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In the rapid process of urbanization, crucial habitats for mid-sized felids such as bobcats are increasingly compromised. This study employs Geographic Information System (GIS) tools and Machine Learning to investigate the subtle impacts of urbanization on bobcat habitats. Focused on the San Jose area, our extensive geospatial analysis has developed a complex ecological model for bobcat habitats. Our findings emphasize the significant influence of factors like vegetation cover, water body distribution, road traffic volume, and intersection density on the suitability of habitats for bobcats. Specifically, we discovered that while vegetation cover typically supports habitat suitability, its proximity to busy roads significantly undermines this advantage, indicating a need for strategic urban planning that incorporates wildlife mobility. By synthesizing natural and urban elements, we offer fresh insights into urban ecosystem management and propose specific conservation tactics: identifying optimal wildlife crossings, integrating corridors with urban infrastructure, and placing fencing and signage strategically to facilitate wildlife movement safely. These measures aim to reduce road-related threats and enhance the integrity of natural habitats, strengthening bobcat conservation efforts. More than its direct implications for bobcat conservation, this study offers actionable insights for urban wildlife conservation and introduces innovative methods for assessing and mitigating the broader ecological impacts of urbanization. [ABSTRACT FROM AUTHOR]

In modern cities, urban public spaces, such as parks, gardens, plazas, and streets, play a big role in people's social activities, physical activities, mental health, and overall well-being. However, the traditional post-occupancy evaluation (POE) process for public spaces such as large urban parks is extremely difficult, especially for long-term user experiences through observations, surveys, and interviews. On the other hand, social media has emerged as a major media outlet recording millions of user experiences to the public, which provides opportunities to inform how public space is used and perceived by users. Furthermore, unlike previous research that primarily presented descriptive characters of park programs, our study employs a network model to elucidate the interactive relationships and intensities among reported park elements, human activities, and experiences. This approach enables us to track the sources within the space that impact people's perceptions, such as weather conditions, food options, and notable landmarks. The utilization of this network model opens avenues for future research to comprehensively investigate the factors shaping people's perceptions in public open spaces. This study uses Bryant Park as an example and presents a new analytical framework, POSE (post-occupancy social media evaluation), to support long-term POE studies for large public spaces. Methods such as data automation, descriptive statistics, and social network analysis were used. The identification and quantification of meaningful park activities, scenes, and sentiments as well as their relationships will help optimize the design and management of park programs. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to apply the theory of system to the field of product design and to research the properties of product materials. According to the sorting and analysis of the relevant research results and literature and based on the systematic method the perception attribute is studied through the humanistic characteristics of product materials; the cultural attribute is studied through the historical characteristics of product materials; the commercial attribute is studied through the economic value characteristics of product materials; the environmental attribute is studied from the perspective of the ecological and sustainable development of product materials. On this basis, the feasibility suggestions for future research in this field are put forward.

In this study, the electromagnetic performances of dual 3‐phase permanent magnet (PM) machines with coil span of two slot‐pitches are comparatively investigated. It mainly focuses on two PM machines with different slot/pole number combinations (Ns/2p), that is, the 24‐slot/10‐pole and 24‐slot/14‐pole machines (2p = Ns/2 ± 2). First, winding configurations are illustrated for these two dual 3‐phase machines with 30° angle displacement. Then, the winding factor, back electromotive force, average torque, torque ripple, iron and PM losses, short‐circuit (SC) current, and PM irreversible demagnetisation are analysed and compared for both machines on the conditions of healthy operation and one set of three‐phase fault, that is, SC or open circuit (OC), respectively. The comparative results show that on healthy condition the 14‐pole PM machine has a slightly larger torque output. Besides, on 3‐phase OC condition, the 14‐pole machine also performs better over‐rating torque capability. In terms of iron and PM losses, the 10‐pole machine has smaller iron losses but larger PM losses than the 14‐pole machine. Moreover, on 3‐phase SC condition, the 14‐pole machine has a significantly lower risk of PM irreversible demagnetisation than the 10‐pole machine, although both machines have very similar SC currents. Finally, the 24‐slot/10‐ and 14‐pole dual 3‐phase PM machines are both prototyped and some tests are carried out for validation. [ABSTRACT FROM AUTHOR]

