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Carbon nitride, considered to be a promising photocatalyst, still has much room to increase the catalytic performance owing to the slow charge transfer and limited light harvesting ability. Herein, carbon doping carbon nitride with hollow tubular structure was successfully developed by using melamine and sodium alginate as precursors via a simple hydrothermal calcination method. The effects of carbon content on the structure and photocatalytic activities of as-obtained carbon nitride were researched in detail. The hollow tubular structure can assist the enhancement of specific surface area, increase of visible light harvesting ability and enhancement of electron transport ability. Simultaneously, carbon doping can adjust the photoelectric performance and band structure of carbon nitride due to the generation of delocalized big π bonds to enhance the photocatalytic activities. The catalytic performance of as-obtained carbon nitride is estimated by hydrogen evolution reaction. And carbon doping carbon nitride with hollow tubular structure accounts for 3 times and 2 times promotion than pristine CN in hydrogen evolution rate under λ > 420 nm and λ > 400 nm, respectively. Especially, the sample CN-40 shows a highly enhanced hydrogen generation efficiency of 1210.3 μmol h-1 g-1, which should be inseparable from the function of carbon doping and hollow tubular structure.

Background. Self-admitted technical debt (SATD) is a special kind of technical debt that is intentionally introduced and remarked by code comments. Those technical debts reduce the quality of software and increase the cost of subsequent software maintenance. Therefore, it is necessary to find out and resolve these debts in time. Recently, many automatic approaches have been proposed to identify SATD. Problem. Popular IDEs support a number of predefined task annotation tags for indicating SATD in comments, which have been used in many projects. However, such clear prior knowledge is neglected by existing SATD identification approaches when identifying SATD. Objective. We aim to investigate how far we have really progressed in the field of SATD identification by comparing existing approaches with a simple approach that leverages the predefined task tags to identify SATD. Method. We first propose a simple heuristic approach that fuzzily Matches task Annotation Tags ( MAT ) in comments to identify SATD. In nature, MAT is an unsupervised approach, which does not need any data to train a prediction model and has a good understandability. Then, we examine the real progress in SATD identification by comparing MAT against existing approaches. Result. The experimental results reveal that: (1) MAT has a similar or even superior performance for SATD identification compared with existing approaches, regardless of whether non-effort-aware or effort-aware evaluation indicators are considered; (2) the SATDs (or non-SATDs) correctly identified by existing approaches are highly overlapped with those identified by MAT ; and (3) supervised approaches misclassify many SATDs marked with task tags as non-SATDs, which can be easily corrected by their combinations with MAT . Conclusion. It appears that the problem of SATD identification has been (unintentionally) complicated by our community, i.e., the real progress in SATD comments identification is not being achieved as it might have been envisaged. We hence suggest that, when many task tags are used in the comments of a target project, future SATD identification studies should use MAT as an easy-to-implement baseline to demonstrate the usefulness of any newly proposed approach.

Modifying the texture of carbon nitride to adjust its physicochemical performance is a fascinating method for achieving high photocatalytic activity. Herein, we synthesized 3D porous carbon nitride with ultra-thin nanosheets by using cyanuric acid-melamine supramolecular and ionic liquid as precursor and template, respectively. The ionic liquid adjusts the morphology of materials and induces the carbon residue into the porous channels owing to its incomplete degradation. The 3D porous framework makes carbon nitride reflect the enhanced surface area, exposes adequate reaction sites, and offers a pathway for charge transport. And carbon residue and ultra-thin nanosheets further promote the photogenerated carriers transport and reduce the recombination rate of charge carriers. Consequently, 3D porous carbon nitride with ultra-thin nanosheets exhibit outstanding and stable hydrogen evolution under visible light irradiation. Significantly, as-fabricated sample CN-100 reflects an improved H2 generation rate, up to 17,028 μmol h−1 g−1, which is 12 times higher than that of CN (1412 μmol h−1 g−1). The present work offers a unique synthesis strategy to develop the novel photocatalyst with efficient photocatalytic performance.

Photocatalytic hydrogen evolution reaction (HER) provides a new way for the development of clean energy. Herein, a high-performance peony-like 3D structure S-doped carbon nitride (SCNx) with a large specific surface area was synthesized through a universal and non-thermal polymerization template-free approach. As an additional component, the introduction of trithiocyanuric acid in the raw material led to the formation of supramolecular intermediates through hydrogen bond self-assembly, and the sulfur was introduced into the framework of g-C3N4 subsequently. The charge separation lifetime of SCNx was studied by transient absorption spectroscopy, and the reason for its excellent optical performance was revealed from a dynamic perspective. Furthermore, the resulting SCNx composite material shows significant photocatalytic hydrogen release performance under visible light irradiation. In particular, the photocatalytic hydrogen rate of SCN1.0 reached 567.7 μmol/h, which was almost 53 times that of BCN, and was also 2.3 times that of SCN0 obtained by the binary self-assembly of melamine and cyanuric acid. Our finding advances the application of simple, environmentally friendly, and scalable strategy for the synthesis of high-performance sulfur-doped g-C3N4 photocatalysts.

Improving the non-magnetic low-frequency electromagnetic (EM) wave performances of common microwave-absorbing materials is yet very difficult and depends on the assistance of structural design to realize tremendous microwave reflectance absorption in a limited space. Herein, a biomimetic three-dimensional coral reef-like graphene oxide (GO)@TiO2 composite framework was prepared with porous TiO2–C inlaid subunits derived from MIL-125 (Ti), which provided an effective platform for concentrating two unusual structures of TiO2 and carbon sources into single particles. The formation mechanism of the material was analyzed in detail. Compared with GO@TiO2/TiO2–C composite materials at varying mass ratios, the minimum RL of GO@TiO2/TiO2–C-15 is −64.4 dB at 7.4 GHz, and the intensity of −25 dB (>99% energy absorption) can be improved at different thickness, which exhibits an excellent low-frequency EM absorption behavior. Simultaneously, GO@TiO2/TiO2–C-15 has obvious extended performances, including antimicrobial activities and low infrared emissivity, which demonstrate the versatility and application potential of non-magnetic low-frequency microwave absorbers in wearable devices and other fields. The new material is beneficial to reducing the EM waves-caused threat to human health in communication band and to attaining the sustainable utilization of EM waves.

