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Evaluation and modification of some empirical and semi-empirical approaches for prediction of area-storage capacity curves in reservoirs of dams

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International Journal of Sediment Research 2017年第1期32卷 127-135页

作者： Issa E.Issa Nadhir Al-Ansari Govand Sherwany Sven Knutsson department of Civil Environmental and Natural Resources EngineeringLulea University of Technology department of dams and water resources engineering University of Mosul

The storage capacity of reservoirs is gradually reduced due to sediment accumulation that causes changes in the area-storage capacity（ASC） *** these curves and predicting their future change is an important issue for planners,designers and operators of *** empirical and semiempirical approaches have been suggested for establishing and predicting the future changes for these *** this study four empirical and semi-empirical methods were evaluated and three of them were modified to be used for the prediction of changes in the ASC curves due to sedimentation,based on the existing sedimentation survey data for 11 reservoirs in the *** evaluation,these approaches were reviewed and used to determine sedimentation depth and establishing the ASC curves for the mosul dam reservoir（MDR）,which is the biggest hydraulic structure on the River Tigris in northern *** started operating in 1986 with a storage capacity of 11.11 km;and a water surface area 380 km2 at normal operation stage（330 m a.s.l.）.The results obtained from these methods were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the *** evaluation results showed three methods had presented more accurate results for estimating water depth or sedimentation depth at dam site with percentage error about 1.06-3.30%.Whilst for establishing ASC curves,one method presented good agreement result with survey ***,ASC and sedimentation depths at dam site of MDR for periods 50,75,100 and 125 years were estimated using the modified approaches and the area reduction *** results of the modified methods provided reasonable agreement when compared with the area reduction method proposed by the *** of Reclamation and the agreement became better with an increase in time period.

关键词： Area-capacity curves Reservoir sedimentation Area reduction method mosul dam

Influence of diversion angle on water and sediment flow into diversion channel

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International Journal of Sediment Research 2020年第6期35卷 600-608页

作者： Nashwan Kamalaldeen Alomari Badronnisa Yusuf Thamer Ahmad Mohammad Abdul Halim Ghazali department of dams and water resources College of EngineeringUniversity of Mosul department of Civil engineering Faculty of EngineeringUniversiti Putra MalaysiaUPM Serdang department of water resources engineering University of Baghdad

Accumulation of the sediment in the stream of the diversion channels adversely affects its operational *** channels are often constructed perpendicular to the main *** this study,the water flow and sediment transport in the diversion channel with different angles were investigated in an attempt to maximize water discharge and minimize sediment discharge.A physical model with movable bed was used to simulate water and sediment flow with five diversion angles(θ) between(30°-90°).Moreover,three bed width ratios(Br)(the relation between diversion to main channel bed width) between 30% and 50% and five total discharges between(7.25 L/s to 12.25 L/s) were considered for each case of(θ).The results showed,up to 10%,increasing in proportion discharge ratios for 30 and 45 diversion angles compared with 90° diversion *** results also showed that the lowest diversion sediment concentration was provided by the(0) of *** all scenarios,the average proportion concentration reduction was 64%,compared with 90°diversion *** observation of the diversion system mechanism confirmed that decreased(θ) result in decreased sediment concentrations in the diversion *** conclusion,the diversion channel water and sediment discharge could be effectively managed by changing the(θ) to 30° or 45° instead of 90°.

关键词： Diversion channel Diversion angle Lowest diversion sediment concentration Bed width ratio Sediment concentration

Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge Duo Xu Xiao Feng Xing Yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao Yong Du Zhe Sun Weilin Xu Jian Fang college of Textile and Clothing engineering Soochow UniversitySuzhou 215123People’s Republic of China National engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China department of Electrical and Computer engineering University of MassachusettsAmherstMA 01003USA department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK college of Textile Science and engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion

No-chattering sliding mode control in a class of fractional-order chaotic systems

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Chinese Physics B 2011年第12期20卷 143-151页

作者：陈帝伊刘玉晓马孝义张润凡 department of Electrical engineering College of Water Resources and Architectural EngineeringNorthwest Agriculture and Forestry University

A no-chattering sliding mode control strategy for a class of fractional-order chaotic systems is proposed in this paper. First, the sliding mode control law is derived to stabilize the states of the commensurate fractional-order chaotic system and the non-commensurate fractional-order chaotic system, respectively. The designed control scheme guarantees the asymptotical stability of an uncertain fractional-order chaotic system. Simulation results are given for several fractional-order chaotic examples to illustrate the effectiveness of the proposed scheme.

关键词： fractional-order system chaos control sliding mode uncertain chaotic systems

Synchronization between a novel class of fractional-order and integer-order chaotic systems via a sliding mode controller

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Chinese Physics B 2012年第12期21卷 135-140页

作者：陈帝伊张润凡马孝义王娟 department of Electrical engineering College of Water Resources and Architectural EngineeringNorthwest Agriculture&Forestry University

In order to figure out the dynamical behaviour of a fractional-order chaotic system and its relation to an integer- order chaotic system, in this paper we investigate the synchronization between a class of fractional-order chaotic systems and integer-order chaotic systems via sliding mode control method. Stability analysis is performed for the proposed method based on stability theorems in the fractional calculus. Moreover, three typical examples are carried out to show that the synchronization between fractional-order chaotic systems and integer-orders chaotic systems can be achieved. Our theoretical findings are supported by numerical simulation results. Finally, results from numerical computations and theoretical analysis are demonstrated to be a perfect bridge between fractional-order chaotic systems and integer-order chaotic systems.

