Solar and wind energy potential assessment for Razavi Khorasan Province in Iran

This study aims to evaluate the solar and wind energy potential across Razavi Khorasan Province,Iran,with a specific focus on the Khaf region.A preliminary assessment of mean solar radiation,mean wind speeds,and Weibull distribution parameters was conducted for different towns and zones within the province.The findings showed that Khaf has favorable characteristics for further analysis.The solar and wind energy metrics examined include global horizontal irradiance,clearness index,wind rose patterns,and turbulence intensity.At a height of 40 m,Khaf’s wind power density reached 1650 W/m^(2),indicating exceptional wind energy generation potential.Additionally,Khaf received an average annual solar radiation of 2046 kW·h/m^(2),representing significant solar energy potential.Harnessing these substantial renewable resources in Khaf could allow Razavi Khorasan Province to reduce reliance on fossil fuels,improve energy sustainability,and mitigate climate change impacts.This research contributes an in-depth assessment of Razavi Khorasan's solar and wind energy potential,particularly for the promising Khaf region.Further work may examine optimal sites for renewable energy projects and grid integration strategies to leverage these resources.

Evaluation of development potential of pumped hydroelectric storage and geothermal utilization system in abandoned coal mine

Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.

Research on pumped storage and complementary energy development models for abandoned mines in China

Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.

Deep learning echocardiographic intelligent model for evaluation on left ventricular regional wall motion abnormality

Objective To observe the value of deep learning echocardiographic intelligent model for evaluation on left ventricular(LV)regional wall motion abnormalities(RWMA).Methods Apical two-chamber,three-chamber and four-chamber views two-dimensional echocardiograms were obtained prospectively in 205 patients with coronary heart disease.The model for evaluating LV regional contractile function was constructed using a five-fold cross-validation method to automatically identify the presence of RWMA or not,and the performance of this model was assessed taken manual interpretation of RWMA as standards.Results Among 205 patients,RWMA was detected in totally 650 segments in 83 cases.LV myocardial segmentation model demonstrated good efficacy for delineation of LV myocardium.The average Dice similarity coefficient for LV myocardial segmentation results in the apical two-chamber,three-chamber and four-chamber views was 0.85,0.82 and 0.88,respectively.LV myocardial segmentation model accurately segmented LV myocardium in apical two-chamber,three-chamber and four-chamber views.The mean area under the curve(AUC)of RWMA identification model was 0.843±0.071,with sensitivity of(64.19±14.85)%,specificity of(89.44±7.31)%and accuracy of(85.22±4.37)%.Conclusion Deep learning echocardiographic intelligent model could be used to automatically evaluate LV regional contractile function,hence rapidly and accurately identifying RWMA.

Real-time shear wave elastography combined with biochemical indicators for evaluating liver injury in patients with chronic kidney disease

Objective To observe the value of real-time shear wave elastography(SWE)combined with biochemical indicators for evaluating liver injury in patients with chronic kidney disease(CKD).Methods Totally 210 patients with CKD(CKD group)and 64 healthy subjects(control group)were retrospectively enrolled.Patients in CKD group were further divided into CKD1—5 subgroups according to CKD stages.SWE parameters of liver and kidney,including mean value,the maximum value and the median value of Young's modulus(EQI mean,EQI max and EQI med)were compared between CKD subgroups and control group.Spearman correlation analysis were performed to explore the correlations of liver and kidney SWE parameters with CKD stage,as well as of liver SWE parameters with biochemical indicators.Multivariate logistic regression analysis was used to screen independent predictors of liver injury in CKD patients.Receiver operating characteristic curves were drawn,the area under the curves(AUC)were calculated to evaluate the efficacy of the independent predictors alone and their combination for assessing liver injury in CKD patients.Results Significant differences of liver and kidney SWE parameters were found among CKD subgroups and control group(all P≤0.001).Pairwise comparison showed that liver SWE parameters in CKD5 subgroup and liver EQI max in CKD4 subgroup were all higher than those in control group(all P<0.003).Kidney SWE parameters in CKD3 subgroup were all higher than those in control group,while in CKD4 subgroup were all higher than those in control group and CKD1—3 subgroup(all P<0.003).Kidney EQI mean and EQI med in CKD5 subgroup were all higher than those in control group and CKD1—4 subgroup,while kidney EQI max in CKD5 subgroup were higher than those in control group and CKD1—3 subgroup(all P<0.003).Liver and kidney SWE parameters were lowly-moderately and positively correlated with CKD stages(r=0.364—0.665,all P<0.001).Liver SWE parameters of CKD were weakly and positively correlated with alkaline phosphatase(ALP)(r=0.229—0.248,all P<0.01).Theγ-glutamyl transferase,ALP and liver EQI max were all independent predictors of liver injury in CKD patients(all P<0.01),with AUC for evaluating liver injury in CKD patients alone of 0.645,0.756 and 0.741,respectively,lower than that of their combination(0.851,all P<0.01).Conclusion Real-time SWE combined with liver function indicators could reflect degree of liver injury in patients with different CKD stages.