Pathogenicity-related studies are of great importance in understanding the pathogenesis of complex diseases and improving the level of clinical medicine. This work proposed a bioinformatics scheme to analyze cancer-related gene mutations, and try to figure out potential genes associated with diseases from the protein domain-domain interaction network. Herein, five measures of the principle of centrality lethality had been adopted to implement potential correlation analysis, and prioritize the significance of genes. This method was further applied to KEGG pathway analysis by taking the malignant melanoma as an example. The experimental results show that 25 domains can be found, and 18 of them have high potential to be pathogenically important related to malignant melanoma. Finally, a web-based tool, named Human Cancer Related Domain Interaction Network Analyzer, is developed for potential pathogenic genes prioritization for 26 types of human cancers, and the analysis results can be visualized and downloaded online.

A hydrophilic terpolymer scale inhibitor (AA–APES–HPAY) was prepared by free radical polymerization with acrylic acid (AA), hydroxypropyl acrylate modified by 2-phosphonobutane-1,2,4-tricarboxylic ...

Nickel–iron foam (NFF) has high air permeability and a high specific surface area because of its connected pore structure and high porosity, making it an ideal catalyst support material. However, it is challenging to effectively utilize metal ions in the NFF to prepare new advanced electrocatalysts without introduction of metal species. Here, we demonstrate that activated metal ions in NiFe foam serve as the support and metal sources for in situ synthesis of NiFe bimetal–organic frameworks (NFF-MOF). Specifically, by further acidification to activate NiFe metal ions on the NFF backbone, and then to generate active NFF-MOF species through the participation of the organic ligand, the resulting NFF-MOF material exhibits significantly improved electrocatalytic performance toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with ultralow overpotentials of 81 and 250 mV at a current density of 10 mA cm–2, respectively. Density functional theory calculations and experimental results suggest that the NFF-MOF from the in situ-activated NiFe foam promotes transport and separation of charge because of highly uniform dispersed metal sites, high porosity, and an ordered 3D skeleton structure, thus accelerating the electrochemical HER and OER. This work brings new insights for the development of next-generation high-efficiency electrocatalysts.

A heterogeneous multi-robot system consisting of Unmanned Ground Vehicles (UGVs) and Unmanned Aerial Vehicles (UAVs) have advantages over a single-robot system in efficiency and flexibility, enabling them to perform a larger range of tasks. To allow heterogeneous platforms to work together in GPS-denied scenarios, it is crucial to build a complete 3D map of the environment. In this letter, a novel method is presented to perform ground and aerial collaborative mapping leveraging visual and range data collected by cameras and 3D LiDAR sensors. In the proposed system, a visual-LiDAR ego-motion estimation module that considers point, line and planar constraints can provide robust odometry information. Thumbnail images representing obstacle outlines are generated and descriptors are extracted using a neural network to help perform data association between separate runs. Map segments and the robot poses are organized together and are updated during a pose graph optimization procedure. The proposed ground-aerial collaborative mapping approach is evaluated on both synthetic and real-world datasets comparing with other methods. Experiment results demonstrate that our method can achieve outstanding mapping results.

It is essential to manufacture microwave absorbers with strong absorption as well as tunable absorption bands at a low filler content. However, it remains challenging for pure biomass material to reach this goal without loading other components. MoSe2, as a transition metal chalcogenide with semiconductor properties, has emerged as a potential microwave absorber filler. Herein, bacterial cellulose (BC)-derived carbon nanofibers/MoSe2 nanocomposite was fabricated and phosphoric acid was used to dope phosphorus in BC, in which MoSe2 microspheres were dropped on the BC network like a dew-covered spider web. This unique network structure enhances conductive loss and multiple reflections of the incident wave. The collocation of BC and MoSe2 is helpful to impedance match and introduces interfacial/dipolar polarization loss; moreover, the P-doping of BC helps to tune the absorption bands. Overall, the optimal reflection loss of undoped one reaches −53.33 dB with only 20 wt.% filler content, whose main absorption peaks focus on X-band. Interestingly, after the P-doping of BC, the main absorption peaks move to Ku-band and the optimal reflection loss gets stronger (−66.84 dB) with the same filler loading. Strong absorption and tunable absorption bands can be realized, and thus wide frequency range is covered. This work is expected to enlighten future exploration of biomass carbon materials on high-performance microwave absorption materials.

Spectrum-based fault localization (SBFL) techniques can automatically localize software faults. They employ the program spectrum, such as code coverage profile with test verdicts, to rank the program entities based on their code suspiciousness. In the past decades, researchers have proposed many approaches to optimize these techniques; however, the program structure, which can influence their performance, is not taken into consideration in developing and improving these techniques. In this article, we identify and analyze the effect of the program structure on the application of SBFL techniques. We observe that some specific program structures may introduce structure bias to code suspiciousness and negatively influence the output of SBFL techniques. To mitigate these effects and improve the performance of fault localization, we propose Delta4Ts, a structure-aware technique. Delta4Ts references debugging history to alleviate the impact of structure bias in the calculation of code suspiciousness. It reasons from the observable suspicious value towards the desired suspicious value and the impact of structure bias. To evaluate Delta4Ts under practical constraints, we conduct a controlled experiment using nine widely-studied SBFL formulae on 12 C programs and 6 Java programs. The experiment results show that Delta4Ts can significantly improve the accuracy of the studied SBFL formulae by an average of 34.8% on 12 C programs and 30.6% on 6 Java programs, and improve more on subject programs associated with more history versions or having larger code sizes.

Cloud computing has promoted the success of big data applications such as medical data analyses. With the abundant resources provisioned by cloud platforms, the quality of service (QoS) of services that process big data could be boosted significantly. However, due to unstable network or fake advertisement, the QoS published by service providers is not always trusted. Therefore, it becomes a necessity to evaluate the service quality in a trustable way, based on the services’ historical QoS records. However, the evaluation efficiency would be low and cannot meet users’ quick response requirement, if all the records of a service are recruited for quality evaluation. Moreover, it may lead to ‘ Lagging Effect ’ or low evaluation accuracy, if all the records are treated equally, as the invocation contexts of different records are not exactly the same. In view of these challenges, a novel approach named Partial H istorical R ecords-based service evaluation approach ( Partial-HR ) is put forward in this paper. In Partial-HR , each historical QoS record is weighted based on its service invocation context. Afterwards, only partial important records are employed for quality evaluation. Finally, a group of experiments are deployed to validate the feasibility of our proposal, in terms of evaluation accuracy and efficiency.

