The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do...The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.展开更多
Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant （PPDs） that resulted from the high content of paraffin, certain poly-acrylic a...Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant （PPDs） that resulted from the high content of paraffin, certain poly-acrylic acid derivatives （PADE） with-COOR, -COOH,-CONHR, and -COO-NH3^＋R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0^# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0^# diesel by 6-7 ℃.展开更多
Synthesis of a cold flow improver （MAVA-a） for diesel fuel and its effect on solidifying point （SP） and cold filter plugging point （CFPP） of diesel fuels were investigated, The cold flow improver was prepared by...Synthesis of a cold flow improver （MAVA-a） for diesel fuel and its effect on solidifying point （SP） and cold filter plugging point （CFPP） of diesel fuels were investigated, The cold flow improver was prepared by using maleic anhydride （MA） and vinyl acetate （VA） as raw materials, toluene as solvent, dibenzoyl peroxide （BPO） as initiator, through alternating polymerization under nitrogen to obtain a binary-polymer and then through aminolysis by using a higher carbon amine as aminating agent at a temperature of 80 ℃. A cold flow improver was designed and prepared for No. 0 diesel fuel from Zhang Jia-Gang Petrochemical Company according to the contents of n-paraffin and its carbon number distribution in the No. 0 diesel fuel. It was also used together with two kinds of ethene-vinyl acetate copolymer improvers （EVA） separately. The test result showed that the CFPP of the No. 0 diesel fuel could be lowered by 3-5 ℃ when the improver MAVA-a was used. The CFPP was lowered by 8℃ when the improver MAVA-a was used together with EVA-2.展开更多
Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude o...Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude oil.However,the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging.In this research,the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated.The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension(DIFT).The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity.Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers,which is attributed to different interactions between the flow improvers and asphaltenes.To investigate these interactions,conductivity,asphaltenes precipitation,dynamic light scattering(DLS),and contact angle experiments are conducted systematically.Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state.The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures.Unlike EVA and POA,the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ.展开更多
The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an ...The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number （RON） of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.展开更多
One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearin...One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.展开更多
The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The struct...The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult.展开更多
The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amid...The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.展开更多
Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil ...Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.展开更多
La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3＋（CO-）3 that weakens the bridge adhesion of carbon structural units and alters the lattice str...La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3＋（CO-）3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3＋（CO-）3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process.展开更多
The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermente...The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermented with EPSs producing LAB strain prior to use. The technological characteristics of the composite flours were determined using an alveograph. The physico-chemical and nutritional characteristics of the composite breads were determined using standard methods and their sensory profiles were evaluated by a panel of 35 consumers. The alveograph results showed an increase in dough resistance, deformation and a decrease in extensibility and elasticity with the level of incorporation of millet flour. From the results of physico-chemical analyses of composite breads, no significant difference (p > 0.05) was observed in the use of the three types of local cereal malts except for the incorporation of 50% of the millet flour. The control sample presented the lowest acidity and dry matter value, the highest water content and pH value. No significant difference (p > 0.05) was observed in the use of the three types of cereal malts for the macronutrient contents of the