A hybrid analytical and lumped-parameter thermal model is proposed in this paper to estimate the transient and steady-state two- and three-dimensional (2/3-D) spatial magnet temperature distributions for an interior permanent magnet synchronous machine (IPMSM). On the basis of a lumped-parameter thermal model (LPTM), the magnet analytical thermal models (ATMs) are synergized to establish the hybrid thermal model. By utilizing the transient or steady-state boundary conditions calculated by the LPTM, the ATMs are obtained by solving the heat conduction equations to estimate the spatial magnet temperature distributions in the 2-D horizontal-vertical and axial-vertical planes, which can also be extended to the 3-D temperature distribution by utilizing the multi-slice method. Meanwhile, the non-uniform magnet eddy current loss is also considered. Finally, both electromagnetic-thermal coupled finite element analysis method and experiments are used for verification based on a totally enclosed IPMSM. [ABSTRACT FROM AUTHOR]

Lumped-parameter thermal models (LPTMs) have been widely used to estimate critical temperatures in permanent magnet synchronous machines (PMSMs). However, in some cases, they may be incapable of predicting the hotspots and even cause temperature misestimation. In this paper, the synergized lumped-parameter and sub-domain thermal models are proposed for surface-mounted PMSMs to track the hotspots in the most vulnerable components, i.e., active/end-windings and rotor magnet. Firstly, the “T-type” elementary network based LPTM is developed to predict the average temperatures in main components and the boundary conditions. Secondly, the boundary conditions are applied to three sub-domain thermal models for the active/end-windings and the rotor magnet to predict the respective hotspots and to further correct the misestimated average temperatures. Finally, the proposed synergized thermal model is verified by the experiments on a prototype surface-mounted PMSM under various load conditions. [ABSTRACT FROM AUTHOR]

Aiming at the surrounding rock failure of heterogeneous and unequal pressure circular roadways, the approximate analytical algorithm of the plastic zone is proposed. Through the comparison of analytical calculations and numerical simulation, the shape characteristics and evolution law of the surrounding rock's plastic zone are studied, and the relative error of the two calculation methods is analyzed. The results show the following: (1) With an increase or decrease in the lateral pressure coefficient, the shape of the plastic zone of the roadway-surrounding rock presents a circular-ellipse-butterfly shape change law, and the outer edge of the plastic zone presents a scattered shape, without a continuous boundary. (2) In the butterfly-shaped plastic zone, the butterfly leaf always lies between the maximum confining pressure and the minimum confining pressure and rotates with the pressure. (3) There is a certain amount of error between the maximum value of the plastic zone solved by an analytical algorithm and numerical simulation, and the relative error is positively related to the burial depth and lateral pressure coefficient of the roadway and negatively related to the strength of the surrounding rock. (4) In addition, the relative error of the plastic zone calculation of the multi-layer heterogeneous combination roadway is larger than that of the single heterogeneous roadway. [ABSTRACT FROM AUTHOR]

In this article, a simplified three-dimensional (3-D) hybrid analytical thermal model for surface-mounted permanent magnet (PM) synchronous machines is proposed and applied to investigate the influence of PM segmenting strategies on the spatial PM temperature distributions and hotspots. The developed 3-D hybrid thermal model synergies the lumped-parameter thermal model and analytical method and is able to estimate 3-D spatial temperature distributions and hotspots for both unsegmented and segmented surface-mounted PMs accounting for the uneven PM eddy current loss distributions. Meanwhile, by utilizing the proposed matrix-based post-processing methods, the developed hybrid analytical thermal model has a simple mathematical expression but persists in high estimation accuracy. Finally, the proposed hybrid analytical modelling method is validated by 3-D electromagnetic-thermal coupled FEA and experiments. [ABSTRACT FROM AUTHOR]

