Search

The objective of this study is to develop a remediation technology for composited heavy metal-contaminated soil. Biochars (BC300, BC400, and BC500) derived from corn were combined with potassium dihydrogen phosphate (KH2PO4) to immobilize and remove heavy metal ions, including mercury (Hg2+), cadmium (Cd2+), and lead (Pb2+). The adsorption kinetics of metal ions in aqueous solutions with different concentrations was tested, and the fitting effects of the two models were compared. The findings demonstrate that the joint application of biochar and KH2PO4 could markedly enhance the immobilization efficacy of Pb2+, whereas the utilization of KH2PO4 on its own exhibited a more pronounced immobilization impact on Cd2+. Furthermore, the present study underscores the shortcomings of various remediation techniques that must be taken into account when addressing heavy metal-contaminated soils. It also emphasizes the value of comprehensive remediation techniques that integrate multiple remediation agents. This study offers a novel approach and methodology for addressing the intricate and evolving challenges posed by heavy metal contamination in soil. Its practical value and potential for application are significant. [ABSTRACT FROM AUTHOR]

Potassium (K+) is an essential macronutrient for appropriate plant development and physiology. However, little is known about the mechanisms involved in the regulation of leaf water relations by K under water deficit. A pot experiment with two K supplies of 0.45 and 0 g K2O per pot (3 kg soil per pot) and two watering conditions (well‐watered and water‐deficit) was conducted to explore the effects of K deficiency on canopy transpiration characteristics, leaf water status, photosynthesis, and hydraulic traits in two rice genotypes with contrasting resistance to drought. The results showed that K deficiency reduced canopy transpiration rate by decreasing stomatal conductance, which led to higher canopy temperatures, resulting in limited water deficit tolerance in rice. In addition, K deficiency led to further substantial reductions in leaf relative water content and water potential under water deficit, which increased the imbalance in leaf water relations under water deficit. Notably, K deficiency limited leaf gas exchange by reducing leaf hydraulic conductance, but decreased the intrinsic water use efficiency under water deficit, especially for the drought‐resistant cultivar. Further analysis of the underlying process of leaf hydraulic resistance revealed that the key limiting factor of leaf hydraulic conductance under K deficiency was the outside‐xylem hydraulic conductance rather than the xylem hydraulic conductance. Overall, our results provide a comprehensive perspective for assessing leaf water relations under K deficiency, water deficit, and their combined stresses, which will be useful for optimal rice fertilization strategies. [ABSTRACT FROM AUTHOR]

Developing high-performance and low-cost protein purification materials is of great importance to meet the demands for highly purified proteins in biotechnological industries. Herein, a facile strategy was developed to design and construct high-efficiency protein absorption and separation media by combining aerogels' molding techniques and impregnation processes. Poly (ethylene-co-vinyl alcohol) (EVOH) nanofibrous aerogels (NFAs) were modified by grafting butane tetracarboxylic acid (BTCA) over them in situ. This modification was carried out using polyphosphoric acid as a catalyst. The resulting EVOH/BTCA NFAs exhibited favorable comprehensive properties. Benefiting from the highly interconnected porous structure, good underwater compressive properties, and abundant absorption ligands, the obtained EVOH/BTCA NFAs possessed a high static absorption capacity of 1082.13 mg/g to lysozyme and a short absorption equilibrium time of about 6 h. A high saturated dynamic absorption capacity for lysozyme (716.85 mg/g) was also realized solely by gravity. Furthermore, EVOH/BTCA NFAs displayed excellent reusability, good acid and alkaline resistance, and unique absorption selectivity performance. The successful synthesis of such aerogels can provide a potential candidate for next-generation protein absorbents for bio-separation and purification engineering. [ABSTRACT FROM AUTHOR]

This study investigates the synergistic effect and mechanism of gelling materials with blast furnace slag (BFS), steel slag (SS) and desulphurization gypsum (DG) as the main components on the hardening of heavy metal ions by lead and zinc tailings. It is found that lead and zinc tailing (LZT) is mainly composed of dolomite and quartz and contain small amounts of calcium, aluminum, iron, magnesium and other elements as well as heavy metals such as lead and zinc. By the mechanical activation method, it is found that the lead and zinc tailings powder has the largest specific surface area and the highest activity index when the ball milling time is 2 h. At a hardening timepoint of 28 d, the calcite crystals in the samples are intertwined with the amorphous C-S-H gel (C-S-H gels are mainly composed of 3CaO∙SiO2 and 2CaO∙SiO2), which enhances the structural strength of the samples. The chemical reaction analysis confirmed that the formation of calcite is a major driver for the hydration reaction of the steel slag–desulphurization gypsum (SSSDG) system. Overall, the slag, steel slag and desulphurization gypsum solid waste-based gelling materials have synergistic effects in hardening heavy metals by limiting the leaching of metal ions, adsorbing metal ions and hardening heavy metals, and facilitating the hydration process through the formation of compound salt precipitates. [ABSTRACT FROM AUTHOR]