Effect of benzoxazine resin on mechanical properties of nitrile rubber composites: Experiment and molecular simulation

Benzoxazine resin,being a new type of phenolic resin deve-loped to overcome the shortcomings of traditional phenolic resins,has been synthesized from phenol,formaldehyde and amine,and does not require solvent elimination or monomer purification to obtain a relatively clean precursor.It has potential application in the field of aerospace due to its low expansion coefficient,high weather resistance,high carbon yield,good mechanical strength,and excellent ablation resistance[1].It can be mixed with various other resins or polymers to produce new resins with a broad range of applications[2-3].

Characteristic and optimization of ferrite-rich sulfoaluminate-based composite cement suitable for cold region tunnels

To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting material)at 20 and 3℃.The results show that low temperature only delays the strength development of FSAC grouting material within the first 3 d.Then,the effect of four typical early strength synergists on the early properties of FSAC grouting material was evaluated to optimize the early(£1 d)strength at 3℃.The most effective synergist,Ca(HCOO)_(2),which enhances the low-temperature early strength without compromising fluidity was selected based on strength and fluidity tests.Its micro-mechanism was analyzed by XRD,TG,and SEM methods.The results reveal that the most suitable dosage range is 0.3 wt%−0.5 wt%.Proper addition of Ca(HCOO)_(2)changed the crystal morphology of the hydration products,decreased the pore size and formed more compact hydration products by interlocking and overlapping.However,excessive addition of Ca(HCOO)_(2)inhibited the hydration reaction,resulting in a simple and loose structure of the hydration products.The research results have reference value for controlling surrounding rock deformation and preventing water and mud inrushes during the excavation in cold region tunnels.

Evolution of mechanical properties,localized corrosion resistance and microstructure of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging

The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,intergranular corrosion test,exfoliation corrosion test,slow strain rate tensile test and electrochemical test,and the mechanism has been discussed based on microstructure examination by optical microscopy,electron back scattered diffraction,scanning electron microscopy and scanning transmission electron microscopy.The NIA treatment includes a heating stage from 40℃to 180℃with a rate of 20℃/h and a cooling stage from 180℃to 40℃with a rate of 10℃/h.The results show that the hardness and strength increase rapidly during the heating stage of NIA since the increasing temperature favors the nucleation and the growth of strengthening precipitates and promotes the transformation of Guinier-Preston(GPI)zones toη'phase.During the cooling stage,the sizes ofη'phase increase with a little change in the number density,leading to a further slight increase of the hardness and strength.As NIA proceeds,the corroded morphology in the alloy changes from a layering feature to a wavy feature,the maximum corrosion depth decreases,and the reason has been analyzed based on the microstructural and microchemical feature of precipitates at grain boundaries and subgrain boundaries.

Tunneling Electrons Triggered Energy Transfer between Coherently Coupled Donor-Acceptor Molecules

Energy transfer is ubiquitous in natural and artificial lightharvesting systems,and coherent energy transfer,a highly efficient energy transfer process,has been accepted to play a vital role in such systems.However,the energy oscillation of coherent energy transfer is exceedingly difficult to capture because of its evanescence due to the interaction with a thermal environment.Here a microscopic quantum model is used to study the time evolution of electrons triggered energy transfer between coherently coupled donoracceptor molecules in scanning tunneling microscope(STM).A series of topics in the plasmonic nanocavity(PNC)coupled donor-acceptor molecules system are discussed,including resonant and nonresonant coherent energy transfer,dephasing assisted energy transfer,PNC coupling strength dependent energy transfer,Fano resonance of coherently coupled donor-acceptor molecules,and polariton-mediated energy transfer.

