Lower Branch Research Articles

Stability analysis of radiative-magnetic hybrid nanofluid slip flow due to an exponentially stretching/shrinking permeable sheet with heat generation

The present article aims to find the duality of solutions and investigate the magneto-radiative hybrid nanofluid flow over an exponentially stretching/shrinking permeable sheet with heat generation and multiple slip boundary conditions. The governing nonlinear partial differential equations are transformed into dimensionless nonlinear ordinary differential equations which are computed by bvp4c in Matlab platform. The hybridisation of alumina and copper nanoparticles enhances the system's heat transfer performance. The dual nature solution is obtained only if the suction is applied to the stretching/shrinking surface. From stability analysis, we can conclude that the first solution is stable, but the other is unstable. It is realistic to have the solution stable with the smallest positive eigenvalues, while the lower solution branch is unstable with the smallest negative eigenvalues. It is found that the upsurges of solid volume fraction of the copper nanoparticle enhanced the skin friction coefficient and the local Nusselt number.

Photonic-assisted multi-frequency measurement based on frequency-to-power mapping and serial channelization

A novel photonic approach to multi-frequency measurement based on frequency-to-power mapping and serial channelization is proposed and demonstrated. In this proposal, a light wave from a laser diode (LD) is split into two branches. In the upper branch, a dual-port Mach–Zehnder interferometer (MZI) is used to perform frequency-to-power mapping. While in the lower branch, an optical wavelength scanner based recirculating frequency shifting (RFS) loop is used to generate multiple serial optical local oscillators (LOs) to down-convert the outputs of the dual-port MZI at the corresponding time window. Therefore, the unknown radio-frequency (RF) frequencies can be unambiguously estimated by the multiple monotonous amplitude comparison functions (ACFs) obtained from the power ratios between two down-converted electrical signals. Only two low-frequency photodetectors (PDs) with narrow bandwidth are employed, which guarantees a simple structure and low cost. In addition, the proposal has robustness to the bias drift of the MZM and input RF power. Simulation results indicate that the multi-frequency identification within 5 μs is achieved over the measurement range up to 19 GHz with an accuracy better than ± 20 MHz. Furthermore, the system is easily extended to higher frequency and larger bandwidth (e.g., 100 GHz).

Flow-induced surface instabilities in a flexible-walled channel with a heavy wall

We consider the stability of laminar high-Reynolds-number flow through a planar channel formed by a rigid wall and a heavy compliant wall under longitudinal tension with motion resisted by structural damping. Numerical simulations indicate that the baseline state (with Poiseuille flow and a flat wall) exhibits two unstable normal modes: the Tollmien–Schlichting (TS) mode and a surface-based mode which manifests as one of two flow-induced surface instabilities (FISI), known as travelling wave flutter (TWF) and static divergence (SD), respectively. In the absence of wall damping the system is unstable to TWF, where the neutrally stable wavelength becomes shorter as the wall mass increases. With wall damping, TWF is restricted to long wavelengths through interaction with the most unstable centre mode, while for wall damping greater than a critical value the system exhibits an SD mode with a two branch neutral stability curve; the critical conditions along the upper and lower branches are constructed in the limit of large wall damping. We compute the Reynolds–Orr and activation energy descriptions of these neutrally stable FISI by continuing the linear stability analysis to the following order in perturbation amplitude. We find that both FISI are primarily driven by the working of normal stress on the flexible wall, lower-branch SD has negative activation energy, while upper-branch SD approaches zero activation energy in the limit of large wall damping. Finally, we elucidate interaction between TS and TWF modes for large wall mass, resulting in stable islands within unstable regions of parameter space.