In this study, wheat straw-derived biochar was prepared by setting a temperature of 400 °C under an oxygen-limited environment using the technique of "programmed temperature increase control". The results showed that the biochar had a strong adsorption capacity for Hg2+, Cd2+ and Pb2+ ions, and the adsorption pattern was Hg2+>Cd2+>Pb2+. There was a competitive adsorption effect during the coexistence of the ions. The results of the soil remediation tests showed that the effects of biochar on soil physicochemical properties and heavy metal distribution was generally greater than those of KH2PO4 in single or combined contaminated soil. The adsorption effect of heavy metal ions in soil was the best in the case of mixed additions. The results can provide a scientific basis for the treatment of heavy metal contaminated soil with wheat straw biochar in the future. [ABSTRACT FROM AUTHOR]

A novel vehicle dynamic model considering the coupling mechanism between the front wheel shimmy and the vehicle lateral handling motions is established to investigate the interacting effect between the steering shimmy instability and the general motion instability, that focuses especially on the influence of the tyre force saturation induced by lateral-longitudinal coupling when different degrees and allocation strategy of braking force are applied. The typical 3-degree-of-freedom front wheel shimmy structure of dependent suspension is dynamically modelled by using the Lagrange method, alongside the equations for plane vehicle handling motions introduced. The stretched-string-based tyre kinematic equations, that describe the transient tyre-road contact status, are proposed by analytically deriving the coupling relations between the angular shimmy variables and vehicle motion status. A theoretically approximated linear tyre model, based on the coupling between vertical, longitudinal, and lateral directional forces, is analytically derived for stability analysis. Meanwhile, a complete PAC-2002 tyre model, with experimentally identified parameters, is employed for simulation verification. The stability chart of linear stability analysis shows the variation of the system bifurcation curves and stable parameter region under different parametric configurations, which gives that the degrees and allocations of braking force largely affect the stable parameter domain and the global stability. The variations of the system characteristic roots indicate that both Hopf and S-N bifurcation could happen due to shimmy oscillations and destabilization of motion, respectively, and their co-existence at certain parameter domains make the dynamic behaviour further unpredictable and complex. Numerical simulation verifies the dynamical characteristics of shimmy, and further analysis shows that three types of vehicle motion instability which coexisted with shimmy instability could be triggered by the coupling effect. In addition, the variation law of limit-cycle amplitude under varying vehicle driving inputs is summarized, and finally, a preliminary experiment is conducted for validations. [ABSTRACT FROM AUTHOR]

Glass-ceramics without nucleating agents usually undergo surface crystallization, which deteriorates the overall performance of the products. In this paper, we evaluated the effects of the metastable MgAl 2 Si 3 O 10 crystalline phase on the crystallization behavior of a MgO–Al 2 O 3 –SiO 2 (MAS) glass without nucleating agents and mechanical properties of the glass-ceramics obtained. The results demonstrated that the precipitation of metastable MgAl 2 Si 3 O 10 crystallites promotes the crystallization mechanism transformed from surface crystallization into volume crystallization with two-dimensional crystal growth. Furthermore, the grain size of MgAl 2 Si 3 O 10 near the surface of the prepared glass-ceramics was larger than that of MgAl 2 Si 3 O 10 inside, which helps to generate compressive stress and improves its mechanical properties. The glass-ceramics containing metastable MgAl 2 Si 3 O 10 phase exhibited an enhanced hardness in the range of 7.6 GPa–9.5 GPa for indentation loads ranging from 2.94 N to 98 N, and indentation size effect behavior was observed in Vickers hardness tests of both MAS glass and glass-ceramics. The load-independent hardness values for MAS glass and glass-ceramics were reliably evaluated by the modified proportional specimen resistance (MPSR) model of 7.1 GPa and 7.6 GPa, respectively, with a high correlation coefficient of more than 0.9999. This work reveals the unexploited potential of the metastable phase in improving the crystallization ability and mechanical properties of glass-ceramics. [ABSTRACT FROM AUTHOR]

To analyze the influence of the road roughness excitation on vehicle shimmy, a 12 degrees-of-freedom dynamic model of vehicle–road system is developed. The Hopf bifurcation theory is used to study the system stability. On this basis, the natural frequency and modal properties of the vehicle system are elaborated. It can be found that the roll mode plays a crucial role in the vehicle stability. Then, the dynamic shimmy behavior exposed to the sinusoidal and random road roughness excitations is investigated with the help of the modal analysis and the largest Lyapunov exponent. Furthermore, the numerical results are verified through the measurement results, and the influence of the front wheel track on vehicle shimmy is also examined. The results show that the decrease of the front wheel track is an effective way to attenuate vehicle shimmy for different road roughness excitations. [ABSTRACT FROM AUTHOR]