Efficient in-situ end-functionalization of polydienes by isothiocyanate via neodymium mediated coordinative chain transfer polymerization system

End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.

三元正极材料清洗废水资源化回收零排放处理工艺

锂电三元正极材料在清洗过程中产生含有Li^(+)、Al^(3+)、SO_(4)^(2-)、镍钴锰氧化物及少量其他离子的废水,对该三元正极材料清洗废水的资源化回收零排放处理工艺进行了阐述。该废水处理系统涉及的成套工艺包括预处理单元、废水减量化单元、沉锂单元和制纯水单元。重点对Al^(3+)的去除、膜浓缩、沉锂等关键工艺进行了重点描述,最后通过实际与理论对比分析,达到了预期的设计目标——锂资源得到有效回收、废水实现全部回用。通过对实际案例的相关数据的例举和分析,证明了本套废水处理工艺的可行性和可靠性,为锂电三元正极材料清洗废水的治理提供了典型的参考工艺路线。

Energy conversion of rocks in process of unloading confining pressure under different unloading paths

Based on energy theory and tests of rocks with initial confining pressures of 10, 20 and 30 MPa under different unloading paths, the processes of strain energy conversion were investigated. The absorbing strain energy for axial compression, the dissipating strain energy for plastic deformation and cracks propagation, the expending strain energy for circumferential deformation, and the storing and releasing elastic strain energy were considered. Unloading paths included the condition of fixing axial pressure and unloading axial pressure, increasing axial pressure and unloading confining pressure, as well as unloading axial pressure and confining pressure simultaneously. Results show that expending strain energy for circumferential deformation has mainly evolved from absorbing strain energy for axial compression in three unloading paths during unloading processes. Dissipating strain energy is significantly increased only near the peak point. The effect of initial confining pressure on strain energy is significantly higher than that of unloading path. The strain energy is linearly increased with increasing initial confining pressure. The unloading path and initial confining pressure also have great influence on the energy dissipation. The conversion rate of strain energy in three paths is increased with increasing initial confining pressure, and the effect of initial confining pressure on conversion rate of strain energy is related with the unloading paths.

Mechanical properties of monodirectional Gutou mortise-tenon joints of the traditional timber buildings in the Yangtze River region

The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.

Seismic performance of double- skin steel- concrete composite box piers: Part Ⅰ——Bidirectional quasi-static testing

To study the seismic performance of double-skin steelconcrete composite box（ DSCB） piers, a total of 11 DSCB pier specimens were tested under bidirectional cyclic loading. The effects of the loading pattern, the steel plate thickness, the axial load ratio, the slenderness ratio and the aspect ratio were taken into consideration. The damage evolution process and failure modes of the tested specimens are presented in detail. Test results are also discussed in terms of the hysteretic curve, skeleton curve, ductility and energy dissipation capacity of DSCB pier specimens. It can be concluded that the hysteretic performance of DSCB piers in one direction is affected and weakened by the cyclic loading in the other direction. DSCB piers under bidirectional cyclic loading exhibit good performance in terms of load carrying capacity, ductility, and energy dissipation capacity. Overall, DSCB piers can meet the basic aseismic requirements. The research results can be taken as a reference for using DSCB piers as high piers in bridges in strong earthquakeprone areas.

Heat-treated wood and its development in Europe

Efficient use of timber is a vital concern problem, especially in these regions where the forestry coverage ratio is decreasing. Studies on physical modification of wood have been taken more attention due to the increasing attentions on environmental protection. Thermal modification is emphasized and developed quickly in developing countries, especially in European countries. A large number of researches have been conducted and some industrial production plants have been built. This paper reviewed the history of heat treatment, exemplifies the industrial developments in several European countries, summarized the basic principle of heat treatment and describes the environmental characteristics. The properties of heat-treated wood and its usage are also summed up.