KryptosChain—A Blockchain-Inspired, AI-Combined, DNA-Encrypted Secure Information Exchange Scheme

Today’s digital world necessitates the adoption of encryption techniques to ensure secure peer-to-peer communication. The sole purpose of this paper is to conglomerate the fundamentals of Blockchain, AI (Artificial Intelligence) and DNA (Deoxyribonucleic Acid) encryption into one proposed scheme, KryptosChain, which is capable of providing a secure information exchange between a sender and his intended receiver. The scheme firstly suggests a DNA-based Huffman coding scheme, which alternatively allocates purines—Adenine (A) and Guanine (G), and pyrimidines—Thymine (T) and Cytosine (C) values, while following the complementary rule to higher and lower branches of the resultant Huffman tree. Inculcation of DNA concepts makes the Huffman coding scheme eight times stronger than the traditional counterpart based on binary—0 and 1 values. After the ciphertext is obtained, the proposed methodology next provides a Blockchain-inspired message exchange scheme that achieves all the principles of security and proves to be immune to common cryptographic attacks even without the deployment of any smart contract, or possessing any cryptocurrency or arriving at any consensus. Lastly, different classifiers were engaged to check the intrusion detection capability of KryptosChain on the NSL-KDD dataset and AI fundamentals. The detailed analysis of the proposed KryptosChain validates its capacity to fulfill its security goals and stands immune to cryptographic attacks. The intrusion possibility curbing concludes that the J84 classifier provides the highest accuracy of 95.84% among several others as discussed in the paper.

High-resolution laser system for the S[formula omitted]-Low Energy Branch

In this paper we present the first high-resolution laser spectroscopy results obtained at the GISELE laser laboratory of the GANIL-SPIRAL2 facility, in preparation for the first experiments with the S3-Low Energy Branch. Studies of neutron-deficient radioactive isotopes of erbium and tin represent the first physics cases to be studied at S3. The measured isotope-shift and hyperfine structure data are presented for stable isotopes of these elements. The erbium isotopes were studied using the 4f126s23H6→4f12(3H)6s6pJ= 5 atomic transition (415 nm) and the tin isotopes were studied by the 5s25p2(3P0)→5s25p6s(3P1) atomic transition (286.4 nm), and are used as a benchmark of the laser setup. Additionally, the tin isotopes were studied by the 5s25p6s(3P1)→5s25p6p(3P2) atomic transition (811.6 nm), for which new isotope-shift data was obtained and the corresponding field-shift F812 and mass-shift M812 factors are presented.

The influence of subsurface architecture on scour hole formation in the Rhine–Meuse delta, the Netherlands

Abstract Scour holes are common features in deltaic rivers which can destabilise embankments through oversteepening of the river bed. Their development has been studied extensively from the hydraulic perspective, but another important control is the erodibility of the river bed which varies considerably due to thickening of heterogeneous deltaic substrate towards the coast. Therefore, we assessed the influence of delta-scale geological heterogeneity and local subsurface architecture on scour hole formation in addition to the hydrodynamic controls. We (1) created an inventory of 165 scour hole locations in the Rhine–Meuse delta, (2) assessed the hydrodynamic conditions at the locations, (3) extracted geometric characteristics and (4) determined the subsurface architecture from geological data. Central and lower delta branches have 0.6–0.7 scours per km while upper delta branches have less than 0.2. Downstream, 58% of scour holes were related to architectural elements, notably sand bodies from former Holocene channel belts and Early Holocene cohesive beds. These scours have steeper slopes due to higher proportions of cohesive sediments near the river bed. Furthermore, scours related to channel belt sand bodies are limited in downstream length and depth, up to maximum of approximately two times the water depth. From our results, we provide a delta-scale explanatory framework that relates the position of present-day river channels with respect to Pleistocene river deposits and Holocene fluvio-deltaic deposits to scour hole formation. Upstream rivers are incised in Pleistocene deposits showing less local variation in erodibility. The majority of scour holes here relate to engineering works. In central and lower delta branches, geologically inherited heterogeneity of the Holocene substrate at critical depths near the channel bottom adds to anthropogenic induced scours and results in high abundances. This demonstrates that downstream variation in subsurface architecture should be considered as a key control on scour locations and characteristics for management purposes.