Developing high-performance, low-cost and large-scale absorbent materials is crucial for the treatment of water pollution caused by pollutants leakage and emission. Herein, superelastic and superhydrophobic thermoplastic polymeric nanofibrous aerogels (NFAs) were created for removal pollutants from water by using a facile and effective method. Poly(vinyl alcohol-co-ethylene) (EVOH) nanofibers fabricated by mass-production techniques were used to construct three-dimensional NFAs through combing freeze-drying process and cross-linking treatment. The optimal parameters for creating EVOH NFAs with good formability and resilience, including composition and ratio of dispersion, dosage of cross-linking agent were obtained through experiments. EVOH nanofibers bonded with each other by glutaraldehyde under acidic conditions to from fibrous network structure in EVOH NFAs. The silane-coated EVOH NFAs were prepared through further modification with vapor-phase methyltrichlorosilane. The deposition of siloxane improved mechanical strength and decreased plastic deformation after 500 cyclic compressions. An asperate fibrous and granular siloxane coating was deposited on the surface of EVOH NFAs. The surface water contact angle increased from 104.4° ± 4.0° to 152.7° ± 1.9°, wettability of NFAs transitioned to being superhydrophobic. Silane-coated EVOH NFAs exhibited superior absorption capacity (40–92 g/g) for a variety of organic pollutants. The organic pollutants would be collected and the sorbents could be reused after distillation or squeezing. A successful scale-up of such materials open up a new insight into design polymeric aerogels in low-cost and large-scale with substantial industrial water purification applications. [ABSTRACT FROM AUTHOR]

The release of polycyclic aromatic hydrocarbons (PAHs) during the pyrolysis of corn straw, brown coal, and their mixtures was investigated in this study. The mixing ratios were the essential factor in determining the release and generation of PAHs. Adjustments to the mixing ratio revealed that the activation energy reached its nadir at a corn straw proportion of 75%. As the corn straw proportion increased, PAHs' yield and toxic equivalents decreased. Furthermore, this study elucidated the generation of PAHs in the products by integrating experiments and reaction kinetics calculations. Low-ring and medium-ring PAHs were generated more readily, while the content of high-ring PAHs and product toxicity decreased rapidly upon adding corn straw. Finally, the high oxygen content in corn straw generates oxygen radicals that reduce the concentration of hydrocarbons and benzenes, which mitigates the generation of PAHs and enhances the quality of the resultant oil. • Study of the effect of mixing ratios on the generation of PAHs by co-pyrolysis. • The incorporation of corn straw increases oil yield and reduces PAHs contribution. • The addition of corn straw reduces PAHs content and TEQ. • The synergistic effect of co-pyrolysis at 3:1 inhibits the generation of PAHs. [ABSTRACT FROM AUTHOR]

The dynamic model of the automobile shimmy system considering the sinusoidal road roughness excitation is established, and the response characteristic of the shimmy system is investigated with numerical simulations. Based on the complexification-averaging (CX-A) method, the slow flow equations of the shimmy system are obtained, and the shimmy angle of the front wheel is available on the basis of the analytical solution of the system. In addition, the bifurcation theory is applied to evaluate the stability of periodic solutions of the shimmy system exposed to the road roughness excitation. Finally, the laws of energy transfer between relevant subsystems of the shimmy system at various speeds are analysed. The suppression mechanism of the automobile shimmy by the damping of the steering system and the damping of the suspension at various speeds is also investigated. The conclusions provide theoretical supports for better anti-shimmy design, thereby improving the stability of the automobile. [ABSTRACT FROM AUTHOR]

The modified rock mass classification system for TBM tunnels and tunneling was proposed to assess rock mass quality, rock mass boreability, and TBM construction suitability. However, the section concerning the impact of adverse geological conditions on TBM utilization was not yet finalized. In this study, the classification system was upgraded to the stressed hard rock tunnels by adding the coefficient. A database comprising 551 instances of rockbursts and their corresponding TBM performance data was compiled from the Yinhan Water Conveyance Tunnel in China. The characteristics of rockbursts occurring in the tunnel excavated by TBM and their formation mechanisms were introduced. The depth of damage to the tunnel wall was used as the assessment index for the intensity grade of rockbursts. Quantitative relationships were established between the intensity grade of rockbursts and TBM performance parameters for the first time. As the intensity grade of rockbursts increased, there was a substantial reduction in TBM utilization, while the penetration rate exhibited no significant changes. The reduction coefficient β A for TBM utilization at the rockburst intensity grades, namely minor damage, moderate damage, and severe damage, was determined to be 0.88, 0.60, and 0.39 respectively. These coefficients were subsequently integrated into the classification system. Finally, a simple case was presented to illustrate the applicability of the rockburst reduction coefficient β A and the upgraded system. • The database was established with different grades of rockburst data. • Rockburst impact on rock mass boreability, stability, and TBM process was analyzed. • The quantitative relationships between rockburst and TBM parameters were obtained. • The rockburst reduction coefficient β A on TBM utilization was determined. [ABSTRACT FROM AUTHOR]

