Quality-Oriented Software Product Line Architecture Design

Software architecture design is a critical step of software development. Currently, there are various design methods available and each is focusing on certain perspective of architecture design. Especially, quality-based methods have received a lot of attentions and have been well developed for single system architecture design. However, the use of quality-based design methods is limited in software product line (SPL) because of the complexity and variabilities existing in SPL architecture. In this paper, we introduce an extra view to the Quality-Driven Architecture Design and quality Analysis (QADA) method, in order to provide a more effective quality-based architecture design framework for SPL. In this framework, the quality attributes of a software system will be taken into account in the early stage of architecture design and the reference architecture of SPL will be elicited based on quality-related consideration.

A Review of the Eco-Environmental Impacts of the South-to-North Water Diversion:Implications for Interbasin Water Transfers

Interbasin water-transfer schemes provide an engineering solution for reconciling the conflict between water demand and availability.In the context of climate change,which brings great uncertainties to water resource distribution,interbasin water transfer plays an increasingly important role in the global water–food–energy nexus.However,the transfer of water resources simultaneously changes the hydrological regime and the characteristics of local water bodies,affecting biotic communities accordingly.Compared with high economic and technical inputs water-transfer projects require,the environmental and ecological implications of water-transfer schemes have been inadequately addressed.This work selects the largest water-transfer project in China,the South-to-North Water Diversion(SNWD)Project,to critically review its eco-environmental impacts on donor and recipient basins,as well as on regions along the diversion route.The two operated routes of the SNWD Project represent two typical water diversion approaches:The Middle Route uses an excavated canal,while the East Route connects existent river channels.An overview of the eco-environmental implications of these two routes is valuable for the design and optimization of future water-transfer megaprojects.

Inducing Flow Velocities to Manage Fish Reproduction in Regulated Rivers

Conservation of endangered or economic fish and control of invasive fish is a great challenge of hydraulic engineering worldwide.Flow velocity has been recognized to affect the spawning of fishes delivering drifting eggs in rivers.However,solid scientific supports and associated mechanisms to establish quantitative relations between flow velocity and fish reproduction,taking into account spawning,fertilizing,hatching,as well as surviving,are lacking.In this paper,we quantified the relationship between flow velocity and reproduction of Chinese carps through both lab and field experiments.The results showed that a minimum velocity was required to trigger Hypophthalmichthys molitrix(H.molitrix)releasing eggs,and a velocity range was preferred to sustain spawning activity.However,the embryo incubation and larvae development of H.molitrix were found to be inhibited with the increase in flow velocity.Considering the requirements of spawning and hatching,as well as larvae surviving,an optimized flow velocity processes was identified for the reproduction of H.molitrix in rivers.These findings were of great significance to the adaptive operation of reservoirs to create reasonable and precise ecological flows for managing fish reproduction,as shown by the promising results in the engineering application to the Three Gorges Reservoir.

The Tightly Super 3-Extra Connectivity and Diagnosability of Locally Twisted Cubes

Diagnosability of a multiprocessor system G is one important measure of the reliability of interconnection networks. In 2016, Zhang et al. proposed the g-extra diagnosability of G, which restrains that every component of G – S has at least (g + 1) vertices. The locally twisted cube LTQn is applied widely. In this paper, we show that LTQn is tightly (4n – 9) super 3-extra connected for n ≥ 6 and the 3-extra diagnosability of LTQn under the PMC model and MM* model is 4n - 6 for n ≥ 5 and n ≥ 7, respectively.

水电梯级开发真的破坏下游河段营养盐情势吗?

River damming is believed to largely intercept nutrients,particularly retain more phosphorus(P)than nitrogen(N),and thus harm primary productivity,fishery catches,and food security downstream,which seriously constrain global hydropower development and poverty relief in undeveloped regions and can drive geo-political disputes between nations along trans-boundary rivers.In this study,we investigated whether reservoirs can instead improve nutrient regimes downstream.We measured different species of N and P as well as microbial functions in water and sediment of cascade reservoirs in the upper Mekong River over 5 years and modelled the influx and outflux of N and P species in each reservoir.Despite partially retaining total N and total P,reservoirs increased the downstream flux of ammonium and soluble reactive phosphorus(SRP).The increase in ammonium and SRP between outflux and influx showed positive linear relationships with the hydraulic residence time of the cascade reservoirs;and the ratio of SRP to dissolved inorganic nitrogen increased along the reservoir cascade.The lentic environment of reservoirs stimulated algae-mediated conversion of nitrate into ammonium in surface water;the hypoxic condition and the priming effect of algae-induced organic matter enhanced release of ammonium from sediment;the synergy of microbial phosphorylation,reductive condition and sediment geochemical properties increased release of SRP.This study is the first to provide solid evidence that hydropower reservoirs improve downstream nutrient bioavailability and N-P balance through a process of retention-transformation-transport,which may benefit primary productivity.These findings could advance our understanding of the eco-environmental impacts of river damming.

Equivalent Hamiltonian Equations Modelling and Energy Function Construction for MMC-HVDC in Hybrid AC/DC Power Systems

This paper proposes an equivalent Hamiltonian equations model for the modular multilevel converter-based high-voltage direct-current(MMC-HVDC)transmission system,and constructs an energy function for multi-machine power systems with MMC-HVDC transmission lines.The equivalent Hamiltonian equations model is verified to be able to track the power output dynamics of the full model of an MMC-HVDC transmission system.Both theoretical and numerical studies have been undertaken to validate that the energy function proposed for hybrid AC/DC systems satisfies the conditions of an energy function.The work of this paper bridges the gap between the well-developed direct methods of transient stability analysis and power systems with MMC-HVDC transmission lines.