In this article, the rotor stress is analysed for a high-speed permanent magnet (PM) machine (HSPMM) with segmented magnets retained by a carbon-fibre sleeve. The influence of rotor PM segmentation is firstly considered in the stress analysis. It is found that when the segmented magnets are under tensile stress, significant sleeve stress concentration will occur due to magnet edging effect. By contrast, the PMs will benefit from the segmentation with reduced tangential stress. This stress reduction effect is enhanced when the number of PM segments is larger. Furthermore, the influence of PM segmentation on the worst operating scenario is determined. In order to avoid stress concentration due to PM segmentation, the design guidelines are then given by investigating the influence of sleeve thickness and interference fit. A new design scheme of sleeve thickness is proposed based on the identified worst case scenarios. Finally, a 6-slot 4-pole high speed PM machine with segmented magnets retained by carbon-fibre sleeve is prototyped and tested at the speed of 90 krpm. The rotor stability indirectly indicts the validity of the theoretical analysis and design scheme. [ABSTRACT FROM AUTHOR]

Current harmonics are ubiquitous in dual three phase (DTP) permanent magnet synchronous machine (PMSM) drives. Due to back electromotive force (EMF) distortion, significant current harmonics are generated in the DTP-PMSM system. The influence of back EMF harmonics is investigated in this paper and a novel switching-table-based direct torque control method to compensate the selected current harmonics caused by the back EMF harmonics is proposed. It shows that by employing different optimal action time durations for voltage vectors in the z1z2 subspace and setting the synthetic voltage vectors to non-zero, the stator flux harmonics caused by the back EMF harmonics can be selectively compensated, as verified by experiments. [ABSTRACT FROM AUTHOR]

Aiming at the problem of surrounding rock deformation and failure of mining roadway and its control, a mechanical model of the circular roadway under the mining environment is established, and the implicit equation of the plastic zone boundary is derived. By analyzing the morphologic evolution law of the surrounding rock plastic zone in the mining roadway, the key factors affecting the morphologic change of the plastic zone are obtained, that is, the magnitude and direction of principal stress. The influence law of the magnitude and direction of principal stress on the plastic zone of the mining roadway is analyzed by using numerical simulation software, and the deformation and failure mechanism of surrounding rock of the mining roadway is revealed. The results showed that the size and morphology of the plastic zone were closely related to the confining pressure ratio (η). Taking the boundary of η valuing 1, the larger or smaller η value was, the more serious the deformation and failure of surrounding rock would be; the morphology of the plastic zone changed with the deflection of the principal stress, with the location of the maximum plastic zone influenced by the principal stress direction. For the surrounding rock control in the mining-influenced roadway, it is advised to take the following methods: firstly, it is necessary to consider how to reduce or remove the influence of mining on surrounding rock, improve the stress environment of surrounding rock, and reduce the failure depth of the plastic zone, so as to better maintain the roadway. Secondly, in view of the deformation and failure characteristics of the mining roadway, the fractional support method of "yielding first and then resisting" should be adopted, which applies the cable supplement support after mining instead of the one-off high-strength support during roadway excavation, so as to control the malignant expansion of the surrounding rock plastic zone and prevent roof falling accidents. [ABSTRACT FROM AUTHOR]

The lumped-parameter thermal network (LPTN) has been widely used in the thermal analysis for electrical machines. Nevertheless, since the thermal resistances are defined based on the one-dimensional (1-D) heat transfer equation, it will cause the misestimation of the average temperatures when the thermal model extends to two dimensions or three dimensions. In this article, a hybrid thermal model utilizing the synergies of LPTN and 2-D analytical thermal models is developed to address this issue and to predict accurate critical temperatures, especially the average and maximum temperatures of the active and end windings. The 2-D analytical thermal models are obtained by solving the Poisson's equations with the Dirichlet boundary conditions extracted from the LPTN. The derived analytical solutions are expressed as the Fourier series, which can be further simplified by utilizing the first term only to represent average and maximum temperatures with sufficient accuracy and short computation time. The hybrid thermal model is applied to a totally enclosed forced convection permanent magnet synchronous machine and validated by numerical techniques and experiments. [ABSTRACT FROM AUTHOR]