Developmental changes in hepatic methionine adenosyltransferase, cystathionine β‐synthase, cystathionase, and glycine N‐methyltransferase were determined in broiler chick embryos and hatched chicks by using radiometric and spectrometric methods. Hepatic free methionine, S‐adenosylmethionine, S‐adenosylhomocysteine, homocysteine, cystathionine, and cysteine levels were also investigated. Results showed an increase in hepatic MAT activity from E10 to E21 during embryogenesis, suggesting greater transmethylation rates throughout the rapid embryonic growth and development period. A strong positive correlation between embryo BW and MAT activity also supports this idea. The MAT specific activity continued to increase after hatching, but there was a negative correlation between chick BW and MAT activities from D1 to D49. This may indicate different MAT isozymes exist for chick embryo hepatic tissue compared to hepatic tissue of hatched chick and growing broilers. The developmental pattern of MAT isozymes could be critical for methionine metabolism to cope with the demand imposed on the embryo, chicks, and growing broilers. Additionally, the specific activity of hepatic CBS in chick embryos was determined to be lower compared to that observed in older broilers (35 and 49 days). Since liver CBS specific activity is at the lowest point from D1‐7 in young chicks, the ability to convert adequate homocysteine to cysteine through transsulphuration may be limiting for cysteine synthesis at this time. Steady‐state hepatic homocysteine levels in chick embryos and chicks may be a function of the rates of homocysteine formation, remethylation, and catabolism via the transsulphuration pathway. The present study indicates young chicks from D1 to D7 may have a limited ability for adequate transsulphuration; therefore, dietary cystine may be needed for optimum performance. [ABSTRACT FROM AUTHOR]

Facial makeup significantly changes the perceived appearance of the face and reduces the accuracy of face recognition. To adapt to the application of smart cities, in this study, we introduce a novel joint subspace and low-rank coding method for makeup face recognition. To exploit more discriminative information of face images, we use the feature projection technology to find proper subspace and learn a discriminative dictionary in such subspace. In addition, we use a low-rank constraint in the dictionary learning. Then, we design a joint learning framework and use the iterative optimization strategy to obtain all parameters simultaneously. Experiments on real-world dataset achieve good performance and demonstrate the validity of the proposed method. [ABSTRACT FROM AUTHOR]

AbstractNitrogen (N) and harvest time are important factors in determining rice production potential. Elucidating reasonable N application rates and the relationship between N rate and harvesting time is necessary to maximize rice yield and efficiency. Two field trials were conducted with four N levels (0, 82.5, 165, and 247.5 kg N ha−1) and five N levels (0, 90, 180, 270, and 360 kg N ha−1) in Shayang (SY) and Wuxue (WX) counties, Hubei Province, respectively. Each was harvested at two time points (T1 and T2), at and after maturation, to investigate grain yield and N use efficiencies of rice. The results showed that the applied N and appropriately adjusted harvesting time significantly increased the grain yield, and compared with zero-N, the N additions increased rice yield by 3.7–26.9% and 8.4–22.5% for the SY and WX sites, respectively. However, with the increase of N application rate, the N use efficiency first increased and then decreased. Effects of harvest time on grain yield and N use efficiency vary with N application rates. At higher N levels, the appropriate delay in harvest time (T2) resulted in an increase in the 1000-grains weight and the rate at which grains were filled. Consequently, this led to an overall increase in grain yield. However, with zero or low N application rates, delayed harvest (T2) resulted in grain abscission, which decreased grain yield. In summary, applying N appropriately significantly increased the rice yield, and adjusting the harvesting time according to the N application rate further increased grain yield and N use efficiency. [ABSTRACT FROM AUTHOR]

The brittle failure induced by high in-site stress occurring at the tunnel face significantly affect the TBM performance. To study the rock mass failure mechanism under the combined effect of high stress and TBM cutters, three groups of true-triaxial rockburst tests were conducted, simulating the failure processes using the loading scheme "one-single face free and the remaining five surfaces loaded". Conditioned granite specimens previously cut by the TBM cutter were prepared, and the different stressed conditions were determined based on the in-situ stress field of the Yinhan water conveyance tunnel. As the confining stress increased, the peak strength of the rock specimen also increased, and the final rupture was more violent, leading to a rockburst. The failure process recorded by the high-speed camera and the failure pattern showed a clear change. The rock conditioned by the TBM cutter was more susceptible to brittle failure under high stress, and the failure depth was greater. The stress-strain curves in the σ 1 direction and the AE characteristics indicated that as the loading stress increased, the damage in the rock changed from a dominant tensile failure to a dominant shear failure, gradually extending to deeper areas of the rock. This alteration changed the rock mass mechanical behavior of the tunnel face, i.e., its stability and boreability, consequently influencing the rock breakage process by TBM cutters. As the severity of failure increased, the TBM performance shifted from a low efficiency rock-breaking performance limited by the cutter thrust to a high efficiency rock-breaking performance limited by the muck capacity and safety control. [ABSTRACT FROM AUTHOR]

