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In this study, a blue-green pigment has been prepared by partially replace Co2+ and Cr3+ in CoCr2O4 spinel structure with Mg2+ and Al3+ using a gel casting method The gel precursor was calcined at various temperatures (900–1400 °C) to obtain Mg0.5Co0.5CrAlO4 spinel pigment. Combining the Rietveld refinement method of XRD and peak fitting of XPS high-resolution spectra, the relationships between the cation distributions (Co2+, Mg2+, Al3+, and Cr3+) in the tetrahedron and octahedron of the spinel structure and the calcination temperature were examined. In the octahedron, the contents of Co2+ and Al3+ decreased with increasing calcination temperature, and the Mg2+ and Cr3+ contents exhibited the opposite trend. The bond lengths of A-O and B–O change with increasing calcination temperature, thereby leading to a change in the unit cell. The optical performance of the pigments was investigated via UV–vis and CIE L*a*b* spectrophotometry, and the study shows that the blue-green hue of the pigment powder is caused by the absorption at υ3～υ8 (370 nm–640 nm) in the visible light region. The varied contents of Co2+ and Cr3+ in the spinel structure among calcination temperatures cause the absorption spectrum intensity change, thereby resulting in various blue-green tones. This study lays the foundations for subsequent investigations of colour modification in MgxCo1-xAlyCr2-yO4 spinel.

The damping properties of fluorinated polyacrylate (FPA) composites with expanded graphite (EG) partially substituted for mica as fillers have been studied. EG was prepared by a rapid expansion method by microwave (MW) irradiation. The effects of the EG and natural graphite (NG) as partial substitutions for mica and the blending of epoxy (EP) resin with the polyacrylate emulsion on the damping performance of the composites was investigated with dynamic mechanical analysis (DMA). The results showed that adding EG as a partial substitute for the mica improved the intensity of the loss peak of the DMA tanδ and broadened the corresponding high loss factor (tanδ > 0.3) temperature range of the PA/EP composites. In comparison with NG or the mica, EG was more efficient in improving the damping properties of the composites. When the weight content of EP was 4% and EG was 6%, tanδ reached the maximum value of 2.16, and the corresponding temperature range with tanδ > 0.3 was about 80 °C.

Hierarchical nanoparticles are of great interest because they possess unique physicochemical properties and multiple functionalities, providing a wealth of possibilities for various applications. In this work, we have developed a well-designed method to prepare hierarchical magnetic nanoparticles Fe3O4@mSiO2@CS by integrating a solvothermal method for synthesizing the Fe3O4 core, a dualtemplating micelle system for preparing a layer of mesoporous silica (mSiO2) shell, and a silane coupling method via γ-glycidoxypropyltrimethoxysilane for binding a chitosan (CS) layer on the silica surface. The porous hierarchical nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering nanoparticle size analyzer, and specific surface area and pore size analyzer. The loading capacity and the release behavior of the as-prepared nanoparticles for doxorubicin hydrochloride were studied, and it was found that the drug release rate was faster at pH 6.0 than at pH 7.4, revealing the pH-responsive property of the nanoparticles.

Nuclear reactor core depletion and thermal-hydraulics coupling have long been calculation-intensive tasks challenging both nuclear industry development and academic research projects regarding computing budgets of memory and time. Albeit future evolution in smart computation hardware with artificial intelligence and quantum computing facilities embedded could continuously push the predictive modelling limit, the fundamental reactor physics model will still tip the balance in underpinning the prediction accuracy, as evidenced by a benchmark of two computational models in this work for characterising the depletion of highly self-shielded Gadolinium burnable poison-bearing fuel pins in assessing the British first European Pressurised Reactor’s start-up core performance. Specifically, a sub-group multi-annular-ring method is verified to efficiently represent the self-shielded skin effect, which addresses the deficiencies of classic equivalence models. The subgroup method is subsequently applied into a deterministic neutron transport code and a Monte Carlo stochastic code, respectively, for another benchmark. Resulting discrepancies in power peaking factors for the same assembly are less than 2% for the first fuel cycle, the agreement of which well demonstrates the validity of the proposed subgroup model. At the forefront of efforts to quantitatively understand the burnable poisons’ behaviour precisely for fuel optimisation (e.g., mitigating power peaking), this work could also be advantageously used for training purposes in boosting safety philosophy and public engagement in the roadmap for decarbonisation.

Biomass transformation is being considered as a green and sustainable strategy for carbon-based functional materials in many fields. To produce porous structure favorable for microwave absorption, we demonstrate herein the successful synthesis of macroporous carbon materials with cornstalk as a biomass precursor. It is found that two kinds of typical biological structures in cornstalk, linear vascular bundles and parenchyma cells, can be well preserved during high-temperature pyrolysis. Mercury intrusion porosimetry and N2 adsorption indicate that these cornstalk-derived carbon materials have very high porosity, which is mainly from desirable macroporous structure rather than conventional micro/mesopores. Electromagnetic (EM) analysis reveals that dielectric loss is the only pathway for the consumption of EM energy, and high pyrolysis temperature favors strong dielectric loss through conductive loss and interfacial polarization loss. Meanwhile, pyrolysis temperature also affects the matching degree of characteristic impedance. When the pyrolysis temperature reaches 750 °C, good dielectric loss and impedance matching endow the sample (CSC-750) with excellent microwave absorption performance, including strong reflection loss, broad response bandwidth, and relatively thin absorber thickness. The advantages of macroporous structure are further highlighted in impedance matching and multiple reflection by comparing with a macropore-free counterpart.

Due to the huge amount of data generated by time-domain airborne electromagnetic (AEM) systems, conductivity depth imaging methods are widely used to help in the interpretation of these data because they can be generated quickly and easily. We have introduced a new imaging method generated using a deep neural network. The network structure combines four convolutional neural networks with a long short-term memory technique and adopts an error back-propagation scheme to update the parameters. A deep hierarchical structure is used to extract and store the complex nonlinear relationship between the model and electromagnetic (EM) responses, creating results close to 1D inversions. To check the effectiveness, we have examined our algorithm on synthetic and survey AEM data. The imaging result shows that this method, when using reasonable network parameters, can not only image well at high speed, but the method also is not very sensitive to noise. Another advantage of this method is that once the training is completed on a well-distributed training set, the network can be used without any changes to process other data sets from an identically configured AEM system.

