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Aquatic ecosystems worldwide are increasingly affected by human activities, with urbanization representing a major source of environmental stress. Channelization and flow depletion are key stressors in urban aquatic ecosystems. However, the combined effects of these factors on benthic macroinvertebrate and fish communities in urban rivers remain poorly understood. We examined the ecological impacts of channelization and flow depletion on benthic macroinvertebrates and fish in four urban rivers in Beijing, China: the natural high-flow Yongding River, the natural low-flow Gaojinggou River, the artificial high-flow Yongding River Diversion Channel, and the artificial low-flow Renmin Channel. By analyzing community composition, diversity, biomass, and water quality parameters, we assessed how river type (natural vs. artificial) and flow conditions (high vs. low) shape macroinvertebrate and fish communities across these urban rivers. Results showed that artificial channels had higher water temperatures, lower pH and DO, and higher concentrations of COD, NH 4 + , TP, fluorides, and sulfides compared to natural rivers, with flow depletion intensifying these effects. Both macroinvertebrate and fish community compositions varied significantly between river types and flow conditions. Channelization and flow depletion significantly reduced species richness, Shannon-Wiener diversity, and biomass in both macroinvertebrates and fish. Furthermore, we found a significant interaction between river type and flow depletion, as revealed by two-way ANOVA, with macroinvertebrate and fish communities in natural rivers being more sensitive to flow reductions than artificial channels. Redundancy analyses (RDAs) revealed that total phosphorus (TP) was the primary driver of macroinvertebrate community variation (contributing 23.6%), while DO played a crucial role in fish assemblages (contributing 20.6%). These findings underscore the significant impacts of channelization and flow depletion on urban river ecosystems, highlighting the vulnerability of natural rivers to flow depletion. Our study calls for urgent implementation of integrated management strategies to mitigate hydrological alterations, restore natural flow regimes, and reduce nutrient inputs, thereby enhancing the ecological resilience of urban aquatic ecosystems.

The performance of advanced materials in environmental applications using green energy is the tremendous interest among researchers. The visible light responsive BiFeO 3 (BFO), BiFeO 3 /CuS (BFOC), and Ag-loaded BiFeO 3 /CuS (Ag-BFOC) heterostructures have been synthesized by reflux method followed by hydrothermal and wetness impregnation method. These synthesized composites are well characterized through X-ray diffraction, UV diffuse reflectance spectroscopy, scanning electron microscope, and Fourier transfer infrared spectroscopy techniques. Compared with BFO and BFOC, Ag-BFOC exhibits the highest photocatalytic performance towards the degradation of antibiotics ciprofloxacin (76%) within 120-min time and also showed better antibacterial performance towards gram-negative ( Escherichia coli , Klebsiella pneumoniae , and Acinetobacter baumannii ) bacteria. Moreover, the novelty of the present work is the addition of CuS on the surface of BiFeO 3 from heterojunction type II and facilitates the electron–hole channelization at the interfaces between BiFeO 3 and CuS. Again, the loading of Ag on BiFeO 3 /CuS helps in shifting the absorption band towards the red end, is eligible to absorb more sunlight due to surface plasmon resonance effect, improves the separation efficiency of photo-generated charge carriers, and enhances the photocatalytic degradation of ciprofloxacin. The antibacterial property of Ag gives a best result towards antimicrobial activity. The prepared composites have proved their durability and stability by four successive cycles and prove the versatility of the composite. Graphical Abstract Schematic representation of removal of antibiotics and antibacterial activities using Ag-loaded BiFeO 3 /CuS heterostructured based composite