The remethylation of homocysteine to methionine is important for chick embryos to sustain the S‐adenosylmethionine transmethylation reactions, which are essential for the rapid proliferation of cells. Developmental changes in hepatic 5‐methyltetrahydrofolate‐homocysteine methyltransferase (MFMT), betaine‐homocysteine methyltransferase (BHMT) and hepatic serine hydroxymethyltransferase (SHMT) were determined in E10‐21 Cobb 500 broiler chick embryos and hatched chicks from D1‐49. Hepatic levels of free serine, glycine, putrescine, spermidine and spermine levels were also determined. Analyses showed hepatic MFMT‐specific activity doubled from E10 to E12, with remaining embryo development experiencing small fluctuations in activity through E21. Hepatic MFMT doubled immediately after hatch, with peak activity occurring at D3. Afterwards, hepatic MFMT‐specific activity steadily declined from D7‐49. Hepatic BHMT activity was higher from E10 to E16 of embryogenesis, decreased rapidly at E17 and remained lower through E21 (p <.05). Hepatic BHMT‐specific activity was also lower in chicks, with the exception of a peak in specific activity on D7. BHMT activity returned to lower levels by D21. Throughout embryogenesis, hepatic SHMT activity in chick embryos remained relatively constant except for a decrease at 13E, followed by an increase at 14E. Maximal activity of SHMT was found the first day post‐hatch. Additionally, SHMT activity was significantly lower in growing chicks than that in embryos. Hepatic‐free serine and glycine levels were negatively correlated with SHMT in hatched chicks. Hepatic polyamine, putrescine and spermidine shared a similar development pattern: peak level in the middle of incubation, low at late embryogenesis and lowest during the post‐hatch period except an increase within one week after hatch. The sharp increase in hepatic concentrations of glycine, serine and putrescine, along with increased specific activities of MHMT, BHMT and SHMT from D1‐7, suggests that methionine conservation (remethylation from homocysteine) and glycine/serine is critical for young chicks for organ growth, maturation, and development. [ABSTRACT FROM AUTHOR]

Quantity–intensity curves were used to evaluate the dynamics of soil potassium (K) at different soil depths under different K management. The equilibrium concentration ratio of K (CR0) increased with increasing K concentration. K fertilization and straw return increased soil K supplying capacity by increasing CR0, non-specific available K (-∆K0) and equilibrium K (CK0). The CR0 increase 107%, 392% and 577% at the 0–20 cm layer and 55%, 102% and 131% at the 20–40 cm layer, respectively, under K fertilization, straw return and the interaction of them. The CK0 and -∆K0 at the 0–20 cm layer significantly increased after K fertilization and straw return. The labile K varied from 0.11 to 0.19 cmol kg−1, contributed 85.3% to 107.6% of NH4OAc extracted K. Soil K potential buffering capacity showed significant differences in soil depths, while little difference was observed under different K management. Th e exchangeable K was meaningless for guiding K application when minimum exchangeable K took up 85.9% to 99.0% of equilibrium exchangeable K. Our results showed K fertilization and straw return was the optimal management to enhance soil K supplying capacity, especially at the 0–20 cm layer. N: nitrogen; P: phosphorus; K: potassium; RS: straw; Q/I: quantity/intensity; CR0: equilibrium concentration ratio of K; KL: labile K; non-specifically available K: -∆K0; PBCK: potential buffering capacity; EK0: equilibrium exchangeable K; CK0: equilibrium solution K; α: magnitude of conversion of added K to exchangeable pool; β: conversion of added K to non-exchangeable K pool; Emin: minimum exchangeable K. [ABSTRACT FROM AUTHOR]

Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibers (flexible and effective bonding together) were combined with stiff and flame-resistant sepiolite nanorods (SEP) to fabricate composite nanofibrous aerogels (NFAs) through a versatile and gelation-free freeze-drying method. The PVA-co-PE nanofibers prepared based on a high-yield Melt-Extrusion-Phase-Separation process could form a continuous fibrous structure, and the fibrous networks and surface wettability of composite NFAs could be tuned by the amount of SEP used. The introduction of an appropriate amount of SEP improved mechanical properties of composite aerogels, while excessive SEP would lead to a decrease in compression strength of them. The mechanical properties of composite NFAs are shown to be governed by a combination of stiffness of SEP and effective bonding of PVA-co-PE nanofibers. More importantly, the presence of SEP can substantially improve flame resistance of aerogels. After a simple thermal chemical vapor deposition treatment with methyltrichlorosilane, the surface of composite NFAs become rougher and siloxane nanoparticles became visible. With this deposition, hydrophilic NFAs became hydrophobic as a significant surface property modification. Furthermore, the maximum stress at 60% strain went up from 15.57 to 19.17 kPa and the resilience of composite aerogels improved. Thermal properties results confirmed silane coating can improve the thermal stability and insulation characteristics of polymeric aerogel. The manufactured NFAs are demonstrated as good thermal insulators (0.0274 W m−1 K−1), excellent refractories, efficient water/oil separators (45–108 g/g, 78.58–91.76%) and reusable absorbers. Consequently, the multifunctional silane-coated PVA-co-PE/SEP composite NFAs could be envisaged for several demanding applications. [ABSTRACT FROM AUTHOR]