How to efficiently treat cancer in a minimally invasive manner has become one of the major focuses of recent developments in biomedicine. In this research, biodegradable sodium alginate (SA) hydrogel encapsulated with NaHCO3 and glucose oxidase (GOX) was synthesized using Fe3+ as the crosslinker for the tumor chemodynamic therapy (CDT) and starvation therapy (ST). Material safety assessments revealed that this hydrogel possesses good in vitro and in vivo security. In tumor microenvrionment (TME), the Fe3+ further reacted with the intracellular glutathione and was transformed into Fe2+, which triggered the Fenton reaction with the H2O2 within TME and produced abundant highly toxic ·OH (hydroxyl radicals) for efficient tumor CDT. Furthermore, the GOX catalyzed the enzymolysis of glucose to consume the nutrient of the tumor and enhance the H2O2 level in TME. Besides, the CO2 bubbles that were generated from the decomposing of NaHCO3 promoted the contact between glucose and GOX. Findings in this research would have important implications for the present status of tumor therapy.

Cold storage is the vital infrastructure of cold chain logistics. In this study, we analyzed the spatial pattern evolution characteristics, spatial autocorrelation and influencing factors of cold storage in China by using kernel density estimation (KDE), spatial autocorrelation analysis (SAA), and spatial error model (SEM). Results showed that: 1) the spatial distribution of cold storage in China is unbalanced, and has evolved from ‘one core’ to ‘one core and many spots’, that is, ‘one core’ refers to the Bohai Rim region mainly including Beijing, Tianjin, Hebei, Shandong and Liaoning regions, and ‘many spots’ mainly include the high-density areas such as Shanghai, Fuzhou, Guangzhou, Zhengzhou, Hefei, Wuhan, Urumqi. 2) The distribution of cold storage has significant global spatial autocorrelation and local spatial autocorrelation, and the ‘High-High’ cluster area is the most stable, mainly concentrated in the Bohai Rim; the ‘Low-Low’ cluster area is grouped in the southern China. 3) Economic developmenficit.

In this letter, we report the demonstration of terawatt (TW)-scale femtosecond vortex laser pulses based on noncollinear optical parametric chirped-pulse amplification (OPCPA) centered at 800 nm. To the best of our knowledge, this is the first experimental study of amplification for OPCPA-based vortex pulses to achieve a powerful ultrafast (TW-scale) vortex pulse output. In this experiment, a 0.5-mJ broadband chirped vortex pulse was amplified to 47 mJ with a 15-mm-long LiB3O5 crystal. The double-pass grating pair compressor with an efficiency of 65% maintained the beam vortex, and a pulse of width 30.1 fs was obtained, corresponding to a peak power of 1.02 TW. This laser can be used in studies on nonlinear optics and relativistic laser-plasma interactions, compact plasma-based accelerators, and light sources.

Organic light-emitting transistors (OLETs) integrate the functions of light-emitting diodes and field-effect transistors into a unique device, opening a new door for optoelectronics. However, there is still a challenge due to the absence of high quality organic semiconductors for OLETs. Herein, we reported a novel molecule 2,6-di(anthracen-2-yl)naphthalene (2,6-DAN), which exhibited mobility of up to 19 cm2·V−1·s−1 and an absolute fluorescence quantum yield of 37.09%, which are good values for organic semiconductors. Moreover, OLETs based on 2,6-DAN single crystals showed bright yellowish-green emission and well-balanced ambipolar charge transport. The excellent ratio of hole to electron mobility can reach up to 0.86, which is superior to most single-component OLETs in typical device configurations reported so far.

High entropy alloys exhibit a composition design route that different from conventional alloys. However, whether the high configurational entropy is the key factor that stabilizes the room temperature single phase solid solution is still under debate. Here we use a perturbation model to evaluate their phase stabilities. According to the calculation results of 7085 alloys, it clearly indicates that a stable single phase is rare when constituent elements increase. The effect of increased entropy cannot balance the fast-increased driving force for the formation of intermetallics. Although it is not favored by thermodynamics, the frequently observed room temperature single-phase solid solutions can still form due to dynamic effect, which from the other side, provides a method to tune the microstructure and therefore the mechanical properties.

The pollution of polycyclic aromatic hydrocarbons (PAHs) in food crops has been drawing worldwide attention due to their toxicity and carcinogenicity. However, the distribution process of PAHs in c...

Nanoparticles (NPs) are increasingly used as agrochemical components through foliar spraying such as foliage fertilizers or pesticides. However, the understanding of the mechanisms of nanoparticle absorption and translocation from the leaf surface is limited. In this study, ZnO NPs (30 nm) labeled with fluorescein isothiocyanate (FITC) were foliar applied to wheat leaf tissues to investigate the process of attachment and absorption. Using laser confocal microscopy, we observed that FITC–ZnO NPs cross the leaf epidermis through the stomata and accumulate first in the apoplast, followed by subsequent transport to mesophyll cells. The Zn concentrations in wheat leaf apoplast and cytoplasm decreased by 33.2% and 8.3% with stomatal aperture diameter reduction, respectively; the apoplastic Zn concentration is influenced more by stomatal aperture than the cytoplasmic Zn level. Scanning electron microscopy with energy-dispersive X-ray analysis was used to map Zn in the wheat leaves and data suggest a different Zn distribution for ZnO NPs and ZnSO4. Zn ions in ZnO NP-treated samples are heterogeneously distributed in comparison with those in ZnSO4-treated samples. The results indicate that the main route to cross the wheat leaf epidermis for ZnO NPs is via the stomata; then these nanoparticles accumulate and release Zn ions in the apoplast, and the released Zn ions and ZnO NPs are absorbed by mesophyll cells. Our findings demonstrate how ZnO NPs cross the wheat leaf epidermis, distribute within mesophyll tissues, and enter into plant cells, and this information is useful for the development of sustainable nano-enabled platforms for nanoscale micronutrient delivery.