composite bread samples. However, differences were observed according to the levels of incorporation. Macronutrients results showed an increase in protein content (11.17% ± 0.28% - 14.01% ± 0.10%/DM);crude fat content (1.86% ± 0.05% - 2.48% ± 0.20%/DM) and a decrease in carbohydrates content (85.36% ± 0.54% - 81.06% ± 0.36%/ DM). Regarding the content of mineral elements, significant differences (p < 0.05) were observed in the use of the three types of cereal malts for the incorporation of 15% (Mg and Fe content), 30% (Fe, Zn and K) and 50% (content of Zn, K, Na and Mg) of millet flour. The free amino acid profile revealed three essential amino acids such as valine, isoleucine and lysine. Breads incorporated with 30% of whole millet flour were the most appreciated by consumers.展开更多
Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to incre...Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.展开更多
In this work, a rheological study of automotive lubricant oils, neutral light paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two commercial viscosity index improvers-VIIs, based on hydrogenated...In this work, a rheological study of automotive lubricant oils, neutral light paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two commercial viscosity index improvers-VIIs, based on hydrogenated poly (isoprene-co-styrene), at different concentrations, was carried out. The study included the determination of the kinematic viscosity of the mixtures, the calculation of the viscosity indexes and their behavior when subjected to various rheometric experiments, including stress sweep, steady state flow, creep and recovery, and temperature ramp oscillatory tests. The obtained results showed the efficacy of the additives as viscosity index improvers, enabling a significant increase in the viscosity index of the pure oils at relatively low concentrations. The determination of the storage (G’) and of the loss (G”) moduli for the mixtures oil/VII additives showed a large predominance of the viscous effect over the elastic one. Except when under low shear stress, the mixtures showed a pseudoplastic behavior, with the flow curves being adjusted to fit the Ostwald-de-Waele model (Power Law), with negative flow behavior indexes.展开更多
This research proposes an improved Puma optimization algorithm(IPuma)as a novel dynamic recon-figuration tool for a photovoltaic(PV)array linked in total-cross-tied(TCT).The proposed algorithm utilizes the Newton-Raph...This research proposes an improved Puma optimization algorithm(IPuma)as a novel dynamic recon-figuration tool for a photovoltaic(PV)array linked in total-cross-tied(TCT).The proposed algorithm utilizes the Newton-Raphson search rule(NRSR)to boost the exploration process,especially in search spaces with more local regions,and boost the exploitation with adaptive parameters alternating with random parameters in the original Puma.The effectiveness of the introduced IPuma is confirmed through comprehensive evaluations on the CEC’20 benchmark problems.It shows superior performance compared to both established and modern metaheuristic algorithms in terms of effectively navigating the search space and achieving convergence towards near-optimal regions.The findings indicated that the IPuma algorithm demonstrates considerable statistical promise and surpasses the performance of competing algorithms.In addition,the proposed IPuma is utilized to reconfigure a 9×9 PV array that operates under different shade patterns,such as lower triangular(LT),long wide(LW),and short wide(SW).In addition to other programmed approaches,such as the Whale optimization algorithm(WOA),grey wolf optimizer(GWO),Harris Hawks optimization(HHO),particle swarm optimization(PSO),gravitational search algorithm(GSA),biogeography-based optimization(BBO),sine cosine algorithm(SCA),equilibrium optimizer(EO),and original Puma,the indicated method is contrasted to the traditional configurations of TCT and Sudoku.In addition,the metrics of mismatch power loss,maximum efficiency improvement,efficiency improvement ratio,and peak-to-mean ratio are calculated to assess the effectiveness of the indicated approach.The proposed IPuma improved the generated power by 36.72%,28.03%,and 40.97%for SW,LW,and LT,respectively,outperforming the TCT configuration.In addition,it achieved the best maximum efficiency improvement among the algorithms considered,with 26.86%,21.89%,and 29.07%for the examined patterns.The results highlight the superiority and competence of the proposed approach in both convergence rates and stability,as well as applicability to dynamically reconfigure the PV system and enhance its harvested energy.展开更多
The International Standardization Youth Star Competition is held for three consecutive years.We have witnessed continuous improvement in the competition each year,which is a result of our collective efforts.
Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging ...Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging stakeholders is essential for any type of organization,public,private,or civil society.In fact,it is a fundamental part of effective governance,continuous improvement,and social responsibility.The principle behind stakeholder engagement is simple yet powerful:those who can influence or be affected by an organization's mission must be given the opportunity to express their views and contribute to shaping the decisions that impact them.展开更多
Many reviewers contributed their insights and advice to the International Journal of Nursing Sciences in 2025,along with suggestions for improving manuscripts that were submitted for publication.These peer reviewers,l...Many reviewers contributed their insights and advice to the International Journal of Nursing Sciences in 2025,along with suggestions for improving manuscripts that were submitted for publication.These peer reviewers,listed below,have generously given their time and wisdom.The editorial team is grateful to all colleagues who have participated in this worthwhile endeavour.展开更多
Small datasets are often challenging due to their limited sample size.This research introduces a novel solution to these problems:average linkage virtual sample generation(ALVSG).ALVSG leverages the underlying data st...Small datasets are often challenging due to their limited sample size.This research introduces a novel solution to these problems:average linkage virtual sample generation(ALVSG).ALVSG leverages the underlying data structure to create virtual samples,which can be used to augment the original dataset.The ALVSG process consists of two steps.First,an average-linkage clustering technique is applied to the dataset to create a dendrogram.The dendrogram represents the hierarchical structure of the dataset,with each merging operation regarded as a linkage.Next,the linkages are combined into an average-based dataset,which serves as a new representation of the dataset.The second step in the ALVSG process involves generating virtual samples using the average-based dataset.The research project generates a set of 100 virtual samples by uniformly distributing them within the provided boundary.These virtual samples are then added to the original dataset,creating a more extensive dataset with improved generalization performance.The efficacy of the ALVSG approach is validated through resampling experiments and t-tests conducted on two small real-world datasets.The experiments are conducted on three forecasting models:the support vector machine for regression(SVR),the deep learning model(DL),and XGBoost.The results show that the ALVSG approach outperforms the baseline methods in terms of mean square error(MSE),root mean square error(RMSE),and mean absolute error(MAE).展开更多
Bread wheat(Triticum aestivum L.)is a staple hexaploid crop with numerous wild relatives.However,domestication and modern breeding have significantly narrowed its genetic diversity,diminishing its capacity to adapt to...Bread wheat(Triticum aestivum L.)is a staple hexaploid crop with numerous wild relatives.However,domestication and modern breeding have significantly narrowed its genetic diversity,diminishing its capacity to adapt to climate change.Wild relatives of wheat serve as a vital reservoir of genetic diversity,offering traits thatenhance its resistance to various biotic and abiotic stresses.Over recent decades,remarkable progress has been made in utilizing superior genes from wild relatives to bolster wheat's defenses against diseases and pests,though the exploration of genes conferring abiotic stress tolerance has lagged behind.In this review,we summarize key advancements in the utilization of wild relatives for wheat enhancement over the past century,emphasizing both theoretical and technological innovations.Furthermore,we evaluate the potential contributions of wild relatives to address production challenges posed by climate change.We also explore strategies for isolating superior genes and developing prebreeding germplasm to support the future development of climate-resilient wheat varieties.展开更多
As sessile organisms,plants must adapt various stresses.Accordingly,they have evolved several plant-specific growth and developmental processes.WRKY53 is a member of the WRKY transcription factor family,which plays a ...As sessile organisms,plants must adapt various stresses.Accordingly,they have evolved several plant-specific growth and developmental processes.WRKY53 is a member of the WRKY transcription factor family,which plays a crucial role in rice growth and development,stress response,and hormone signal transduction.This review discusses the role of WRKY53 in stress response,focusing on its functions in cold tolerance,salt tolerance,disease resistance,and pest defense,and explores its role in regulating rice leaf senescence and seed germination.This article also proposes future research directions,including functional genomics studies,protein interaction network analyses,hormone signal transduction pathways,genetic improvement strategies,applications of gene editing technologies,molecular basis of stress responses,cross-species functional conservation,and bioinformatics and comparative genomics research.This review highlights the importance of WRKY53 in rice biology and provides new perspectives and strategies for future research and genetic improvement of rice.展开更多
基金supported from the Natural Science Foundation Project of Shanghai(Nos.23ZR1425300 and 22ZR1426100)Experimental Technical Team Construction Project of Shanghai Education Commission(No.10110N230080)+1 种基金National Natural Science Foundation of China(No.22075183)Research and Innovation Project of Shanghai Municipal Education Commission(No.2023ZKZD54).
