Consumer‐diet discrimination of δ13C and δ15N: Source‐ and feeding‐oriented patterns based on gut content analysis in a large subtropical river of China

Understanding the trophic discrimination (?¹³C and ?¹⁵N) between consumers and diets in fluvial systems remains difficult because of the variable food sources and complex predator–prey interactions from headwaters to the estuaries. Here, stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes in fish and invertebrates from a large subtropical river in southern China were determined to explore trophic discrimination in conjunction with a gut content analysis. The ?¹³C values showed significant differences (p < .05) among functional feeding groups, with fish, shrimp, and insect scrapers presenting higher ?¹³C values (1.20 ± 0.23‰ to 1.51 ± 0.31‰) than other groups. The ?¹⁵N values varied significantly between invertebrates (0.64 ± 0.17‰ of insect collector‐gatherers to 1.63 ± 0.36‰ of shrimp predators) and fish (1.98 ± 0.19‰ of detritivores to 2.71 ± 0.43‰ of crustaceavores) and exhibited an increasing tendency from primary to secondary consumers. A linear regression analysis revealed that the longitudinal changes in ?¹³C and ?¹⁵N were closely associated with the δ¹³C of periphyton, the δ¹⁵N of particulate organic matter (POM) in water, and the relative contribution (%) of periphyton and organic detritus to the diet composition of consumers. These results indicated that discrimination factors might not only be influenced by the isotope signatures of basal food sources but also downstream shifts in dominant food items utilized by consumers. In particular, trophic discrimination between periphyton– and detritus–based food chains, such as “epilithic diatoms–shrimp scrapers–crustaceavorous fish” and “POM–bivalves–molluscivorous fish,” displayed regionally specific patterns. When back‐calculating to the diet assimilation and trophic position in subtropical streams and rivers, we suggest using the basin‐scale ?¹³C value of 0.96 ± 0.26‰ for all consumers and ?¹⁵N values of 1.07 ± 0.32‰ for invertebrates and 2.38 ± 0.37‰ for fish.     

Full color white light,temperature self-monitor,and thermochromatic effect of Cu+ and Tm3+ codoped germanate glasses

Lighting sources with full-color visible output are widely preferred in practical applications. In addition, modern lighting sources also tend to be intelligentized, and the intelligentization asks for smart luminescence materials. In this work, we attempt to develop novel full-color emitting material with temperature sensing and thermochromatic ability. To this end, the Cu²⁺ is successfully reduced to Cu⁺ which is incorporated into the germanate glasses. The glasses are prepared via a melt-quenching technique using graphite powders as reducing reagent. The supper-broadening of the excitation and the emission spectra of Cu⁺ in the germanate glasses are observed. Full-color emission is realized by introducing Tm³⁺ as co-dopant to provide the blue component in the spectra. The energy transfer behavior between Cu⁺ and Tm³⁺ is investigated, and it is found that these two luminescence centers are independently existent without energy transfer between them. The chromatic properties of the Cu⁺/Tm³⁺ co-doped glasses are tuned by Tm³⁺ concentration and excitation wavelength. The temperature sensing based on the fluorescence intensity ratio technique is demonstrated, and a constant sensitivity for the temperature detection is obtained. Moreover the thermochromatic property is also investigated, and it is found that the studied Cu⁺/Tm³⁺-doped glasses exhibit excellent thermochromatic performance.     

一种飞跨电容型MMC的低频控制策略

飞跨电容型模块化多电平换流器(FC-MMC)在低频工况运行时,相比传统模块化多电平换流器(MMC),在抑制子模块电容电压波动方面具有不引入额外高频共模电压的优势,但依然存在引入较大高频电流问题.针对该问题,提出一种基于准比例谐振(PR)控制器的FC-MMC低频控制策略.该策略利用每相飞跨电容支路作为高频功率转移通道,通过在每相上、下桥臂内的子桥臂间注入差模高频方波电压与高频基波正弦和3次谐波混合电流的方法,在抑制子模块电容电压波动的同时,减小注入的高频电流以降低开关器件电流应力和系统损耗.另外,还给出子模块电压均衡控制策略.通过实验验证了所提控制策略的正确性.     