Given a bucket of crash reports, it would be helpful for developers to find and fix the corresponding defects if the crash-inducing software changes can be automatically located. Recently, an approach called ChangeLocator was proposed, which used ten change-level features to train a supervised model based on the data from the historical fixed crashes. It was reported that ChangeLocator achieved a good performance in terms of Recall@1, MAP, and MRR, when all the ten features were combined together. However, in ChangeLocator, the redundancy between features are neglected, which may degrade the localization effectiveness. In this paper, we propose an improved approach ChangeRanker with a rank-performance-based feature selection technology (Rfs) to boost the effectiveness of crash-inducing change localization. Our experimental results on NetBeans show that ChangeRanker can achieve an improvement of 35.9%, 17.4%, and 15.3% over ChangeLocator in terms of Recall@1, MRR, and MAP, respectively. Furthermore, compared with three popular feature selection approaches, Rfs is able to select more informative features to boost localization effectiveness. In order to assess the real generalization capability of the proposed extension, we adapt ChangeRanker and ChangeLocator to locate bug-inducing changes on three additional data sets. Again, we observe that, on average, ChangeRanker achieves an improvement of 115.3%, 37.6%, and 41.2% in terms of Recall@1, MRR, and MAP, respectively. This indicates that our proposed rank-performance-based feature selection method has a good generalization capability. In summary, our work provides an easy-to-use approach to boosting the performance of the state-of-the-art crash-inducing change localization approach.

Transition metals are increasingly attracting interest in electrocatalysts for use in water decomposition due to their excellent catalytic activity and stability. Simultaneously, metal-organic frameworks with designable metal ion centers and organic ligands are the promising precursors for the one-step synthesis of metal encapsulated in carbon composites for alkaline hydrogen evolution reaction (HER). Herein, we report the successful construction of Co-CoO/ZnFe2O4 encapsulated in carbon nanowires (Co-CoO/ZnFe2O4@CNWs) by annealing as-synthesized nanowire Co/Zn/Fe-MOF at 400 °C in N2. This structure provides the rich defect sites and active centers, and the synergy of Co, CoO and ZnFe2O4 lead to efficient hydrogen evolution when the composite is used as a catalytic electrode for HER in 1.0 M KOH. The catalyst shows a low initial overpotential (97 mV) and a small Tafel slope (138 mV dec−1), and the overpotential at 10 mA cm−2 is only 226 mV. In addition, this composite material exhibits excellent long-term durability even after 1000 cycles. It is expected that it is a potential alternative catalyst for rational utilization in the field of electrolytic water decomposition.

This article has presented a physics-based model which replicates the failure of SiC MOSFET under short-circuit (SC) case. The model is constructed on the base of the traditional circuit model of SiC MOSFET by introducing two leakage current mechanisms; one is the leakage current between the drain and the source, and another is the gate leakage current. Furthermore, the carrier mobility characterized with trapped charges at the interface of SiC/SiO2 is adopted. The failure model had been validated against the experimental results. With the developed failure model, the failure mechanism of SiC MOSFET under a SC event is analyzed; the impact of interface trapped charges on the SC performances of SiC MOSFET is exploited. Moreover, the SC failure for SiC MOSFET with different OFF-state gate voltages has been addressed; the behavior of interface trapped charges has been analyzed.

New catalysts based on polymeric ionic liquids were synthesized and applied into selective oxidation of benzyl alcohol. Polymeric ionic liquid microspheres (PILM) were prepared by radical polymerization, and then the cations in the imidazole ring were exchanged with the metal anions. After that, the metal anions were reduced to Pd nanoparticles that was supported on the surface of PILM. This metal loading method favored the maximum amount of supported Pd nanoparticles that were uniformly distributed on the surface of PILM. In addition, the introduction of CeO2 prevented the aggregation of Pd nanoparticles and finally formed PILM/Pd/CeO2 catalysts with a core-shell structure. The performance of the PILM/Pd/CeO2 catalysts was evaluated by changing the [K2CO3] : [alcohol] molar ratio, reaction temperature and oxygen flow rate in the oxidation reaction of benzyl alcohol. The conversion and selectivity under the optimal reaction conditions reached 48% and 98% respectively The catalysts were effective and reusable after 5 cycles of experiments. In the end, a mechanism underlying the reaction pathway in benzyl alcohol oxidation was put forward.

Generic programming is a key paradigm for developing reusable software components. The inherent support for generic constructs is therefore important in programming languages. As for C++, the generic construct, templates, has been supported since the language was first released. However, little is currently known about how C++ templates are actually used in developing real software. In this study, we conduct an experiment to investigate the use of templates in practice. We analyze 1,267 historical revisions of 50 open source systems, consisting of 566 million lines of C++ code, to collect the data of the practical use of templates. We perform statistical analyses on the collected data and produce many interesting results. We uncover the following important findings: (1) templates are practically used to prevent code duplication, but this benefit is largely confined to a few highly used templates; (2) function templates do not effectively replace C-style generics, and developers with a C background do not show significant preference between the two language constructs; (3) developers seldom convert dynamic polymorphism to static polymorphism by using CRTP (Curiously Recursive Template Pattern); (4) the use of templates follows a power-law distribution in most cases, and C++ developers who prefer using templates are those without other language background; (5) C developer background seems to override C++ project guidelines. These findings are helpful not only for researchers to understand the tendency of template use but also for tool builders to implement better tools to support generic programming.

The inhibition effect of three inhibitors with different chain lengths of their ether groups on Q235 steel in 0.5 M HCl solution at 318 K was determined by means of weight loss measureme nt, electrochemical methods (Tafel and EIS) and surface analysis (SEM). Moreover, the further study of corrosion inhibition mechanism was also conducted by computational methods (Quantum chemical calculations and Molecular dynamics simulations). Results reveal that the three inhibitors exhibit an excellent inhibition performance for carbon steel, and the corrosion inhibition efficiency of the three inhibitors increases with the increase of the chain length, which favors the formation of a protection film adsorbed on the surface. Analysis of polarization data informs that the adsorption type of three inhibitors basically obeys the Langmuir monolaye r adsorption, which is mainly of chemisorptive nature. Computational methods also tell that the three inhibitors possess a high reactivity and strong interaction with the iron surface, furthermore, the interaction is increased with the increase of the chain length of three inhibitors. The conclusion is in good agreement with the experimental results.

