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Transition metal phosphide is regarded as one of the most promising candidates to replace noble‐metal hydrogen evolution reaction (HER) electrocatalysts. Nevertheless, the controllable design and synthesis of transition metal phosphide electrocatalysts with efficient and stable electrochemical performance are still very challenging. Herein, a novel hierarchical HER electrocatalyst consisting of three‐dimensional (3D) coral‐like Mn‐doped Co2P@an intermediate layer of Ni2P generated in situ by phosphorization on Ni foam (MnCoP/NiP/NF) is reported. Notably, both the incorporation of Mn and introduction of the Ni2P interlayer promote Co atoms to carry more electrons, which is beneficial to reduce the force of the Co−H bond and optimize the adsorption energy of hydrogen intermediate (|ΔGH*|), thereby making MnCoP/NiP/NF exhibit outstanding HER performance with onset overpotential and Tafel slope as low as 31.2 mV and 61 mV dec−1, respectively, in 1 m KOH electrolyte. [ABSTRACT FROM AUTHOR]

Rational construction of high‐efficiency and low‐cost catalysts is one of the most promising ways to produce hydrogen but remains a huge challenge. Herein, interface engineering and heteroatom doping were used to synthesize V‐doped sulfide/phosphide heterostructures on nickel foam (V‐Ni3S2/NixPy/NF) by phosphating treatment at low temperature. The incorporation of V can adjust the electronic structure of Ni3S2, expose more active sites, and protect the 3D structure of Ni foam from damage. Meanwhile, the heterogeneous interface formed between Ni3S2 and NixPy can provide abundant active sites and accelerate electron transfer. As a result, the V‐Ni3S2/NixPy/NF nanosheet catalyst exhibits outstanding activity in the hydrogen evolution reaction (HER) with an extremely low overpotential of 90 mV at a current density of 10 mA cm−2 and stable durability in alkaline solution, which exceeds those most of the previously reported Ni‐based materials. This work shows that rational design by interfacial engineering and metal‐atom incorporation has a significant influence for efficient hydrogen evolution. [ABSTRACT FROM AUTHOR]

Improving the performance of catalysts by adjusting the vacancy engineering is currently one of the main ways to design effective catalysts. However, there are no reports in the literature on the influence that fluorine vacancies (FVs) have on the electronic structures of materials. In this work, we report the generation of FVs for the first time and discuss in depth their regulation mechanism on materials and their role in the electrochemical N2 reduction reaction (NRR). The catalyst optimized by FVs showed good NRR performance in Li2SO4 solution. At 0 V vs. RHE, the faradaic efficiency (FE) reaches the highest value of 36.01%. When the potential is increased to −0.10 V vs. RHE, the highest ammonia yield is 7.99 μg h−1 cm−2. The specific activity of the FV-optimized LaF3 nanosheets (NSs) is 9.5 times higher than that of the defect-free LaF3 NSs. It is currently reported as the most effective non-noble metal catalyst in the nitrogen reduction process under low overpotential. In addition, this catalyst also demonstrates long-term structural stability. In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) show that the LaF3 NSs with the optimal defects have a multi-step promoting effect. [ABSTRACT FROM AUTHOR]

Although intensive efforts have been made and great progress has been achieved relating to the electrocatalytic hydrogen evolution reaction (HER), an advanced synthesis strategy for an efficient electrocatalyst is still the most significant goal. In this paper, we introduce PdFeCoNiCu high-entropy alloy (HEA) nanoparticles as an efficient electrocatalyst for the HER, which has been prepared in an oil phase under facile conditions for the first time. PdFeCoNiCu/C shows excellent alkaline HER catalytic performance with an overpotential of only 18 mV and a Tafel slope of 39 mV dec−1. Meanwhile, we achieved the highest mass activity (6.51 A mgPd−1 at −0.07 V vs. RHE) in the alkaline HER among all non-Pt electrocatalysts. PdFeCoNiCu/C also shows surprisingly stable catalytic properties for over 15 days without notable decay. Based on theoretical calculations, the HEA surface demonstrates the optimization of electronic structures based on a synergistic effect between all metals. Pd and Co are confirmed to be the dominant electroactive sites for both H2 formation and initial water splitting, which are assisted by Ni, Fe, and Cu promotion, enhancing electron transfer and optimizing the binding energies of hydrogen intermediates. This work has supplied significant insight into the design of an efficient electrocatalyst based on HEA materials. [ABSTRACT FROM AUTHOR]