Computation of Stagnation Point Convection Flow of Carbon Nanotube Nanofluids From a Stretching Sheet With Melting: Dual Solutions

Abstract A theoretical study in stagnation point flow is presented where melting heat transfer effects of carbon nanotube (CNT) from a stretching surface is appeared. Both carbon nanotubes like single-wall CNT (SWCNT) and multiwall CNT (MWCNT) are homogeneously dispersed in the base fluid. As the ordinary (or base) fluids, water and kerosene oil are employed. A set of nonlinear ordinary differential equations with appropriate boundary conditions is formed by transforming the governing equations via similarity transformations. The transformed nonlinear ordinary differential equations are then solved numerically using the bvp4c solver in matlab, an efficient numerical finite difference method. The impact of nanoparticle volume fraction, velocity, melting, stretching parameter, and CNT type on transport characteristics are explored and visualized graphically and in tabular forms. Verification of the matlab computations with available data in certain limiting cases is included showing excellent agreement. Existence of dual (upper and lower branch) solution is shown for a certain range of stretching sheet parameter. The obtained dual solutions are examined for velocity and temperature in detail. A stability analysis demonstrates that the first solution is a stable solution, and the second solution is an unstable solution. Local skin friction and local Nusselt number are also computed in order to determine critical values that can permit dual solutions. It is observed that when a dimensionless melting parameter is greater than 1, SWCNT nanofluids attain greater velocities than MWCNT nanofluids for water as well as kerosene oil base fluids. Moreover, the flow is accelerated for SWCNT compared with MWCNT for both water and kerosene oil. With increasing stretching parameter, the heat transfer rate (Nusselt number) increases, whereas skin friction coefficients decrease. Higher skin friction and Nusselt number are obtained for SWCNTs compared to MWCNTs due to their greater density and thermal conductivity. The study is relevant to phase change manufacturing fluid dynamics of nanomaterials.

The fuzzy fractional acoustic waves model in terms of the Caputo-Fabrizio operator

<abstract><p>This paper proposes an analytical solution for a fractional fuzzy acoustic wave equation. Under the fractional Caputo-Fabrizio operator, we use the Laplace transformation and the iterative technique. In the present study, the achieved series type result was determined, and we approximated the estimated values of the suggested models. All three problems used two various fractional-order simulations between 0 and 1 to obtain the upper and lower portions of the fuzzy results. Since the exponential function is present, the fractional operator is non-singular and global. Due to its dynamic behaviors, it provides all fuzzy form solutions that happen between 0 and 1 at any level of fractional order. Because the fuzzy numbers return the solution in a fuzzy shape with upper and lower branches, the unknown quantity likewise incorporates fuzziness.</p></abstract>

First Report of Phytophthora nicotianae Causing Leaf Necrosis on Magnolia ‘Butterflies’ in a Virginia Ornamental Plant Nursery

Magnolia ‘Butterflies’ is a hybrid cultivar resulting from a cross between M. acuminata and M. denudata. On July 6, 2021, during a survey at a Fairfax County, VA ornamental plant nursery, 6 out of 11 plants in 18.9-liter pots exhibited leaf necrosis and premature senescence on the lower branches. Phytophthora nicotianae was identified as the causal agent by morphology and sequencing. A segment of the internal transcribed spacer (ITS) and the cytochrome c oxidase subunit 1 (COX1) was deposited in Genbank under accession numbers ON586858 and ON605612, respectively. Koch’s postulates were fulfilled by an attached leaf, living plant inoculation trial. To our knowledge, this is the first report of this species causing foliar necrosis on Magnolia ‘Butterflies’ in a nursery or in the field. Further pathogenicity tests are needed to understand whether hybrids of Magnolia differ in susceptibility to infection when compared with their progenitors.

A forgotten participant in pore deblocking of zeolites: dicarbonate in NaMeA zeolites, Me = Na, K, Rb, Cs.

The dynamics of carbon dioxide, carbonate anion (CO32-), and dicarbonate anion (C2O52-) in NaKA zeolite is studied at the DFT GGA level using ab initio molecular dynamics (AIMD). We show the easy formation of C2O52- dicarbonate from the reaction between CO32- and CO2 at high CO2 loading and their equilibrium at low CO2 loading. We have found that the dicarbonate anion can contact up to six cations (Me+ and Na+, Me = Na, K, Rb, Cs), which could reduce the separation properties of NaMeA zeolites relative to CO2 mixtures. The K+ interaction with dicarbonate C2O52- species pushes the cation from 8R site in full analogy with the carbonate's deblocking studied earlier. The easy C2O52- formation in NaMeA is confirmed by modeling reaction of C2O52- formation at the DFT GGA (PBE-D3) and hybrid levels (B3LYP, HISS, HSE06) with cNEB. The calculated intensities for high and low frequency branches of valence vibrations in C2O52- are compared with calculated ones for Me2C2O5 molecules and known IR spectroscopic data in the NaMeA zeolites. This new mechanism of deblocking could be important for a wide family of narrow pore zeolites (CHA, RHO, KFI, etc.) at room temperature where the carbonates are observed in the IR spectra. The possibility of tricarbonate formation is discussed.