Transient Stability Analysis of Large-scale Power Systems:A Survey

Transient stability analysis is a key problem in power system operation and planning.This paper aims at giving a comprehensive review on the modeling ideas and analysis methods for transient stability of large-scale power systems.For model construction,the general modeling of traditional power systems and special modeling for renewable generations and high-voltage direct-current transmissions are introduced.For transient stability analysis,Lyapunov based methods and non-Lyapunov based methods are thoroughly reviewed.In Lya-punov based methods,we focus on the energy function method,the sum-of-squares based method and decentralized stability analysis methods.Meanwhile,in non-Lyapunov based methods,the time-domain simulation,extended equal-area criterion and data-driven based methods are considered.The basic working principles,features and recent research progresses of all the above-mentioned methods are described in detail.In particular,their performances on several aspects,such as computational speed,conservativeness of stability region estimation or stability margin calculation,and adaptability to various types of system models,are mentioned.Finally,a brief discussion of potential directions for future research on transient stability analysis of large-scale power systems is included.Index Terms-connective stability,large-scale system analysis,Lyapunov functions,power systems,transient stability analysis.

A novel miR167a-OsARF6-OsAUX3 module regulates grain length and weight in rice

Grain size is one of the most important factors that control rice yield,as it is associated with grain weight(GW).To date,dozens of rice genes that regulate grain size have been isolated;however,the regulatory mechanism underlying GW control is not fully understood.Here,the quantitative trait locus qGL5 for grain length(GL)and GW was identified in recombinant inbred lines of 9311 and Nipponbare(NPB)and fine mapped to a candidate gene,OsAUX3.Sequence variations between 9311 and NPB in the OsAUX3 promoter and loss of function of OsAUX3 led to higher GL and GW.RNA sequencing,gene expression quantification,dual-luciferase reporter assays,chromatin immunoprecipitation-quantitative PCR,and yeast one-hybrid assays demonstrated that OsARF6 is an upstream transcription factor regulating the expression of OsAUX3.OsARF6 binds directly to the auxin response elements of the OsAUX3 promoter,covering a single-nucleotide polymorphism site between 9311 and NPB/Dongjin/Hwayoung,and thereby controls GL by altering longitudinal expansion and auxin distribution/content in glume cells.Furthermore,we showed that miR167a positively regulate GL and GW by directing OsARF6 mRNA silencing.Taken together,our study reveals that a novel miR167a-OsARF6-OsAUX3 module regulates GL and GW in rice,providing a potential target for the improvement of rice yield.

生长素输出载体PIN家族研究进展

生长素极性运输调控植物的生长发育。生长素极性运输主要依赖3类转运蛋白:AUX/LAX、PIN和ABCB蛋白家族。生长素在细胞间流动的方向与PIN蛋白在细胞上的极性定位密切相关。PIN蛋白由1个中心亲水环和2个由中心亲水环隔开的疏水区组成。中心亲水环上含多个磷酸化位点,其为一些蛋白激酶的靶点。PIN蛋白受多方面调控,包括转录调控、转录后修饰以及胞内循环与降解,以响应内源和外源信号。目前,利用全基因组测序方法在禾谷类作物水稻(Oryzasativa)、玉米(Zea mays)和高粱(Sorghum bicolor)中分别鉴定出12、15和11个PIN基因,但仅有少数PIN基因的功能被报道。该文从蛋白结构、活性调控和功能验证等方面综述了PIN蛋白在拟南芥(Arabidopsis thaliana)和禾谷类作物中的研究进展,以期为探究PIN蛋白家族介导的生长素极性运输过程提供新的思路与线索。

Superoxide-like Cu/GO single-atom catalysts nanozyme with high specificity and activity for removing superoxide free radicals

Although nanozyme has become an emerging area of research attracting extensive attention recently,the activity and specificity of currently reported nanozymes are generally lower than those of natural enzymes.Developing highly active and specific nanozymes is therefore extremely necessary and also remains a great challenge.Superoxide dismutase(SOD)catalyzes the disproportionation of cytotoxic O_(2)·^(−)into hydrogen peroxide and oxygen,and plays an important role in reducing human oxidative stress.In this work,we prepare Cu single-atom catalysts(Cu/GO SACs,GO=graphene oxide)through a simple and low-cost strategy at room temperature using Cu foam and graphene oxide.Cu/GO SACs can maintain excellent catalytic activity under harsh environment.Compared with the natural enzyme,SOD-like Cu/GO SAC nanozyme has higher catalytic activity and meanwhile,it does not possess the common properties of other mimic enzymes often existing in nanomaterials.Based on the excellent SOD-like enzyme activity of Cu/GO SACs,it successfully eliminates the active oxygen in cigarette smoke.This work not only provides a new idea for the design and synthesis of nanozymes with excellent SOD mimetic properties,but also is promising in the treatment of lung injury and inflammatory diseases related to free radical production.

On Edge Connectivity and Parity Factor

By Petersen＇s Theorem, a bridgeless cubic graph has a 2-factor. Fleischner （Discrete Math., 101, 33-37 （1992）） has extended this result to bridgeless graphs of minimum degree at least three by showing that every such graph has an even factor without isolated vertices. Let me〉 0 be even and mo〉 0 be odd. In this paper, we prove that every me-edge-connected graph with minimum degree at least me ＋ 1 contains an even factor with minimum degree at least me and every （mo ＋ 1）- edge-connected graph contains an odd factor with minimum degree at least too, which further extends Fleischner＇s result. Moreover, we show that our results are best possible.