The Rayleigh-Plesset equation is the fundamental model of bubble dynamics and is widely used in the study of cavitation mechanisms. Since cavitation bubble often occurs at the micro-scale, the effect ...of surface tension will have an important influence on the bubble motion. Based on the Sundman transformation and Weierstrass elliptic function theory, this paper studies the Rayleigh-Plesset equation considering surface tension, and establishes the parametric theoretical solutions of vapor bubble and gas bubble respectively. The results show that the vapor-bubble and gas-bubble dynamic equations can be solved theoretically. Further, based on the theoretical solutions, the effects of the surface tension on the motion of vapor bubbles and gas bubbles are studied in detail. For the two types of bubbles, the influence of the surface tension on the bubble motion will increase gradually as the scale of the bubble gets smaller. Especially when the bubble scale is reduced to 10 µm, the effect of the surface tension becomes too significant to be negligible.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Chromium (III) salts are the most extensively used tanning agents due to the higher quality and stabilization ability to leather collagen. However, chromium (III) salts tanning agent has a strong ...impact on the environment owing to the pollution of wastewater and the solid waste containing chrome. In order to crosslink the collagen by a cleaner method, three kinds of sulfonated calix4arenes {sulfonated calix4arene (SC), sulfonated tetraphenyl calix4resorcinarene (STCR), and sulfonated tetramethylene tetraphenyl calix4resorcinarene(STTCR)} were prepared and utilized for the collagen crosslinking and leather tanning. The collagen crosslinking degree of sulfonated calix4arenes was investigated by fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), scanning electron micrograph (SEM), and X-ray photoelectron spectroscopy (XPS). The results show that the collagen can be crosslinked by phenol hydroxyl groups on sulfonated calix4arenes. Moreover, STCR shows better crosslinking effects than others because the number of phenol hydroxyl groups and the position of sulfonic groups on sulfonated calix4arenes play important roles in the crosslinking process. These results can be confirmed by sulfonated calix4arenes tanning processes, and STCR tanned leather shows the higher shrinkage temperature. This paper provides a promising chrome-free method to reduce the pollution of chromium tanning waste.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
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•The essential oil of C.sinensis showed effective insecticidal activity both in laboratory and greenhouse bioassays•Five insecticidal compounds from CSEO were isolated and ...identified.•β-Phellandrene, caryophyllene oxide, β-caryophyllene and α-pinene exhibited potent contact and fumigant activity.•This is the first report of insecticidal activities of CSEO and its main components.
Plant essential oils (EOs) could be used as new alternatives of synthetic insecticides due to their environmental friendliness, safety to non-target organisms, and low-level resistance. In this study, the essential oil of Cephalotaxus sinensis (CSEO), an important Chinese medicinal species, showed potent insecticidal activity against Megoura japonica, Plutella xylostella and Sitophilus zeamais in laboratory bioassays; CSEO 20 % emulsifiable concentrate exhibited the control efficacy of 85.67 % against M. japonica after 7 days treatment at concentration of 0.25 % (w/v) in the greenhouse experiment. The GC-MS results showed that the main components of CSEO were α-pinene (37.89 %), β-caryophyllene (16.78 %) and germacrene D (10.79 %). Five active compounds, β-elemene (1), β-caryophyllene (2), β-phellandrene (3) caryophyllene oxide (4) and α-pinene (5) were isolated from CSEO. β-Caryophyllene (2) exhibited highest contact toxicity against M. japonica and P. xylostella, with the median lethal dose (LD50) values of 0.072 μg/adult and 0.32 μg/larva, respectively. α-Pinene (5) showed the highest fumigant toxicity against M. japonica and P. xylostella, with the median lethal concentration (LC50) values of 6.74 and 7.35 mg/L, respectively. Furthermore, β-phellandrene (3) had the potent contact and fumigant toxicity against S. zeamais with the LD50 and LC50 value of 2.19 μg/adult and 3.57 mg/L, respectively. Thus, CSEO and their major components have the potential to be developed as novel botanical insecticides for the control of agricultural pests.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
With the gradual attention of global climate change, a series of carbon emission plans have been formally implemented in the field of energy. There is a consistent relationship between the carbon ...market and the electricity market in promoting clean energy development and improving carbon dioxide emission reduction targets. The market design of a low‐carbon power system should be considered as a whole to promote the coordinated development of carbon and power markets. Taking an industrial park in China as the research object, an internal market trading model of an industrial park considering carbon dioxide emission reduction targets is proposed. The proposed trading mechanism considers both carbon dioxide emission reduction targets and social welfare maximization. The proposed market trading model connects day‐ahead and intraday electricity markets, which deal with uncertainty about renewable energy sources.