Fractional-slot permanent magnet (PM) machines with an odd number of stator slots are attractive candidates for industrial applications due to their high torque density and low torque ripple. However, the unbalanced magnetic force is detrimental to the bearing and yields noise and vibration. This paper determines the existence criterion of UMF on both open-circuit and on-load conditions by analysis of air gap field and magnetic force waves. Only when the machine periodicity is one, will the open-circuit UMF be generated due to the mutual interaction between the modulated PM harmonics and the original PM harmonics. In addition, the existence of on-load UMF in machines with a periodicity of one is confirmed even when the slotting effect is ignored. Furthermore, among the five investigated machines with a given odd slot number of 9 but different pole numbers, the UMF in a machine with two poles is the smallest since the magnitude of the 2nd harmonic in the armature reaction is the smallest compared with other contributing harmonics. Meanwhile, the UMF in a machine with pole number 2p = Ns−1 is the largest due to the relatively larger magnitude of the (p + 1)th armature reaction harmonic and the additive effect between the first order radial and tangential stresses. [ABSTRACT FROM AUTHOR]

In this article, a current profiling technique is proposed for the torque density enhancement in switched reluctance machines (SRMs). The novel current profile is initially developed from the harmonic current injection method and is then modified into a unipolar waveform to allow the application of an asymmetric bridge inverter. It is found that, neglecting the magnetic saturation, the optimal current profile for the maximum torque per ampere operation in an SRM is close to a pulse with high-order harmonics. However, an optimized current with relatively low-order harmonics can provide better performance in the practical situation. Based on the analytical and the finite element results, the proposed method is proved to be able to enhance the torque density by 20% at the light load condition and by 15% at the rated condition compared with the conventional SRM excitation. Also, the large torque ripple and core loss in SRMs are suppressed and the efficiency is improved. More importantly, unlike many other current profiling techniques, the proposed current profile has fixed parameters and is easily adaptable to different machine specifications. The effectiveness of the proposed method is verified by both the finite-element analyses and the experiments. [ABSTRACT FROM AUTHOR]

The second harmonic current injection method is recently developed to enhance the torque density of variable flux reluctance machines (VFRMs). This article investigates the feasibility and effectiveness of the second harmonic current injection method in VFRMs with different stator/rotor pole combinations. By using magnetic gearing effect, it is found that the second harmonic injection method can only be applied to the 6j/(6i ± 2)j (i, j = 0, 1, 2…) stator/rotor pole VFRMs for the torque density enhancement. For the other stator/rotor pole combinations, the second harmonic current has no contribution in average torque production but only leads to excessive torque ripple. Further, by using global optimization method and finite element analysis, 6/8 stator/rotor pole combination is proved to be the optimal stator/rotor pole combination for 6-stator-slots VFRMs with the second harmonic current injection method, being able to exceed the maximal torque density of conventional VFRMs by 12% at a fixed copper loss. [ABSTRACT FROM AUTHOR]

Artemisinin and its analogues (ARTs) are currently the most effective anti-malarial drugs, but the precise mechanism of action is still highly controversial. Effects of ARTs on Plasmodium genes expression are studied in our Lab. The overexpression of an interesting amidotransferase, NADH-dependent glutamate synthase (NADH-GltS) was found in treated by dihydroartemisinin (DHA). The increased expression occurred not only from global transcriptomics analysis on the human malaria parasite Plasmodium falciparum (P. falciparum) 3D7 and gene expression screening on all of iron-sulphur cluster proteins from P. f. 3D7 in vitro but also from Plasmodium berghei (P. berghei) ANKA in mice. Influence of DHA on NADH-GltS was specifically at trophozoite stage of P. falciparum and in a dose-dependent manner below the effective doses. L-glutamine (Gln) and L-glutamate (Glu) are the substrate and product of NADH-GltS respectively. Azaserine (Aza) is specific inhibitor for NADH-GltS. Experimental data showed that Glu levels were significantly decreasing with DHA dose increasing but NADH-GltS enzyme activities were still remained at higher levels in parasites, and appropriate amount of exogenous Glu could significantly reduce anti-malarial action of DHA but excessive amount lost the above effect. Aza alone could inhibit proliferation of P. falciparum and had an additive effect in combination with DHA. Those results could suggest that: Glutamate depletion is one of the anti-malarial actions of DHA; overexpression of NADH-GltS would be a feedback pattern of parasite itself due to glutamate depletion, but not a direct action of DHA; the "feedback pattern" is one of protective strategies of Plasmodium to interfere with the anti-malarial actions of DHA; and specific inhibitor for NADH-GltS as a new type of anti-malarial agents or new partner in ACT might provide a potential. [ABSTRACT FROM AUTHOR]