Effect of KOH treatment on structural and photovoltaic properties of ZnO nanorod arrays

ZnO nanorod arrays （NRs） were synthesized on the fluorine-doped SnO2 transparent conductive glass （FTO） by a simple chemical bath deposition （CBD） method combined with alkali-etched method in potassium hydroxide （KOH） solution. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and current-voltage （I-V） curve were used to characterize the structure, morphologies and optoelectronic properties. The results demonstrated that ZnO NRs had wurtzite structures, the morphologies and photovoltaic properties of ZnO NRs were closely related to the concentration of KOH and etching time, well-aligned and uniformly distributed ZnO NRs were obtained after etching with 0.1 mol/L KOH for 1 h. ZnO NRs treated by KOH had been proved to have superior photovoltaic properties compared with high density ZnO NRs. When using ZnO NRs etched with 0.1 mol/L KOH for 1 h as the anode of solar cell, the conversion efficiency, short circuit current and open circuit voltage, compared with the unetched ZnO NRs, increased by 0.71%, 2.79 mA and 0.03 V, respectively.

Adsorption/reaction energetics measured by microcalorimetry and correlated with reactivity on supported catalysts: A review

The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved heat is helpful in terms of understanding the nature of the interactions be- tween the catalyst and the adsorbed species, and provides insights into the reactivity of the catalyst. Although various techniques have previously been applied to assessments of evolved heat, direct measurements using a Tian-Calvet microcalorimeter are currently the most reliable method for this purpose. In this review, we summarize the relationship between the adsorption/reaction energetics determined by microcalorimetry and the reactivities of supported catalysts, and examine the im- portant role of microcalorimetry in understanding catalytic performance from the energetic point of view.

Experimental study and energy saving analysis of a novel radiant ceiling heating system

In order to have an in-depth understanding of the metal ceiling radiant panel with capillary tubes, a radiant ceiling heating system is constructed to study the actual heating performance and thermal comfort by experiments. In addition, the energy saving potential of the novel heating system is discussed in terms of the COP （coefficient of performance） of the ground source heat pump and the exergy efficiency of the radiant terminal. The results indicate that the heating system shows high thermal stability and thermal comfort. When the system reaches a stable condition, the radiant heat transfer accounts for 62.7% of the total heat transfer, and the total heat transfer can meet the heating demands of most buildings. Compared to a radiant floor heating system, it offers advantages in a shorter preheating time, a lower supply water temperature and a stronger heating capability. The COP of the ground source heat pump is increased greatly when the supply water temperature is 28 to 33 ℃, and the exergy efficiency of the metal ceiling with capillary tubes is 1.6 times that of the radiant floor when the reference temperature is 5 ℃ The novel radiant ceiling heating system shows a tremendous energy saving potential.

Performance characterization, of rigid polyurethane foam with refined alkali lignin and modified alkali lignin

The two kinds of rigid polyurethane （PU） foams were prepared with respectively adding the refined alkali lignin and alkali lignin modified by 3-chloro-1,2-epoxypropane to be instead of 15% of the polyether glycol in weight. The indexes of mechanical performance, apparent density, thermal stability and aging resistance were separately tested for the prepared PU foams. The results show that the mechanical property, thermal insulation and thermal stability for PU foam with modified alkali lignin are excellent among two kinds of PU foams and control samples. The additions of the refined alkali lignin and modified alkali lignin to PU foam have little effect on the natural aging or heat aging resistance except for decreasing hot alkali resistance apparently. Additionally, the thermal conductivity of modified alkali lignin PU foam is lowest among two kinds of PU foams and control samples. The alkali lignin PU foam modified by 3-chloro-1,2-epoxypropane could be applied in the heat preservation field.

Microstructure,mechanical properties and creep resistance of Mg-(8%-12%)Zn-(2%-6%) Al alloys

The microstructural characteristics, mechanical properties and creep resistance of Mg-（8%-12%） Zn-（2%-6%） A1 alloys were investigated to get a better overall understanding of these series alloys. The results indicate that the microstructure of the alloys ZA82, ZA102 and ZA122 with the mass ratio of Zn to A1 of 4-6 is mainly composed of a-Mg matrix and two different morphologies of precipitates （block τ-Mg32（Al, Zn）49 and dense lamellar ε-Mg51Zn20）, the alloys ZA84, ZA104 and ZA124 with the mass ratio of 2-3 contain α-Mg matrix and only block r phases, and the alloys ZA86, ZA106 and ZA126 with the mass ratio of 1-2 consist of a-Mg matrix, block r precipitates, lamellar Ф-Al2Mg5Zn2 eutectics and flocculent β-Mg17Al12 compounds. The alloys studied with the mass ratio of Zn to A1 of 2-3 exhibit high creep resistance, and the alloy ZA124 with the continuous network of r precipitating along grain boundaries shows the highest creep resistance.