The diffuse-interface model for two-phase flows with soluble surfactants has garnered considerable attention due to its ability to circumvent the need for a Robin boundary condition in the bulk surfactant transport equation. However, the coupling between surfactant concentration and the phase field within this framework underscores the importance of accurately resolving interfacial equilibrium profiles. To address this limitation, we have developed a two-dimensional (2D) profile-preserving phase-field model for simulating surfactant transport and adsorption-desorption in two-phase flow systems. This approach iteratively refines interfacial profiles and delta functions, removing concentration singularities and improving mass conservation. The effectiveness of the model is demonstrated through two benchmark simulations: surfactant transport in a vortex-deformed droplet, which quantitatively reveals reduced mass error over time, and adsorption-desorption dynamics on a stationary spherical interface, showing strong agreement with one-dimensional analytical solutions for surfactant concentration distributions. Additionally, we validate the model’s accuracy by simulating the deformation of a surfactant-laden droplet in shear flow and comparing the results with previous numerical data. We further highlight the model’s capability by simulating the settling behavior of a surfactant-laden droplet, underscoring the critical role of adsorption-desorption kinetics in governing droplet dynamics.

In water electrolysis, smaller bubble departure sizes are traditionally considered beneficial for electrolysis efficiency. However, we show that this paradigm breaks down at high current densities, where bubble coalescence fundamentally reshapes departure dynamics. By tuning coalescence via electrolyte composition, we find that coalescence-prone systems—despite forming larger bubbles—achieve up to 30% higher HER efficiency than coalescence-inhibited ones in both acidic and alkaline media. Experiments and simulations reveal a coalescence-induced delayed departure mechanism, where just-detached bubbles linger near the electrode and continuously merge with surface-anchored microbubbles. This coalescence delays the just-detached bubble from departing and allows it to grow further. Simultaneously, it promotes early anchored-microbubble removal (<10 μm), frees active sites, and induces intense local mixing (>1 m/s), enhancing interfacial mass and heat transport. This efficiency gain is suppressed when coalescence is inhibited, but it can be restored by promoting bubble coalescence. These findings challenge the long-standing assumption that smaller bubbles always yield higher efficiency, and establish coalescence promotion as a broadly applicable strategy for improving performance, particularly in intrinsically coalescence-inhibited systems such as alkaline/seawater electrolysis and chlor-alkali processes.

Hydrodynamic coarsening of bicontinuous domains is a central process in liquid-liquid phase separation, yet how soluble surfactants regulate this process remains poorly understood. Using a validated two-order-parameter phase-field model coupled to the incompressible Navier-Stokes equations, we show that hydrodynamic coarsening is suppressed primarily by surfactant-induced Marangoni stresses rather than by the reduction of mean interfacial tension alone. These stresses hinder interfacial coalescence, reorganize the local vortical flow, and thereby redirect the morphological evolution of bicontinuous domains. A central result is that this suppression depends non-monotonically on the surfactant Péclet number, with the strongest inhibition occurring at an intermediate value, Pe_ψ=10, rather than at Pe_ψ=1 or 100. Analyses of force evolution, interfacial surfactant statistics, and decomposed surfactant flux budgets show that this non-monotonicity arises from a competition between surfactant replenishment and gradient retention. At low Pe_ψ, diffusion efficiently replenishes the interface but smooths interfacial concentration gradients; at high Pe_ψ, advection preserves interfacial heterogeneity but leaves the interface insufficiently supplied with surfactant. The strongest suppression therefore occurs when sufficient interfacial surfactant loading coexists with persistent concentration gradients. These results establish a transport-controlled mechanism by which soluble surfactants regulate bicontinuous hydrodynamic coarsening.

