Proof of Six-Wave Resonance Conditions of Ocean Surface Gravity Waves in Deep Water

A necessary big step up in the modern water wave theories and their widespread application in ocean engineering is how to obtain 6-wave resonance conditions and to prove it. In the light of the existing forms and characteristics of 3-wave, 4-wave and 5-wave resonance conditions, the 6-wave resonance conditions are proposed and proved for currently a maximum wave-wave resonance interactions of the ocean surface gravity waves in deep water, which will be indispensable to both the Kolmogorov spectrum of the corresponding universal wave turbulence and a synthetic 4-5-6-wave resonant model for the ocean surface gravity waves.

A Comparative Analysis of the New -3(-n) - 1 Remer Conjecture and a Proof of the 3n + 1 Collatz Conjecture

This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.

Three-dimensional hydrodynamic model of Xiamen waters

A semi-implicit and Eulerian - Lagrangian finite difference method for three-dimensionalshallow flow has been extended to a more complete system of equations incorporating second-moment turbulence closure model and transport equations of salinity and temperature. The simulation for flooding and drying of mudflats has been improved. The model is applied to Xiamen waters. Based on extensive survey data, water level elevation, temperature and salinity field along the eastern open boundary and at the Jiulong River inlets and runoffs are analyzed, specified and calibrated. The computed results show good agreement with the measured data, reproduce flooding, emergence of large and complex mudflat region.

The diffusive fluxes of inorganic nitrogen across the intertidal sediment-water interface of the Changjiang Estuary in China

Ammonium and nitrate concentrations were analyzed in near-bottom water and pore water collected from ten stations of the intertidal flat of the Changjiang Estuary during April, July, November and February. The magnitudes of the benthic exchange fluxes were determined on the basis of concentration gradients of ammonium and nitrate at the near-bottom water and interstitial water interface in combination with calculations of a modified Fick＇ s first law. Ammonium fluxes varied from - 5.05 to 1.43 μg/（ cm^2·d） and were greatly regulated by the production of ammonium in surface sediments, while nitrate fluxes ranged from - 0. 38 to 1.36 μg/ （ cm^2·d） and were dominated by nitrate concentrations in the tidal water. It was found that ammonium was mainly released from sediments into water columns at most of stations whereas nitrate was mostly diffused from overlying waters to intertidal sediments. In total, 823.75 t/a ammonium-N was passed from intertidal sediments to water while about 521.90 t/a nitrate-N was removed from overlying waters to intertidal sediments. This suggests that intertidal sediments had the significant influence on modulating inorganic nitrogen in the tidal water.

Using irrigation intervals to optimize water-use efficiency and maize yield in Xinjiang,northwest China

Worldwide, scarce water resources and substantial food demands require efficient water use and high yield.This study investigated whether irrigation frequency can be used to adjust soil moisture to increase grain yield and water use efficiency(WUE) of high-yield maize under conditions of mulching and drip irrigation.A field experiment was conducted using three irrigation intervals in 2016: 6, 9, and 12 days(labeled D6, D9, and D12) and five irrigation intervals in 2017: 3, 6, 9, 12, and 15 days(D3, D6, D9, D12, and D15).In Xinjiang, an optimal irrigation quota is 540 mm for high-yield maize.The D3, D6, D9, D12, and D15 irrigation intervals gave grain yields of 19.7, 19.1–21.0, 18.8–20.0, 18.2–19.2, and 17.2 Mg ha^-1 and a WUE of 2.48, 2.53–2.80, 2.47–2.63, 2.34–2.45, and 2.08 kg m-3, respectively.Treatment D6 led to the highest soil water storage, but evapotranspiration and soil-water evaporation were lower than other treatments.These results show that irrigation interval D6 can help maintain a favorable soil-moisture environment in the upper-60-cm soil layer, reduce soilwater evaporation and evapotranspiration, and produce the highest yield and WUE.In this arid region and in other regions with similar soil and climate conditions, a similar irrigation interval would thus be beneficial for adjusting soil moisture to increase maize yield and WUE under conditions of mulching and drip irrigation.

Layer regrouping for water-flooded commingled reservoirs at a high water-cut stage

Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to improve oil recovery for high water-cut multilayered reservoirs. Dif- ferent regroup scenarios may lead to different production performances. Based on unstable oil-water flow theory, a multilayer commingled reservoir simulator is established by modifying the production split method. Taking into account the differences of layer properties, including per- meability, oil viscosity, and remaining oil saturation, the pseudo flow resistance contrast is proposed to serve as a characteristic index of layer regrouping for high water-cut multilayered reservoirs. The production indices of multi- layered reservoirs with different pseudo flow resistances are predicted with the established model in which the data are taken from the Shengtuo Oilfield. Simulation results show that the pseudo flow resistance contrast should be less than 4 when the layer regrouping is implemented. The K-means clustering method, which is based on the objec- tive function, is used to automatically carry out the layer regrouping process according to pseudo flow resistances. The research result is applied to the IV-VI sand groups of the second member of the Shahejie Formation in the Shengtuo Oilfield, a favorable development performance is obtained, and the oil recovery is enhanced by 6.08 %.