Variable flux reluctance machines (VFRMs) are developed as magnetless electrical machines. To extend the application of VFRMs, the enhancement of torque density is a key during machine design. In this paper, a novel second-harmonic current injection method is developed for torque density enhancement for 6-stator-slot/4-rotor-tooth (6/4) VFRM. By using the analytical method, the optimal current profile with injected second-harmonic current is obtained. The average torque of 6/4 VFRM is improved by 20% with the proposed method under all load conditions. Moreover, the proposed current profile has fixed harmonic proportions and is easily applicable to machines with different specifications. All the conclusions are confirmed by both finite-element analyses and experimental results. [ABSTRACT FROM AUTHOR]

This study investigates the underlying mechanism of low‐power factor issue of variable flux reluctance machines (VFRMs) from the perspective of magneto‐motive force (MMF)‐permeance model. On the basis of a simplified analytical model, the relationship between the design parameters and the power factor is identified and systematically summarised into three predictable ratios: the rotor permeance ratio, stator/rotor‐pole ratio and DC/AC winding ampere turns ratio. Specifically, the smaller the rotor‐pole arc, the air‐gap length, the rotor‐pole number and the AC/DC winding ampere turns ratio are, the higher the power factor will be. In addition, the weak coupling between the field and armature windings caused by the modulation effect of the salient rotor is responsible for the low‐power factor issue of VFRMs, regardless of the control scheme, winding configuration or saturation effect. A 6‐stator‐pole/4‐rotor‐pole VFRM is prototyped and tested for verification. [ABSTRACT FROM AUTHOR]

The split ratio of rotor outer diameter to stator outer diameter is one of the most important design parameters due to its significant impact on machine torque density and efficiency. It has been optimised analytically in existing papers with due account given only for the thermal limitations. Here, the optimised split ratio for high‐speed permanent magnet machines (HSPMM) with consideration of the mechanical constraints is investigated analytically. In addition, the influences of flux density ratio, maximum operating speed and sleeve material on the optimised split ratio are discussed in detail. The analytical results are verified by finite‐element analyses. It is demonstrated that the optimised split ratio as well as the achievable torque of HSPMM is significantly reduced when the mechanical constraints are taken into consideration. The experimental results on a 6/slot‐4pole HSPMM confirm the validity of previous analyses. [ABSTRACT FROM AUTHOR]

In this paper, the iron loss models for electrical machines are first reviewed. One of the most accurate iron loss models, when the temperature is constant, is identified. An improved temperature-dependent iron loss model is also introduced. By applying the improved iron loss model to the electrical machine thermal analysis, the thermal and loss analyses can be fully coupled. Based on this, an improved thermal-loss coupling analysis method for electrical machine is developed in this paper. The electrical machine iron loss tests are carried out. The analysis and measurement results are then compared in order to validate the improved thermal-loss coupling analysis method. The comparison results indicate that the temperature prediction accuracy can be significantly improved by using the improved thermal-loss coupling analysis method. [ABSTRACT FROM AUTHOR]