Using a regularized delta function to distribute surfactant interfacial concentration can simplify the computation of the surface gradient operator del s, enabling the phase-field model to effectively simulate Marangoni flows involving surfactant transport. However, the exact conservation of total surfactant mass is compromised due to deviation from the equilibrium phase field profile, numerical diffusion, and mass non-conservation in each phase. To overcome these limitations, we have developed a new model for simulating two-phase flow with surfactant transport along the interface. This model employs a profile-preserving strategy to maintain the equilibrium interface profile, ensuring accurate calculation of the regularized delta function and improving surfactant mass conservation. Within the framework of the advective Cahn-Hilliard phase-field model, we utilize a regularized delta function with a reduced gradient to minimize numerical diffusion. Furthermore, we introduce a hybrid surface tension model that integrates the free-energy and the continuum-surface force models to mitigate spatial discretization errors, particularly in scenarios with high density and viscosity ratios. Verification tests demonstrate the model's effectiveness in simulating surface diffusion on stationary and expanding drops, suppressing spurious currents, and capturing the deformation of a two-dimensional drop in shear flow. The results closely align with analytical solutions and previous numerical studies. Finally, we apply the model to investigate the contraction and oscillation dynamics of a surfactant-laden liquid filament, revealing the role of the Marangoni force in shaping filament behavior.

In this paper, we introduce an interfacial profile-preserving approach for phase field modeling for simulating incompressible two-phase flows. While the advective Cahn-Hilliard equation effectively captures the topological evolution of complex interfacial structures, it tends to displace the fluid interface from its equilibrium state, impacting simulation accuracy. To tackle this challenge, we present an interfacial profile-preserving formulation that relies on a phase-field-related signed distance function, rather than the phase field function itself. It is solved iteratively to restore the equilibrium interface profile after each time step. This approach effectively minimizes discretization errors and enhances mass conservation accuracy for each phase. Our formulation is discretized using a second-order Total Variation Diminishing (TVD) Runge-Kutta method within iterations and a finite volume scheme in spatial discretization. We quantitatively compare our present profile-preserving method with the original method in terms of accuracy and convergence rate through simulations of a deforming drop in a single vortex and a rising bubble in quiescent fluid, and further validate the applicability through simulations of a two-dimensional contracting liquid filament, a drop impacting a deep liquid pool, and three-dimensional drop deformation in shear flow. Our results exhibit good agreement with analytical solutions, prior numerical results, and experimental data, demonstrating the effectiveness and accuracy of our proposed approach.

Hydrogen sulfide (H2S) has emerged as a potential regulator of plant responses to abiotic stress. In this study, we investigated the effects of exogenous sodium hydrosulfide (NaHS) on tobacco seedlings subjected to polyethylene glycol (PEG)-induced drought stress. Compared to control conditions, drought stress significantly reduced several parameters in tobacco seedlings, including shoot dry weight (22.83%), net photosynthesis (37.55%), stomatal conductance (33.56%), maximum quantum yield of PSII (Fv/Fm) (11.31%), photochemical quantum yield of PSII (ΦPSⅡ) (25.51%), and photochemical quenching (qP) (18.17%). However, applying NaHS, an H2S donor, mitigated these effects, ultimately enhancing photosynthetic performance in tobacco seedlings. Furthermore, optimal NaHS concentration (0.4 mmol/L) effectively increased leaf relative water content (RWC) and root activity while promoting the accumulation of soluble sugars and proline content to maintain osmotic pressure balance under drought stress. NaHS pretreatment also bolstered the antioxidant defense system in leaves, leading to a reduction in hydrogen peroxide (H2O2) and malondialdehyde (MDA) content and an increase in the activities of antioxidant enzymes such as ascorbate peroxidase (APX), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Consequently, NaHS protected chloroplast structure and attenuated chlorophyll degradation, thus mitigating severe oxidative damage. Overall, our findings provide valuable insights into exogenous NaHS's role in enhancing tobacco drought tolerance. These results lay the foundation for further research utilizing H2S-based treatments to improve crop resilience to water deficit conditions.

南太行地区旅游资源丰富,富硒西瓜产业农旅融合发展特色突出,瓜农增收显著.从地块选择、品种选择、播种育苗、定植、田间管理、病虫鸟害防治和适时采收等方面阐述了河南济源丘陵山区富硒西瓜的栽培技术,为南太行丘陵山区富硒西瓜生产提供有价值的种植技术措施.