The Coupling Coordination Evolution Research of Economy - Ecology - Society System in Xinjiang：Based on the Interaction Perspective of Water Resources

Under the water resources perspective,coupling coordination of economy-ecology-society system in Xinjiang was taken as the research object. By building the coupling evaluation index system of the water resources-economy-ecology-society system,quantitative evaluation and analysis of the coupling coordination of the water resources-economy-ecology-society system from 2001 to 2014 were conducted. The results showed that benefit indexes of economic system and social system grew rapidly,while benefit indexes of water resources system and ecosystem fluctuated smoothly from 2001 to 2014; coupling state of the whole system was at rival stage,and coupling coordination was reluctant coordination type,and the coupling index was slightly higher than the coupling coordination index. Moreover,it showed that the more the coupling systems,the lower indices of coupling and the coupling coordination.

Effects of Different NH_4^+/NO_3^- Ratio and Water Condition on Physiological Characteristics of Rice Seedlings

[Objective] This study aimed to further explore the dynamics of related physiological indexes of rice seedlings under different NH4＋ /NO3- ratio and different water condition. [Method] Under the hydroponic condition in laboratory, 3 NH4＋/NO3- ratios （0/100, 50/50 and 100/0） and 2 water conditions （＋PEG,-PEG） were designed for Fengliangyou 7203. [Result] The root-canopy ratio of rice seedlings increased under any of the NH4＋/NO3- ratios and water conditions. Under water stress, the root-canopy ratio of rice seedlings changed most greatly at the NH4＋/NO3- ratio of 0/ 100; the overall water potential of rice seedlings reached the lowest at the NH4＋/ NO3- ratio of 100/0; and the changes of water potential and xylem flow pH were relatively stable at the NH4＋/NO3- ratio of 50/50. Under the condition of no water stress, the growth of rice seedlings was best at the NH4＋/NO3- ratio of 50/50, followed by the NH4＋/NO3- ratios of 0/100 and 100/0. [Conclusion] This study will pro- vide a basis for understanding the relationship between water potential and xylem flow.

Lithium Behavior in Salt-water System Explored by Molecular Dynamics Simulation

The molecular dynamics simulation method was adopted to study the transient characteristics of Li^+,CO3^2-,and SO4^2- in Na^+,K^+,Li^+,Cl^-,and SO4^2-/H2O system.The composition of Na^+,K^+,Li^+,Cl^-,SO4^2- and CO3^2- was selected to optimize the initial structural model and conduct dynamic simulation.The mean azimuth shift and diffusion coefficient of Li^+,CO3^2-,and SO4^2- in the system,the radial distribution function and potential energy between Li^+ and -OW,SO4^2- and -OW as well as CO3^2- and -OW,and the dielectric constant of hydrogen bond were expounded and analyzed.At the same time,the Li enrichment behavior in the evaporation process of salt lake brine was analyzed based on the simulated data.The results show that the simulation results are in good agreement with the experimental values,which verifies that,compared with other ions,the crystallization of Li^+ and SO4^2- occurs earlier after reaching saturation.

Determination of 16 Species of OCPs in Water by Liquid-liquid Extraction-GC

[Objective] The research aimed to study the determination of 16 kinds of OCPs in water by liquid-liquid extraction -GC. [Method] The new method for determining 16 kinds of OCPs in water by liquid-liquid extraction -GC was established, and the influencing factors such as nitrogen pressure and water bath temperature were discussed. [ Result] Detection limit of the method was from 3.2 to 14.1 ng/L, the relative standard deviation was between 4.0% and 9.6%, and the average recovery ranged from 80.8% to 106.0%. By optimizing nitrogen pressure and water bath temperature in the sample pretreatment process, when nitrogen pressure was ＋0.087 kPa, and water bath temperature was ±36 ℃, recovery effect of this method was better. [ Conclusion] The determination method had accurate qualitative and quantitative results, and met detection requirement of 16 kinds of OCPs in water.

