响应面法优化热泵-热风联合干燥小黄鱼(Pseudosciaena polyactis)的节能参数

为了减少小黄鱼(Pseudosciaena polyactis)干燥过程的能耗, 在前期实验的基础上, 采用响应面分析法, 以单位能耗除湿值(SMER)和挥发性盐基总氮值(T-VBN)两者的综合指标Y为最终评价指标, 对热泵干燥阶段的温度A、分阶段干燥的转换点含水率B、后期热风干燥阶段的温度C三个条件进行优化, 模拟得到回归方程的预估模型。结果表明, 小黄鱼联合干燥的最优条件为热泵干燥温度A=50℃、转换点含水率B=32.62%和热风干燥温度C=44.01℃, 在此条件下比较热泵干燥(HPD)、热泵-热风联合干燥(HPD+AD)、热风干燥(AD)三种干燥方式下的样品品质和耗能, 联合干燥得到的小黄鱼干品质高于热风干燥, 而且干燥能耗降低了34.8%。     

基于马氏珠母贝(Pinctada fucata)血细胞全长转录组数据补体样组分的鉴定与分析

补体系统作为先天免疫的重要组成部分,是一种复杂的限制性蛋白水解系统,其在免疫系统中发挥着重要的防御作用。为分析马氏珠母贝补体系统的组成及作用机制,使用血细胞样品进行了全长转录组测序建库、基因比对、功能注释,共挖掘到212个潜在补体样组分相关基因。补体样组分基因经同源性比对和结构域检测分析表明,检索到的基因分别编码89个含C1q结构域蛋白、57个C型凝集素蛋白、33个纤维胶凝蛋白、11个纤维蛋白原相关蛋白、8个甘露糖结合型凝集素关联丝氨酸蛋白酶、2个含硫酯蛋白(1个C3分子,1个TEP分子)、1个补体受体、2个补体因子、9个丝氨酸蛋白酶。随机选择12个补体相关基因,使用溶藻弧菌刺激前后的血细胞样品进行实时定量PCR检测其表达水平,结果显示C1q(C1q domain containing protein)、C-lectin、MBL(mannose-binding lectin)、ficolin、MASP(mannan-binding lectin serine protease)等基因均呈现出显著差异表达,表明马氏珠母贝补体系统是一个复杂的多组分效应系统,且可能通过凝集素途径或类似于凝集素途径激活补体系统的免疫作用。研究结果为进一步验证马氏珠母贝中存在的原始补体系统提供了分子生物学证据,同时对深入了解马氏珠母贝免疫防御机制,丰富和发展海洋无脊椎动物免疫学内容也具有重要理论意义。     

缢蛏耐高盐性能及其与生长性状的相关性分析

缢蛏(Sinonovacula constricta)是我国重要的水产经济贝类,开展耐高盐新品种选育对平衡不同地区缢蛏良种养殖意义重大。本研究对不同家系缢蛏幼贝进行高盐胁迫,运用统计学方法和相关性分析探究了缢蛏耐高盐性能及其与生长性状的相关性。结果显示,缢蛏家系间壳长、壳高、壳宽和体质量表型值差异较大,体质量变异系数达15.53%。不同家系对高盐耐受性差异较大,家系间死亡率范围在0～100%。胁迫实验共持续9 d,各家系缢蛏首粒死亡时间在第1～9 d之间,而且死亡率较高的家系内缢蛏死亡时间离散程度较大,说明不同个体间高盐耐受性差异也较大。缢蛏开始出现大量死亡的时间主要在胁迫后第8 d,第9 d部分家系死亡率高于80%,说明缢蛏对高盐耐受存在一个阈值,超过该阈值会开始或大量死亡。皮尔逊和斯皮尔曼相关性分析显示,缢蛏存活时间和生长性状为正相关,其中存活时间与缢蛏壳长、体质量相关性均达到显著水平(P<0.05)。缢蛏存活率与体质量、生长速度均显著正相关(P<0.05)。整体而言,壳长较长和体质量较重的缢蛏个体耐高盐性能较强,在高盐环境中具有生长优势。本研究揭示了缢蛏的高盐耐受性及...     

海南新村潟湖潮汐、潮流特征及其对营养盐的影响

基于海南新村潟湖2020年12月水文和水质多要素实测数据,研究了该海域的潮汐、潮流变化特征,并探讨了潮位变化对潟湖营养盐的影响。结果表明,新村潟湖的潮汐为不规则全日潮,潟湖口门处的潮流为往复流,涨潮历时15 h,落潮历时10 h。大、小潮期间3个观测站点溶解性无机氮(DIN)浓度变化范围为0.91~20.87 μmol/L,磷酸盐(PO3-4)浓度变化范围为0.11~5.92 μmol/L,硅酸盐(SiO2-3)浓度变化范围为2.36~134.75 μmol/L。大、小潮期间,潟湖内3个观测站点DIN、PO3-4、SiO2-3浓度随着涨、落潮过程发生变化。潟湖口门处流速对观测站点潮位变化有着重要的影响,潮通量基本决定了潮位的变化。潟湖口门处和渔排密集区域的营养盐浓度与潮位呈现显著的负相关关系,潮流流速对口门处和渔排密集区域的营养盐变化有着重要影响。该研究结果将为新村潟湖的污染治理及生态修复提供科学依据。     