为获得优质根际促生细菌资源,采用平板分离技术对烟草根际土壤中的可培养细菌进行分离,通过平板拮抗试验筛选抑菌活性菌株,同时进行解磷、解钾、产吲哚乙酸(IAA)活性检测,采用盆栽试验验证菌株对烟草的促生效果,并对目标菌株进行了多相分类学鉴定.结果表明:从烟草根际土壤分离获得35株不同形态菌株,依次编号为YC-1至YC-35;平板拮抗试验筛选发现YC-25抑菌最广,同时对6种病原真菌具有较为显著的抑制作用,平均抑菌率达到48%;促生功能活性鉴别显示,YC-25还具有溶无机磷、解钾、分泌IAA和产纤维素酶能力;多相鉴定结果表明,菌株YC-25为不动杆菌属(Acinetobater)的一个种,暂命名为Acinetobater pittii YC-25;盆栽试验结果显示,YC-25处理下的烟草株高增加26.29%,茎围增加27.54%,最大叶面积增加17.26%,说明菌株YC-25对烟草的农艺性状促生效果良好,作为烟草专用微生物菌剂备选遗传资源开发前景广阔.

以野生络石Trachelospermum jasminoides为试验材料,采用组织平板法从其植株体内分离培养出31株内生细菌活体纯培养物,以烟草黑胫病原Phytophthora parasitica var.nicotianae为指示菌株筛选出的HHH12具有明显的抑菌作用,抑菌圈直径达到24 mm,初步定性为具有生防活性菌株.HHH12的多相鉴定结果为假单孢菌属Pseudomonas菌株,暂定名Pseudomonas sp.HHH12.盆栽试验证实,HHH12菌悬液的灌根+叶面喷雾混合处理对烟草黑胫病不同发病阶段均表现出比叶面喷雾和灌根单一处理有更好的应用效果,药后14 d时的防治效果达到72.86％.菌株HHH12具有良好的开发应用前景.

以野生型K326土培烟草为试验材料,对NtCCX2基因进行克隆与表达模式分析,明确其在烟草响应镉等胁迫应答中的作用.结果表明,NtCCX2基因全长2 464 bp,CDS区1 926 bp,编码641个氨基酸,具有CCX家族显著的特征,在跨膜区有2个α-重复区域:α1模式基序GNGAPD和α2模式基序G(N/D)SxGD.NtCCX2基因具有明显的时空表达特性,在幼苗期和旺长期叶中的相对表达量最高,在成熟期根和花中的相对表达量较高.NtCCX2基因启动子含有脱落酸(ABA)等激素信号以及抗逆相关的响应元件,在根和叶中的表达除了受干旱、盐和镉胁迫诱导外,还对ABA、茉莉酸甲酯(MeJA)和乙烯利产生不同的响应.其中,ABA处理2 h后,NtCCX2基因在根中相对表达量是Oh的3.7倍;MeJA处理8 h后,叶中NtCCX2基因相对表达量是Oh的2.1倍;乙烯利处理2h后,NtCCX2基因在根和叶中相对表达量均增加.降镉灵等降镉药剂能够下调该基因的表达.

为筛选拮抗烟草黑胫病病原烟草疫霉(Phytophthora parasitica var.nicotianae)的生防菌资源,本研究对连作烟田烟草黑胫病发病地块的健康烟株根际土壤中的细菌进行了分离培养、筛选,并对抑菌效果较好的菌株进行了鉴定及生防效果试验.结果表明:从根际土壤中共分离到35株菌,其中菌株SYT-SF对烟草疫霉的拮抗作用最强,抑菌率达到77.15％;菌株SYT-SF具有较好的抑菌广谱性;依据菌株SYT-SF的形态特征、生理生化特征、16S rDNA序列及gryA基因序列分析,将SYT-SF归属于假单胞菌属(Pseudomonas),暂定名为Pseudomonas sp.SYT-SF.盆栽试验表明,菌株SYT-SF预防组和治疗组对烟草黑胫病的生防效果分别达到71.97％和65.05％.菌株SYT-SF在烟草黑胫病生防菌剂及植烟土壤保育菌剂开发方面具有良好的应用潜力.