Green and facile strategies for fabricating hollow microwave absorption materials without harmful solvent etching have attracted extensive attention but still remain a challenge. Herein, the cubic hollow Co/N/C@MnO2 composites were prepared through metal–organic frameworks (MOFs) self-templated eco-friendly method with polydopamine (PDA) as carbon source and hierarchical MnO2 nanosheets were incorporated for improving impedance mismatch caused by excessive permittivity in Co/N/C. Such a uniform distribution of Co particles in the N-doped porous carbon matrix, in association with the hollow structure and hierarchical MnO2 nanosheets, endow the composites with enhanced electromagnetic (EM) wave absorption. Notably, Co/N/C@MnO2 sample with a filler loading of 15 wt% shows extraordinary EM wave absorbing performance with the minimum reflection loss (RL) of −58.9 dB and wide absorption bandwidth of 5.5 GHz. Several minimum RL values at a thickness in the range of 1.5–5 mm, are below than −50 dB, outperforming many similar materials reported previously. Besides, the possible microwave absorption mechanism was elaborated in detail. Our work provides an environmentally friendly and facile route for fabricating MOFs self-templated hollow carbon-based microwave absorbers.

Enhancing the kinetics of electrocatalytic water splitting, including the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), under alkaline conditions is of key importance for producing high purity and renewable hydrogen on a large scale. Owing to their unique structural features, two-dimensional (2D) heterostructures have been regarded as promising next-generation electrocatalysts for overall water splitting. Herein, we successfully synthesized three-dimensional (3D) flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres assembled from heterostructural 2D nanosheets. Benefiting from well-exposed interfaces and favorable diffusion channels, the as-prepared 3D flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres manifest excellent overall water splitting performance in an alkaline solution with a low Tafel slope of 71 and 41 mV dec−1 for oxygen and hydrogen evolution reactions, and show significantly improved long-term durability. Furthermore, the 3D flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres used in both the anode and cathode show a low cell voltage of 1.53 V at a 10 mA cm−2 current density. Using DFT calculations, we found the outstanding chemisorption of hydrogen and oxygen-containing intermediates making Co–Ni–P/MoS2 heterostructures an efficient bifunctional overall electrochemical water splitting catalyst. In summary, this work opens up an important direction for exploring efficient and durable bifunctional electrocatalysts for the overall water splitting.

We report a facile one-pot solvothermal synthesis of NiPd alloy homogeneously encapsulated between reduced graphene oxide sheets and N-doped carbon layers (rGO@NiPd@NC) with sandwich structure. In this study, dopamine served as both carbon-nitrogen source and green reagent, which cannot only form N-doped carbon layers encasing metal nanoparticles through high-temperature roasting but also co-reduce metal ions to form NiPd alloy. The rGO@NiPd@NC nanocomposite exhibits enhanced hydrogen evolution reaction (HER) activity with a small overpotential of 56 mV at 10 mA cm−2 and a Tafel slope approaching 33 mV dec−1 in acidic aqueous media, which are similar to the HER activity of commercial Pt/C catalyst (52 mV at j = 10 mA cm−2; Tafel slope, 31 mV dec−1). Additionally, the electrocatalyst which reveals excellent electrochemical stability is reflected in that the polarization curve shows negligible difference after 1000 cycles and the current density only slightly decreases within 20 h test, providing more possibilities for practical application in the future.

CaO and Fe₂O₃ are effective mineral sorbents to inhibit the damage of arsenic and selenium release into the atmospheric environment. Density functional theory was applied to explore the adsorption mechanism of different arsenic and selenium species (atom, hydride, oxide, and chloride) on CaO and Fe₂O₃ surfaces. The effect of the As₄O₆ cluster on the adsorption behavior of CaO and Fe₂O₃ surfaces was also examined. The results show that the O top sites serve as the active sites for arsenic and selenium atom adsorption on the CaO(001) surface. For the Fe₂O₃(001) surface, the adsorption energy of the As atom at the Fe top and O bridge site can reach −381.38 and −439.55 kJ/mol, respectively. The results show that the Fe top site and O bridge site are both effective chemical adsorption sites. CaO and Fe₂O₃ also exhibit a good performance to adsorb atomic arsenic and selenium under the condition of multicoverage. In addition, the interactions between two adsorbents and complex arsenic/selenium species are weakened in different degrees, but still belong to chemical adsorption. The adsorption of the As₄O₆ cluster on the CaO surface is mainly attributed to the interaction between As atoms and O atoms on the CaO surface. The As₄O₆ adsorption on the Fe₂O₃ surface depends on the interaction between O atoms of As₄O₆ and Fe atoms on the Fe₂O₃ surface. However, the interactions can both lead to the formation of more stable arsenate, which contributes to the reduction of detrimental arsenic release.

Achieving sustainable energy technology with outstanding performance and clean materials for overall water splitting, while fascinating, still include many challenges. Herein, the masterly CoNi2S4@CoS2/NF 3D microspheres assembled by peapod-like nanorods with a mass of CoS2 particles are successfully prepared on nickel foam. The well-preserved 3D porous materials with unique heterostructure have various merits including more electronic channels, small electrons transfer resistance and open interior space. Besides, the unique peapod-like structure endows the catalyst plentiful, dispersive and exposed reactive sites, which is vital important to significantly increase the electrochemical performance. Notably, the as-prepared CoNi2S4@CoS2/NF catalysts achieve optimized electrocatalytic activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at low overpotentials of 259 mV and 173 mV while deliver 10 mA cm−2 current density, respectively. It can be anticipated that it is a potential alternative catalyst for rational utilization in electrolytic water splitting fields.

Magnetic biochar (MBC) has been proven to be an efficient sorbent for elemental mercury (Hg0) removal from coal-fired flue gas in our previous studies. However, SO3 is an acidic component of flue g...

Coordination is important in software development. Socio-Technical Congruence (STC) is proposed to measure the match between coordination requirements and actual coordination activities. The previous work of Cataldo et al. computes STC in commercial projects and finds it related to software failures. In this paper, we study the relationship between file-level STC and bug proneness in Open Source Software (OSS) projects. We apply the fundamental STC framework to the OSS data setting and present a method of computing file-level STC based on our available data. We also propose a derivative STC metric called Missing Developer Links (MDL), which is to measure the amount of coordination breakdowns. In our empirical analysis on five OSS projects, we find that MDL is more related to bug proneness than STC. Furthermore, STC or MDL can be computed based on different types of file networks and developer networks, and we find out the best file network and the best developer network via an empirical study. We also evaluate the usefulness of STC or MDL metrics in bug prediction. This work is promising to help detect coordination issues in OSS projects.