Aluminum‐oxygen batteries (AOBs) own the benefits of high energy density (8.14 kWh kg−1), low cost, and high safety. However, the design of a cathode with high surface area, structure integrity, and good catalytic performance is still challenging for rechargeable AOBs. Herein, the fabrication of a robust self‐supporting cathode using 3D graphene aerogel (3DGA) for rechargeable AOBs is demonstrated. Electroanalysis showed that the 3DGA presented good catalytic activity in both oxygen reduction and evolution reactions, which allowed the AOB to operate for >90 cycles with low overpotentials at a current density of 0.2 mA cm−2, and a high Coulombic efficiency of ca. 99% using ionic liquid as electrolyte. In comparison, the cell with the carbon paper cathode can only cycle for 50 rounds. The excellent cyclic performance can be attributed to the porous structure, large surface area, good electric conductivity, and catalytic activity of the 3DGA, which is prospective to be applied for other metal‐air batteries, fuel cells, and supercapacitors. [ABSTRACT FROM AUTHOR]

System structures and developing process of large-scale complex weapon are characterized with networks. Research on risk evolution mechanism is useful to control risk and reduce complexity. Based on dynamic data samples presented by system process modeling and simulations, risk evolution networks was refined by Bayesian learning to recognize correlations among nodes with different risk levels. By this way, subjectivity is reduced than risk networks built only by experience. The risk networks from Bayesian learning was further used to implement Bayesian inference and calculate risk posterior probability distributions of risk network nodes under the conditions of system total risk at high level, and then the critical nodes and propogation chains of risk evolution were identified. Finally, comparing with static characteristics based on complex network characteristic indicators, the differences between dynamic and static characteristics of risk networks were under discussion. It is found that the critical nodes and chains of risk evolution are jointly determined by network structure characteristics and dynamic features of risk evolution. [ABSTRACT FROM AUTHOR]

A method of program load spectrum compilation suitable for ALT (accelerated life test) of parabolic leaf spring was presented. In order to shorten the design and test period, road test is conducted on proving ground roads. The displacement spectrum of shock absorber connecting the point of the parabolic leaf spring seat on a commercial vehicle exposed to roads was obtained. The FEA (finite element analysis) method was used to obtain stress spectrum of hot spots on leaf spring by the displacement spectrum, and the fatigue life of the leaf spring is predicted using Palmgren-Miner's rule. Statistical characteristics of the amplitudes and means of the displacement spectrum is investigated. The amplitudes and means of displacement spectrum found in experiment obey Weibull distribution and normal distribution respectively, and the distributions of amplitudes and means are independent. Based on the Conover principle, the two-dimensional spectrum with eight levels is established by applying the cycle extrapolation method, and then it is converted into one-dimensional spectrum with the variable mean method. Follow the theory of equal damage, the program load spectrum is compiled suitable for bench test of fatigue life of leaf spring. The method of program load spectrum compilation can provide reference for fatigue life test and life prediction of parabolic leaf spring assembly. [ABSTRACT FROM AUTHOR]

In this study, carbon microspheres (CMSs) and magnetic carbon microspheres (MCMSs) were synthesized and applied to remove Se(IV) and Cr(VI) in Se(IV), Cr(VI), and Se(IV)-Cr(VI) coexisting systems, respectively. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Vibrating-sample magnetometry (VSM), and X-ray diffraction (XRD) were employed to investigate the physical properties, compositions, and structures of CMSs and MCMSs. X-ray photoelectron spectroscopy (XPS) was employed to reveal the removal mechanism of Se(IV) and Cr(VI) with MCMSs. Under optimum conditions, 100% Se(IV) and 100% Cr(VI) can be removed by MCMSs in 120 min from Se(IV)-Cr(VI) coexisting system containing initial concentration of 10.0 mg/L Se(IV) and 10.0 mg/L Cr(VI). Cr(VI) was removed due to the hydrogen bonding interaction between Cr(VI) and carboxylate groups and redox reaction of Cr(VI) with alcoholic hydroxyl groups on CMSs. Besides, the Fe 3 O 4 nanoscale particles on the surface of CMSs can form outer-sphere complexes with Cr(VI) and reduce Cr(VI) to Cr(III). Se(IV) can form precipitates with the generated Cr(III). Moreover, the Fe 3 O 4 nanoscale particles can form inner-sphere complexes with Se(IV) and reduce Se(IV) to elemental selenium (Se 0 ) by Fe(II). [ABSTRACT FROM AUTHOR]