Nonlinear excitation of energetic-particle-driven geodesic acoustic mode by ions drift waves

Nonlinear excitation of geodesic acoustic mode (GAM) by ions drift waves in the presence of energetic particles (EPs) is investigated through the hybrid model of fluid description and gyro-kinetic description, while the bulk ions temperature anisotropy and toroidal rotation are taken into account simultaneously. The coupling relation of EPs and the nonlinear effects on GAM is analytically derived and discussed. It is found that the nonlinear excitation can split inherent energetic-particle-driven GAM (EGAM) branches into different growth rates. For the intrinsic stable high frequency EGAM branch, the nonlinear effect generates a growth/damping rate. For the low frequency branches with inherent growth/damping rates due to the EPs, the nonlinearity cooperates with EPs in the excitation process.

Coarse-to-Fine Feedback Guidance Based Stereo Image Quality Assessment Considering Dominant Eye Fusion

Considering that the human brain always follows a coarse-to-fine (low-to-high spatial frequency) visual processing and fusion mechanism, we propose a coarse-to-fine feedback guidance based stereo image quality assessment (SIQA) network which considers a coarse-to-fine feedback guidance and adaptive dominant eye mechanism. The proposed network consists of two main sub-network streams, each of which has three branches to extract low, middle and high spatial frequency information in parallel. To better realize the guidance of the high-level features in the low spatial frequency branch to the low-level features in the high spatial frequency branch, an information feedback guidance module (IFGM) is proposed, which realizes a top-down guidance mechanism in each sub-network stream. Simultaneously, according to the theory of ocular dominance in human visual system (HVS), we design an adaptive bi-directional parallax-based binocular fusion module (BPBFM), which synthesizes two types of fusion feature by taking the left and right view features as dominant eye input. Furthermore, in order to obtain the better perceptual quality of stereo images, we design a weighted fusion strategy to weigh the quality scores from the two types of fusion features obtained by using an ensemble model with two multi-layer perceptrons (MLPs). The experimental results on four public stereo image datasets show that the proposed method is superior to the mainstream metrics and achieves an excellent performance.

Anomalous mediastinal left lower lobe anterior segmental artery (A8) accidentally divided during left VATS upper lobectomy: a case report

: Bronchovascular anatomical variations can pose technical challenges during lobectomy and especially segmentectomy where these structures are embedded deep in the lung parenchyma. Familiarity with these anatomical variations helps avoid intraoperative injury and accidental division. Mediastinal origin of left upper lobe apicoposterior (truncus superior) and lingula arterial branches (A4+5) is common. However mediastinal origin of left lower lobe segmental pulmonary branches is very rare and has not been reported in the literature. An anomalous mediastinal origin of left lower lobe anterior segmental artery (A8) noted during a left video-assisted thoracic surgery (VATS) upper lobectomy in a 69 years old male with stage 1 lung cancer is described. The artery was mistaken for a mediastinal lingula branch (A4+5) during surgery and was divided accidentally. The injury was recognised intraoperatively and primary end to end vascular repair was done by VATS, with the patient making an uneventful recovery. Awareness of this rare anatomical variant can help prevent intraoperative vascular injury or accidental ligation during left VATS lobectomy. Injuries due to anomalous bronchovascular anatomical variations can be prevented by preoperative planning by 3-dimensional contrast enhanced computer tomography and by careful intraoperative dissection and identification of mediastinal and interlobar vessels distally into the respective segments before ligation.

Unveiling re-entrant phase behavior and crystalline-amorphous interactions in semi-conducting polymer:small molecule blends.

