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Self-Admitted Technical Debt (SATD) is an intentionally introduced software code comment describing potential defects or other technical debt. Currently, deep learning is widely used in fields such as Natural Language Processing. Deep learning can be used for SATD detection, but there is a class imbalance problem and a large number of easily classified SATD instances that may potentially affect the loss value. As a result, we proposed a weighted focal loss function based on particle swarm to address the problem. Meanwhile, there is no empirical research based on local explanations for SATD detection. We have investigated local interpretation models such as Saliency Maps, Integrated Gradients, which are currently widely used in deep learning, and conducted empirical research for shared data sets. The research results show that our proposed weighted focal loss function can achieve the best performance for SATD detection; our model achieves 12.27%, 5.97%, and 5.62% improvement in Precision, Recall, and AUC compared to the baseline model, respectively; Local explanation models, including Saliency Maps and Integrated Gradients can cover nearly half of the manually labeled paradigms; these two interpretation models can also discover potential new paradigms. &nbsp

Additional file 1: Supplementary Table 1. Incidence of MZT among different ART methods

Additional file 2: Supplementary Table 2. Pregnancy Outcome of MZT among different days of embryo

Additional file 1. Supplementary methods

位于西藏班公湖-怒江成矿带西段多龙矿集区内的拿厅斑岩Cu（Au）矿床是近年来开展勘查取得重大找矿突破的矿床之一，控制Cu资源量已达到大型规模。但目前对该矿床的地质特征、成矿岩石成因及成矿物质来源还缺乏深入的了解和研究。本文基于系统的野外地质观察、岩相学研究，结合精细的锆石SIMS U-Pb定年、锆石Hf-O同位素、岩石地球化学和蚀变-矿石矿物的H-O-S同位素分析，认为该矿床是形成于121~118Ma的斑岩型Cu（Au）矿床，与多龙Cu（Au）矿集区内多不杂、波龙、拿顿、色那、拿若和铁格隆南（荣那）矿床为同一期岩浆-热液成矿事件，其成岩-成矿峰期为120~118Ma。拿厅斑岩铜（金）矿床成矿岩体显示轻稀土富集的分配型式和缺少Eu异常，且富集大离子亲石元素（如Rb、Ba等），而亏损高场强元素（如Nb、Ta等），显示弧岩浆的特征，形成于班公湖-怒江洋向北俯冲的大陆边缘弧背景。锆石Hf-O同位素模拟结果显示，矿区早期的安山-英安质次火山岩（eHf（t）=-2.0~10.3；δ18O=5.07‰~6.77‰）具有早期幔源岩浆和经历MASH过程混入壳源的岩浆（10%~20%壳源物质）的特征；而二长花岗斑岩和成矿花岗闪长斑岩（eHf（t）=1.7~3.3；δ18O=6.40‰~6.95‰）则是MASH过程逐渐演化（壳源-幔源混合，约20%~40%壳源物质）的产物。在形成拿厅斑岩铜金矿成矿岩浆的过程中，没有发生陆壳加厚的过程；岩浆演化过程中有较少斜长石分离结晶，主要为角闪石和钛铁氧化物结晶分异。另外，热液蚀变（石英、磁铁矿）和硫酸盐-硫化物（硬石膏、黄铜矿、黄铁矿）的H-O-S同位素结果显示，拿厅成矿流体和成矿物质主要来源于岩浆，与岩浆流体出溶过程密切有关。

The input constraints of control surfaces may lead to saturations, which could limit the achievable performance or even cause instability of vertical take-off and landing (VTOL) tail-sitter unmanned aerial vehicle (UAV). To improve flight safety and attitude tracking performance, a novel L1 adaptive control architecture for attitude tracking of a tail sitter subjected to input constraints is proposed in this study. The imprecise mathematical model, low weight, and small size all present different challenges when designing a control system. In this work, a feedforward compensator is first used to narrow down the uncertain bounds with the consideration of finite accuracy from prior knowledge. Second, according to the linearized model, a baseline controller is designed to offer basic performance for a nominal system without uncertainty. Finally, the L1 adaptive controller is developed to compensate for unmatched uncertainties based on the control system developed before. The stability and performance bounds of the closed-loop system are analyzed to illustrate the impact of input constraints. The numerical simulations and flight tests are carried out to verify the improved attitude tracking performance when input saturation exists.