关键词： synchronization fractional-order system integer-order chaotic system sliding mode

On-line diagnosis method of crack behavior abnormality in concrete dams based on fluctuation of sequential parameter estimates

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Science China(Technological Sciences) 2015年第3期58卷 415-424页

作者： LI ZhanChao GU ChongShi WANG ZhengZhong WU ZhongRu college of water resources and Architectural engineering Northwest A&F University State Key Laboratory of Hydrology-water resources and Hydraulic engineering Hohai University college of water Conservancy and Hydropower engineering Hohai University

Research on on-line diagnosis method of crack behavior abnormality in concrete dams can provide support for timely grasping abnormality state of the crack itself and achieving real-time monitoring of the dam *** that samples of crack effects in concrete dams increase actually over monitoring time,a superiority criterion for the on-line diagnosis is determined so as to detect the abnormality moments timely and *** integrating the safety monitoring statistical model of crack effect variable with change point theory,a fluctuation method of regression coefficients is established for the on-line *** addition,each abnormality moment is detected by the cumulative sum of regression model *** indicate that abnormality of crack behavior in concrete dams can be characterized by structural instability of crack monitoring *** causes of crack behavior abnormality can be analyzed by the established method,which will play an important role in dam safety ***,taking the crack in a concrete gravity-arch dam as an example,the scientific rationality and validity of the established on-line diagnosis method are confirmed.

关键词： concrete dams crack behavior abnormality on-line diagnosis fluctuation of regression coefficients

Controllability of fractional-order Chua's circuit

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Chinese Physics B 2015年第3期24卷 26-30页

作者：张浩陈帝伊周坤王一琛 department of Electrical engineering College of Water Resources and Architectural EngineeringNorthwest A&F University

The ultimate proof of our understanding of nature and engineering systems is reflected in our ability to control *** fractional calculus is more universal, we bring attention to the controllability of fractional order systems. First,we extend the conventional controllability theorem to the fractional domain. Strictly mathematical analysis and proof are presented. Because Chua＇s circuit is a typical representative of nonlinear circuits, we study the controllability of the fractional order Chua＇s circuit in detail using the presented theorem. Numerical simulations and theoretical analysis are both presented, which are in agreement with each other.

关键词： controllability Chua's circuit fractional order circuit

Smart Cellulose‑Based Janus Fabrics with Switchable Liquid Transportation for Personal Moisture and Thermal Management

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Nano-Micro Letters 2025年第1期17卷 333-347页

作者： Jianfeng Xi Yanling Lou Liucheng Meng Chao Deng Youlu Chu Zhaoyang Xu Huining Xiao Weibing Wu Jiangsu Co‑Innovation Center of Efficient Processing and Utilization of Forest resources International Innovation Center for Forest Chemicals and MaterialsJiangsu Provincial Key Lab of Sustainable Pulp and Paper Technology and Biomass MaterialsNanjing Forestry UniversityNanjing 210037People’s Republic of China college of Materials Science and engineering Nanjing Forestry UniversityNanjing 210037People’s Republic of China department of Chemical engineering University of New BrunswickFrederictonNB E3B 5A3Canada Macromolecular Chemistry and Bavarian Polymer Institute University of BayreuthBayreuth 95440Germany

The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human ***,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a ***,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/*** cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport ***,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability *** fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too *** addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic *** smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.

关键词： Directional water transport Cotton fabric Anti-gravity directional liquid transportation Janus wettability

Transient simulation of a pump-turbine with misaligned guide vanes during turbine model start-up

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Acta Mechanica Sinica 2014年第5期30卷 646-655页

作者： Ye-Xiang Xiao Ruo-Fu Xiao State Key Laboratory of Hydroscience and engineering & department of Thermal engineering Tsinghua University college of water resources and Civil engineering China Agricultural University

Experimental studies of a model pump-turbine S-curve characteristics and its improvement by misaligned guide vanes （MGV） were extended to prototype pump turbine through 3-D transient flow simulations. The unsteady Reynolds-averaged Navier-Stokes equations with the SST turbulence model were used to model the transient flow within the entire flow passage of a reversible pump-turbine with and without misaligned guide vanes during turbine model start-up. The unstable S-curve and its improvement by using misaligned guide vane were verified by model test and simulation. The transient flow calculations were used to clarify the variations of pressure pulse and internal flow behavior in the entire flow passage. The use of misaligned guide vanes can eliminate the S-curve characteristics of a pump-turbine, and can significantly increase the pressure pulse amplitude in the entire flow passage and the runner radial forces during start-up. The MGV only decreased the pulse amplitude on the guide vane suction side when the rotating speed was less than 50% rated speed. The hydraulic reason is that the MGV dramatically changed the flow patterns inside the entire flow passage, and destroyed the symmetry of the flow distribution inside the guide vane and runner.

关键词： Transient flow. Pump turbine. Misaligned guide vane Model test Pressure pulse