A heterogeneous structure formed by coupling two or more phases can reinforce the activity of active sites and expedite electron transfer, which is conducive to boosting its electrocatalytic activity. Herein, we designed nickel foam supported (NiCo2)Se@Ni(OH)2 (NCS@NH) heterojunction nanosheets by a two-step method. First of all, the NiCo2S4@Ni(OH)2 (NiCo2S4@NH) nanosheets coated on nickel foam were acquired via a hydrothermal method. In the selenization treatment that followed, NiCo2S4@NH was converted into NCS@NH heterogeneous nanosheets in which the selenide nanoparticles decorated on the surface of the Ni(OH)2 nanosheets formed heterojunction interfaces, and the heterogeneous structure could accelerate electron transfer, thus improving the catalytic activity. The Ni(OH)2 nanosheets can adequately contact the electrolyte and promote the decomposition of water. Meanwhile, the thickness of the Ni(OH)2 nanosheets gradually decreases with the increase of Co doping (1.5–2.5 mmol), consequently affecting the HER properties. Notably, when the amount of Co salt added is 2 mmol, NCS@NH exhibited superior HER properties (with a voltage of 253 mV at 100 mA cm−2) and excellent stability for 24 h. [ABSTRACT FROM AUTHOR]

In this article, a flame retardant microcapsule ammonium polyphosphate microencapsulated by polyurea (POAPP) was successfully synthesized by interfacial polymerization method using ammonium polyphosphate (APP) as core and polyurea as shell. The microencapsulation is observed by scanning electron microscopy and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and hydroscopicity test, which prove the success in synthesizing microencapsulation. When the POAPP is added into rigid polyurethane foam (RPUF), the flame retardant and mechanical properties are investigated using cone calorimeter, limited oxygen index test, and compressive strength test. The PHRR of RPUF‐POAPP20 decreased from 336.52 kW/m2 (Ref. RPUF) to 203.84 kW/m2 and the THR of RPUF‐POAPP20 was only 7.6 MJ/m2, which is 33.9% lower than that of Ref. RPUF. Furthermore, the limiting oxygen index of RPUF‐POAPP20 reaches 24.8%, which increased by 36.3% compared to Ref. RPUF. Whereas the maximum compressive strength of RPUF‐POAPP5 was 7.46 MPa, which is higher than that of RPUF‐APP5. [ABSTRACT FROM AUTHOR]

A three-dimensional mathematic model based on segmentation that joins the electromagnetic field, melt flow, heat transfer, solidification and solute transport in the whole casting domain has been established to study the solute transport at the final stage of solidification in a bloom continuous casting process. The effects of the final electromagnetic stirring (F-EMS) positions on the macrosegregation degree of the as-cast bloom are compared and analyzed. The results show that the maximum carbon segregation degree, the ratio of the local carbon concentration to the initial carbon concentration, is reduced from 1.292 to 1.254 with the application of F-EMS. In addition, the position of F-EMS is also an important factor. The maximum carbon segregation degrees are 1.254, 1.237 and 1.269 when the installation location of F-EMS is 14 m, 16 m and 18 m away from the meniscus, respectively. The optimal center solid fraction is about 0.1 at the F-EMS center for this study. [ABSTRACT FROM AUTHOR]

To improve the flame retardant of thermoplastic polyurethane elastomer (TPU) is a very important issue in fire hazard fields. In this article, the structure of copper (II) chelate salicylaldehyde (CuSA) was characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). The influence of CuSA on the fire safety performances of TPU/APP composites was intensively investigated using cone calorimeter test (CCT), smoke density test (SDT), micro‐scale combustion calorimetry (MCC), thermogravimetric‐Fourier transform infrared spectrum (TG‐FTIR), and other testing methods. The CCT test results showed that the peak heat release rate (pHRR) value of CuSA2 sample was 128.1 kW/m2, which was much lower than that of TPU‐APP sample with the pHRR value of 161.9 kW/m2. The SDT test results showed that the luminous flux of CuSA4 is much higher than that of TPU‐APP sample. Therefore, an appropriate amount of CuSA had obvious improvement of fire safety performances in TPU composites. This work provides a new idea for the design and manufacture of fire safety materials. [ABSTRACT FROM AUTHOR]

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With requirements to improve life quality, smart homes, and healthcare have gradually become a future lifestyle. In particular, service robots with human behavioral sensing for private or personal use in the home have attracted a lot of research attention thanks to their advantages in relieving high labor costs and the fatigue of human assistance. In this paper, a novel force-sensing- and robotic learning algorithm-based teaching interface for robot massaging has been proposed. For the teaching purposes, a human operator physically holds the end-effector of the robot to perform the demonstration. At this stage, the end position data are outputted and sent to be segmented via the Finite Difference (FD) method. A Dynamic Movement Primitive (DMP) is utilized to model and generalize the human-like movements. In order to learn from multiple demonstrations, Dynamic Time Warping (DTW) is used for the preprocessing of the data recorded on the robot platform, and a Gaussian Mixture Model (GMM) is employed for the evaluation of DMP to generate multiple patterns after the completion of the teaching process. After that, a Gaussian Mixture Regression (GMR) algorithm is applied to generate a synthesized trajectory to minimize position errors. Then a hybrid position/force controller is integrated to track the desired trajectory in the task space while considering the safety of human-robot interaction. The validation of our proposed method has been performed and proved by conducting massage tasks on a KUKA LBR iiwa robot platform. [ABSTRACT FROM AUTHOR]