The objective of this study was to investigate the structure characteristics of flavonoids that act as inhibitors for heterocyclic aromatic amines (HAAs) formation. Five quantitative structure-activity relationship models for predicting the inhibitory rates of HAAs (norharman, harman, PhIP, MeIQx, and 4,8-DiMeIQx) were established using selected chemometric parameters (R2 : 0.591-0.920), and indicated that the hydrophobicity, hydroxyl groups, and topological structure of flavonoids played important roles in the inhibition of HAAs formation. The 5,7-dihydroxyls in meta-position of the A-ring and the 4'-hydroxyl in the B-ring of flavonoids were critical for the inhibitory effects of HAAs, whereas the introduction of 3-hydroxyl and 3-O-glucoside in the C-ring reduced the inhibitory effects. Catechin served as the most effective inhibitor of HAAs followed by luteolin and genistein. The study can bring us a broader idea for controlling the formation of HAAs according to the structure of flavonoids. PRACTICAL APPLICATIONS: Heterocyclic aromatic amines (HAAs) are a class of organic substances with carcinogenic and mutagenic effect formed during the heating process of meat products. The formation of HAAs can be inhibited by adding natural antioxidants such as flavonoids to the meat during pretreatment. This inhibition is influenced by the unique structure of flavonoids. Thus, there has been an increasing demand to exploit the effective HAAs inhibitors from flavonoids by structure characteristics. Our study showed that the inhibitory effect of flavonoids on the formation of HAAs was mainly depended on their hydrophobicity, hydroxyl groups, and topological structure using the multiple QSAR models. Thus, effective HAAs inhibitors can be explored from dietary flavonoids according their structure characteristics.

Purpose The purpose of this paper is to develop a propeller performance measurement method for high-altitude platforms by analyzing of the propeller aerodynamic characteristics and application of a mobile testing system. Design/methodology/approach An experimental approach is adopted for this study. Considering the aerodynamic characteristics of the high-altitude propeller, the similitude of the scaled propeller model in the experiment is analyzed and determined. Then, the experimental method and procedure to obtain the propeller’s performance under different altitudes are presented, and the structure of hardware and software and the key techniques of the testing system are introduced in detail. Findings The applicability and effectiveness of the testing system is verified through comparison between experimental and numerical results. In addition, the performance of the 6.8-m propeller for a high-altitude airship is tested, which proves that the high-altitude propeller can meet the requirements of the propulsion system. Practical implications The testing methodology and the mobile testing system could be applied to aerodynamic performance evaluation of the high-altitude propellers under different altitudes. Originality/value This testing approach exhibits significant time and cost benefits over many other experimental methods to obtain the performance of the high-altitude propellers, which is important in the preliminary design of the propulsion system for high-altitude platforms.

The multi-objective optimization design method and experimental validation of the propeller for high altitude airships are presented in this paper. The method of predicting the propeller’s aerodyna...

Leaf color mutants are ideal materials for chloroplast development and photosynthetic mechanism research. Here, we characterized an EMS (ethyl methane sulfonate)-mutagenized sorghum (Sorghum bicolor) mutant, sbe6-a1, in which the severe disruption in chloroplast structure and a chlorophyll deficiency promote an albino leaf phenotype and lead to premature death. The proteomic analyses of mutant and its progenitor wild-type (WT) were performed using a Q Exactive plus Orbitrap mass spectrometer and 4,233 proteins were accurately quantitated. The function analysis showed that most of up-regulated proteins in mutant sbe6-a1 had not been well characterized. GO-enrichment analysis of the differentially abundant proteins (DAPs) showed that up-regulated DAPs were significantly enriched in catabolic process and located in mitochondria, while down regulated DAPs were located in chloroplasts and participated in photosynthesis and some other processes. KEGG pathway-enrichment analyses indicated that the degradation and metabolic pathways of fatty acids, as well as some amino acids and secondary metabolites, were significantly enhanced in the mutant sbe6-a1, while photosynthesis-related pathways, some secondary metabolites' biosynthesis and ribosomal pathways were significantly inhibited. Analysis also shows that some DAPs, such as FBAs, MDHs, PEPC, ATP synthase, CABs, CHLM, PRPs, pathogenesis-related protein, sHSP, ACP2 and AOX may be closely associated with the albino phenotype. Our analysis will promote the understanding of the molecular phenomena that result in plant albino phenotypes.