文摘The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.
文摘Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant （PPDs） that resulted from the high content of paraffin, certain poly-acrylic acid derivatives （PADE） with-COOR, -COOH,-CONHR, and -COO-NH3^＋R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0^# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0^# diesel by 6-7 ℃.
基金Supported by the Basic Research Program of the State Key Laboratory of Heavy Oil Processing (200310) China University of Petroleum,Beijing,China
文摘Synthesis of a cold flow improver （MAVA-a） for diesel fuel and its effect on solidifying point （SP） and cold filter plugging point （CFPP） of diesel fuels were investigated, The cold flow improver was prepared by using maleic anhydride （MA） and vinyl acetate （VA） as raw materials, toluene as solvent, dibenzoyl peroxide （BPO） as initiator, through alternating polymerization under nitrogen to obtain a binary-polymer and then through aminolysis by using a higher carbon amine as aminating agent at a temperature of 80 ℃. A cold flow improver was designed and prepared for No. 0 diesel fuel from Zhang Jia-Gang Petrochemical Company according to the contents of n-paraffin and its carbon number distribution in the No. 0 diesel fuel. It was also used together with two kinds of ethene-vinyl acetate copolymer improvers （EVA） separately. The test result showed that the CFPP of the No. 0 diesel fuel could be lowered by 3-5 ℃ when the improver MAVA-a was used. The CFPP was lowered by 8℃ when the improver MAVA-a was used together with EVA-2.
基金supported by the National Natural Science Foundation of China(51704315)。
文摘Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude oil.However,the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging.In this research,the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated.The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension(DIFT).The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity.Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers,which is attributed to different interactions between the flow improvers and asphaltenes.To investigate these interactions,conductivity,asphaltenes precipitation,dynamic light scattering(DLS),and contact angle experiments are conducted systematically.Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state.The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures.Unlike EVA and POA,the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ.
基金support was provided by the National Science Foundation of China(Grant Nos.20806091,20976194,and 21036008)
文摘The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number （RON） of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.
文摘One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.
文摘The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult.
基金supported financially by the Heilongjiang Postdoctorial Financial Foundation of China (Project NO. LBH-Zo8290)The Daqing Oil Field of China was thanked for providing the financial support and the crude oil
文摘The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.
基金Supported by the Key Research and Development Program for Industrial Keytechnologies of Shandong Province(2016CYJS05A01-2)the Key Research and Development Program for Public Welfare of Shandong Province(2018GNC111001)the Special Fund for the Construction of Oversea Taishan Scholars
文摘Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.
基金the National Key Laboratory in University of Science and Technology Beijing of China （KFI3-02） and the Natural Science Foundation of Hebei province （E2013209339）.
文摘La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3＋（CO-）3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3＋（CO-）3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process.
文摘The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermented with EPSs producing LAB strain prior to use. The technological characteristics of the composite flours were determined using an alveograph. The physico-chemical and nutritional characteristics of the composite breads were determined using standard methods and their sensory profiles were evaluated by a panel of 35 consumers. The alveograph results showed an increase in dough resistance, deformation and a decrease in extensibility and elasticity with the level of incorporation of millet flour. From the results of physico-chemical analyses of composite breads, no significant difference (p > 0.05) was observed in the use of the three types of local cereal malts except for the incorporation of 50% of the millet flour. The control sample presented the lowest acidity and dry matter value, the highest water content and pH value. No significant difference (p > 0.05) was observed in the use of the three types of cereal malts for the macronutrient contents of the composite bread samples. However, differences were observed according to the levels of incorporation. Macronutrients results showed an increase in protein content (11.17% ± 0.28% - 14.01% ± 0.10%/DM);crude fat content (1.86% ± 0.05% - 2.48% ± 0.20%/DM) and a decrease in carbohydrates content (85.36% ± 0.54% - 81.06% ± 0.36%/ DM). Regarding the content of mineral elements, significant differences (p < 0.05) were observed in the use of the three types of cereal malts for the incorporation of 15% (Mg and Fe content), 30% (Fe, Zn and K) and 50% (content of Zn, K, Na and Mg) of millet flour. The free amino acid profile revealed three essential amino acids such as valine, isoleucine and lysine. Breads incorporated with 30% of whole millet flour were the most appreciated by consumers.