Background: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is currently the most promising approach for wheat heterosis utilization in China. However, during past 20 years only few TPSGMS lines were developed in hybrid wheat breeding, which has been the main limiting factor to create heterotic hybrids. Application of doubled haploid (DH) breeding provides a useful strategy to efficiently develop practically usable TPSGMS lines. Results: F1s and selected F2 and F3 sterile plants of eight crosses made from two commercial TPSGMS lines were used to produce DH lines. We developed a total of 24 elite DH sterile lines with stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, as well as desirable plant height (50–60 cm). These DH lines were developed within 4 years through at least 1 year of evaluation. The stability of male sterility was confirmed for most (20/24) of these elite DH sterile lines by multiple tests in two or 3 years. These lines are expected to be used in hybrid wheat breeding. The percentage of elite lines developed from the tested DH lines produced from filial generations was in the order of F2 > F3 > F1. Conclusions: We demonstrate that coupling DH techniques with conventional breeding is an efficient strategy for accelerating the development of more practical wheat TPSGMS lines. Generation of DHs from F2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency. [ABSTRACT FROM AUTHOR]

The application of chitosan (CS) in new materials is a hot research topic. In this paper, CS was used alone as flame retardant to prepare thermoplastic polyurethane elastomer (TPU) composites. Then, the flame retardancy and thermal decomposition behavior of TPU/CS composites were intensively investigated using cone calorimeter test (CCT), scanning electron microscope (SEM), microscale combustion colorimeter (MCC) test, thermogravimetric analysis/infrared spectrometry (TG‐IR), and gas chromatography‐mass spectrometry (GC‐MS). The results showed that CS can reduce the fire risk of TPU; 2.0‐wt% CS could make the peak value of heat release rate (pHRR) decreased to 457.2 kW/m2, reduced by 65.9% compared with TPU. And the peak value of smoke production rate (pSPR) and total smoke release (TSR) of the same sample was decreased by 79.4% and 54.2%, respectively. The TG‐IR and GC‐MS results confirmed that CS could promote TPU decomposition in advance, reacting with the decomposition products of TPU. Therefore, the production of combustible gas was reduced. The GC‐MS results showed that the production of isocyanates and ethers was reduced with the addition of CS. The digital photographs of SEM for the samples after CCT were shown that the char residue layer of the sample containing 2.0‐wt% CS was fibrous in shape. It could be speculated that the thermal decomposition products from TPU could react with CS at low temperature, which reduced the production of flammable gases. So CS had a good prospect in reducing the fire hazard for TPU. [ABSTRACT FROM AUTHOR]

Ramie fiber (RF) with excellent tensile strength was treated by a flame retardant and obtained the modified RF (MRF) that is incombustible. Then, MRF was used to improve the performance of rigid polyurethane foams (RPUF). The mechanical properties of the composite were investigated by compressive strength test and shear stress test. The fire characteristics were studied using a cone calorimeter. And the thermal decomposition and flammable properties were further evaluated using thermogravimetric analysis and limiting oxygen index. The results showed that MRF improve the mechanical properties of RPUF and eliminate the harm of flammability of RF on the RPUF. [ABSTRACT FROM AUTHOR]

Summary: The dripping phenomena affect fire hazards significantly. In the UL‐94 test, the dripping has been classified into the small‐size dripping due to surface melting and the large‐size dripping originating from bulk softening. Both types of dripping result from the gravity resisted by the forces including the viscous force. Based on the mechanical mechanism, a pendant experiment to reflect the ability of polymer melt to resist the gravity and a simple model equation were developed. The pendant experimental data of 7 polymers verified the model equation, and the regressed model parameter values of activation energy were close to reported data to some extent for most polymers. Correlations between the predicted pendant mass and the dripping behavior featured by the maximum drop mass showed that the pendant mass predicted at the glass transition temperature was proportional to the maximum drop mass. For polymers of large‐size dripping, the pendant mass predicted at typical decomposition temperatures such as the onset decomposition temperature was generally proportional to the maximum drop mass. Moreover, the model equation indicated that for the large‐size dripping the product of drop mass and first dripping time should be proportional to the specimen thickness, which was verified by reported dripping data. [ABSTRACT FROM AUTHOR]