This paper proposes a novel scheme for the identification of the whole flux linkage map of permanent magnet synchronous machines, by which the map of dq-axis flux linkages at different load or saturation conditions can be identified by the minimization of a proposed estimation model. The proposed method works on a conventional three-phase inverter based vector control system and the immune clonal based quantum genetic algorithm is employed for the global searching of minimal point. Besides, it is also noteworthy that the influence of uncertain inverter nonlinearity and circuit resistance are cancelled during the modeling process. The proposed method is subsequently tested on two PMSMs and shows quite good performance compared with the finite element prediction results. [ABSTRACT FROM PUBLISHER]

In this paper, the different temperature dependencies of hysteresis and eddy current losses of non-oriented Si-steel laminations are investigated. The measured iron loss results show that both the hysteresis and eddy current losses vary linearly with temperature between 40 °C to 100 °C, a typical temperature range of electrical machines. Varying rates of hysteresis and eddy current losses with the temperature are different and fluctuate with flux density and frequency. Based on this, an improved iron loss model which can consider temperature dependencies of hysteresis and eddy current losses separately is developed. Based on the improved iron loss model, the temperature influence on the iron loss can be fully considered by measuring iron losses at only two different temperatures. The investigation is experimentally validated by both the tests based on a ring specimen and an electrical machine. [ABSTRACT FROM PUBLISHER]

In this paper, the temperature dependencies of iron loss under different flux densities, frequencies, and dc bias flux densities are systematically investigated. The temperature dependence of the hysteresis loss varies significantly with the dc bias flux density while that of the eddy current loss is independent of the dc bias flux density. Based on these different characteristics of the hysteresis and the eddy current iron losses, an improved iron loss model is developed. The temperature dependence of iron loss under dc bias condition can be considered by utilizing the improved iron loss model. The developed iron loss model is validated by both tests on laminations and an electrical machine. [ABSTRACT FROM AUTHOR]

In this paper, the investigation is focused on the iron loss prediction for electrical machines fed by low switching frequency inverter. An improved iron loss model is developed after reviewing various existing iron loss models considering pulse-width modulation (PWM) influence. In order to validate the improved iron loss model, iron loss tests are carried out on an electrical machine. The predicted iron loss results match well with the measured results, which shows that the improved iron loss model is able to predict iron loss in electrical machine fed by an inverter. The comparison between the predicted iron losses with and without considering the PWM influence shows that the iron loss can be significantly increased due to the influence of PWM, especially when the switching frequency is low. [ABSTRACT FROM AUTHOR]

This study proposes a novel method for the parameter determination of permanent magnet (PM) synchronous machines under different load conditions. It can identify the total dq‐axis flux linkages and also the PM flux linkage separately by the addition of a pair of negative and positive position offsets. It is also noteworthy that the influence of uncertain inverter non‐linearity and winding resistance is cancelled during the modelling process, and the experimental results on two different PM synchronous machines show a good agreement with the finite‐element prediction results. More importantly, it shows good performance in online tracking the variation of PM flux linkage, which is an important feature for aiding the condition monitoring of PMs, for example, monitoring the temperature of PMs. [ABSTRACT FROM AUTHOR]

In this study, the temperature influence on iron loss of non‐oriented steel laminations is investigated. The iron loss variation under different flux densities, frequencies and temperatures is systematically measured and analysed by testing two typical non‐oriented steel laminations, V300‐35 A and V470‐50 A. The iron loss variation with temperature is almost linear in the typical operating temperature range of electrical machines. Furthermore, the varying rate of iron loss with temperature varies with flux density and frequency. A coefficient which can fully consider the temperature influence is introduced to the existing iron loss model to improve the iron loss prediction accuracy. The predicted and measured results show that the temperature influence on the iron loss can be effectively considered by utilising the improved model, i.e. the prediction accuracy of the improved iron loss model remains constant, even when the temperature varies significantly. A potential simplification of this improved model is also discussed in this study. [ABSTRACT FROM AUTHOR]