文摘Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.
文摘In this work, a rheological study of automotive lubricant oils, neutral light paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two commercial viscosity index improvers-VIIs, based on hydrogenated poly (isoprene-co-styrene), at different concentrations, was carried out. The study included the determination of the kinematic viscosity of the mixtures, the calculation of the viscosity indexes and their behavior when subjected to various rheometric experiments, including stress sweep, steady state flow, creep and recovery, and temperature ramp oscillatory tests. The obtained results showed the efficacy of the additives as viscosity index improvers, enabling a significant increase in the viscosity index of the pure oils at relatively low concentrations. The determination of the storage (G’) and of the loss (G”) moduli for the mixtures oil/VII additives showed a large predominance of the viscous effect over the elastic one. Except when under low shear stress, the mixtures showed a pseudoplastic behavior, with the flow curves being adjusted to fit the Ostwald-de-Waele model (Power Law), with negative flow behavior indexes.
基金funded by the Deanship of Scientific Research and Libraries,Princess Nourah bint Abdulrahman University,through the Program of Research Project Funding After Publication,grant No.(RPFAP-82-1445)。
文摘This research proposes an improved Puma optimization algorithm(IPuma)as a novel dynamic recon-figuration tool for a photovoltaic(PV)array linked in total-cross-tied(TCT).The proposed algorithm utilizes the Newton-Raphson search rule(NRSR)to boost the exploration process,especially in search spaces with more local regions,and boost the exploitation with adaptive parameters alternating with random parameters in the original Puma.The effectiveness of the introduced IPuma is confirmed through comprehensive evaluations on the CEC’20 benchmark problems.It shows superior performance compared to both established and modern metaheuristic algorithms in terms of effectively navigating the search space and achieving convergence towards near-optimal regions.The findings indicated that the IPuma algorithm demonstrates considerable statistical promise and surpasses the performance of competing algorithms.In addition,the proposed IPuma is utilized to reconfigure a 9×9 PV array that operates under different shade patterns,such as lower triangular(LT),long wide(LW),and short wide(SW).In addition to other programmed approaches,such as the Whale optimization algorithm(WOA),grey wolf optimizer(GWO),Harris Hawks optimization(HHO),particle swarm optimization(PSO),gravitational search algorithm(GSA),biogeography-based optimization(BBO),sine cosine algorithm(SCA),equilibrium optimizer(EO),and original Puma,the indicated method is contrasted to the traditional configurations of TCT and Sudoku.In addition,the metrics of mismatch power loss,maximum efficiency improvement,efficiency improvement ratio,and peak-to-mean ratio are calculated to assess the effectiveness of the indicated approach.The proposed IPuma improved the generated power by 36.72%,28.03%,and 40.97%for SW,LW,and LT,respectively,outperforming the TCT configuration.In addition,it achieved the best maximum efficiency improvement among the algorithms considered,with 26.86%,21.89%,and 29.07%for the examined patterns.The results highlight the superiority and competence of the proposed approach in both convergence rates and stability,as well as applicability to dynamically reconfigure the PV system and enhance its harvested energy.
文摘The International Standardization Youth Star Competition is held for three consecutive years.We have witnessed continuous improvement in the competition each year,which is a result of our collective efforts.