Developing high-performance chromatographic media is of great significance for efficient protein adsorption and separation. Herein, the thermoplastic-poly(vinyl alcohol-co-ethylene) (EVOH) nanofibrous membranes (NFMs) were fabricated through structure controlled high-speed flow deposition process from EVOH nanofibrous suspensions. Butane tetracarboxylic acid (BTCA) was grafted onto EVOH NFMs to form chromatographic media by impregnation method. The obtained EVOH/BTCA NFMs with highly tortuous structure, excellent structural stability, good hydrophilicity and abundant active carboxyl groups possess selective absorption to positively charge proteins via electrostatic interaction. With increasing BTCA contents, the absorption capacity (take lysozyme as template protein) increased gradually and achieved a maximum absorption capacity of 749.3 mg/g. Meanwhile, the protein absorption performance of EVOH/BTCA NFMs is optimized by the properties of protein solution, physical properties of substrate EVOH NFMs and grafting temperature. EVOH/BTCA NFMs exhibit good reusability and maintain a relatively stable absorption capacity after 10 absorption-elution cycles. Furthermore, superior acid and alkaline resistance of EVOH/BTCA NFMs was proved through being treated in acid and alkaline solutions for 24 h. EVOH/BTCA NFMs can effectively extract lysozyme from egg white. A successful scale-up of such low-cost and high-performance membranes could provide some insights for the design and development of thermoplastic polymeric nanofibrous-based materials with protein separation and purification. [Display omitted] [ABSTRACT FROM AUTHOR]

Joints with clearance always exist in steering mechanism of vehicles due to the machining tolerances, deformations and wear, which should not be neglected in modeling and analysis of vehicle shimmy system. Based on Lagrange equation method, a six-DOF dynamic model of vehicle shimmy system with consideration of multi-clearance joints was established. The model of movement pairs with clearance was built based on Hertzian contact law. The nonlinear cornering force of pneumatic tire was described based on PAC2002 tire model, and its parameters were obtained by an identification method based on experimental data. Then numerical examples were employed to evaluate the dynamic response of the shimmy system. The influence of multi-clearance joints on the response of shimmy was analyzed, and it is compared with that of one clearance joint. The acting mechanism of contact force between movement pairs was investigated, and global dynamic analysis was carried out by using point mapping method. Moreover, the dynamic mechanism for vehicle shimmy was investigated based on energy input. The conclusions can provide theoretic evidence for attenuation of vehicle shimmy, especially for those in-service vehicles. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3 ) volatilization and nitrogen (N) surface runoff from rice ( Oryza sativa L.) paddies contribute to air and water pollution in China and everywhere else. The purposes of this study were to assess N losses through NH 3 volatilization and surface runoff and to determine the grain yield and N use efficiency (NUE) of early rice in double rice cropping system in southern China. We implemented six treatments viz., control with 0 kg N ha −1 (CK), basal application and split application (1/2 at transplanting, 1/4 at tillering, and 1/4 at panicle stages) of urea (U), and basal applications of three controlled-release urea (CRU) sources (polyurethane-coated urea [CRU-1], degradable polymer-coated urea [CRU-2], and water-based polymer-coated urea [CRU-3]) all applied at 165 kg N ha −1 . Results showed that CRU-1 and CRU-2 significantly reduced NH 3 volatilization (23 to 62%) and N surface runoff losses (8 to 58%) compared with U. Precipitation and ammonium-nitrogen (NH 4 -N) concentration in surface water from rice paddy were predominant factors defining N losses through NH 3 volatilization and surface runoff. Application of CRU reduced NH 4 -N concentration and pH of surface water and N losses through surface runoff. The CRU produced similar (−3 to 4%) or higher (5–16%) rice grain yields and increased NUE (3 to 34%) and N uptake (3–55%) compared with U. Polymer-coated urea can reduce environmental risks of N losses through volatilization and surface runoff while maintaining rice yield and N uptake, it also enhances NUE compared with urea in double rice cropping system in southern China. [ABSTRACT FROM AUTHOR]

A mesoporous composite of magnetic carbon microspheres (MCMSs) was synthesized via introducing Fe 3 O 4 nanoscale particles to the surface of carbon microspheres (CMSs) by coprecipitation. Scanning electron microscopy and transmission electron microscopy showed the Fe 3 O 4 nanoscale particles were dispersedly immobilized on the surface of CMSs. The MCMSs demonstrated effective removal of selenite (Se(IV)) from wastewater. MCMSs showed the regular pattern where the lower pH value, the lower residual Se(IV) concentration. The coexisting sulfate, nitrate, chloride, carbonate, and silicate had no significant effect on Se(IV) removal, whereas phosphate hindered the removal of Se(IV) by competing with Se(IV) and formed inner–sphere complexes with Fe 3 O 4 on the surface of MCMSs. Through X–ray photoelectron spectroscopy analysis, Se(IV) can not only form inner–sphere complexes with MCMSs, but also be reduced to insoluble elemental selenium (Se 0 ) by Fe 3 O 4 which was oxidized and formed γ–Fe 2 O 3 . Moreover, the superparamagnetic MCMSs can be easily separated from solution by means of an external magnetic field. The high removal efficiency for Se(IV) and rapid separability of MCMSs made them promising materials for the application in the practice. [ABSTRACT FROM AUTHOR]