A novel electromagnetic functionalized Ni@PPy composite was synthesized with a cleaning method. XRD and FTIR analyses showed that the Ni@PPy composite was successfully prepared. SEM, TEM, and HRTEM results proved that Ni nanoparticles, produced by the γ-irradiation-induced reduction method, were wrapped with polypyrrole (PPy) shell to form core–shell structure. There existed many Ni cores in a PPy shell, which could induce more interfacial and dipolar polarization than the structure with one core in a shell. With an increase in Ni content, the dielectric loss was obviously decreased and the magnetic loss had little change. Attenuation constant decreased gradually, which was influenced jointly by conductivity loss and dipolar and interfacial polarization loss. When nPy/nNi/nAPS was 1.75:1:1.75, the as-prepared Ni@PPy composite exhibited the highest microwave absorption (RLmax of − 48 dB at 7 GHz and EAB of 3.8 GHz) owing to suitable impedance matching as well as attenuation ability. Therefore, such core–shell structured Ni@PPy composite would be a promising microwave absorber.

Photo-induced cancer therapies, mainly including photothermal therapy (PTT) and photodynamic therapy (PDT), have attracted numerous attentions owing to the high selectivity, convenience, and few side effects. However, single PTT usually requires high laser power density, and single PDT usually needs a high photosensitizer dosage. Herein, a kind of composite nanocarrier based on clay (laponite)-polypyrrole (LP) nanodisks was synthesized via the in situ polymerization of pyrrole in the interlayer space of laponite. LP composite nanodisks were then coated with polyvinylpyrrolidone (PVP) to form the LP-PVP (LPP) composite nanodisks which show an excellent colloidal stability and in vitro and in vivo biocompatibility. The interlayer space of LPP can be further used for the loading of Chlorin e6 (Ce6), with an ultrahigh loading capacity of about 89.2%. Furthermore, the LPP nanocarrier can enhance the PDT effect of Ce6 under the irradiation of a 660 nm laser, through enhancing its solubility and cellular uptake amount. Besides, it was found that LPP nanodisks exhibit a more outstanding photothermal performance under a 980 nm near-infrared laser (NIR) than a 808 nm NIR laser, with the photothermal conversion efficiency of 45.7 and 27.7%, respectively. The in vitro and in vivo tumor therapy results evidently confirm that the Ce6-loaded LPP nanodisks have a combined tumor PTT and PDT effect, which can significantly suppress the tumor malignant proliferation.

Calcined ginger nut (CGN) has been applied in grouting mortars for anchoring unstable earthen sites, but the lack of scientific research limits its application. In this study, CGN-based grouts admixed with fly ash (F), quartz sand (S), or both are evaluated. To explore the optimal mixture ratios, three types of mixing groups (five proportion gradients in each group) are established. All the grout specimens are buried and maintained outdoors, and their physical (shrinkage rate, density, elastic wave velocity, and permeability) and mechanical properties are continuously examined over 180 days. The solidification processes at different ages are simultaneously observed by means of scanning electron microscopy (SEM) images. The results indicate that the physical properties of grouts are influenced significantly by initial moisture content but then remain steady for approximately 15 days. Quartz sand can effectively reduce the shrinkage rate of grouts as well as adjust their density and permeability, and might be considered as an ideal mixing material for CGN. In the solidification process, grouts are rapidly solidified after the initial hydration reaction, and the carbonation reaction in the later stage constantly improves their mechanical strength, with physical properties kept relatively stable. SEM images show fly ash and quartz sand particles are cemented by CaCO3 crystals. Through comprehensive comparison, the grouts with the mass ratio of CGN and S at 1:1 are found to better satisfy requirements that grouts should be compatible with earthen sites.

An amphiphilic polymer, carboxymethyl cellulose-laurate (CMC-C12), was synthesized by esterification of water-soluble carboxymethyl cellulose (CMC) and hydrophobic lauroyl chloride. Folate, a cancer-cell-specific ligand, was conjugated to CMC-C12 to obtain folate-CMC-C12 (FA-CMC-C12) which could be targeted to folate-receptor-overexpressing cancer cells. FA-CMC-C12 was characterized by Fourier transform infrared (FT-IR) spectra and nuclear magnetic resonance (NMR). The amphiphilic polymer, FA-CMC-C12, can self-assemble into micelles with spherical morphology. The anticancer drug doxorubicin (DOX) was entrapped inside FA-CMC-C12 micelles. The sustained release of DOX was studied in phosphate buffered saline (PBS) at pH 5.6. It indicates that the drug release rates of DOX is about 85% with excess β-cyclodextrin (β-CD) which far exceed the drug release rates of DOX without β-CD.

Based on a concept of asymptotic exponential arbitrage proposed by Follmer-Schachermayer, the author introduces a new formulation of asymptotic arbitrage with two main differences from the previous one: Firstly, the realising strategy does not depend on the maturity time while the previous one does, and secondly, the probable maximum loss is allowed to be small constant instead of a decreasing function of time. The main result gives a sufficient condition on stock prices for the existence of such asymptotic arbitrage. As a consequence, she gives a new proof of a conjecture of Follmer and Schachermayer.

We theoretically and experimentally demonstrate that high-purity Laguerre-Gaussian beams can be efficiently obtained from Gaussian vortex beams using a typical 4F spatial filtering optical system, in which spatial filtering does not affect the spiral phase and the energy loss is very small. In the Fourier frequency domain, aperture filtering specifically removes the high-frequency component corresponding to the central singularity region. In the spatial domain, aperture filtering corresponds to a convolution, which can smooth the central singularity region. This approach is simple and effective and has practical implementations in the generation and amplification of relativistic vortex beams.