A core-shell structure Au-based catalysts mSiO2/Au/Co3O4 HS were successfully derived from in-situ growth ZIF-67 hollow spheres, which were synthesized by a one-step soft template method. The samples were characterized by SEM, TEM, EDX, XPS, XRD and BET to confirm its successful preparation and structural features. The catalytic performance of the catalysts were evaluated by liquid phase oxidation of benzyl alcohol to benzaldehyde with O2 as the oxidant under alkaline conditions. The experimental results illustrated that reaction conditions, including effect of catalyst amount, oxygen flow rate, reaction temperature and reaction time, were optimized to be 40 mg, 50 ml/min, 140 °C and 5 h, respectively. Meanwhile, 55% conversion of benzyl alcohol and 84% selectivitiy to benzaldehyde together with the excellent reusability and stability were achieved under optimal reaction conditions, which was attributed to the core-shell structure leading to the encapsulation of Au NPs and provision of multiple active reaction interface. Based on the intermediates formed from the de-protonation of substrate, a plausible oxidation reaction mechanism with mSiO2/Au/Co3O4 HS catalysts was tentatively proposed to study the relationship between structure and catalytic performance.

A facial, template-free and green strategy was developed to prepare C-doped hollow spherical g-C3N4 derived from supramolecular self-assembly of melamine, glucose and cyanuric acid. Especially, the precursors were tightly connected by hydrogen bonds, wherein glucose was served as a source of doped carbon. Spectroscopic and electrochemical analysis confirmed that the endmost nitrogen was replaced by the doped carbon to combine two melon parts, leading to the possible existence of the delocalized big π bonds in the system. Moreover, the GCN-x not only maintained the excellent properties of the hollow sphere, such as high surface area, moderate porosity and short charges diffusion distance, but also overcame the drawbacks of low visible light response and high electron-holes recombination rate from bulk g-C3N4. Thereby, the visible light utilization rate and the photogenerated electron-holes separation efficiency of the catalyst were improved. The highest hydrogen yield of 305 μmol h−1 from GCN-0.2 was 28.5 times that of bulk g-C3N4. Finally, a possible mechanism underlying the photocatalytic performance of C-doped g-C3N4 hollow spheres was proposed tentatively.

The abatement of mercury from oxyfuel combustion flue gas should be paid special attention due to the metal embrittlement and aluminum corrosion for CO2 compression device. The effects of enriched CO2 and H2O in oxyfuel combustion atmosphere on mercury removal over biochar (BC) and magnetic biochar (MBC) was studied. Hg0 was firstly captured by physical adsorption and then oxidized to various mercury compounds. A large amount of organic groups, especially C O group, were formed with the assistance of enriched CO2. As a result, more Hg0 was oxidized over BC and more organic Hg (Hg-OM) was formed on BC and MBC. However, the content of chemisorbed oxygen on MBC was reduced under oxyfuel combustion atmosphere, hence reducing the formation of HgO on MBC compared with air combustion atmosphere. The enriched H2O significantly inhibited the removal of mercury over MBC. Chlorine was demonstrated as the most significant active components for mercury removal, since HgCl2 was the dominant species on MBC. This work clarified the effects of enriched CO2 and H2O on Hg0 adsorption over BC and MBC, which is essential for further improving the adsorption activity.

Carbon doped honeycomb-like graphitic carbon nitride (g-C3N4) was prepared by one-step thermal polymerization, which derived from chitosan as a carbon source together with the melamine-cyanuric acid complex as a supramolecular precursor. Interestingly, the carbon doped g-C3N4 displayed an increased specific surface area and a more negative conduction band energy level, which not only provided a large number of reaction sites for the photocatalytic hydrogen production, but also effectively enhances the separation of photogenerated electrons-holes. And the experimental results showed that the hydrogen evolution rate of the optimal sample was as high as 320 μmol·h−1, which is 29.10 times than that of bulk g-C3N4 (11 μmol·h−1). More importantly, this work may provide a promising idea for the design of efficient g-C3N4 by controlling the material morphology and combining the electronic modulation strategy.

As one of the ideal catalysts, noble metal materials can realize the conversion from benzyl alcohol to benzaldehyde. However, in previous reports, the loss of surface noble metal is one of the important reasons for the decrease in reaction performance. Here, a simple method was reported for stepwise fabrication of SiO 2 @Co 3 O 4 /Au@m-SiO 2 catalysts with core–shell structure. On the one hand, the core–shell structure provided abundant reaction sites for the oxidation of benzyl alcohol to benzaldehyde. On the other hand, the outer layer of m-SiO 2 effectively prevents the loss of Au nanoparticles. In this process, we studied the effects of multiple factors on the target reaction by controlling a single variable. The experimental results show that under the optimal conditions (the catalyst dosage, reaction temperature, reaction time and O 2 flow rate are 40 mg, 160 °C, 6 h, 60 ml/min, respectively), the conversion rate of the target reaction reaches 58% and the selectivity is as high as 82%. In the end, a mechanism was put forward to illustrate the underlying reaction pathway in benzyl alcohol oxidation.

The first snail shell-shaped helical polyacetylenes (SHPAs) were synthesized from the copolymerization between l-serine-grafted propargylamine (LSA) and propargylamine (PA). The novel structure was obtained at the monomer input proportion of 50%. The monomer (LSA) and copolymers (poly(LSAm-co-PAn)) were characterized by 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, circular dichroism and transmission electron microscopy. The infrared emissivity of poly(LSA50-co-PA50) investigated at 8–14 μm was 0.451, which was much lower than the other copolymers. This was because the poly(LSA50-co-PA50) could form the obvious intramolecular interaction and self-assembled to a snail-shell shape by intermolecular hydrogen bonding in MeOH solution. Meanwhile, the conjugation performance of the main chain was enhanced. Consequently, the abundant hydrogen bonds formed through N–H and C=O bonding and the strong conjugate properties both could decrease the unsaturation degree, as well as change the heat conduction mode in the molecules, thereby reducing the infrared emissivity. This strategy provided a new direction to achieve the controllable infrared stealth.

Herein, a novel strategy is established to synthesize Mo-doped graphitic carbon nitride (g-C3N4) with excellent photocatalytic activity through a green approach of biological template. The addition of biotemplates provides a microenvironment for the formation of hydrogen bonds in which the flower-like g-C3N4 is formed by self-assembly between precursors, which not only increases the specific surface area of the material but also exposes more catalytic activity edge. Benefiting from the non-localized of Mo(VI) 4d orbital, Mo-doped g-C3N4 constructs a suitable band structure and a built-in electric field that promotes electron delocalization, which improves the absorption range of visible light and separation efficiency of photo-generated electron-hole pairs. Subsequently, a possible chelation-hydrogen bond coordination mechanism was proposed based on the characterization results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and 15N solid-state NMR (15N NMR). As a result, the π-conjugated system of g-C3N4 was extended by forming a chelate centered on Mo(VI). Photocatalytic hydrogen evolution (PHE) showed that the optimal hydrogen evolution rate of Mo-doped g-C3N4 was as high as 2008.9 umol/g·h, which was 9.6 times than that of bulk g-C3N4.