Efficient flame-retardant TPU/TiO2 nanocomposites were synthesized by molten blending method. The morphological and structural analysis indicated that TiO2 nanoparticles could be well dispersed in TPU and increased compatibility with the polymer. The obtained mechanical and thermal data suggested that intense cross-linking interaction between TiO2 and TPU promoted more stable network structure, which increased tensile length at break, storage modulus and loss modulus and thermal stability. Furthermore, the cone results demonstrated that TiO2 could not only decrease HRR, but also provide more stable char due to its high heat resistance, and catching and isolating oxygen molecules. Though ignition was inevitably earlier and peak value appearance caused transient thermal conductivity, TiO2 could greatly deplete combustible smoke particulates on the surface of TPU by accelerating degradation of combustible gases to prevent further penetration and destruction from TPU surface as oxygen insulation barrier. Therefore, TiO2 as a kind of effective flame-retardant and smoke suppression material can be applied in the flame retardancy of TPU. [ABSTRACT FROM AUTHOR]

This paper developed a character recombination technology based on dynamic movement primitive (DMP) segmentation using verbal command on a Baxter robot platform. Movements are recorded from a human demonstrator. The operator physically guides the Baxter robot to perform the movements for five times. This training data set is also utilized for playback process. Subsequently, the dynamic time warping is employed to pre-treat the data. The DMP is used to model and generalize every single movement. Gaussian mixture model is used to generate multiple patterns after the teaching process. Then the Gaussian mixture regression algorithm is applied to reduce the position errors in 3D space after the generation of a synthesized trajectory. A remote PC is used to control the command of Baxter to record or playback any trajectories via user datagram protocol (UDP) by typing commands in a text file. In addition, Dragon NaturalSpeaking software is used to transfer the voice data to text data. This proposed approach is tested by performing a Chinese character writing task with a Baxter robot, where different Chinese characters are written by teaching only one character. [ABSTRACT FROM AUTHOR]

Flame-retardant polyurethane elastomers (PUEs) have been prepared using trichloroethyl phosphate (TCEP) as flame retardant. The combustion performances and thermal decomposition properties of PUEs were studied using cone calorimetry test and thermogravimetric analysis, respectively. Kissinger method and Flynn–Wall–Ozawa (FWO) method were adopted to discuss the pyrolysis kinetics of PUEs. The experimental results showed that TCEP has good flame-retardant effect for PUE. With the increase of TCEP, the peak heat release rate and total heat release values decrease. A good diagram of linear regression can be obtained from both Kissinger and FWO methods. The activation energy values of flam- retardant PUE can be calculated from FWO method at different conversion rates. [ABSTRACT FROM AUTHOR]

Flame retardant thermoplastic polyurethane (TPU) composites with low smoke release have been prepared by melt-blending TPU with commercially available carbon black (CB) and ammonium polyphosphate (APP). The experimental data from SDT indicated that an appropriate amount of CB and APP can decrease the amount of smoke production in the test with or without flame. The CCT results showed that CB and APP greatly decrease smoke production rate, total smoke release, and smoke factor of flame retardant TPU composites compared with that of pure TPU. Indeed, CB is considered as an effective smoke suppression agent and a good synergism with APP in flame retardant TPU composites, which can greatly improve the structure of char residue realized by TG and SEM results. The TG and DTG results showed that CB can decrease the initial decomposition temperature and improve the thermal stability at high temperature for flame retardant TPU composites. More interest, the TG-IR study indicates that the volatilized products are CO, ammonia compound, acid anhydride, water, alkane compounds, and aromatic compounds according to the temperature of onset formation. This is a very meaningful result in fire safety materials fields. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, the smoke production behaviors of crosslinked epoxy/polyamide resin (EP/PA) and intumescent fire retardant (IFR) in epoxy-based intumescent fire-retardant coating (IFR-EP) have been investigated using cone calorimeter, smoke density instrument, and thermogravimetric analysis and Fourier transform infrared spectroscopic measurement. The static and dynamic smoke production behaviors of EP/PA and IFR-EP indicate that the IFR has an excellent smoke suppression effect on EP/PA by forming protective char layer in the late combustion stage, while the epoxy crosslinked structure in IFR-EP can enhance the thermal stability and reduce smoke production in the early combustion stage. In addition, according to the discussion of pyrolysis gas products, the IFR can effectively suppress the production of toxic and inflammable gases during the combustion process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43912. [ABSTRACT FROM AUTHOR]

The hypothesis that nitrogen and phosphorus can have a positive effect on the bloom formation of Ulva prolifera along the southern coast of the Yellow Sea was examined. The nutrient enrichment on the growth and photosynthetic carbon assimilation of U. prolifera were investigated in laboratory. Four nitrogen and phosphorus treatments were established: high nitrogen and high phosphorus (HNHP), high nitrogen and low phosphorus, low nitrogen and high phosphorus, and low nitrogen and low phosphorus (LNLP). Fresh weights, relative growth rate (RGR), chlorophyll fluorescence parameters, photosynthetic rate, and the uptake of dissolved inorganic carbon (DIC) in U. prolifera were measured. The results showed that nitrogen and phosphorus enrichment significantly increased RGR of U. prolifera. The chlorophyll fluorescence parameters all reached maximum values under the HNHP treatment. The photosynthetic rate under the HNHP treatment also was the highest, which was 1.52 times that of the LNLP treatment. The DIC uptake under the HNHP treatment was 1.63 times greater than under the LNLP treatment. The photosynthesis and carbon fixation were significantly promoted by N and P enrichment. This work may further clarify the mechanisms of U. prolifera bloom formation and decline in the Yellow Sea. [ABSTRACT FROM AUTHOR]