With the development of large-scale aquaculture, livestock and poultry manure pollution has become one of the priorities of rural environmental governance. Feeding treatment of livestock and poultry manure is an effective method for safe disposal and utilization of livestock and poultry manure. Separation and harvesting of earthworm manure, earthworm living bodies and residual organic wastes is a key link in the treatment, and the separating sieve of earthworm manure is one of the key equipment. On the basis of the overall scheme design and working principle analysis of the earthworm excrement vibration separating sieve, the innovative design of earthworm excrement vibration separating sieve is carried out from the following aspects: adopting eccentric rotating mechanism to vibrate rotating sieve cylinder, adopting crank rocker feeding mechanism to vibrate dynamic feeding, adopting three-stage sieving mode, adopting feeding barrier plate to slow down material moving speed, and adopting detachable structure of sieve cylinder, etc., it can effectively improve the sieving efficiency of earthworm excrement vibration separating sieve, improve the convenience of disassemble and assembly, reduce the space occupied by transportation, and improve the popularization of earthworm excrement vibration separating sieve.

This paper proposes an attitude control scheme for the Dove flapping wing micro air vehicle in intermittent flapping and gliding flight. The Dove flapping wing micro air vehicle adopts intermittent flapping and gliding flight to make the wing movements more natural; this strategy also has the potential to reduce energy consumption. To implement this specific flight mode, this paper proposes a closed-loop active disturbance rejection control strategy to stabilize the attitude during the processes of flapping flight, transition and gliding flight. The active disturbance rejection control controller is composed of three parts: a tracking differentiator, a linear extended state observer and a nonlinear state error feedback controller. The tracking differentiator estimates the given target signal and the differential signal in real time. The extended state observer estimates the system states and system nonlinearity. Moreover, the bandwidth parameterization method is applied to determine the observer gains. The stability of the closed-loop system is verified using Lyapunov’s theorem. Several outdoor flight experiments have been conducted to verify the effectiveness of the proposed control method, and the results show that the proposed method can guarantee the stability of intermittent flapping and gliding flight.

We examine the evolution of dust attenuation curve using a sample of 9504 disk star-forming galaxies (SFGs) selected from the CANDELS and 3D-HST surveys and a new technique relying on the fact that disk SFGs of similar stellar masses at the same cosmic epoch are statistically identical in stellar populations. We attribute the discrepancy in median magnitude between face-on (b/a>0.7) and edge-on (b/a, Comment: 6 Pages, 3 Figures, submitted to ApJL: comments are welcome

Honeycomb sandwich materials have been widely used in aerospace industry as secondary structural materials or interior panels. Recently the research of full thermoplastic honeycomb sandwich materials has been of interest due to their recyclability. In their production, they usually demand an adhesive-free process, namely fusion bonding, to connect thermoplastic honeycomb core and face sheets. It is a heat induced process where a parameter of temperature should be well controlled to guarantee the product quality. This article presents a mathematical model of heat conduction to analyze the transient temperature distribution from heating tools towards inner part of the core under fusion bonding conditions. In order to simplify the complexity of 3D honeycomb geometry, a homogenization method is used to obtain average thermal properties of the honeycomb along the major heat flux direction. The model is validated by comparing with the results of in-situ temperature measurement during fusion bonding. The presented model can also be applied to analyzing general out-of-plane heat conduction through honeycomb sandwich structures made from other materials.

The load dependences of dynamic viscoelasticity of casting novolac epoxy 648 and its composites, reinforced by glass fiber (GFRP) or carbon fiber (CFRP), were investigated by dynamic mechanical thermal analysis under high loads. The fiber property and load pattern were considered to analyze the complicated variations in storage modulus and loss tangent with the change of loads. The load effects are comprehensively addressed by a phenomenological theory about suppression effect of static load on the motion of microstructure units, combined with the influence of shear stress and interface properties between fiber and resin.