Carbon nitride is a promising candidate for photocatalysis but exhibits the limited activity due to the poor mass rate and insufficient light harvesting properties. Herein, an efficient synthesis a...

Hydrogen is a source of sustainable and clean energy poised to replace fossil fuels. Bifunctional electrocatalysts are actively pursued to simultaneously drive the two key reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), for hydrogen production by electrolysis water. One of the most promising candidates based on bimetallic layered double hydroxide salts (LHSs) and cobalt-based organic framework (ZIF-67) suffer from poor interface coupling. Herein, we present a new approach based on fusing NiCo LHSs nanowire arrays with ZIF-67 to fabricate three-dimensional flower-like structures on a Ni-Fe foam support. To improve interfacial coupling and catalytic performance, simple oxidation, carbonization, sulfurization, and selenization are performed to study the effects of different post-treatments and discover the optimum bifunctional electrocatalysts. The optimized S-doped catalyst reveals the highest electrocatalytic characteristic quantified by the low overpotentials of 170 and 100 mV for OER and HER at 10 mA cm -2 in 1 M KOH, respectively. This outstanding electrocatalytic property is ascribed to strong interfacial coupling between the NiCo-LHSs and ZIF-67 derivatives, as well as the rational electronic structures, dense catalytic active sites, and large specific surface area. This work opens new prospects for fabricating efficient and low-cost electrocatalysts for renewable hydrogen energy production.

In this study, a highly efficient and simple in situ one-step hydrothermal process is demonstrated to synthesize the yolk-shell polysiloxane@3D flower-like hollow Mg Al layered double hydroxides (LDH). The morphology analysis further confirmed its unique structure and the polysiloxane@3D flower-like hollow Mg Al LDH was 2–3 μm in diameter with 100 nm shell thickness. Moreover, solvent-free UV curing process was employed to prepare the optical diffusers based on the polysiloxane@3D flower-like hollow Mg Al LDH and the optical properties of the diffusers were investigated in detail. Interestingly, suitable light transmittance, good diffusion capacity, and low incident angle dependence can be achieved by the as-prepared films. Especially, when the concentration of the fillers was up to 15 wt%, the optical diffusers possessed superior diffusing properties. Therefore, this study may help to open up a new door in developing light scattering materials for the high-performance optical diffusers.

A series of fluorine-silicon block urethane acrylates (PSi-FMPG-IPDI-HEMA) were synthesized from hydroxypropyl-terminated polysiloxane (PSi), newly-prepared fluorodiol (FMPG), isophorone diisocyanate (IPDI) and hydroxyethyl methacrylate (HEMA). Their molecular structures were characterized by Fourier transform infrared and gel permeation chromatography. The compatibility of the oligomers with HFMA was validated using UV–vis transmittance analysis. The thermal stability, water and chemical resistance, contact angles and anti-adhesive performance of the films were measured. It was found all the films had good thermal properties, and excellent water and chemical resistance. The FMPG content affected the surface energy and anti-adhesive performance of the films. The films with more FMPG presented lower surface energy, lower peel strength, and higher residual adhesion. More importantly, the release films designed based on the fluorine-silicon block urethane acrylates had tremendous application potential.

Developing highly active electrocatalysts with rich oxygen vacancies and precisely distributed metal sites holds exceptional promise for various renewable and sustainable energy technologies. However, the great challenge is to ensure the stability of oxygen vacancies (VO) during the oxygen evolution reaction (OER) process. Herein, we implement an innovative approach to produce a highly active and stable OER electrocatalyst by plasma-enabled Fe doping of Co-based 2D metal–organic framework (MOF) nanosheets, followed by a carbonization process to fabricate unique triangular-shaped “cheese-like” Fe/Co–carbon nanosheets with a mesoporous structure, and densely and evenly distributed reactive centers, and without damaging the frameworks. The O2–Ar radio frequency (RF) plasma ensured two critical effects, namely oxygen vacancy generation, and forming and modifying the oxidation states of the catalytically active metals in the framework leading to high OER performance. It is shown that filling the oxygen vacancies with Fe heteroatoms helps tune the atomic sites of the two metals in the MOFs and achieve a unique heterostructure where electron currents can be directed between metal sites of different oxidation states. Benefiting from the demonstrated unique advantages of our plasma-enabled approach, the optimized Fe1Co3/VO-800 exhibits a significantly enhanced OER performance and long-term stability, evidenced by a low overpotential of 260 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1. This work provides a new effective approach for the development of next-generation electrocatalysts for diverse applications in environmental and energy fields.

Herein, a novel strategy was proposed for the fabrication of hierarchical porous silica materials templated by a poly ionic liquid (PIL, a copolymer of 1-butyl-3-vinylimidazolium bromide and acrylamide) and P123 (PEO20PPO70PEO20). The PIL acts as a co-solvent as well as a co-template in the system. The effects of the concentration of the PIL and pH on the morphology and structure of silica materials were systematically investigated. Hierarchical porous silica materials were characterized by X-ray diffraction, N2 adsorption–desorption, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. Moreover, the results demonstrated that the porous silica materials were equipped with a dual-mesoporous channel structure and possessed a high surface area and large pore volumes up to 1274 m2 g−1 and 1.41 cm3 g−1, respectively. Furthermore, a high-performance catalyst-based supported ionic liquid phase (SILP) was obtained by surface modification with the IL (1-(tri-ethoxy-silyl-propyl)-3-methylimidazolium chloride) of the carrier and anion exchange with HPW. Catalytic performances were investigated in the alkylation of styrene with o-xylene. Moreover, it was found that the as-synthesized catalysts showed high catalytic performance in terms of styrene conversion and selectivity to 1-phenyl-1-xylyl ethane (PXE). Specifically, the catalyst PIL-1.0g-2-IL-HPW showed excellent activities in both the yield (91.5%) and selectivity (96.8%) for this alkylation reaction.