700年以来冲绳海槽西南部粘土矿物来源及其对沉积环境的响应

利用X射线衍射（XRD）技术对冲绳海槽南部HOBAB4-S2站700年以来的黏土矿物组成以及结晶学特征进行了研究和分析,并对该区的沉积特征、物质来源以及黏土矿物所记录的东亚季风的演化历史进行了探讨。研究发现冲绳海槽南部HOBAB4-S2站黏土矿物组合总体是以伊利石（59–77 %,平均含量69 %）和绿泥石（11–17 %,平均含量14 %）为主,而蒙脱石（5–23 %,平均含量12 %）和高岭石含量（2–6 %,平均含量4 %）则相对较低。通过黏土矿物研究对物源进行分析,发现冲绳海槽南部研究站位的黏土矿物中,蒙脱石主要是来自于长江或者东海大陆架的再沉积。伊利石,绿泥石以及高岭石主要来自于台湾河流,尤其是兰阳溪。蒙脱石/（伊利石+绿泥石）比值的大小可以用来指示东亚夏季风的强弱变化。1320 AD以来的黏土矿物组合的变化较好地记录了部分中世纪暖期后期、小冰期以及现代暖期3个时期在百年时间尺度上的气候波动。该指标显示,相对于中世纪暖期后期,东亚季风强度在小冰期（1405–1850 AD）和在现代暖期（1955 AD）均存在明显的减弱,指示该时期台湾东北部-冲绳海槽南部地区处于相对湿润强降雨的气候环境。     

The other's perception of a streamflow sample: From a bottle of water to a data point

In scientific communication, ambiguities in term usage can go unnoticed due not only to the distance between reader and writer but also to the existence of highly specialized scientific subcommunities. This commentary therefore aims at raising awareness about the use of terms that have different meanings within different hydrological subcommunities such as field hydrology, hydrological modelling, or statistical hydrology. To do so, we discuss the use of the following commonly used hydrological terms: sample, runoff, discharge, and streamflow. We performed three types of analyses to provide evidence of term usage and understanding, including both qualitative and quantitative approaches: a drawing exercise, a survey, and a literature corpus analysis. These analyses allow for a comparison of spontaneous definitions and the actual use of these terms in scientific publications. Our various information sources revealed that the dialogue between hydrologists within and across subdisciplines is substantially influenced by personal conceptualizations of terms that are not always shared across conversational partners. The terms discussed and illustrated in this commentary have to be seen as a small sample used to demonstrate the need for a thoughtful use of hydrological terms when communicating research, not only to a general audience but even across subdisciplines within hydrology.     

Numerical evaluation of soft inter‐slab joint in concrete‐faced rockfill dam with dual mortar finite element method

Recently constructed concrete‐faced rockfill dams (CFRDs) often use soft inter‐slab joints to prevent axial compression‐induced extrusion damage in the concrete face. Due to the complexity of the multibody contact and the lack of information on the actual behavior of soft joints, it is highly challenging to numerically assess the effect of soft joints in CFRDs. In this paper, we present a numerical approach for the three‐dimensional modeling of CFRDs with hard and soft joints. A dual mortar finite element method with Lagrange multiplier is developed to treat the multibody contact in hard joints with impenetrability condition. The soft joint slab‐filler‐slab contact system is modeled using an equivalent contact interface approach, where the soft contact constraints are imposed using a perturbed Lagrange formulation. Through a series of laboratory tests, the mechanical behavior of soft joint is investigated. An extrusion model for the soft joint is presented and implemented in the dual mortar finite element method. The proposed numerical method is applied to the three‐dimensional analysis of Tianshengqiao‐1 CFRD. Despite the complex multibody contact and strong material and geometry nonlinearities in the CFRD, the proposed method is stable and capable of capturing salient characteristics of the CFRD. Numerical results show that in Tianshengqiao‐1, the employment of soft joints can effectively reduce the axial compression stress, thus greatly alleviating the risk of extrusion damage in the concrete face.     

Stability analysis of shotcrete supported crown of NATM tunnels with discontinuity layout optimization

For tunnel constructed by New Austrian Tunnelling Method, the crown is the upper part of tunnel section, constructed during excavation process and supported by shotcrete. The stability of the crown has great influence on the safety of tunnel itself and the buildings above, which correlates, among others, with geometrical setup of tunnel and material properties of shotcrete and soil/rock. In this paper, aiming at analyzing the stability of shotcrete supported crown, a recently presented numerical method discontinuity layout optimization is adopted, which introduces a great amount of potential discontinuities cross over one another and provides a wide search space for efficient upper limit analysis. In the analysis, a well‐established hydration model of cementitious material is implemented for accounting the hydration of shotcrete. Then assumptions based on convergence‐confinement method are used for accounting the 3‐dimensional effect in 2‐dimensional analysis, finally providing time‐space–dependent assessments of stability of shotcrete supported crown.     

A discontinuous finite element suspended sediment transport model for water quality assessments in river networks

Suspended sediment plays an important role in the distribution and transport of many pollutants (such as radionuclides) in rivers. Pollutants may adsorb on fine suspended particles (e.g. clay) and spread according to the suspended sediment movement. Hence, the simulation of the suspended sediment mechanism is indispensable for realistic transport modelling. This paper presents and tests a simple mathematical model for predicting the suspended sediment transport in river networks. The model is based on the van Rijn suspended load formula and the advection–diffusion equation with a source or sink term that represents the erosion or deposition fluxes. The transport equation is solved numerically with the discontinuous finite element method. The model evaluation was performed in two steps, first by comparing model simulations with the measured suspended sediment concentrations in the Grote Nete–Molse Nete River in Belgium, and second by a model intercomparison with the sediment transport model NST MIKE 11. The simulations reflect the measurements with a Nash‐Sutcliffe model efficiency of 0.6, while the efficiency between the proposed model and the NST MIKE 11 simulations is 0.96. Both evaluations indicate that the proposed sediment transport model, that is sufficiently simple to be practical, is providing realistic results.