As bifunctional materials, phenanthrene derivatives 2,7-diphenylphenanthrene and 2,7-di(styryl)phenanthrene ( DPPa and DSPa ) were designed and studied. Both materials show charge transport properties and strong solid-state emission. The hole mobility was measured to be 1.6 and 0.4 cm2 V−1 s−1 for DPPa and DSPa , respectively. While the photoluminescence quantum yield of DPPa and DSPa was as high as 37.13% and 62.36%, respectively.

Nanoporous Au (NPG) films possess excellent and stable surface enhanced Raman scattering (SERS) activity. Sputtering followed by dealloying is one of the most used techniques to prepare NPG films. The morphology of the NPG can be controlled by changing the dealloying time, therefore tuning the SERS performance of the NPG. In the present work, Au-Ag alloy film was prepared on the Si wafer with a Cr transition layer by sputtering from a Au40Ag60 target. NPG films with tailorable average pore diameter ranging from 13 nm to 52 nm were successfully prepared by changing the dealloying time. The effect of the morphology evolution on the SERS performance of the NPG film was investigated. The dealloyed NPG film exhibits good SERS activity with a high EF of 2.4 × 105. This work provides important insights into the understanding of the correlation between the dealloying time controlled morphology and the SERS performance of the NPG films.

Polycyclic aromatic hydrocarbons and zinc oxide nanoparticles are ubiquitous pollutants in the environment. However, little information is available about their toxicity interaction in food crops. In this study, seed germination and hydroponic experiments were conducted to assess the impact of ZnO (NPs and bulk at 250, 500 and 1000 mg L−1) individual and combined with phenanthrene (1 mg L−1) on wheat growth for 15 days. Under ZnO (NPs and bulk) alone and combined with phenanthrene exposure, dose-dependent toxicity in some indexes (germination rate, biomass, shoot height, root length) was observed. Both ZnO NPs and bulk inhibited plant growth at high concentrations, but no significant difference was observed between them (P > 0.05). The chlorophyll concentration of wheat leaves decreased by 0.43–0.60 fold when the levels of ZnO NPs and bulk treated were elevated. There was a negative correlation between ZnO (NPs and bulk) and total chlorophyll. Hill reaction activity also exhibited the same tendency. Through transmission electron microscopy, ZnO NPs were found in wheat seedling root apoplast and symplasm at 1000 mg L−1 with or without phenanthrene. High doses (500 and 1000 mg L−1) of ZnO (NPs and bulk) caused more DNA damage to wheat seedling root cells, and ZnO NPs induced stronger genotoxicity than bulk ones to wheat root cells. Superoxide dismutase (SOD) and catalase (CAT) activities of wheat seedling roots decreased at 1000 mg L−1 ZnO (NPs and bulk), especially in the co-exposure treatments. Hence, ZnO (NPs and bulk) combined with phenanthrene cause more damage to wheat seedling roots, and even destroy the antioxidant system. Our findings are helpful for not only assessing the individual and combined toxicity between phenanthrene and ZnO (NPs and bulk), but also for understanding the different response of plants to individual and combined pollution.

The exposure of polycyclic aromatic hydrocarbons (PAHs) can cause wheat leaf chlorosis. Thus, we hypothesize that chloroplast inner structure damage is the reason for leaf chlorosis. This study was conducted with the wheat seedlings exposed to Hoagland nutrient solution containing 1.0 mg L−1 phenanthrene for 9 days. Subcellular observation showed that chloroplast turns round and loses its structural integrity. Herein, iTRAQ (isobaric tag for relative and absolute quantification) was applied to analyze the changes of protein profile in chloroplast exposed to phenanthrene. A total of 517 proteins are identified, 261 of which are up-regulated. Eight proteins related with thylakoid (the structural component of chloroplast) are down-regulated and the expression of related genes further confirms the proteomic results through real-time PCR under phenanthrene treatment, suggesting that the thylakoid destruction is the reason for chloroplast deformation. Four proteins related with envelope and stroma are up-regulated, and this is the reason why chloroplast remains round. This study is useful in discussing the carcinogenic and teratogenic effects of PAHs in plant cells in the environment, and provides necessary knowledge for improving crop resistance to PAH pollution. Keywords: Polycyclic aromatic hydrocarbons, Leaf cell, Proteomics, Chloroplast deformation, Toxicity, iTRAQ

An asymmetric anthracene derivative (4-HDPA) was designed and synthesized. With the optimization of proper scenario of fabrication process, top-contact thin film devices based on 4-HDPA exhibit mobility as high as 3.59 cm2 V–1 s–1, while its single-crystal devices exhibit mobility as high as 5.12 cm2 V–1 s–1, which is higher than the symmetrical counterpart of 4-HDPA in both single-crystal and thin film devices.

In this paper, a laser metal deposition (LMD) process has been applied to the fabrications of CrMnFeCoNi high entropy alloys. The microstructures and mechanical properties of the CrMnFeCoNi alloys prepared using casting technique and LMD technique have been investigated. It has been found that the CrMnFeCoNi samples prepared using casting show a coarse dendritic structure. The microstructures of LMD samples contain both columnar grains and/or equiaxed grains, and the proportion of columnar grains and equiaxed grains can be adjusted by changing the laser power. Besides, the mechanical properties of LMD samples can be adjusted by changing laser power, due to columnar to equiaxed transitions (CET) that are effected by solidification mode and the heat flux direction of LMD process. It is worth to mention that the mechanical properties of the 1400 W samples produced using LMD are better than those produced by casting, which is rarely observed. Furthermore, CrMnFeCoNi alloys prepared using LMD show excellent mechanical properties at cryogenic temperatures.

In this paper, a laser melting deposition (LMD) technique has been applied to fabricate CrMnFeCoNi high entropy alloys (HEAs). The microstructures and tensile properties of CrMnFeCoNi HEAs prepared under different laser power and scanning strategies have been investigated. It has been observed that the laser power and scanning strategy have significant effects on the columnar to equiaxed transitions (CET) of the microstructure of LMD CrMnFeCoNi HEAs because of their effects on heat flux direction and the temperature gradient. Due to small molten size and rapid cooling rate in LMD process which results in a significant solute-trapping effect and thus avoids component segregation, the elements distribution of LMD samples are more homogeneous than as-cast samples. Besides, tensile properties of the LMD samples can be adjusted by changing laser power and scanning strategy, which be corresponding to the changes of microstructure.