It has been reported recently that conjugated polymer:small molecule systems might exhibit complex, re-entrant phase behavior with hourglass or closed-loop miscibility gaps due to an 'apparent' lower critical solution temperature branch. However, the study did not firmly establish if the observations were reflecting equilibrium or not. To assure that the observed shapes of the binodals via a mixing experiment represent local near-equilibrium conditions that capture complex molecular interactions or equation-of-state effects, we present here the liquidus and the binodal for the exact same systems, i.e., PTB7-Th:PC61BM, PffBT4T-C9C13:PC71BM and PTB7-Th:EH-IDTBR, with the liquidus measured via a demixing experiment with long annealing time of days to weeks. We observe that the binodal displayed consistent trends with the liquidus, revealing an underlying thermodynamic and not microstructural or kinetic cause behind the complex phase behavior. Our results highlight the need for a novel, sufficiently complex physical model for understanding these non-trivial phase diagrams of semi-conducting materials. We also discover that the composition difference (Δϕ) between liquidus and binodal reflects the crystalline-amorphous interaction, exhibiting a linear relationship with the binodal composition (ϕb,polymer), i.e., Δϕ increases as χaa decreases. This possibly provides a new approach for obtaining the crystalline-amorphous interaction parameter χca(T) beyond the commonly used melting point depression method, which estimates χca near the melting temperature Tm of the crystalline component. The capability of obtaining χca(T) over a more extended temperature range may encourage more extensive studies and facilitate the understanding of χca in general, but particularly for all the novel non-fullerene acceptors that are able to crystallize.

Water flow in graphene nanochannels driven by imposed thermal gradients: the role of flexural phonons.

Accurate control of fluid transport in nanoscale structures is key to enable the design of foreseeable nanofluidic devices with applications in many fields such as chip cooling, energy conversion, drug delivery and medical diagnosis. Here, inspired by the experimental observation of intrinsic thermal ripples in graphene and by recent advances in the manipulation of 2D nanomaterials, we introduce a graphene-based thermal nanopump which produces controlled and continuous liquid flow in nanoslit channels. We investigate the performance of this thermal nanopump employing large scale molecular dynamics simulations. Upon systematically imposing thermal gradients, a net water flow towards the low-temperature zone is observed, achieving flow velocities up to 4 m s-1. We observe that water flow rates increase monotonically due to larger ripple fluctuations on the graphene layers as higher thermal gradients are applied. Moreover, we find that the out-of-plane flexural phonons in graphene are responsible for flow generation wherein lower frequency phonon branches are activated with higher imposed thermal gradients. Furthermore, by modifying the wettability of the channel walls, an increase of 50% in the water flow rates is observed, showing that the efficiency of the proposed thermal pump can be enhanced by tuning the channel wall hydrophobicity. Our results indicate that thermal gradients can be employed to drive continuous water flow in graphene nanoslit channels with potential applications in nanofluidic devices.

Surgical Management of Vascular Trauma; A Systematic Review

Vascular trauma is a significant public health concern, and there have been numerous incidents globally in recent years. Peripheral vascular injuries, including axillobrachial and upper extremity branches, as well as femoropopliteal and lower limb branches, account for 40% to 75% of all vascular injuries. Our systemic review aimed to examine surgical management strategies for vascular trauma. Data sources included PubMed/Medline and Embase. Our review investigated English-language articles (from 2010 to 2023) according to the PRISMA guidelines. Overall, there were 7 articles. Surveys and analyses of national databases were the most widely used methods (n=7 studies). The search identified 777 studies, 7 were eligible for inclusion in the analysis. Further understanding of vascular trauma, and treatment protocols may help improve evaluation and management in the future. Our research covered a range of treatment options; the proportion of vascular injuries treated without surgery or utilizing endovascular techniques has increased. Individuals who receive medications intravenously, especially drug users, often present late in the course of their diseases and are notoriously difficult to treat. Despite the challenges in control, it is crucial to remain vigilant for vascular problems that might be fatal. Patient education and awareness may lead to the early detection and treatment of these diseases, which have high morbidity and mortality rates. Revascularization is necessary for limb salvage in patients with severe vascular damage. Simultaneous orthopedic injuries pose significant challenges and increase the risk of limb amputation. Multiple fractures and a MESS score of 6 indicate limited potential for limb salvage.