Improving the spatial resolution of remote sensing satellites has long been a challenge in the field of optical designing. Although the use of large-aperture reflective mirrors significantly improves the resolution of optical systems, controlling the film thickness uniformity remains an issue. The planetary rotation system (PRS) has received significant attention owing to the excellent uniformity of the coating applied to the large-aperture reflective mirror. However, the development of the PRS remains hindered by a lack of research on its properties and the design method of the shadow mask. To address this, we performed a theoretical analysis of the distribution of film thickness and uniformity in the PRS, which is impacted by parameters of geometric configuration in the vacuum chamber. We present a film thickness expression based on Knudsen’s law and the geometric configuration of the vacuum chamber that incorporates an additional shading function. Moreover, the variation of uniformity in the standard and counter PRSs was elucidated by changing the location of the evaporation source. Finally, a fixed-position shadow mask, which was obtained by theoretical design, allows the nonuniformity of the concave reflective mirror (with a 700 mm aperture) to reduce from 2.43% to 0.7%, highlighting the importance of initial shape design.

Software projects are increasingly forming social-technical ecosystems within which individual projects rely on the infrastructures or functional components provided by other projects, leading to complex inter-dependencies. Through inter-project dependencies, a bug in an upstream project may have profound impact on a large number of downstream projects, resulting in cross-project bugs. This emerging type of bugs has brought new challenges in bug fixing due to their unclear influence on downstream projects. In this paper, we present an approach to estimating the impact of a cross-project bug within its ecosystem by identifying the affected downstream modules (classes/methods). Note that a downstream project that uses a buggy upstream function may not be affected as the usage does not satisfy the failure inducing preconditions. For a reported bug with the known root cause function and failure inducing preconditions, we first collect the candidate downstream modules that call the upstream function through an ecosystem-wide dependence analysis. Then, the paths to the call sites of the buggy upstream function are encoded as symbolic constraints. Solving the constraints, together with the failure inducing preconditions, identifies the affected downstream modules. Our evaluation of 31 existing upstream bugs on the scientific Python ecosystem containing 121 versions of 22 popular projects (with a total of 16 millions LOC) shows that the approach is highly effective: from the 25490 candidate downstream modules that invoke the buggy upstream functions, it identifies 1132 modules where the upstream bugs can be triggered, pruning 95.6% of the candidates. The technique has no false negatives and an average false positive rate of 7.9%. Only 49 downstream modules (out of the 1132 we found) were reported before to be affected.

Lightweight and compatible metal-organic framework (MOF)-derived carbon-based composites are widely used in electromagnetic (EM) absorption. Their combination with laminated TiO2-C (derived from Ti3C2T x) is expected to further strengthen the EM attenuation ability. Herein, novel laminated Co/TiO2-C hybrids were derived from Ti3C2T x/Co-MOF using heat treatment. Compared with pristine MOF-derived carbon-based composites, the EM absorption ability of Co/TiO2-C was improved by multiple reflections between multilayered microstructures and the improved polarization loss (due to the heterogeneous interfaces, residual defects, and dipole polarization) and the strengthened conductivity loss caused by the carbon layers. Specifically, for the Co/TiO2-C hybrids at thicknesses of 3.0 and 2.0 mm, the optimal reflection loss (RL) was -41.1 dB at 9.0 GHz and -31.0 dB at 13.9 GHz, with effective bandwidths (RL ≤ -10 dB) of 3.04 and 4.04 GHz, respectively. This study will underline the preparation of carbon-based absorbing materials starting from MXene/MOF hybrids.

Hollow microtubule structured nano-/micromaterials of hollow tubular g-C3N4 (TCN) enwrapped with nanosheets were fabricated by a three-step method. By calcining NiCo-layered-double-hydroxides/tubular-cyanuric acid-melamine (NiCo-LDH/TCM) precursor prepared through using 2-methylimidazole as precipitant and methanol as solvent, the as-prepared NiCo-alloy@tubular-g-C3N4 (NC@TCN) shown excellent microwave absorption in the frequency range of 2–18 GHz. The optimal reflection loss (RL) of −35.63 dB was observed at 5.00 GHz and an effective absorption bandwidth of 4.80 GHz at a matching layer thickness of 2.0 mm. Our results indicated that the deposition of NiCo-alloy nanoparticles on g-C3N4 microtubule was an efficient way to fabricate g-C3N4-based high-performance microwave absorbers.

Developing bifunctional electrocatalysts of high-efficiency and new structures for overall water splitting are highly desirable and ongoing challenge. Herein, CoxNi10-x layer double hydroxide salts with controllable structure and morphology induced by 2-methylimidazole to derive ZIF-67 on Ni/Fe foam is reported. The as-prepared 3D CoxNi10-x layer double hydroxide microspheres are constructed by self-assembly of 2D nanoflake and 1D nanorod with ZIF-67 particles due to the double influence of Ni and 2-methylimidazole. It is discovered that the Ni and 2-methylimidazole can simultaneously modulate morphology and structure of CoxNi10-x layer double hydroxide to distinctly increase the electrochemical active surface area for exposing more accessible active sites. Notably, the 3D microsphere heterogeneous catalysis of the self-assembly combines the merits of low dimensions (1D and 2D) materials, providing high structural void porosity and fast charge transport channels. Particularly, the Co7Ni3 layer double hydroxide salts@ZIF-67/Ni/Fe foam exhibits the highest electrocatalytic activity with the lower overpotentials of 260 and 165 mV toward oxygen evolution reaction and hydrogen evolution reaction at current density of 10 mA cm−2, respectively. The outstanding activity originates from the strong electronic coupling between the 3D microsphere and ZIF-67. This work can bring a new prospect for fabricating highly-active and new structure electrocatalysts.

Recommending appropriate product items to the target user is becoming the key to ensure continuous success of E-commerce. Today, many E-commerce systems adopt various recommendation techniques, e.g., Collaborative Filtering (abbreviated as CF)-based technique, to realize product item recommendation. Overall, the present CF recommendation can perform very well, if the target user owns similar friends (user-based CF), or the product items purchased and preferred by target user own one or more similar product items (item-based CF). While due to the sparsity of big rating data in E-commerce, similar friends and similar product items may be both absent from the user-product purchase network, which lead to a big challenge to recommend appropriate product items to the target user. Considering the challenge, we put forward a Structural Balance Theory-based Recommendation (i.e., SBT-Rec ) approach. In the concrete, (I) user-based recommendation: we look for target user's “enemy” (i.e., the users having opposite preference with target user); afterwards, we determine target user's “possible friends”, according to “enemy's enemy is a friend” rule of Structural Balance Theory, and recommend the product items preferred by “possible friends” of target user to the target user. (II) likewise, for the product items purchased and preferred by target user, we determine their “possibly similar product items” based on Structural Balance Theory and recommend them to the target user. At last, the feasibility of SBT-Rec is validated, through a set of experiments deployed on MovieLens-1M dataset.