The metabolites like proline (Pro), Δ1-pyrroline-5-carboxylate (P5C), methylglyoxal (MG), γ-aminobutyric acid (GABA), glycine-betaine (gly-bet) and polyamines (PAs) are known to be shared between and commonly utilized in the aroma production pathway and/or osmotolerance regulation pathway during environmental stress. In the present study, the responses of four popular indigenous aromatic rice varieties, viz. Tulaipanji (TP), Radhunipagal (RP), Kalonunia (KN) and Gobindobhog (GB), to gradually increasing concentration of NaCl were studied against the non-aromatic rice cultivar (IR-64), so as to understand the channelization of the aforementioned common metabolites for aroma formation and salt stress amelioration in the selected rice cultivars. The pattern of accumulation of these metabolites supported by multidimensional scaling and determination of aroma content illustrated that all the aromatic cultivars except KN sequester the metabolites towards aroma production. Immunoblot analysis revealed high accumulation of betaine aldehyde dehydrogenase 2 (BADH2) protein in KN, which is uncharacteristic of aroma production. The BADH2 isozymes were also differentially expressed in the stressed rice cultivars. Of all the aromatic cultivars examined, stressed KN seedlings strategically siphoned the metabolites towards protection against salt-induced injuries and exhibited lower aroma production. The present work therefore clearly illustrates the notable differences, observed during the predominant channelization of relevant metabolites associated with both fragrance and stress amelioration in rice, even at the varietal level.

In order to improve the accuracy of the real-time signal acquisition, a real-time signal acquisition system based on high speed ADC and FPGA is proposed in this paper. AD9208 is used to realize high speed acquisition and DDC processing of original signal. FPGA 7V690T is used to realize digital channelization and fine FFT processing. This system can realize massive data storage and real-time signal display. The test results show that this system can effectively realize real-time signal acquisition and processing, and has strong anti-interference ability.

The migration of fluids, such as aqueous fluids and melts, is often channelized and crucial for trace element transport. However, trace elements typically migrate slower than the fluid due to partitioning between solid and fluid phases, known as retardation. The influence of channelization intensity on trace element retardation remains poorly quantified. Here, we use two‐dimensional numerical simulations to investigate trace element transport during compaction‐driven flow involving porosity waves and channelization caused by decompaction weakening. We employ a small‐amplitude porosity perturbation to study fluid segregation. A data collapse of systematic numerical results quantifies how the increase in channelization intensity cancels out the decrease in trace element transport caused by retardation, showing that channelized porosity waves enable segregated trace element mass transport. We illustrate changes of trace element distributions during fluid migration using multi‐element (spider) and ternary diagrams as well as trace element profiles across channels.

New strategies for converting signals between optical and microwave domains could play a pivotal role in advancing both classical and quantum technologies. Traditional approaches to optical-to-microwave transduction typically perturb or destroy the information encoded on intensity of the light field, eliminating the possibility for further processing or distribution of these signals. In this paper, we introduce an optical-to-microwave conversion method that allows for both detection and spectral analysis of microwave photonic signals without degradation of their information content. This functionality is demonstrated using an optomechanical waveguide integrated with a piezoelectric transducer. Efficient electromechanical and optomechanical coupling within this system permits bidirectional optical-to-microwave conversion with a quantum efficiency of up to −54.16 dB. Leveraging the preservation of the optical field envelope in intramodal Brillouin scattering, we demonstrate a multi-channel microwave photonic filter by transmitting an optical signal through a series of electro-optomechanical waveguide segments, each with distinct resonance frequencies. Such electro-optomechanical systems could offer flexible strategies for remote sensing, channelization, and spectrum analysis in microwave photonics. The authors showcase an optical-to-microwave conversion method using an optomechanical waveguide integrated with a piezoelectric transducer. The presented system allows bidirectional optical-to-microwave conversion with a quantum efficiency of up to—54.16 dB.