Preliminary Study on Water Demand Law of 1-0 Rooted Cuttings of Populus szechuanica

In order to provide theoretical basis and technical support for the afforestation and artificial water supply of P.szechuanica in arid areas,the characteristics of water consumption of P.szechuanica were explored,and the law of water demand of P.szechuanica was grasped.In this paper,potted seedlings of 1-0 rooted cuttings of P.szechuanica were taken as research objects,and change situation of water consumption under different water control gradients was measured regularly by using weighing method,further analyzing dynamic change of water consumption of P.szechuanica and revealing water demand law of 1-0 rooted cuttings of P.szechuanica.The results showed that total change of water consumption of 1-0 rooted cuttings of P.szechuanica had"slow-fast-slow-fast"double-peak trend in the growth period of the current year,and corresponded with univariate linear relation(R^(2)=0.7137),with significant difference.In whole growth period,water consumption in August was the highest,which was 2.7 times of that in June and July and 1.5 times of that after September.In different water control treatments,the dynamic changes of daily and monthly water consumption were significantly different.In seven water control treatments,monthly water consumption was between(6315.95±1690.70)and(10105.28±3065.30)g/month,and mean was(8211.07±2308.23)g/month.With intensification of water control treatment,water consumption increased,but there was no seedling death due to water shortage.P.szechuanica has great plasticity in water demand,and can survive in both arid and humid environments.Meanwhile,it is revealed that P.szechuanica is the most widely distributed tree species in the region.

2015 IWA Alternative Water Resources Conference Nanjing,China(May 26-28,2015)

The IWA Alternative Water Resources（AWR）Conference is organized by the International Water Association,Hohai University,the IWA China Chapter of the AWR Cluster,and the Seawater Desalination and AWR Utilization Research Center of Hohai University.

Water-Deficit Response Is Not Affected by Glutathione Deficiency in Arabidopsis thaliana pad2-1 Plants

Changes in glutathione and ascorbate content, hydrogen peroxide and abscisic acid were studied in developing leaves in wild-type (Col-0) and glutathione-deficient mutant pad2-1 lines of Arabidopsis thaliana over a time period of 9 days of drought followed by re-watering. Glutathione deficient mutant (pad2-1) presents mechanisms of acclimation to water stress through the reduction of plant biomass and increase in endogenous concentrations of ascorbate and glutathione. These acclimation responses to stress appeared along with the first symptoms of stress and we suggest here that they are regulated by ABA and H2O2. Normally, wild type plants under conditions of stress require an initial response phase in which a decrease in antioxidants is observed before reaching acclimation through the increase in levels of antioxidants. pad2-1 is more sensitive to stress and reacts to it;however, it did not suffer more oxidative stress than Col-0 plants, even though pad2-1 had higher levels of endogenous H2O2 relative to wild-type. In both water stressed Col-0 and pad2-1 plants increases in ABA were observed, however, more sharply in wild-type stressed plants. Low levels of glutathione together with high levels of H2O2 may regulate endogenous ABA concentrations and could be related to the slow growth rates which were observed during the experiment. The results highlighted the double function of glutathione as an antioxidant and signal molecule and also, the different response patterns of wild-type and pad2-1 when faced with drought stress. The results bring new insights to the responses of pad2-1 under conditions of water stress.

Water and nitrogen transport characteristics of single-line interference infiltration under film hole irrigation with muddy water and fertilizer

Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.

Isobaric Vapor–Liquid Equilibrium for tert-Butyl Alcohol + Water + Propane-1,3-Diol + 1-Ethyl-3-Methylimidazolium Chloride at 101.3 kPa

In this study, we used a mixture of organic liquid propane-1,3-diol and ionic liquid 1-ethyl-3-methylimidazolium chloride([emim]Cl) as the entrainer to separate tert-butyl alcohol(TBA) + water. We measured the isobaric vapor–liquid equilibrium(VLE) for the quaternary system TBA + water + propane-1,3-diol + [emim]Cl at 101.3 kPa, and found the VLE data to be well correlated with the nonrandom two-liquid model. These results show that the mixed solvent of propane-1,3-diol + [emim]Cl can increase the relative volatility of TBA to water and break the azeotropic point. We found no notable synergetic effect between them, and observed that the liquid mixed solvent of propane-1,3-diol and [emim]Cl had lower viscosity than [emim]Cl, which makes it a promising entrainer for separating the TBA + water azeotrope in industrial applications.