利用豫南烟区2010-2017年累计8年的气温数据,运用描述统计、线性趋势拟合等基本统计分析方法对豫南烟区气温进行适宜性评价、趋势分析和风险分析.结果表明,2010-2017年该烟区在烤烟伸根期和旺长期的平均气温均在优质烟生长适宜范围内,分别为21.26、25.71℃,成熟期平均气温比适宜温度略高,为27.42℃,整体随年份增加呈先升高后降低再升高的趋势.各市在伸根期日平均最低气温比烤烟生长最适温度偏低,在旺长期和成熟期的日平均最高气温比烤烟生长最适温度略高,均呈下降趋势.驻马店市和南阳市在伸根期出现极端低温和在旺长期出现极端高温比例较高,信阳市和南阳市在成熟期出现温度大于38℃的极端高温天气概率较高.

笔者介绍了济源发展富硒功能农业助力乡村产业振兴的一些举措,如强化高层次富硒功能农业平台建设、深化富硒功能农业技术研究、打造富硒功能农业标准化示范基地、促进富硒功能农业提质增效和三产融合发展提高富硒产品附加值等,同时分析了济源富硒功能农业发展中存在的一些问题,如科普宣传不到位、富硒产品研发能力不强、区域性品牌建设力度不足等,并从强化富硒科技攻关、发展富硒主导产业、培育富硒经营主体、强化富硒品牌创建等方面提出了相应的对策与建议,以促进富硒产业为实施乡村振兴战略提供产业支撑.

以模糊数学原理为基础,采用多元统计法对河南省4个主植烟区2010-2017年气象数据进行分析,并结合气候适宜性指标进行综合评价.针对烤烟不同生长时期的各气候因子变化趋势,利用线性和三次多项式曲线进行拟合分析.结果表明,河南省各烟区适宜性好,各项气候指标均能满足优质烤烟生产的需要.旺长期均温总体呈下降趋势,而伸根期和成熟期均温总体呈上升趋势,豫南烟区和豫西南烟区在各生育期的均温相对较高.伸根期和成熟期降雨量总体呈下降趋势,而旺长期降雨量总体呈上升趋势,豫南烟区在整个生育期的降雨量均值最高.大田期日照时间整体呈明显的上升趋势,期间经历短暂下降,豫西南烟区大田期日照时间最长.河南省烟区伸根期应注意预防低温冷害,而大田后期应注意防涝、防高温等恶劣气候.

为筛选出适合南太行地区种植的西瓜品种,对秀都、美都、麒麟、中科3号、中科182、美莎特、豫艺甜宝7个品种的物候期、生长指标、果实特征、品质、产量、叶片光合特性等指标进行比较,并利用模糊数学隶属函数法对参试品种进行综合分析.结果表明:参试西瓜品种生育期基本一致,同属中早熟品种;麒麟生长势强,蔓长为322.6 c m,茎粗为6.4 c m;豫艺甜宝硒富集能力最强,果肉总硒含量为0.30 m g/k g,极显著高于其他品种;秀都、豫艺甜宝、美莎特中心可溶性固形物含量显著高于其他品种,分别为11.8％、11.8％、11.4％;中科182的667 m2产量极显著高于其他品种,为4565.00 kg;美都净光合速率最高,为24.87μmol/(m2·s),品种间差异不显著;经模糊数学隶属函数法综合排名,豫艺甜宝总隶属函数值排名第1,为3.88,豫艺甜宝、美莎特、秀都3个品种综合表现较好,可作为该地区西瓜品种引进的首要选择.模糊数学隶属函数法能够较客观地评价各品种表现,可辅助引种者对品种进行综合评价.