In polar regions, vegetation is especially sensitive to climate dynamics and thus can be used as an indicator of the global and regional environmental change. However, in Antarctica, there is very little information on vegetation distribution and growth status. To fill this gap, we evaluated the ability of both linear and nonlinear spectral mixture analysis (SMA) models, including a group of newly developed modified Nascimento’s models for Antarctic vegetated areas (MNM-AVs), in estimating the abundance of major Antarctic vegetation types, i.e., mosses and lichens. The study was conducted using WorldView-2 satellite data and field measurements over the Fildes Peninsula and its surroundings, which are representative vegetated areas in Antarctica. In MNM-AVs, we introduced secondary scattering components for vegetation and its background to account for the sparsity of vegetation cover and reassigned their coefficients. The new models achieved improved performances, among which MNM-AV3 achieved the lowest error for mosses (lichens) abundance estimation with RMSE = 0.202 (0.213). Compared with MNM-AVs, the linear model performed particularly poor for lichens (RMSE = 0.322), which is in contrast to the case of mosses (RMSE = 0.212), demonstrating that spectral signals of lichens are more prone to mix with their backgrounds. Abundance maps of mosses and lichens, as well as a map of moss health status for the entire study area, were then obtained based on MNM-AV3 with around 80% overall accuracy. Moss areas account for 0.7695 km2 in Fildes and 0.3259 km2 in Ardley Island; unhealthy mosses amounted to 40% (49%) of the area in the summer of 2018 (2019), indicating considerable environmental stress.

If we execute a test case and find a failure in the program, we need to locate the location of the faults, i.e., fault localization. Fault localization is a very costly and time-consuming process. In this paper, an improved spectrum-based fault localization method IOchiai is proposed. According to the execution of passed and failed test cases, we can calculate the suspiciousness score of software element which is the probability of the element contains faults. The passed and failed test cases have different contributions to the calculation of the suspiciousness scores, we divide them into three groups according to different contribution degrees. IOchiai gives higher suspiciousness scores to the element with faults and locates faults faster. Finally, the method proposed in this paper and the traditional spectrum-based fault localization are applied to stereo matching software and found that the method proposed in this paper has stronger fault localization capability.

Radiotherapy (RT) is becoming a pervasive therapeutic pattern in clinical cancer therapy. However, the hypoxic microenvironment of tumors has a strong resistance to radiotherapy and could lead to a potential recurrence and metastasis after the treatment. Therefore, the use of synergistic strategies for improving and supplementing the RT efficiency is important. Herein, a novel Bi2S3/alginate (ALG) hydrogel containing tirapazamine (TPZ) was designed for the effective suppression of tumor recurrence, by introducing Bi3+ into the ALG, Na2S and TPZ solution. In this formulation, Bi3+ was used to crosslink with the ALG to form the hydrogel and react with S2- to simultaneously form Bi2S3 nanoparticles in the hydrogel matrix. The resulting Bi2S3 nanoparticles not only exhibit the superb radiosensitization effect to boost the effective eradication of tumors during RT but also manifest an excellent photothermal transforming performance for tumor hyperthermia and computed tomography (CT) imaging capacity for tumor monitoring. Furthermore, the RT caused hypoxia could activate the reductive prodrug TPZ and enhance its therapeutic efficiency. The reported hydrogel system provides an efficient and safe therapeutic strategy for current local tumor therapy.

A laser metal deposition (LMD) process has been applied to the fabrications of the (CrMnFeCoNi)1-xFex (x = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) Multi-principal elements alloys (MPEAs). It is found that the LMD-fabricated (CrMnFeCoNi)50Fe50 alloy keeps a single-phase solid solution microstructure. Compared with the CrMnFeCoNi MPEA, the (CrMnFeCoNi)50Fe50 alloy obtains remarkably improved plasticity from 45% to 77%, while maintaining tensile strength (415 MPa to 470 MPa), due to the strain-induced FCC to BCC phase transformation. Furthermore, the (CrMnFeCoNi)50Fe50 alloy shows excellent mechanical properties at cryogenic temperatures. This alloy has lower cost and better mechanical property than the well-known CrMnFeCoNi MPEA by the addition of inexpensive Fe elements. The present work provides important pathways in the development of low-cost LMD-fabricated MPEA for cryogenic engineering applications.

Data center infrastructure uptime increasing, unplanned downtime reduction and data integrity main-taining are increasingly critical in today’s real-time, service-level agreement (SLA)-driven cloud service business environment. Server, as backbone of cloud computing, has been developing and evolving with diverse challenges of preserving data integrity, increasing availability, minimizing planned downtime, especially in high temperature ambient (HTA) data center environment So, rock robust server system design for reliability, availability, and serviceability (RAS) are crucial for cloud service providers.Memory errors in server are among the most common hardware causes of machine crashes in production sites with large-scale systems. The higher temperature environment, the more errors. The typical response to memory failures is to replace any affected memory modules, which makes memory modules among the most commonly replaced server components. So, memory failures and their correction are very costly. Based on data collection and failure analysis from Baidu infrastructure maintenance group, server system memory (uncorrectable error) failure rate is Top 1 in data center. For reducing memory failure rate and related server downtime, Baidu developed an advanced server handling memory correctable and uncorrectable errors throughout a "6 pillars" complete application stack, from the underlying hardware to the scheduling system. Such solutions involve three components: (1) reliability, how the solution preserves data integrity; (2) availability, how it guarantees uninterrupted operation with minimal degradation; and (3) serviceability, how it simplifies proactively and reactively dealing with failed or potentially failed components. Availability is not an independent vector.This paper addresses Baidu rack server memory RAS architecture and design, scoping from Intel Xeon processor hardware errors avoidance, detection and correction RAS features for system reliability and improves fault tolerance; failure identification and reconfiguration such as leakage bucket based software-enhanced error recovery and error containment; extending to kernel level page retirement as well as high availability scheduler. Also, Memory RAS system design specific for HTA data center environment is detail introduced. Then, the related lab test procedure, data, and observations are summarized at the end of each section. Overall conclusion and future work plan are summarized in the end.