Four Poems from Black Swan Theory

Four Poems from Black Swan Theory Kyle Marbut (bio) The water I draw from the well may come up wine, but I still have to scrape my plates clean nightly like anyone else. Before every meal I swallow pictures of my mother at ever, at after, at rest. The hour, inconsistent. Caught dozing again in the light with a mouthful of what. Full sun fixed in nocturne, wreathed nightly in the galaxy arm. No moon. The only one I could tell is lost in the mirror. Her brow, my brow; my lid, her eye. [End Page 59] Sister, were we early. Sister, were we late. We lost every star to day, and another night is not promised. Once left, I spoke in our mother’s voice just to hear it. With your eyes closed, you would mistake me for her or any other god. I swallowed that tongue, another draught, moonshine cut with winterberry. What I crave more than death, numb lightning, candlelight infinite in parallel windows. If this voice were really hers, I would wish for a second, truer sun. [End Page 60] I’m through with amazement! I don’t mean to sound so sure, but the flowers are getting to me. One tree sheds its blossoms, another bursts open in its place. Long season of color so desperate for touch we don stripes and stroke from stamen to pistil. How to explain lack to such plenty. Mouthfuls of dead bees, sexless haze of slow ecodeath. Rabid hounds snap their jaws at low branches of dogwoods. Finches pluck weeping cherries bald en masse. Streets lined with Callery pears, fruitless and reeking of cum. The unbearable rain of petals. Close the blinds. A vision: petrified trunks shade a field aflame, smoke aglow in infinite sunset, lovers fossilized in ash. It’s useless to behold endings as if they have already happened. Doom, too, is a hunger. [End Page 61] Dressed in just your blue jockstrap, you come to me whirling through the graveyard. Bearing honeycomb and black lace veils, foam at the mouth. Not the moonlight but what’s beneath it makes the night real. If the moon is still there while I’m looking at you, I’ll summer away the midnights you, drunk on cosmos, called my name wrong. Sight is only a measure of distance. Through every window I spy you heaving secrets behind the sunflowers. Darling, don’t tell me you ate another star! You’ll spoil your winter. [End Page 62] Kyle Marbut KYLE MARBUT lives in Virginia. They wrote two chapbooks called Dawn Chorus Fascicle and Ecliptic Tongues. They have one more secret to tell. I dropped a mirror and reflected in the shards I split into a hundred eyes, and through them I saw that other world where my mother married a tree and birds could whisper facts and the grave was a door the rain walked through, and I knew it was all true there. That was before I had teeth. Now I only write about real life. Copyright © 2023 Wayne State University Press

Correlation and sequential path analysis of oil yield and related characteristics in camelina under seasonal variations

The objectives of the current study were to determine the usefulness of sequential path analysis in camelina to obtain information about the relationship between yield and yield components and to evaluate their relative importance in camelina oil yield under summer and winter cultivation. A split-plot design, with two varieties as the main plot and four sowing times as the subplot, was carried out over two growing seasons (2017–2019) in Samsun, Turkey. Sequential path analysis revealed that, as first-order predictors, grain yield and oil content displayed the most significant and positive direct effects on oil yield in both summer and winter cultivation. The sequential path analysis of second-order variables over the first-order variable revealed that seed number per pod and pod number explained approximately 90% of the variation of the grain yield in summer cultivation and branch number explained approximately 67% of the variation grain yield in winter cultivation. These results indicated that grain yield, as a main predictor of oil yield, had different pathways to affect oil yield in the summer and winter seasons. A higher magnitude of seed number per pod compared to pod number in this study indicated that selecting for higher grain yield can be done indirectly using plants with lower pod number and higher seed number per pod in the summer season. Moreover, branch number was the only trait that had a direct negative effect on grain yield in the winter season, indicating that plants with lower branch number should be selected for higher grain yield. Different environmental factors, including the seasonal cultivation of camelina in this study, were found to be a key factor in improving oil yield and, hence, should be considered as criteria indices in camelina breeding programs in the future.