YCl_3－AECl_2（AE＝Mg，Ca，Sr，Ba）二元相图的研究

用差热分析法测定了ＹＣｌ_３一ＳｒＣｌ_２体系二元相图，并用Ｘ时线衍射法验证了该二元体系中新相的生成。使用ＣＡＬＰＨＡＤ技术评估和优化了ＹＣｌ_３一ＡＥＣｌ_２（ＡＥ＝Ｍｇ，Ｃａ，Ｓｒ，Ｂａ）系列四个二元相图和热力学性质，取得了热力学性质和相图自相一致的结果。     

动态加权蛋白质相互作用网络构建及其应用研究

一个蛋白质可能在不同条件或不同时刻与不同的蛋白质发生相互作用,这称为蛋白质的动态特性.蛋白质在分子处理的不同阶段参与到不同的模块,与其他的蛋白质共同完成某项功能.因此, 动态蛋白质相互作用的研究有助于提高蛋白质功能预测的准确率.结合蛋白质相互作用网络和时间序列基因表达数据,构建动态蛋白质相互作用网络.为降低PPI网络中假阴性对功能预测产生的负面影响,结合结构域信息和复合物信息,预测和产生新的相互作用,并对相互作用加权.基于构建的动态加权网络,提出一种功能预测方法D-PIN (Dynamic protein interaction networks). 基于三个不同的酵母相互作用网络实验结果表明, D-PIN 方法的综合性能比现有方法提高了14%以上.结果验证了构建的动态加权蛋白质相互网络的有效性.     

基于GPU加速的超精简型编码数据库系统

在数据爆发式增长的今天,特别是通信、金融、互联网等领域产生的大规模数据,在存储和查询方面给业界带来了前所未有的压力.在这种背景下,当前的数据库和数据仓库系统通过对数据进行压缩编码,在节约空间的同时减少了数据表查询时所需的I/O,获得性能上的提升,但大部分系统在面对实际大规模企业数据应用时依然无法在压缩比、导入时间或查询性能上完全满足企业需求.通过基于一定的规则对数据重新进行编码和精简,实现了一种新型超精简型编码的数据库系统HEGA-STORE.采用行列混合存储的架构;提出基于列内和列间规则挖掘和编码的数据导入存储计划;同时在规则挖掘和编码中使用GPU作为协处理器并行处理算法从而提高效率.通过开发编解码原型系统,对大规模网易易信通信记录数据和网易后台日志数据的导入和查询分别进行了测试,并与其他压缩编码算法和数据库、数据仓库产品进行比较.对比实验结果表明,相比同类数据库和数据仓库产品,原型系统拥有极高的压缩比,并且在导入速度和全表扫描查询速度也处于领先地位,同时使用GPU和CPU协作进行数据处理时也能进一步提高系统性能,验证了提出的超精简型编码数据库系统的实际应用价值.     

基于流程描述的测试程序开发平台的研究与应用

为提高通用自动测试系统中测试软件的通用性和开发效率,以STD（测试和信号定义,IEEE1641）标准为基础,借鉴该标准中信号分类及处理的方法,对测试流程进行描述。并以测试流程描述为基础,提出基于流程描述的测试软件开发平台。该平台通过对测试流程的描述和自动解析,实现无编程的测试程序开发。目前,该测试程序开发平台已经在某新型通用测试诊断系统中得到初步应用。     

SDN智能管控编排系统技术方案研究

随着用户对网络提出更为苛刻的服务质量要求,运营商着力进行各专业网络的智能化改造建设。首先,简单介绍了产业界各专业网络软件定义网络（software defined network,SDN）改造建设现状,并对改造过程中存在的问题进行了分析;然后,提出了SDN智能管控编排系统方案,以满足用户对跨专业业务端到端自动开通的需求,并在网络层面实现资源数据的智能分析,提升运维效率;最后,介绍了在提出架构下的专线业务开通流程和实时告警流程与实践。     

双碳及能源安全背景下中国电煤月度需求组合预测

双碳发展背景下,准确及时的电煤需求预测有利于国家制定电煤供需计划及能源安全供给。现有研究对电煤月度需求预测的较少,且精度欠佳,难以保证电煤月度需求感知的及时性和准确性。提出由回归加权融合反向传播神经网络、门控循环单元网络和长短期记忆网络的组合预测模型预测我国电煤月度需求。首先采用格兰杰因果检验从月度经济及能源生产因素中筛选显著影响电煤需求的变量。然后构建单一及组合模型进行预测,其中,组合模型权重由回归计算得到。结果表明,相较单一模型,组合预测模型在电煤需求预测中性能更好。