In this article, smoke suppression and synergistic flame retardancy properties of zinc borate (ZB) and diantimony trioxide (SbO) in epoxy-based intumescent fire-retardant (IFR) coating were investigated based on cone calorimeter test, smoke density test, scanning electron microscopy, thermogravimetric and Fourier transform infrared spectroscopic analyses. The measurement results of the dynamic combustion and smoke production behaviors and static smoke production behaviors of these IFR coatings showed that the values of heat release rate, smoke production rate, smoke factor and fire growth index all decreased significantly with the addition of ZB and SbO. At the same time, the specific optical densities were remarkably reduced due to the existence of ZB and SbO. These attractive data clearly demonstrated that the ZB and SbO had a good effect on smoke suppression and synergistic flame retardancy of the IFR coating. Besides, the scanning electron microscopy and the infrared spectroscopic analyses during coating thermal degradation were also carried out to explore the outstanding synergistic smoke suppression and flame retardancy mechanism of ZB and SbO. With the melt of ZB and SbO, a lot of heat was absorbed, and then, the glassy protective layer associated with the graphite char would effectively retard heat and suppress smoke. [ABSTRACT FROM AUTHOR]

In this paper, fumed silica has been used as smoke suppression and flame-retardant synergism in thermoplastic polyurethane (TPU) composites based on ammonium polyphosphate (APP). And, the synergistic smoke suppression property and flame-retardant effect of fumed silica in flame-retardant TPU composites are mainly intensively investigated by several methods, including smoke density test (SDT), cone calorimeter test (CCT), scanning electron microscopy (SEM), limiting oxygen index, and thermogravimetric analysis. The results of SDT show that fumed silica can significantly decrease smoke production of flame-retardant TPU composites. The results of CCT present that the addition of fumed silica can effectively reduce smoke production rate, total smoke release, smoke factor, heat release rate, and mass loss in the combustion process of flame-retardant TPU composites. The SEM results show that fumed silica can improve the quality of char residue after cone calorimeter test. All the results show that fumed silica is an effective smoke suppression agent and a good flame-retardant synergism with APP in TPU composites. [ABSTRACT FROM AUTHOR]

A series of intumescent flame-retardant epoxy resins (IFREP) were prepared based on bisphenol A epoxy resin (EP) as matrix resin, ammonium polyphosphate (APP) and pentaerythritol as intumescent flame retardants (IFRs), and ferrite yellow (goethite) as smoke suppressant. Then, the synergistic flame-retardant and smoke suppression properties of α-FeOOH on IFR epoxy composites were intensively investigated using cone calorimeter test and scanning electron microscopy. The thermal degradation process of IFR epoxy composites were studied using thermogravimetric analysis–infrared spectrometry under nitrogen atmosphere. Then, the pyrolysis kinetics parameters were investigated using Kissinger and Flynn–Wall–Ozawa methods. The results showed that goethite can significantly reduce heat release rate, total heat release, smoke production rate, and total smoke release. There are obvious synergistic flame-retardant and smoke suppression effects between goethite and IFRs in epoxy composites. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic intumescent flame retardant, expandable graphite modified with charring agent (EGM), was synthesized using expandable graphite (EG), phosphorus oxychloride, and pentaerythritol. Then, EGM was used as flame retardant for epoxy resin. And the flame-retardant properties of epoxy composites were investigated by cone calorimeter test (CCT). The thermal degradation behaviors of epoxy composites were studied by thermogravimetric analysis (TG) in nitrogen atmosphere. And the pyrolysis kinetics of the composites was investigated using Kissinger and Flynn-Wall-Ozawa methods. The CCT result indicated that EGM can reduce the heat release rate and smoke production rate more than EG in flame-retardant epoxy composites: a more compact char residue formed on the surface of the sample with EGM than that of the sample with EG during the combustion process. The TG result showed that the sample with EGM has higher thermal stability than the sample with EG. And the data calculated from Kissinger and Flynn-Wall-Ozawa methods showed that both EP-0 and EP-3 had two thermal degradation stages; EGM can improve the E value of epoxy resins. [ABSTRACT FROM AUTHOR]