Metal-organic framework (MOF)-derived porous metal/C composites have drawn considerable attention from the microwave absorption field owing to their large pore volumes and surface areas. Exploring single-MOF-derived materials with high intensity and broadband absorption is largely needed but remains a challenge. Here, porous Co/ZnO/C (CZC) microrods were fabricated easily from cuboid-shaped heterobimetallic MOFs. CZC provides an efficient platform for integrating different semiconductors (ZnO), magnetic metal (Co), and carbon sources into one particle, which enhances the electromagnetic (EM) wave-absorbing ability. The carbonization temperature which is critical for EM parameters was studied in detail. CZC annealed at 700 °C outperformed those obtained at 600 or 800 °C in terms of microwave wave-absorbing properties. The reflection loss (RL) was optimized to -52.6 (or -20.6) dB at 12.1 (or 14.8) GHz with an effective bandwidth (RL ≤ -10 dB) of 4.9 (or 5.8) GHz at the coating thickness of 3.0 (or 2.5) mm. Such enhancement of EM wave-absorbing capabilities is ascribed to the well-built porous structure, dielectric loss, and magnetic loss. This work offers a new way to prepare porous magnetic metal/C composites with excellent microwave-absorbing properties starting from heterobimetallic MOFs.

In this work, g-C3N4 with different morphologies is prepared using melamine as precursor via self-assembly and calcination. Compared with pristine g-C3N4, the resultant materials possess thinner lamellar structure and abundant nitrogen defects. Hydrolysis of partial melamine occurs in a hydrothermal process, and a consequent supramolecular intermediate is formed between melamine and its hydrolysates via hydrogen bonding. In addition to enlarging the π–π conjugated systems of the polymer, the formation of intermolecular hydrogen bonds is also interesting for increasing the lifetime of fluorescence as well as for decreasing the recombination rate of electron–hole pairs. Optical absorption characterization indicates that the samples formed by surface self-assembly show remarkably extended light absorption in the visible-light region in comparison with the original g-C3N4. Under visible-light irradiation, all modified materials have outstanding photocatalytic activity, especially the optimally modified cataly...

The controllability of glass surface radiation is of great significance on regulating temperature for applications in energy conservation in residential buildings. In this work, nano-scale hybrid films with tunable surface radiation are successfully prepared via layer-by-layer assembly of exfoliated layered double hydroxide (LDH) nanosheets with In2O3 quantum chips covering the surface of glass substrates. In this hybrid system, the ultra-thin LDH nanosheets are exfoliated from hexagonal plate-like particles of Mg-Al-NO3- LDH nanosheets after anion-exchange of Mg-Al-CO32- LDH nanosheets. And In2O3 semiconductor quantum chips are obtained after an annealing treatment from In(OH)3 nanosheets which are prepared in sodium oleate/indium chloride hydrothermal system. The prepared LDH nanosheets and In2O3 quantum chips are assembled layer-by-layer onto glass substrates to form the multilayer films. Morphological and structural evolution of the hybrid films is investigated by X-ray diffraction (XRD) and UV–vis absorption spectra. The characterization results show that the hybrid films exhibit ordered tunable structures, which predicts that the infrared emissivity can be adjusted throughout the infrared spectrum. The surface radiation properties of the hybrid films are studied, and the results show that the number of the layers has a significance influence on the surface radiation properties of the films. Attractively, the hybrid films possess thickness-dependent surface radiation properties with the lowest infrared emissivity of 0.420. The nano-scale hybrid films obtained in this work show great tunability on infrared emission and illustrate to be good candidates for saving energy in the field of energy conservation buildings and smart windows.

Tunable and high-efficiency electromagnetic wave (EMW) absorption materials composed of a three-dimensional (3D) hierarchical reduced graphene oxide (RGO) aerogel network entrapped with TiO2/Ti3C2Tx hybrids were fabricated by a hydrothermal method and a mild chemical reduction treatment. The incorporation of the TiO2/Ti3C2Tx micronanoheterostructure and construction of the 3D well-designed hierarchical interconnected network can significantly reduce the agglomeration of RGO sheets together with the beneficial effect of a better impedance match. When the filler loading is 10 wt %, the maximum reflection loss of the composite aerogel reaches up to −65.3 dB with a matching thickness of 2.5 mm. Meanwhile, the effective absorption bandwidth (RL < −10 dB) is 4.3 GHz with the coating thickness of only 2.0 mm, and the tunable absorption bandwidth achieves at 13.74 GHz via modulating the absorber thicknesses in a range from 1.5 to 5.0 mm. The enhanced EMW absorbing performance is closely related to highly porous c...

Mesoporous carbon nitride with novel morphology has been successfully fabricated by using ionic liquid and supramolecular precursor cyanuric acid-melamine complex as the template and precursor, respectively. The texture of carbon nitride is controlled by adjusting the ionic liquid concentration and type. The results find that a disordered hollow carbon nitride box morphology with pores in the wall can be obtained under lower IL1 concentration. With increasing of ionic liquid content, the texture turns to be a layered structure. The disordered nanosheets and hollow tube with large pores in the shell can be fabricated by using IL-2 and IL-3 as templates, respectively. Besides, as-prepared mesoporous carbon nitride samples display the excellent light harvesting properties and fast separation rate of photogenerated carrier. Moreover, mesoporous carbon nitride CN-0.1 exhibits a higher photocatalytic hydrogen evolution rate (120.3 μmol h–1) under visible light irradiation owing to the special structure and the ...

Imidazole (IMI)-based polyethylene glycol monomethyl ether (MPEC-IMI) as a novel green corrosion inhibitor was synthesized to protect the Q235 steel in 0.5 M HCl corrosive medium at 318 K. The inhibition performance of MPEC-IMI was investigated by weight loss measurement, the electrochemical method (Tafel and EIS) and surface analysis (SEM and EDX). The results reveal that the MPEC-IMI shows enhanced anticorrosion performance for carbon steel, which is attributed to the formation of the adsorptive protection film on the surface, and the type of adsorption basically obeys the Langmuir monolayer adsorption. Furthermore, when the concentration of MPEC-IMI is 300 mg L−1, the corrosion inhibition efficiency can reach up to 92.00%. In support of further study of the corrosion inhibition behavior by virtue of quantum chemical calculation and molecular dynamics simulations, the results show that the MPEC-IMI molecule has high reactivity and strong interaction on the iron surface.