水仓防隔水煤柱安全评价及注浆加固治理研究

某煤矿水仓的砌碹巷道在开采的扰动、防隔水煤柱宽度留设不足、砌碹壁后充填不密实等情况下,使得周边采空区水渗漏至水仓,极大影响了水仓的安全稳定。为进一步加强水仓煤柱的稳定性,运用地面钻孔及井下钻孔相结合的方法进行注浆加固。采用地面钻孔注浆充填井下硐室,硐室充填沙子245~328 m^(3)、水泥487~650 t,充填材料体积远远大于硐室体积220 m^(3),有效增加了煤柱厚度;利用井下钻孔在砌碹处进行水泥注浆与水化学注浆,使得砌碹裂缝处涌水量由15 m^(3)/h降至为零,砌碹壁后空隙充填效果良好。通过对煤柱及砌碹壁后空隙的注浆充填,有效提高了水仓防隔水煤柱的稳定性。

短链含氟聚丙烯酸酯功能整理剂的制备及应用

为制备耐水洗性能优良的三防整理剂,以丙烯酸十三氟辛酯(Tridecooctyl acrylate,C6F)和丙烯酸十八酯(Octaglycidyl acrylate,SA)为主要单体,甲基丙烯酸缩水甘油酯(Glycidyl methacrylate,GMA)为交联单体,通过细乳液聚合法制备了一种短链含氟丙烯酸酯共聚物细乳液,并将其作为整理剂应用在棉织物上;通过红外光谱分析、粒径分析和热重分析对乳液进行表征,采用场扫描电镜和X射线光电子能谱仪对棉织物表面结构进行分析,探究C6F和SA的用量对该共聚物薄膜表面能的影响。结果表明:当C6F质量分数为50%,SA质量分数为25%时,共聚物薄膜的表面能低至9.16mN/m;整理后棉织物的水接触角为150.8°,橄榄油接触角为141.2°,拒水等级4级,拒油等级4级,耐沾污等级5级;整理后棉织物经过20次水洗后水接触角仍有135.7°,橄榄油接触角为124.8°,表现出良好的耐水洗性能。该文可为制备短链C6型含氟丙烯酸酯共聚物提供数据参考。

软土深基坑变形及环境影响分析方法与控制技术

随着基坑规模日益增大以及邻近环境设施愈加复杂,合理评估并控制基坑变形及对周边环境影响成为软土基坑工程面临的重要挑战。基于理论分析与工程应用,对软土深基坑变形与环境影响分析方法及控制技术进行了系统研究。首先,在统筹考虑安全与经济的前提下,提出了软土深基坑环境保护等级和变形控制指标,为基坑周边不同类型环境设施的保护提供了依据。其次,系统建立了便于工程应用的基坑变形影响简化分析方法,并提出了基于土体小应变特性的基坑开挖对环境影响的计算分析方法以及确定全套小应变本构模型参数的实用方法,为复杂环境下深基坑环境影响分析提供了重要手段。同时,针对承压水降水影响难以准确量化评估的难题,提出了根据群井抽水试验反演确定关键水文地质参数并评估深层承压水降水对地层和环境变形影响的计算方法,满足了复杂地层承压水降水影响分析的工程需求。此外,还提出了包括支护结构与主体地下结构相结合、数字化微扰动搅拌桩加固、混凝土支撑主动变形控制、承压水控制超深隔渗帷幕等绿色、低碳、环境低影响的基坑变形控制新技术。成果在全国大量工程中成功应用,促进了软土深基坑工程全过程变形影响精细化分析和系统化控制技术的发展,为大规模地下空间的开发利用提供了技术支撑。

含氟水性聚氨酯-丙烯酸酯涂料的制备及其成膜强度和耐水性的研究

采用原位乳液聚合法,合成了含氟自交联型水性聚氨酯-丙烯酸酯(FPUA)乳液。研究了单体物质的量比、环氧基团含量和氟单体含量对乳液制备过程、乳液及涂膜性能的影响。通过红外光谱、热重分析对其结构和膜性能进行表征,并对涂膜表面的水接触角进行了研究。结果表明:n(—NCO)∶n(—OH)=1.4、n(—NHNH2)∶n(—CO—)=1、GMA用量为4%、含氟单体用量为6%时,合成乳液稳定性良好,涂膜的耐水性和热稳定性良好。在成膜时复合乳液中的氟基团向空气/聚合物界面伸展,有效地覆盖涂膜表面,降低涂膜表面能,水在涂膜上的接触角达到117.2°。

棉织物溶胶-凝胶法的无氟拒水整理研究

以接触角作为评价依据,研究了纯棉织物经不同改性二氧化硅溶胶处理纯棉织物后的拒水性能。讨论了改性剂结构、浓度、处理物表面粗糙程度及洗涤次数对接触角的影响。试验表明,整理棉织物的拒水性随溶胶中烷基硅烷添加剂浓度和烷基链长度的增加而提高;改性溶胶处理后,织物的拉伸强力减小,而白度和透湿量变化不大。