For the planning of the QiTai radio Telescope ultrawide bandwidth low-frequency pulsar receiving system, we designed and implemented a Field-Programmable Gate Array (FPGA)+CPU/GPU hybrid architecture digital backend system based on the Polyphase FilterBank (PFB) channeling algorithm. We used the FPGA signal acquisition and processing platform to implement ultrawide bandwidth signal sampling and designed the PFB algorithm to realize the digital channelization of multiple analog bandwidth signals. We also developed data encapsulation and multichannel parallel distribution firmware algorithms and realized the real-time parallel transmission of high-speed astronomical data streams based on the VLBI Data Interchange Format. We developed the Ultra Wide bandwidth Low-frequency pulsar data process PIPEline, which realized the real-time processing and data packaging of massive pulsar signals. Using the L-band (964–1732 MHz bandwidth) receiving system of the Nanshan 26 m radio telescope, we conducted a systematic test on the designed digital backend system and obtained high-quality observation data. By using the professional pulsar data processing software DSPSR to process the observation data, we obtained high signal-to-noise ratio pulse profiles.

The nexus of remittances and CO2 emission is very important and gathers a significant place in empirical research. This paper tries to find out the asymmetric relationship between carbon emissions, remittances, and financial development in India for the period 1980–2014. Based on the theoretical linkages, we develop a nonlinear ARDL model with the use of time series data in this study. The results of the NARDL bound test suggest that there is long-run cointegration among the variables. The findings show that positive shock in remittances causes an increase in CO2 emissions, where negative shock reduces it. The coefficient for financial development is positive but becomes statistically insignificant. Empirical results also support the existence of asymmetric long-run relationship among the variables. Based on the findings, the paper recommends the proper channelization of remittances and financial development towards environment-friendly energy sources and projects without compromising economic growth.

Our research introduces the river regulation effects on three sections of the upper and middle Odra River (south-western Poland), with differently channelized parts. In the upper and lower reaches, the river was straightened, narrowed, and trained with groins, whereas in the middle section, it was also impounded by numerous barrages. The discharge duration (DD) and water stage duration (WSD) curves for water-gauge stations from these river sections were analyzed to recognize changes in river flows and channel morphology since the mid-20th century. This analysis is supplemented by an examination of repeated surveys of the gauge cross sections of the river, annual precipitation totals in its catchment, and their relationship to the variation of the North Atlantic Oscillation (NAO) index. Our findings provide new hydrological insights for the region. The three river sections exhibited different patterns of the adjustment of the channel morphology to the river channelization: upper section was typified by channel incision, middle section by channel stability, and lower section by channel incision in its upper part and vertical stability of the channel bed in the lower part. Barrages in the middle section stabilized water stages in a wide range of hydrological conditions. Annual precipitation totals and river run-off did not change systematically over the study period. The variation in precipitation totals was inversely related to annual values of the NAO index. The study confirms the usefulness of DD/WSD curves to analyze changes in river run-off and the vertical position of the channel bed.

Recently observed rapid climate changes have focused the attention of researchers and river managers on the possible effects of increased flooding frequency on the mobilization and redistribution of historical pollutants within some river systems. This text summarizes regularities in the flood-related transport, channel-to-floodplain transfer, and storage and remobilization of heavy metals, which are the most persistent environmental pollutants in river systems. Metal-dispersal processes are essentially much more variable in alluvia than in soils of non-inundated areas due to the effects of flood-sediment sorting and the mixing of pollutants with grains of different origins in a catchment, resulting in changes of one to two orders of magnitude in metal content over distances of centimetres. Furthermore, metal remobilization can be more intensive in alluvia than in soils as a result of bank erosion, prolonged floodplain inundation associated with reducing conditions alternating with oxygen-driven processes of dry periods and frequent water-table fluctuations, which affect the distribution of metals at low-lying strata. Moreover, metal storage and remobilization are controlled by river channelization, but their influence depends on the period and extent of the engineering works. Generally, artificial structures such as groynes, dams or cut-off channels performed before pollution periods favour the entrapment of polluted sediments, whereas the floodplains of lined river channels that adjust to new, post-channelization hydraulic conditions become a permanent sink for fine polluted sediments, which accumulate solely during overbank flows. Metal mobilization in such floodplains takes place only by slow leaching, and their sediments, which accrete at a moderate rate, are the best archives of the catchment pollution with heavy metals.