文摘Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging stakeholders is essential for any type of organization,public,private,or civil society.In fact,it is a fundamental part of effective governance,continuous improvement,and social responsibility.The principle behind stakeholder engagement is simple yet powerful:those who can influence or be affected by an organization's mission must be given the opportunity to express their views and contribute to shaping the decisions that impact them.
文摘Many reviewers contributed their insights and advice to the International Journal of Nursing Sciences in 2025,along with suggestions for improving manuscripts that were submitted for publication.These peer reviewers,listed below,have generously given their time and wisdom.The editorial team is grateful to all colleagues who have participated in this worthwhile endeavour.
基金funding support from the National Science and Technology Council(NSTC),under Grant No.114-2410-H-011-026-MY3.
文摘Small datasets are often challenging due to their limited sample size.This research introduces a novel solution to these problems:average linkage virtual sample generation(ALVSG).ALVSG leverages the underlying data structure to create virtual samples,which can be used to augment the original dataset.The ALVSG process consists of two steps.First,an average-linkage clustering technique is applied to the dataset to create a dendrogram.The dendrogram represents the hierarchical structure of the dataset,with each merging operation regarded as a linkage.Next,the linkages are combined into an average-based dataset,which serves as a new representation of the dataset.The second step in the ALVSG process involves generating virtual samples using the average-based dataset.The research project generates a set of 100 virtual samples by uniformly distributing them within the provided boundary.These virtual samples are then added to the original dataset,creating a more extensive dataset with improved generalization performance.The efficacy of the ALVSG approach is validated through resampling experiments and t-tests conducted on two small real-world datasets.The experiments are conducted on three forecasting models:the support vector machine for regression(SVR),the deep learning model(DL),and XGBoost.The results show that the ALVSG approach outperforms the baseline methods in terms of mean square error(MSE),root mean square error(RMSE),and mean absolute error(MAE).
基金supported by the Biological Breeding-National Science and Technology Major Project(2023ZD04071)the National Key Research and Development Program of China(2023YFF1000600)and the National Natural Science Foundation of China(32272084,32372089,and 31971887).
文摘Bread wheat(Triticum aestivum L.)is a staple hexaploid crop with numerous wild relatives.However,domestication and modern breeding have significantly narrowed its genetic diversity,diminishing its capacity to adapt to climate change.Wild relatives of wheat serve as a vital reservoir of genetic diversity,offering traits thatenhance its resistance to various biotic and abiotic stresses.Over recent decades,remarkable progress has been made in utilizing superior genes from wild relatives to bolster wheat's defenses against diseases and pests,though the exploration of genes conferring abiotic stress tolerance has lagged behind.In this review,we summarize key advancements in the utilization of wild relatives for wheat enhancement over the past century,emphasizing both theoretical and technological innovations.Furthermore,we evaluate the potential contributions of wild relatives to address production challenges posed by climate change.We also explore strategies for isolating superior genes and developing prebreeding germplasm to support the future development of climate-resilient wheat varieties.
基金supported by the Hubei Provincial Natural Science Foundation,China(Grant No.2024AFB917).
文摘As sessile organisms,plants must adapt various stresses.Accordingly,they have evolved several plant-specific growth and developmental processes.WRKY53 is a member of the WRKY transcription factor family,which plays a crucial role in rice growth and development,stress response,and hormone signal transduction.This review discusses the role of WRKY53 in stress response,focusing on its functions in cold tolerance,salt tolerance,disease resistance,and pest defense,and explores its role in regulating rice leaf senescence and seed germination.This article also proposes future research directions,including functional genomics studies,protein interaction network analyses,hormone signal transduction pathways,genetic improvement strategies,applications of gene editing technologies,molecular basis of stress responses,cross-species functional conservation,and bioinformatics and comparative genomics research.This review highlights the importance of WRKY53 in rice biology and provides new perspectives and strategies for future research and genetic improvement of rice.