Three-dimensional rotating viscous flow past a permeable stretching/shrinking sheet with convective boundary condition

The study of three-dimensional rotating boundary layer flow approaching a stretching or shrinking surface under convective boundary conditions is presented in this paper. This study expands the scope of previous researchers' work to encompass broader scenarios, including situations involving mass transfer (suction) on the wall, the Biot number and cases featuring a shrinking surface. It is found that the increase of suction and rotating parameters leads to a noticeable rise in both the local skin friction coefficients and the local Nusselt number, and the solutions to the governing ordinary differential equations exhibit a dual-branch nature, comprising both upper and lower branch solutions, within a specific range of the governing parameters.

Runoff variation in the middle and lower branches of Yangtze River and the two lakes (Dongting and Poyang Lake) before and after Three Gorges Reservoir's operation

为探索三峡水库运行前后长江中下游干流及两湖径流过程的变化及其驱动因素,利用宜昌、监利、大通、七里山、湖口共5个水文站的流量资料,分析了各站径流过程的变化特征及其成因。结论:(1)各站年径流量均减少,但除七里山站之外,其它各站减少比例均小于10%且变化不显著;(2)干流各站月径流量最大减幅发生在10月,而七里山站、湖口站分别发生在7月、4月;(3)干流各站月径流量最大增幅发生在3月,而七里山站、湖口站分别发生在1月、6月;(4)宜昌站,1-4月径流量增加是三峡水库入库径流增加和水库调度的共同作用结果,6-8月径流量减少的主因是三峡水库入库径流量减少,5、9、10月径流量变化的主因是三峡水库调度;(5)监利站,径流量的变化与宜昌站表现出高度的一致性,但冬季各月径流量的增幅均大于宜昌站;(6)大通站,4-6月径流量变化方向与湖口站一致,其它月份变化方向均与宜昌站一致。(7)七里山站,7月径流量减少的主因是洞庭湖流域来水减少,9、10月径流量减少的主要原因是荆江分流减少,但洞庭湖流域来水减少也是重要原因。(8)湖口站,4、5月径流量减少的主因是流域降水减少,9、10月径流量减少的主要原因是鄱阳湖汛期水位降低、低水位提前、蓄水量减少。;To explore and explain the changes of runoff process in the middle and lower Yangtze River mainstream and the two lakes of Dongting and Poyang before and after the operation of the Three Gorges Reservoir (TGR), the runoff data of five hydrological stations, which are Yichang, Jianli, Datong, Qilishan, and Hukou, were used. The stations of Yichang, Jianli, and Datong locate along the mainstream of the Yangtze River, while the other two stations locate at the exit of the Dongting and Poyang Lake, respectively. The runoff changes at each station before and after the TGR's operation and its causes were analyzed. Conclusions include: (1) The annual runoff at each station decreased, except at Qilishan Station, the reduction ratio of runoff at other stations was less than 10% and their changes were not significant; (2) The maximum decrease in monthly runoff at each mainstream station occurred in October, except that at Qilishan Station and Hukou Station it occurred in July and April, respectively; (3) The maximum increase in monthly runoff at each mainstream station occurred in March, while at Qilishan Station and Hukou Station it occurred in January and June, respectively; (4) At Yichang Station, the increase of monthly runoff from January to April resulted from both the inflow increment of the TGR and its operation. The main reason for the decrease in monthly runoff from June to August was the decrease in the inflow of the TGR. The main reason for the runoff change in May, September and October was the operation of the TGR; (5) At Jianli Station, the change of runoff was highly consistent with that at Yichang Station, but the increase of runoff at Jianli Station in each month in winter was greater than that at Yichang Station; (6) At Datong Station, from April to June the change direction of monthly runoff was the same as that at Hukou Station, and the change direction of other months was the same as that at Yichang Station. (7) At Qilishan Station, the main reason for the runoff reductions in July was the reduction of rainfall in Lake Dongting basin, and while the reduction of the diversion from Jingjiang River is the main cause to the runoff reduction in September and October, the reduction of rainfall in Lake Dongting basin also played an important role; (8) At Hukou Station, the decreases in runoff in April and May resulted from the reduction of rainfall in Lake Poyang basin, while the main reason for the runoff decreases in September and October was the reduction of water level in Lake Poyang during the previous months, which led to the early low water level season and the reduction of water storage.