In the last 40 years, the Beijing section of the Yongdinghe River evolved from a perennial and wandering river reach to a channellized and fragmentation dry river channel. Such changes threatened the local safety, eco-environment health, and economy development. In order to clarify the channel change patterns and its mechanisms, the spatial and temporal changes of the river channel and the causes are analysed. The results show that the river channel was greatly reshaped by the intensive land using, with a total of 66.95 km2 degraded area including the overflow land, water area, and agricultural land. The overflow land was mainly changed to dry riverbed, agricultural land, water conservancy construction land, planted woodland, and bare land. The water area was mainly replaced by dry riverbed, channellized watercourse, water conservancy construction land, and agricultural land. Agricultural land was mainly changed to residential land, dry riverbed, and bare land. The abrupt river runoff and sediment change after construction of the Guanting Reservoir (the largest reservoir in the Yongdinghe River) indicates a potential trigger for the river channel changes. The river channel change processes are finally concluded: before 1980, the large number of the water conservancy projects' construction including the reservoirs, check dams, and sluice in the Guanting Gorge (upstream of the study river reach) changed the river connectivity and the flow continuity of the upstream river channel. Together with the water use, the soil and water conservation activities, and the variable precipitation, almost all the runoff and sediment to the study river reach were intercepted; then the perennial dry up river and the increased land requirement impelled people to occupy the downstream river space. [ABSTRACT FROM AUTHOR]

In the last 50 years, the hydrological system of the Haihe River Basin in northern China has undergone great changes, such as declines in runoff and discharge, rivers drying up, and groundwater depletion. Both climate variability and human activities have been regarded as causes for these changes, but which is the major reason was not clear in the past. This paper aims to quantify the impact of climate variability, particularly changes of precipitation, and human activities (water storage projects, agricultural development, soil and water conservation projects, and agricultural water saving) on the hydrological system of the basin. A basin-level water consumption balance model was used to simulate the changes of the hydrological system during the period of 1958-2008. The non-parametric Mann-Kendall test and Pettitt's test methods were adopted to identify trends and change points of the hydrological factors. And the contribution of climatic variability and human activities was calculated based on the multi-year average of all the climatic and hydrological parameters of different river basin management stages and their relative changes between adjacent periods. The results show that from 1958 to 1965 the basin hydrological system was in the natural state of equilibrium. During 1966-1978 human activities were the main factors with the contribution of 96.1 and 76.6 % for the upstream and downstream area. During the period of 1979-1988, the change of precipitation was the main factor to cause the upstream and downstream hydrological system changes with contributions of 73.8 and 64.1 %. In the period of 1989-2000 and 2001-2008, the climate variability still dominated the impact of the hydrological system changes in the upstream and downstream areas. Based on these findings, some measures were recommended to improve the balance of the hydrological system in this basin including recharging the downstream area with water that is currently stored in the upstream, implementing agricultural water-saving practices in the basin, and using treated sewage from the cities for river environmental flow recovery and wetland restoration. [ABSTRACT FROM AUTHOR]

We proposed a passively Q-switched fiber laser with switchable wavelength based on two parallel fiber Bragg gratings. By increasing the input power, a single wavelength with a center wavelength of 1545.63 nm and dual wavelengths with a center wavelength of 1545.63 nm and 1553.60 nm can be obtained respectively. The wavelength spacing of the dual wavelengths is 8.17 nm, and the maximum repetition frequency of Q-switching is 24.27 kHz, and the narrowest pulse width is 5.48 ms. The combination of parallel fiber grating and erbium-ytterbium co-doped fiber (EYDF) saturable absorber provides a simple and feasible method to obtain stable (single and double wavelength switching) passively Q-switched pulses. [ABSTRACT FROM AUTHOR]