New silicone rubbers(SR)-based hybrid material containing intumescent flame retardant (IFR) and ferric hydroxide (FeOOH) has been developed in order to improve flame retardancy of SR. The synergistic effects of FeOOH with IFR in halogen-free flame retardant SR/IFR blends have been studied by cone calorimeter test (CCT) and thermogravimetric analysis (TG). The data obtained from the CCT indicate that the SR/IFR/FeOOH sample with 4.0 mass% FeOOH has the lowest HRR, SPR, TSR, THR, and SF among all samples. The digital photo graphs give positive evidence that there is a synergistic effect between IFR with FeOOH. The TG results reveal that FeOOH can enhance the thermal stability of SR/IFR/FeOOH at high temperature. Besides the traditional investigations on cone calorimeter tests, an intensive study on the thermo-degradation kinetics was carried out to reveal the mechanism of the outstanding flame retarding performance of the SR/IFR/FeOOH. FeOOH can improve the flame retardancy, increase the thermal stability during the whole process of degradation, and strengthen the ability to form a thermally stable and condensed barrier for heat and mass transfer. These attractive features of SR/IFR/FeOOH suggest that the method proposed herein is a good approach to prepare very effective flame retardants and corresponding super flame retarding SR. [ABSTRACT FROM AUTHOR]

Photosynthetically active radiation (PAR) is an important parameter in agricultural applications. Some researchers showed that many parameters, such as leaf area index (LAI), leaf angle distribution (LAD) and the heterogeneity of vegetation, were concerned with the distribution of PAR. Many models were used to simulate the distribution of PAR effectors, such as the structure of canopy and sun zenith angle. This paper simulated the vertical distribution of PAR in the canopy and analyzed the relationships between PAR and some parameters, such as solar zenith angle, LAD, LAI, maize canopy structure, special for the heterogeneous canopies such as that crop with width and narrow ridges. It took account the effects of structural features of different type canopies. In this study, the distributions of solar radiation at different heights in maize canopy were simulated based on the radiation transfer model. The row structure model was used to simulate the vertical distribution of PAR in canopies. It accounted for direct radiation including radiation paths going through one or more rows. Leaf angle distribution was generated by using this model to measure leaf angle distributions in canopies. Intensive investigation was made on the effect of these canopy architecture on the penetration of total visible radiation into the canopy at various solar zenith angle. The simulation result of PAR in maize canopy was validated with the measured data, and it appeared good accuracy. By simulation with box model, the regularity of vertical distribution of PAR in the canopy showed that: 1) the transmittance of solar incidence was affected by the effective light path; 2) the attenuation of light in the canopy was diminishing exponentially along the light path. It could be reflected by the vertical distribution of light extinction coefficient (K); 3) the solar altitude angle varying from 60° to 45° or 30° solar altitude angle with the RMSE value of 0.07 or 0.08, it could improve PAR estimation accuracy. The vertical distribution of leaf area was affected by the light attenuation through the canopy. In this paper, we proposed the method based on the regularity of vertical distribution of PAR by using Beer-Lambert law for inversion of the vertical distribution of LAI in maize canopy. The relationships between the vertical distribution of the leaf area index and solar zenith angle was analyzed, and the results were validated with the measured data. Results showed that the algorithm of Bonhomme&Chartier was proved to be effective for inversion of the vertical distribution of LAI. There were differences in inversion results with different solar zenith angles. In the upper canopy, the solar altitude angle varying from 30° to 45° solar altitude angle could improve LAI estimation accuracy with the RMSE of 0.18, and from 45 to 30 solar altitude angle with the RMSE of 0.30 in the middle canopy, 30° and 45° with the RMSE value of 0.11 and 0.09 in the under canopy. The result showed that it had a fairly good agreement between calculated and observed data, which proved the validity of the theoretical model. [ABSTRACT FROM AUTHOR]

In this work, an organic inorganic hybrid intumescent flame retardant (functionalized expandable graphite, FEG) was synthesized and characterized by Fourier transform infrared spectrometry (FTIR). The flame retardant effects of FEG in silicone rubber (SR) composites were investigated by cone calorimeter test (CCT), and the thermal stability of SR composites was studied using TGA. The CCT results showed that FEG can effectively reduce the flammable properties including peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), total smoke release (TSR), and smoke factor (SF). An improvement of thermal stability of SR/FEG was also observed. Compared with EG, FEG can further reduce THR, SPR, and TSR of SR/FEG composites in combustion process. Moreover, there is a more obvious intumescent char layer formed from the sample with FEG than the sample with EG at the same loading in SR composites. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Flame retardant epoxy resin (FREP) were synthesized from phosphoric acid and bisphenol A epoxy resin (BAEP). The structure of the FREP was characterized using FTIR and P NMR. Then, several FREP/BAEP mass ratios were used to obtain materials with different phosphorus contents. The properties of the thermosetting materials were evaluated by limiting oxygen index, UL 94, cone calorimeter test, and thermogravimetric analysis. The results showed that the heat release rates and smoke production rates decreased greatly, and char residue increased with the increasing of FREP. It indicates that good flame retardant properties are related to the formation of a protective phosphorus-rich char layer. [ABSTRACT FROM AUTHOR]