南太行地区位于河南省西北部,属于典型的暖温带大陆性季风气候,该地区为典型的干旱半干旱气候,加上山区昼夜温差大等得天独厚的自然条件,生产出来的西瓜含糖量高,品质较优,西瓜产业地方特色突出[1,2].南太行济源地区西瓜生产以早春露地地膜覆盖和小拱棚栽培为主,病毒病是该地区西瓜生产中的重要病害之一,发病田块一般减产10％～20％,严重发病时减产50％以上,同时会降低西瓜品质,对产业的健康发展影响很大.

本研究对普通烟草钾离子通道AKT1蛋白进行生物信息学分析.结果表明,9个烟草钾离子通道蛋白中6个为碱性,3个为酸性;5个为疏水性蛋白,4个为亲水性蛋白.烟草NIATv7_g04651钾离子通道蛋白由4个亚基组成,一半作为跨膜结构通道,一半在膜外作为辅助开关结构.NIATv7_g04651、NIATv7_g07244和NIATv7_g14627等3个钾离子通道蛋白磷酸化位点在蛋白两端分布比较密集,在中间分布比较稀疏;NIATv7_g04651、NIATv7_g07244和NIATv7_g14627等3个基因的组织表达具有特异性,在不同生长发育阶段有不同钾离子通道基因发挥作用.

为探讨富硒西瓜生产中硒富集特性,以豫艺甜宝等西瓜品种为试材,观测喷施硒肥后叶片硒残留量变化,采用L9(34)正交试验,分析亚硒酸钠喷施时期、次数、每次用量等3因素对果肉总硒含量的影响,并比较不同西瓜品种间硒富集能力的差异,评价富硒西瓜生产示范效果.结果表明,喷施硒肥后叶片总硒含量(w,后同)最高达3350μg·kg-1,硒在叶片残留期约15 d左右;影响西瓜果实硒含量最大的因素是硒肥施用时期,其次是硒肥用量及喷施次数,以组合A3B1C2(膨果定个期+1次+800 mg·667 m-2)硒富集效果最好,果实总硒含量达130μg·kg-1;不同西瓜品种硒富集能力差异极显著,在南太行丘陵地区进行富硒西瓜生产示范,平均果肉总硒含量63.3μg·kg-1.富硒西瓜生产中以膨大定个期喷施硒肥1次效率最高,硒肥用量可根据设定的果实硒含量要求合理选择.

针对济源市富硒西瓜产业发展现状,从品种和播期选择、种子处理、选茬整地、育苗、田间管理、病虫害防治和适时采收等方面对富硒西瓜绿色栽培技术进行研究,以期为济源市富硒西瓜发展提供参考.

我国西瓜产业在全球占有重要地位,改革开放以来,西瓜产业发展迅速,面积、产量均位居全球第一[1].河南省地处中原地区,是全国西瓜生产重要的优势产区之一.据统计,多年来,河南省西瓜栽培面积居全国第一[2,3].南太行地区位于河南省西北部,区域范围包含安阳市、鹤壁市、新乡市、焦作市及济源示范区5市(区)、25个县(市、区),总面积约14000 km2,总人口约1.67 × 107人,常驻人口约1.53×107人,区域内地形西部高、东部低,最高海拔1221 m左右,属于典型的暖温带大陆性季风气候,四季分明,气候适宜,具有鲜明的地域特征,生物资源、矿产资源丰富,是河南省重要的能源、粮食生产、食品加工和新型先导产业基地[4～6].河南有18个省辖市,其中,周口、商丘、开封、南阳及驻马店 5个地区西瓜种植面积就占河南西瓜总种植面积的 70％左右,南太行地区并不是河南省重要的西瓜主产区[3,7],但由于具有典型的干旱半干旱气候加上山区昼夜温差大等得天独厚的自然条件,该地区生产出来的西瓜品质较优,含糖量高,西瓜产业地方特色突出.2019年,南太行地区西瓜种植面积达1.0万hm2,以露地和小拱棚栽培为主,效益高,667 m2收入0.6万～1.2万元.