• A dual pulse with low repetition rate is obtained, which can be widely used in laser marking. • EYDFA is used as the light source which simplifies the experimental structure. • The EOM is used to realize actively Q-switching, which adds the research content in this field. In this paper, a multi-wavelength fiber laser based on electro-optical Q-switching is proposed to achieve stable dual-pulse output. The addition of a tunable filter outside the cavity to filter out different wavelengths separately proves that the dual-pulse is generated due to the time delay between different wavelengths. When the input power is 160 mW, we observed single pulses with pulse widths of 28.94 μs and 23.25 μs were obtained at 1544.11 nm and 1546.77 nm, respectively. We changed the average output power and pulse width by changing the input power or frequency of the external modulated signal, and simultaneously discussed the effect of the modulation amplitude of the electro-optical modulator (EOM) on the output of dual-pulse. [ABSTRACT FROM AUTHOR]

• Circ_0000518 promotes multiple sclerosis. • FUS promotes multiple sclerosis. • FUS activates the CaMKKβ/AMPK pathway. Evidence has shown that circ_0000518 is upregulated in peripheral of multiple sclerosis (MS) patients, suggesting that it may play an important role in the progression of MS. However, its specific mechanism in MS progression is unclear. In this study, the human microglial clone 3 (HMC3) cells were treated with 100 ng/mL of LPS for 24 h, then the short hairpin RNA against hsa_circ_0000518 (sh-hsa_circ_0000518) was transfected into cells and incubated for 48 h. We found increased circ_0000518 expressions, increased apoptosis and oxidative stress, increased M1 phenotype marker expression, and decreased M2 phenotype marker expression in cells, and that interfering with circ_0000518 expression reversed the effect of LPS on HMC3 cells. Online bioinformatics database analysis indicated that FUS is an RNA binding protein of circ_0000518. Next, we observed increased FUS expression in LPS treated HMC3 cells, and interfering with FUS expression reduced LPS triggered apoptosis and oxidative stress, decreased M1 phenotype marker expression, and promoted M2 phenotype marker expression. Mechanistic studies revealed that interfering with FUS promoted the polarization of HMC3 cells from the M1 phenotype to the M2 phenotype via activation of CaMKKβ/AMPK-PGC-1α pathway, whereas this promoting effect was counteracted by STO-609. In an experimental autoimmune encephalomyelitis (EAE) mouse model, we observed that circ_0000518 knockdown reduced circ_0000518 and FUS expression in brain and spinal cord tissues, reduced neurological scores in mice, and alleviated inflammatory cell infiltration in the CNS. Summarily, our study identified that circ_0000518 promotes macrophage/microglial M1 polarization through the FUS/CaMKKβ/AMPK pathway and aggravates MS. [ABSTRACT FROM AUTHOR]

The graphene supported SnO 2 nanoparticles (SnO 2 /graphene nanocomposites) were synthesized by a facile microwave-assisted polyol reduction method. The Na-storage performance of the as-prepared SnO 2 /graphene nanocomposites was evaluated as an anode material for sodium-ion batteries (SIBs), presenting a high initial reversible capacity of ~220 mA h g −1 at a current density of 0.1 A g −1 and an acceptable rate capability. This work provides an effective approach on synthesizing the SnO 2 /graphene nanocomposites and a potential anode material for SIBs. [ABSTRACT FROM AUTHOR]

Abstract: Water conservancy projects are commonly constructed with different purposes. This usually results in improved flooding control, but may lead as well to environmental problems, such as river dry up, river morphology change, and reduction in biodiversity. The present study considers water conservancy projects in the Haihe river basin, following the major flood in 1963. It maps the water projects as well as the surface water bodies in 1964, 1980 and 2004, by using an integrated method of remote sensing and field surveys. The impact of the water conservancy projects on the hydro-ecological processes and the ecological environment is analyzed. Construction of the controlled reservoir resulted in a sharp drop of the river discharge and sediment. It also resulted in a reduction of river infiltration, an increase of evaporation and a change in regional water balance characteristics. Furthermore, the projects separated the hydraulic connection between upstream and downstream areas, weakened the river’s natural connectivity, and changed the dynamic conditions of the river water. On the basis of the study, we propose changing the operation mode of the existing controllable water conservancy projects and removing the projects with degraded and unreasonable functions as two optional ways to resolve the hydro-ecological problems of the basin. [Copyright &y& Elsevier]