Thermophysical properties of intumescent fire-retardant (IFR) materials are important parameters as input data in modeling the combustion process of IFR materials in a fire. In this paper, the influences of several thermophysical properties on burning behavior of IFR materials are simulated based on a combustion model of IFR materials. Thermophysical properties selected here are thermal conductivity of virgin material and char layer, specific heat capacity of virgin material, density of virgin material, surface emissivity of virgin material and char layer, heat of decomposition, heat of combustion, and intumescent temperature. Predicted heat release rates curves for the IFR material at an incident heat flux of 50 kW m are shown for the varied thermophysical parameters' values. The results show that these varied parameter values can affect the burning behavior of materials remarkably. A comparison with experimental results demonstrates that the predictions of heat release rates are in reasonably good agreement with the experiment. [ABSTRACT FROM AUTHOR]

Co-microencapsulated ammonium polyphosphate (APP) and pentaerythritol (PER) [M (A&P)] is prepared using melamine-formaldehyde resin by in situ polymerization method and characterized using energy dispersive spectrometer and Fourier transform infrared spectra. Thermal stability and fire resistance behavior have been analyzed and compared. The co-microencapsulation of APP and PER leads to a great improvement of its thermal stability investigated by thermogravimetric analysis. The temperature of maximum mass loss rate of M (A&P) is 30 °C higher than that of APP/PER mixture. The flame-retardant effect of M (A&P) in coating composite is evaluated by carbonization volume, flame spread rate, and cone calorimeter. Results show that the flame-retardant properties of M (A&P) in coating composite is much better than that of APP/PER mixture coating composite. [ABSTRACT FROM AUTHOR]

A novel hyperbranched polyphosphate ester (HPE) was synthesized via the polycondensation of bisphenol-A and phosphoryl trichloride. The formed HPE was characterized by FTIR, H NMR and P NMR to confirm its structure. Then, a series flame retardant epoxy resins from bisphenol-A epoxy cured with HPE and bisphenol-A were prepared. The combustion behavior of the flame retardant epoxy resins was studied using limiting oxygen index (LOI) and cone calorimeter test. The LOI value increased from 23 to 32 when HPE, instead of bisphenol-A, was used as a curing agent. The cone calorimeter test data revealed that the cured bisphenol-A epoxy resin with HPE as a curing agent possessed improved flame retardancy. The photo graphs and scanning electron microscopy (SEM) of char residues confirmed the cone calorimeter results. [ABSTRACT FROM AUTHOR]

Lang Yuan and Andrew Kao are guest editors for the Solidification Committee of TMS and coordinated the topic Solidification Behavior in the Presence of External Fields in this issue. Ren et al. presented a new method by introducing a pulsed electric current for the first time to a solidifying silicon ingot in the paper titled "Separation of Impurity Iron from Polysilicon by Pulsed Electric Current." The model has been established to study solute transport at the final stage of solidification in a bloom continuous casting process. [Extracted from the article]

A new type of flush/fill equipment driven by high-pressure (1MPa) nitrogen gas for filling the capillary is demonstrated. High-viscous and microlitre grade volume solution can be filled into a capillary by means of this equipment. The capillary coated by cross-linked polyacrylamide and filled with “interpenetrating polymer networks” non-gels sieving matrix (0.8% hydroxyethyl cellulose, 10% sucrose in 1×TBE buffer) was applied for separating DNA fragments. All 11 fragments of Ø174/Hae III DNA were successfully separated. The man-made circle plasmid from E. coli were separated and detected. [ABSTRACT FROM AUTHOR]

The Laguerre-Gaussian beam is a typical example of the optical vortices, which can be generated by computer-generated holograms (CGHs) with the topological charge controlled. Here, we fabricated transmission-amplitude CGH gratings (up to 100 lines per millimeter) on metal film by photolithography technique. Such CGH grating grooves feature high resolution and fine smoothness, so that the gratings can be used to generate Laguerre-Gaussian beam with perfect mode. They are also applicable for the generation of femtosecond optical vortices due to the high damage threshold of the metal film. [ABSTRACT FROM AUTHOR]

Designing electrocatalysts with high-performance for both reduction and oxidation reactions faces severe challenges. Here, the uniform and ultrasmall (~3.4 nm) high-entropy alloys (HEAs) Pt18Ni26Fe15Co14Cu27 nanoparticles are synthesized by a simple low-temperature oil phase strategy at atmospheric pressure. The Pt18Ni26Fe15Co14Cu27/C catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The catalyst shows ultrasmall overpotential of 11 mV at the current density of 10 mA cm−2, excellent activity (10.96 A mg−1Pt at −0.07 V vs. reversible hydrogen electrode) and stability in the alkaline medium. Furthermore, it is also the efficient catalyst (15.04 A mg−1Pt) ever reported for MOR in alkaline solution. Periodic DFT calculations confirm the multi-active sites for both HER and MOR on the HEA surface as the key factor for both proton and intermediate transformation. Meanwhile, the construction of HEA surfaces supplies the fast site-to-site electron transfer for both reduction and oxidation processes. The design of nanostructured catalysts plays a key role in the electrocatalytic redox reaction performances. Here, authors prepared uniform and small-sized high-entropy alloy PtNiFeCoCu nanoparticles that showed improved activities for H2 evolution methanol oxidation reactions. [ABSTRACT FROM AUTHOR]