A novel nickel-free gold-plated enclosed coplanar waveguide is experimentally demonstrated for a liquid crystal tunable delay line phase shifter at 60 GHz. By numerical investigations, we find that conventional surface impedance model (without meshing inside metals) fails to accurately characterise the effect of gold-plating thickness on conductor loss, especially when the plating thickness is smaller than 4 times of the gold's skin depth. To address this, adaptive meshing inside metals is performed for accurate modelling of the device. The gold-plating thickness is then experimentally optimised and tailored for the liquid crystal-based device-making procedures, i.e. taking into account the accelerated copper migration into gold problem during the alignment agent baking process at 200°C. Measurement results of assembled phase shifters at 60 GHz verify that a direct gold plating of 2μm on Cu can reduce the insertion loss by 1.79 dB and 2.85 dB as compared with that with a thinner plating of 50 nm, and no plating, respectively. The maximum insertion loss of -2.996 dB demonstrated at 60 GHz for the 0-π phase shifter delivers a figure-of-merit of 60°/dB, an improvement of 42°/dB as compared with up-to-date literature.

Microwave phase shifters based on tunable dielectrics such as nematic liquid crystals (NLC) have attracted considerable research attention in the last two decades. To electronically drive the permittivity variations based on the NLC’s molecular anisotropy, conventional device configuration is based on externally wiring three-port bias tees as diplexers for frequency-domain multiplexing, i.e. isolating the RF port from the low-frequency high-amplitude bias field. The multi-stage bulky solution significantly impedes its applicability for phased array feeds. To the best of the author’s knowledge, limited research has attempted the integration of compact bias tees into the phase shifter. To this end, this work demonstrates a bias-tees-embedded standalone phase shifter integrated on a double-sided RO4003 substrate using advanced fabrication and assembly techniques (photolithography, surface mounting, reflow soldering). The measured differential phase shift reports 391.75° at 10 GHz with the insertion loss up to -5.66 dB (including bias tees) for an optimised design. A figure-of-merit of 69°/dB is achieved, which even outperforms recent advances in NLC-based planar phase shifters without bias tees.

Keeping images safe and secure in data transmission or storage by optical cryptography has emerged as a revolutionary technology to meet the challenge posed by the evolving cyber threat landscape. This paper reviews the states-of-the-arts optical cryptography and cryptanalysis techniques with a special focus on different optical encryption technologies and their limitations. Specifically, security gaps in the classic Double Random Phase Encoding approach and its variants are identified. Case studies into vulnerable attacking scenarios are conducted for cryptanalysis purposes. Perspectives on the future directions of optically inspired cryptology research are given accordingly.

This paper selects the data of big data industry in China’s “Guangzhou Development Zone Big Data Industrial Park” and “Zhaoqing Big Data Cloud Service Industrial Park” from 2014 to 2018, uses the improved knowledge production function to establish an OLS model, and compares the impact of MAR and Jacobs external aggregation on the R&D input and patent output in Guangzhou and Zhaoqing. It is found that: (1) MAR externality is not conducive to the technological innovation of the two cities, and has a stronger negative effect on innovation in Zhaoqing; Jacobs externality can actively promote the innovation of the two cities, and has a stronger positive effect on innovation in Guangzhou. (2) In the impact of Jacobs externality on innovation output of the two cities, R&D plays a part of intermediary effect, and the effect on Guangzhou is stronger; in the impact of MAR externality on innovation output of the two cities, R&D only plays a part of negative intermediary effect in Zhaoqing. The conclusions show that the MAR and Jacobs agglomeration in big data industry all play more effective roles in promoting technological innovation in economically developed cities.

We present a comprehensive study of the electrochemical capacitance between a one-dimensional electronic material and an electrolyte. In contrast to a conventional, planar electrode, the nanoscale dimension of the electrode (with diameter smaller than the Debye length and approaching the size of the ions in solution) qualitatively changes the capacitance, which we measure and model herein. Furthermore, the finite density of states in these low dimensional electronic systems results in a quantum capacitance, which is comparable to the electrochemical capacitance. Using electrochemical impedance spectroscopy (EIS), we measure the ensemble average, complex, frequency dependent impedance (from 0.1 Hz to 1 MHz) between a purified (99.9%) semiconducting nanotube network and an aqueous electrolyte (KCl) at different concentrations between 10 mM and 1 M. The potential dependence of the capacitance is convoluted with the potential dependence of the in-plane conductance of the nanotube network, which we model using a transmission-line model to account for the frequency dependent in-plane impedance as well as the total interfacial impedance between the network and the electrolyte. The ionic strength dependence of the capacitance is expected to have a root cause from the double layer capacitance, which we model using a modified Poisson-Boltzmann equation. The relative contributions from those two capacitances can be quantitatively decoupled. We find a total capacitance per tube of 0.67-1.13 fF/μm according to liquid gate potential varying from -0.5 to -0.7 V.

Two novel 2D bisthienoacenes with annulated thiophene units at different positions were developed. Both 1,2- and 1,4-addition of the α,β-unsaturated ketone moieties lead to the major formation of four-fold alkylsilylethynyl substituted 2D heteroacenes (namely BTT-4TIPS and BTP-4TIPS). The photophysical, electrochemical properties, crystal packing structures, and charge carrier transport performances were investigated in detail.