The chemical durability and mechanical properties of a kind of alkali-proof basalt fiber BF-CMD-01 and its reinforced F46 epoxy resin matrix composites are presented. The basalt fiber was boiled in distilled water, sodium hydroxide and hydrochloric acid, respectively. Then the mass loss and strength change of the fibers were studied showing that the alkali resistance of the basalt fiber is better than acid resistance. The flexural properties and surface morphologies of the composites were investigated after being immersed in 8 kinds of chemical mediums for 15, 30 and 90 days. Due to the difference of basalt fiber resistance in two kinds of mediums, the composites corrosion behaviors differ greatly in acid and alkaline reactions. In acid mediums, the flexural strength and flexural modulus change in the same way. In alkaline mediums, the flexural modulus keeps close to the original value while the flexural strength declines gradually. Additionally, the mechanical properties of basalt fiber reinforced polymer (BFRP) and S-2 glass fiber reinforced polymer (GFRP) have been tested, and analyzed contrastively. The results show that the interface formed between basalt fiber and epoxy resin is better than that of glass fiber and epoxy resin.

The load applied on the specimen in common dynamic mechanical thermal analysis (DMTA) is of the order of several Newtons to several tens of Newtons, far lower than that in service life. In this study a dynamic mechanical thermal analyser (EPLEXOR 500, with a total load up to 500 N) was applied to investigate the effects of static load and dynamic load (sine-wave load) on the dynamic viscoelasticity of unidirectional carbon fibre reinforced epoxy resin composites. The effects of the load on the dynamic viscoelasticity of polymer matrix composites (PMCs) are expressed mainly in two ways. On the one hand, the load affects the magnitude of the dynamic viscoelastic parameters. The storage modulus increases with increasing static load and decreases with increasing dynamic load. Such variations are obviously related to the interaction between the two kinds of load. The increase in load, whether static or dynamic, can result in a decline in the loss tangent. On the other hand, there exists a frequency-temperature-load equivalence for a carbon fibre-reinforced polymer's dynamic viscoelasticity. An increase in static load raises the glass-transition temperature and pushes the frequency spectrum curve towards a low frequency, while the effects of dynamic load are the reverse.

My dissertation comprises of three essays: 1) Accounting information and financial derivatives: a literature review 2) The Effect of Option Transaction Costs on Informed Trading in the Option Market around Earnings Announcements; and 3) The Effects of Credit Default Swaps trading on Analyst Forecast Properties. The first essay surveys the previous researches on accounting information and financial derivatives. The financial derivate instruments we mainly focus on are stock option and credit default swaps. Then we also identify some research gaps for future research. The second essay investigates the effect of transaction costs related to trading options on the directional and volatility informed trading in the option market. We find that both forms of informed trading are significantly stronger among firms with lower option bid-ask spread. Importantly, the effect of transaction costs is significant around earnings announcements, but not significant (on average) around randomly chosen dates with no events of consequence. This suggests that transaction costs play a particularly important role during information intensive periods. Trading strategies based on directional informed trading and option transaction costs earn monthly abnormal returns of 1.39% to 1.91%. The third essay investigates whether the initiation of credit default swaps (CDSs) trading can affect analysts' forecast properties. Using a difference-in-difference research design, we find that the onset of CDS trading help analysts to increase forecast accuracy, which is consistent with notion that a new financial market facilitate information discovery and dissemination. This effect is more pronounced for firms with greater information asymmetry and higher leverage. We also find that CDS initiation can depress analysts' strategic forecast optimism. Relying on several proxies for analysts' strategic optimism, we find that the depressing effect is more pronounced for subsamples with higher optimism level. In addition, we find that the depressing effect is stronger when bad news is realized ex post in the earnings announcement date.

The possibility of curing of epoxy resin induced by femtosecond laser beam was explored through choosing different initiators. Absorption spectroscopy, infrared spectroscopy (IR), stereomicroscopy and scanning electron microscopy (SEM) were applied to analyze the structure of epoxy resin systems after irradiation with a femtosecond laser beam. The experimental results show that the epoxy resin systems containing diaryliodonium salts can be cured by irradiation of femtosecond laser pulse, while the systems containing benzoin can not be cured. It is found that diaryliodonium salts decompose under the irradiation of femtosecond laser pulse through multi (two)-photon absorption, initiating the ring-opening polymerization of epoxy resin. And the appearance of cured area has a sheet structure consisting of many tiny lamellar structures.

A concentric micro-ring resonator with different waveguide width was investigated. This optimized structure can eliminate the resonance effect between rings. Meanwhile, the resonant frequency shift is improved when used in sensing.