To improve sulfuric acid recovery from sodium sulfate wastewater, a lab-scale bipolar membrane electrodialysis (BMED) process was used for the treatment of simulated sodium sulfate wastewater. In order to increase the concentration of sulfuric acid (H2SO4) generated during the process, a certain concentration of ammonium sulfate solution was added into the feed compartment. To study the influencing factors of sulfuric acid yield, we prepared different concentrations of ammonium sulfate solution, different feed solution volumes, and different membrane configurations in this experiment. As it can be seen from the results, when adding 8% (NH4)2SO4 into 15% Na2SO4 under the experimental conditions where the current density was 50 mA/cm2, the concentration of H2SO4 increased from 0.89 to 1.215 mol/L, and the current efficiency and energy consumption could be up to 60.12% and 2.59 kWh/kg, respectively. Furthermore, with the increase of the volume of the feed compartment, the concentration of H2SO4 also increased. At the same time, the configuration also affects the final concentration of the sulfuric acid; in the BP-A-C-BP ("BP" means bipolar membrane, "A" means anion exchange membrane, and "C" means cation exchange membrane; "BP-A-C-BP" means that two bipolar membranes, an anion exchange membrane, and a cation exchange membrane are alternately arranged to form a repeating unit of the membrane stack) configuration, a higher H2SO4 concentration was generated and less energy was consumed. The results show that the addition of the double conjugate salt is an effective method to increase the concentration of acid produced in the BMED process. [ABSTRACT FROM AUTHOR]

In order to reduce the fire risk of rigid polyurethane foams (RPUF), three kinds of zeolitic imidazolate frameworks (ZIFs) were prepared. The results of Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM and X-ray diffraction (XRD) showed that ZIFs were successfully prepared. The combustion test results showed that the heat and smoke production of the composite containing ZIFs was obviously reduced. In particular, the peak heat release rate (PHRR) of ZIF-8/RPUF decreased from 740.85 kW/m2 (Ref. RPUF) to 489.56 kW/m2, while the PHRR of ZIF-7/RPUF and ZIF-11/RPUF is 598.39 and 583.36 kW/m2, respectively. The addition of ZIFs improved the thermostability of the composite. The T50% of ZIF-8/RPUF, ZIF-7/RPUF and ZIF-11/RPUF increased to 364, 382 and 380 °C, respectively. The maximum light absorption of ZIF-7/RPUF and ZIF-11/RPUF was about 88%, which is higher than that of ZIF-8/RPUF (75%). The results of Raman spectroscopy showed that the ID/IG value of Ref. RPUF is 2.96, while the ID/IG value of ZIFs/RPUF reduces to less than 2.80. The main mechanism of ZIFs for reducing the fire risk of RPUF was the catalysis and incarbonization of ZIFs during combustion based on the results of thermogravimetric analysis and Raman spectroscopy of char residue. [ABSTRACT FROM AUTHOR]

Ammonium polyphosphate (APP) is an effective phosphorus‐containing flame retardant. But APP also has excellent hygroscopic capacity and decreases the mechanical property of composite. The aim of the study was to microencapsulate APP with polymethyl methacrylate (PMMA) to prepare microencapsulated ammonium polyphosphate (PMAPP) in order to eliminate the harmful effects caused by the mechanical property of composite. The microcapsules are characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and hydroscopicity test and observed by scanning electron microscopy (SEM). Fire hazard of rigid polyurethane foam (RPUF) is evaluated using a cone calorimeter and limited oxygen index test. The mechanical property of RPUF is studied by compressive strength test. The results show that APP has been microencapsulated by PMMA successfully and the shell does not decrease the beneficial effect of APP on fire hazard of RPUF. Furthermore, the shell also reduces the damage of APP on the mechanical property of composite. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48307. [ABSTRACT FROM AUTHOR]

Novel fluorinated polyhedral oligomeric silsesquioxane (POSS) acrylic copolymers were synthesized by the radical solution polymerization. The superhydrophobic coating was prepared using a one-step breath figure method. Chemical constitution, morphology, hydrophobicity, and anticorrosion ability of as-prepared coatings were investigated by the corresponding equipment. The addition of proper fluorinated POSS can synchronously promote the formation of the micro-nano convex structure and the enrichment of fluorinated groups on the surface. Compared to commercial acrylic coating, the fluorinated POSS coating presented enhanced anticorrosion performance. The impedance was the highest and the corrosion current density was the lowest for superhydrophobic coating with 25 wt % fluorinated POSS. [ABSTRACT FROM AUTHOR]