continuous intravenous infusion of propofol.•Changes in the abundance and diversity of intestinal flora were assessed ...by 16s ribosomal RNA sequencing and fecal sample analysis.•The results indicate that continuous intravenous infusion of propofol had little effect on intestinal flora of rats in a short period of time.
Under normal circumstances, the gut microbiota, host, and external environment establish a dynamic ecological balance and maintain human health. Once this balance is broken, the intestinal flora dysregulation will form, manifested by changes in the diversity, richness, proportion, location and biological characteristics of the gut microbiota. The hypothesis that propofol alters gut microbes was tested in a rat model with continuous intravenous infusion of propofol. Eight male wistar rats underwent tail vein puncture and catheterization respectively, and were continuously pumped with propofol for 3 h. Feces were collected from each rat before and on the 1 st, 3rd, 7th and 14th days after intervention. Finally, the effect of continuous intravenous infusion of propofol on the intestinal flora of rats was analyzed by high-throughput 16S rRNA gene amplification sequencing. Through high-throughput 16S rRNA gene amplicon sequencing analysis, we found that continuous intravenous infusion of propofol had little effect on intestinal flora in rats. Analysis of Alpha (shannon diversity index) showed that group A-7 was different from group P and group A-1 (P = 0.034), and recovered on the 14th day. Although the species diversity analysis showed a significant difference among the five groups (P = 0.049), the distribution of most fecal samples in the PCoA showed a clustered distribution, indicating similarity. In addition, no significant difference was found in the statistical KEGG difference pathway through LEfSe analysis.
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