Metallic ordered porous structures have attracted increasing attention due to their wide range of applications, but their preparation is usually accompanied with the employing of consumable templates. The development of template-free method to prepare metallic ordered porous structure can significantly reduce the cost as well as streamline the procedures. In the present work, a new template-free method of additive manufacturing combined with etching was proposed to prepare ordered porous structures. (Cu, Ni) honeycomb structure with pore size of ~11 μm and wall thickness of ~200 nm was successfully prepared from the Fe-Cu-Ni precursor alloy. The morphology evolution and the potential formation mechanism of the (Cu, Ni) honeycomb structure were studied. This work provides important insights into the preparation of ordered metallic porous structure without template.

In this paper, we utilize the variational limiting equilibrium (LE) procedure to theoretically determine the slope stability of homogeneous coral sand in the South China Sea. By establishing a reasonable functional and calculating its extremum, we can deduce the stability factor of a coral reef identical to that obtained by upper bound analysis. To determine the accuracy of the results obtained using the variational LE procedure, we present some classical examples of homogeneous sand slopes without a hard shell and compare our results with those obtained by the upper bound theorem of plasticity. A series of extensive calculations and comparisons reveal that the results obtained by our proposed analysis method and those obtained using classical methods are slightly different, but the variational results are believable. On the other hand, our method solves some stability factors for reef slopes covered with a hard shell, which indicates that the existence of a hard reef shell may significantly enhance the stability of a reef slope, and that there is strong nonlinear relationship between reef stability and the mechanical characteristics of the reef shell, such as its thickness and strength. Finally, based on the variational results presented in this paper, we present a useful chart that offers a convenient and straightforward way to determine the maximum stability factor of reef slopes. Taking into account the influence of the hard reef shell, we found that, in some limit equilibrium cases, the limit stability factor and critical height of a coral slope could be improved significantly. Therefore, this issue deserves careful attention in engineering practice.

A laser melting deposition (LMD) technique has been applied to fabricate thin wall V-5Cr-5Ti samples. By applying a scanning speed of 400 mm/min, laser powers of 1200W, 1400W, 1600W, and 1800W, and scanning strategies of single directional scanning and dual directional scanning, full dense thin wall samples have been successfully prepared. Microstructures at the bottom region of walls mainly consist of coarse columnar grains, showing a 〈100〉 fiber texture. Microstructures in the middle and at the top regions of walls mainly consist of fine columnar grains or equiaxed grains, showing random textures. Columnar dendritic growth takes place for columnar grains. The columnar dendrites grow epitaxially from parent grains, following one [100] axis closest to the heat flux direction. However, the integral growth directions of columnar grains are opposite to the heat flux direction. Including a small deviation of one [100] axis from heat flux direction, the growth space of columnar dendrites also counts for the success in competitive growth for columnar grains. Deposition height, laser power, and scanning strategy show significant effects on the grain structure evolutions of thin wall samples, due to their effects on the temperature gradient. As the deposition height increases, columnar to equiaxed transitions (CETs) have been observed for all samples. The CETs happen faster for higher laser power, and for dual directional scanning compared to single directional scanning. Due to the differences in local composition caused by microsegregation, clusters containing lath-like precipitates are observed to delineate the dendrites. The effects of processing parameters on microstructures can be represented by a metric of volumetric energy density. A decrease of energy density will lead to CETs.

Polycyclic aromatic hydrocarbons (PAHs) are a kind of pollutants which could stimulate stress reaction in plant cells. In this study, we systematically verify that PAHs could induce an oxidative stress in plants, and describe their damages on wheat leaf subcellular structure and organelle, together with the contributions of antioxidants working against reactive oxygen species. The observation of transmission electron microscope exhibits that cell structures become plasmolyzed and distorted, and organelles disappear under phenanthrene (a model PAH) treatments. Osmiophilic granules arise with increasing phenanthrene concentrations, displaying the evidence for oxidative stress. As more H2O2 produce, and the accumulation of H2O2 is a fatal reason for cell death under PAH treatments. Through cluster analysis, Pearson correlation coefficient, principal component analysis and redundancy analysis, carotenoid and superoxide dismutase are the two most effective antioxidants to scavenge superoxide radicals among nine major antioxidants (ascorbate, glutathione, polyamines, α-tocopherol, carotenoid, catalases, ascorbate peroxidase, superoxide dismutase and glutathione-S-transferase), glutathione-S-transferase is a potential antioxidant, and Asa-GSH cycle would turn active under higher phenanthrene treatments. Ascorbate peroxidase and α-tocopherol would cause leaf moisture increase. Thus, this work provides better comprehension on the antioxidant performances and their potential application to improving plants' resistance under PAH pollution in the environment.

In this work, we synthesized a series of microcrystalline MnxN100−x-MOF-74 (N = Fe, Co and Ni) materials by a one-pot reaction. Powder X-ray diffraction (PXRD) patterns of MnxN100−x-MOF-74 matched well with those of single-metal MOF-74, and the scanning electron microscopy (SEM) images exhibited homogeneous nanocrystallites aggregated together. The amounts and dispersion of metals were analyzed by using inductively coupled plasma (ICP) and energy-dispersive X-ray spectroscopy (EDS), separately. MnxN100−x-MOF-74 could remain crystalline and efficiently catalyze the epoxidation of alkenes in DMF with NaHCO3 and 30% H2O2. In particular, Mn29.39Fe70.61-MOF-74 can achieve almost 100% conversion for styrene with 95.0% selectivity towards styrene oxide and be reused at least five times without loss of activity.

Two new anthracene derivatives were designed and synthesized. Ant-Th-Ph and Ant-ThPh show high single crystal mobilities of 1.1 cm2 V−1 s−1 and 4.7 cm2 V−1 s−1. Moreover, strong solid state emission was determined to be 36.52% and 33.32% for Ant-Th-Ph and Ant-ThPh respectively.