The intra‐park market trading model combining the day‐ahead market and the domestic market is established, which provides a new way to deal with the uncertainty of new energy and reduce carbon emissions. The clearing model of the low‐carbon electricity market is established to maximize social welfare, and the settlement mechanism of each market participant is given.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Androgenic alopecia (AGA), also known as male pattern baldness, is one of the most common hair loss diseases worldwide. The main treatments of AGA include hair transplant surgery, oral medicines, and ...LDL laser irradiation, although no treatment to date can fully cure this disease. Animal models play important roles in the exploration of potential mechanisms of disease development and in assessing novel treatments. The present study describes androgen receptor (AR) in C57BL/6 mouse hair follicles that can be activated by dihydrotestosterone (DHT) and translocate to the nucleus. This led to the design of a mouse model of androgen-induced AGA in vivo and in vitro. DHT was found to induce early hair regression, hair miniaturization, hair density loss, and changes in hair morphology in male C57BL/6 mice. These effects of DHT could be partly reversed by the AR antagonist bicalutamide. DHT had similar effects in an ex vivo model of hair loss. Evaluation of histology, organ culture, and protein expression could explain the mechanism by which DHT delayed hair regrowth.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
•We examined the biochar-induced priming effects in relation to aggregate size class and biochar level.•Percent of biochar-derived CO2 emission to the total mineralized C increased as the aggregate ...size decreased.•Stronger negative priming effect was expressed in >0.25 mm macroaggregates.•Higher biochar level brought about stronger negative priming effect in >0.25 mm macroaggregates.
The priming effect in soils is known to depend in part on the size distribution and decomposability of aggregate-associated soil organic carbon. However, the biochar-induced carbon mineralization priming effects within aggregates of different size classes are poorly understood. In this study, the bulk soils were firstly separated into three fractions (>1 mm macroaggregate, 0.25−1 mm macroaggregate, and <0.25 mm microaggregate). Then, the bulk soils and different aggregate-size fractions were incubated for 180 days following the incorporation of biochar (C4 source) with two levels (2.5 % and 5.0 %). Sources of C decomposition (biochar derived C, primed C, and basal soil derived C) were partitioned. The percent of biochar-derived CO2 emission to the total mineralized C increased as the aggregate size decreased. The short-term positive priming effects appeared in the early stage for all three aggregate-size fractions. Predominantly negative priming effects were observed after 56 days of incubation in the bulk soils and>0.25 mm macroaggregates. However, a weak negative priming effect was only detected after 180 days at a high biochar level in the <0.25 mm microaggregates. Furthermore, much stronger repression of soil C mineralization was induced by a higher biochar level, with 10.1–53.4 % higher negative priming effects under 5.0 % biochar treatments than 2.5 % biochar treatments over 180 days. The results suggest that a greater portion of total readily decomposable soil organic C in >0.25 mm macroaggregates has probably been protected by biochar amended and made unavailable. Our study indicates that the priming effects of biochar on the soil organic carbon in Ultisols depend on the aggregate size.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Land-use scene classification (LUSC) is a key technique in the field of remote sensing imagery (RSI) interpretation. A convolutional neural network (CNN) is widely used for its ability to ...autonomously and efficiently extract deep semantic feature maps (DSFMs) from large-scale RSI data. However, CNNs cannot accurately extract the rich spatial structure information of RSI, and the key information of RSI is easily lost due to many pooling layers, so it is difficult to ensure the information integrity of the spatial structure feature maps (SSFMs) and DSFMs of RSI with CNNs only for LUSC, which can easily affect the classification performance. To fully utilize the SSFMs and make up for the insufficiency of CNN in capturing the relationship information between the land-use objects of RSI, while reducing the loss of important information, we propose an effective dual-branch hybrid framework, HFCC-Net, for the LUSC task. The CNN in the upper branch extracts multi-scale DSFMs of the same scene using transfer learning techniques; the graph routing-based CapsNet in the lower branch is used to obtain SSFMs from DSFMs in different scales, and element-by-element summation achieves enhanced representations of SSFMs; a newly designed function is used to fuse the top-level DSFMs with SSFMs to generate discriminant feature maps (DFMs); and, finally, the DFMs are fed into classifier. We conducted sufficient experiments using HFCC-Net on four public datasets. The results show that our method has better classification performance compared to some existing CNN-based state-of-the-art methods.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In the present work, a Ti(C7N3)-based cermet micro end-milling tool was developed. Thereafter, the cutting characteristics and tool performance were investigated during machining of aluminum alloy ...2024. The burr formation, tool wear and chip information were analyzed at various cutting parameters. Further, failure mechanism of Ti(C7N3)-based cermet micro end-mill tools were thoroughly discussed. The results indicated that the burr was initiated after six minutes of micro milling using the WC micro end-mill tool but after thirteen minutes of micro milling using the Ti(C7N3)-based cermet micro end-mill tool. The main wear mechanisms of the Ti(C7N3)-based cermet micro end-mill tool were micro-crack initiation and crack propagation resulting in tool failure. Chip information was also discussed in combination with uncut chip thickness. However, different properties and characteristics of Ti(C7N3)-based cermet indicate its superiority over other commonly used tool materials especially WC.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
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