A numerical model consisting of 12 species and 65 reactions is developed and experimentally verified to be valid for the investigation of electrical characteristics and electron energy transformation in oxygen-fed pulsed dielectric barrier discharge (DBD) for ozone generation. The simulation results show that there are two obvious discharges with opposite polarity in one pulse which agrees with many experimental observations. The first discharge is at the rising edge of pulse voltage, and the second discharge is at the falling edge. The former has a much higher current density than that of the latter. Moreover, a higher peak voltage results in an earlier and higher ignition voltage as well as a higher maximum current density. The contrary behavior for rising time is observed, and the ignition and maximum current density are independent of pulsewidth. In addition, the temporal distributions of total input power density, electron power density, and power density of electron consumed by reactions are obtained for the first discharge in DBD for the ozone generation. Only 19.35% of the total input energy within the first discharge is absorbed by electrons when peak voltage, rising time, and pulsewidth are 9 kV, 63.8 ns, and 100 ns, respectively, and 41.09% of electron energy is utilized effectively to form ozone.

The hierarchical architecture constitutes one of the key factors affecting the performance of microwave absorbing materials (MAMs). Herein, core-shell Fe3O4 with a dendritic hierarchical structure is fabricated successfully by the melting method in a SiO2-B2O3-Al2O3-CaO-Fe2O3 multi-component system. The multiple transmission scattering absorption mechanism is mediated by the unique microstructure, thus improving the impedance matching and the microwave loss ability of the material. According to its reflection loss curve, the microwave absorption was efficiently optimized, yielding a minimum reflection loss (RL) of − 54.26 dB when the thickness was 3.47 mm, and the effective bandwidth (RL

Polycyclic aromatic hydrocarbons (PAHs), ubiquitous organic pollutants in the environment, can accumulate in humans via the food chain and then harm human health. MiRNAs (microRNAs), a kind of non-coding small RNAs with a length of 18-30 nucleotides, regulate plant growth and development and respond to environmental stress. In this study, it is demonstrated that miR164 can regulate root growth and adventitious root generation of wheat under phenanthrene exposure by targeting NAC (NAM/ATAF/CUC) transcription factor. We observed that phenanthrene treatment accelerated the senescence and death of wheat roots, and stimulated the occurrence of new roots. However, it is difficult to compensate for the loss caused by old root senescence and death, due to the slower growth of new roots under phenanthrene exposure. Phenanthrene accumulation in wheat roots caused to generate a lot of reactive oxygen species, and enhanced lipoxygenase activity and malonaldehyde concentration, meaning that lipid peroxidation is the main reason for root damage. MiR164 was up-regulated by phenanthrene, enhancing the silence of NAC1, weakening the association with auxin signal, and inhibiting the occurrence of adventitious roots. Phenanthrene also affected the expression of CDK (the coding gene of cyclin-dependent kinase) and CDC2 (a gene regulating cell division cycle), the key genes in the cell cycle of pericycle cells, thereby affecting the occurrence and growth of lateral roots. In addition, NAM (a gene regulating no apical meristem) and NAC23 may also be related to the root growth and development in wheat exposed to phenanthrene. These results provide not only theoretical basis for understanding the molecular mechanism of crop response to PAHs accumulation, but also knowledge support for improving phytoremediation of soil or water contaminated by PAHs.

In this research, MnO2/IrO2 nanoplatform was one-step synthesized from the heat-induced oxidation-reduction between potassium permanganate and iridium chloride and modified with polyvinylpyrrolidone (PVP) on the surface to obtain MnO2/IrO2-PVP nanoparticles (MIP NPs) with excellent colloidal stability of biocompatibility. Then, the photosensitizer Chlorin e6 (Ce6) was loaded onto the surface of MIP NPs. The IrO2 can efficiently transform the 808 nm near-infrared laser into heat with a photothermal conversion of 27.57 % for tumor photothermal therapy. Interestingly, the MnO2 can not only react with the redundant H+ and realize the magnetic resonance imaging of the tumor but also catalytic the decomposition of H2O2 in the tumor to generate O2 and relieve the hypoxia status of the tumor. The in-situ formed O2 can promote the production of cancer cell-toxic singlet oxygens (1O2) under the irradiation of 660 nm laser and boost the tumor photodynamic therapy efficiency. Moreover, it was found that PVP can fall off from the MIP NPs to increase their accumulation in the tumor. Such a MIP/Ce6-based nanoplatform which plays the synergism with tumor microenvironment shows promising potential for the combined photo-therapy of the tumor.

Metallic glasses are perfect materials for preparing nanostructures by dealloying, but the obtained nanostructures are commonly of porous structures. Through the combination of chemical dealloying and ultrasonic vibration, ultrathin Cu&Ag bimetallic nanoporous membranes (NPMs) have been prepared from a Zr48Cu36Ag8Al8 MG ribbon. Furthermore, by introducing oxygen into the Zr48Cu36Ag8Al8 MG ribbon to change the mechanism of the dealloying process, nanoporous (Cu&Ag)@Ag core-shell alloy was synthesized by the one-pot chemical dealloying of Zr–Cu–Ag–Al–O amorphous/crystalline composite, which provides a new way to prepare metallic core–shell nanostructures by a one-pot method. The introducing of oxygen can enable the dissolution and redeposition of Cu, and tunes the Cu&Ag NPM into the nanoporous (Cu&Ag)@Ag core-shell alloy. The nanoporous (Cu&Ag)@Ag core-shell alloy exhibits better and robust antibacterial activity against E. Coli DH5α due to its better oxidation resistance caused by the Ag skin. The present work provides important insights into the tuning of nanostructures through simple dealloying.

The effect of F content on the structure, high-temperature viscosity and dielectric properties was investigated in a borosilicate glass system with SiO2-Al2O3-B2O3-RO-TiO2. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) served to study glass structural changes through peak fitting calculations. The results showed that the addition of F from 0.26 wt% to 0.63 wt% promoted the conversion of the network outer body [BO3] into [BO4] and [AlO6] into [AlO4] during the melting cooling period. The increase of bridging oxygen enhances the integrity of the network structure and improves the dielectric performance at ambient temperature. In the high-temperature stage, the introduction of an appropriate amount of F decrease the viscosity of the liquid, which is beneficial to the homogenization, refining and drawing operations. These results could help elucidate the changes in properties of glass on the addition of F.