Accurate and nondestructive assessment of leaf nitrogen (N) nutritional status is important for site-specific N management in winter oilseed rape production. To develop a method for determining leaf N concentration (LNC) in oilseed rape, a field experiment with different N fertilizer levels was conducted in two successive years by measuring leaf spectral reflectance (400–1300 nm) and LNC at varying developmental stages. A partial least square (PLS) regression analysis was performed with four spectral methods: (i) the raw spectral reflectance (R), (ii) inverse-log reflectance data (log(1/R)), (iii) continuum removal (CR) method and (iv) first derivative reflectance (FDR). The results indicated that LNC and leaf reflectance significantly varied with the levels of N fertilization, and a good correlation was observed for all the spectral methods. Using a calibration dataset, the best results were obtained with the FDR-PLS method, which yielded the highest coefficient of determination (r 2 cal ) of 0.963, the ratio prediction to deviation (RPD cal ) of 5.207, and the lowest root mean square error (RMSE cal ) of 0.294. Tests with the independent validation dataset also showed that the FDR-PLS method could well predict LNC in oilseed rape, with the values of r 2 val , RPD val , and RMSE val being 0.966, 5.488 and 0.276, respectively. The variable importance in projection (VIP) scores resulting from this PLS regression analysis were used to determine the effective wavelengths and reduce the dimensionality of the spectral reflectance data. The newly-developed FDR-PLS model using the effective wavelengths (432, 467, 519, 614, 772, 912 and 1072 nm) performed well in LNC prediction with r 2 val = 0.884, RPD val = 2.971 and RMSE val = 0.508. The overall results indicate that the LNC of winter oilseed rape could be reliably estimated with the in situ developed FDR-PLS method in this study. [ABSTRACT FROM AUTHOR]

Leaves exposed to potassium (K) deficiency usually present decreased mesophyll conductance ( gm) and photosynthesis ( A). The relative contributions of leaf anatomical traits in determining gm have been quantified; however, anatomical variabilities related to low gm under K starvation remain imperfectly known. A one-dimensional model was used to quantify anatomical controls of the entire CO2 diffusion pathway resistance within a leaf on two Brassica napus L. cultivars in response to K deficiency. Leaf photosynthesis of both cultivars was significantly decreased under K deficiency in parallel with down-regulated gm. The mesophyll conductance limitation contributed to more than one-half of A decline. The decreased internal air space in K-starved leaves was associated with the increase of gas-phase resistance. Potassium deficiency reduced liquid-phase conductance by decreasing the exposed surface area of chloroplasts per unit leaf area ( Sc/ S), and enlarging the resistance of the cytoplasm that can be interpreted by the increasing distance of chloroplast from cell wall, and between adjacent chloroplasts. Additionally, the discrepancies of A between two cultivars were in part because of gm variations, ascribing to an altered Sc/ S. These results emphasize the important role of K on the regulation of gm by enhancing Sc/ S and reducing cytoplasm resistance. [ABSTRACT FROM AUTHOR]

In this paper, the performance and application of zero-valent iron (ZVI) assisted by ultrasonic irradiation for the removal of selenite (Se(IV)) in wastewater was evaluated and reaction mechanism of Se(IV) with ZVI in such systems was investigated. A series of batch experiments were conducted to determine the effects of ultrasound power, pH, ZVI concentration, N 2 and air on Se(IV) removal. ZVI before and after reaction with Se(IV) was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results indicated that ultrasound can lead to a significant synergy in the removal of Se(IV) by ZVI because ultrasound can promote the generation of OH and accelerate the advanced Fenton process. The primary reaction products of ZVI and Se(IV) were Se 0 , ferrihydrite, and Fe 2 O 3 . [ABSTRACT FROM AUTHOR]

Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N) mineralization. The quantity and quality of particulate organic matter (POM) and potentially mineralizable-N (PMN) contents were measured in soils from 16 paired rice-rapeseed (RR)/cotton-rapeseed (CR) rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile), intermediate (25th and 75th percentiles), and high (90th percentile) levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C) and N (POM-N) contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN) contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively) than CR rotations (45.6% and 19.5%, respectively). Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials) in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils. [ABSTRACT FROM AUTHOR]

Crop rotations play crucial roles in maintaining soil fertility and crop productivity. However, crop nitrogen (N) fertilizer management under different rotation systems has not been well assessed. A total of 194 field experiments with different N application rates were conducted around the Yangtze River Basin with the objective of supporting rice N fertilizer management in rapeseed-rice (RR) and wheat-rice (WR) rotations. In the present study, a soil quality index (SQI) based on soil chemical parameters was adopted to estimate the indigenous N supply under different crop rotations. The optimum N application rate for rice in the two rotations with different SQI values was also further analyzed. The results indicated that rice yields under RR rotation were significantly higher than those under WR rotation, especially in the no N (N 0) and low N (LN) treatments. The RR rotation also improved the partial factor productivity of N (PFP N). The rice yield of the N 0 treatment was significantly positively correlated with the SQI value, indicating that the SQI value could be used to evaluate the indigenous N supply capacity of the soil. The SQI value of the RR rotation was 19.4% higher than that of the WR rotation. Principal component analysis (PCA) showed that soil organic matter, total nitrogen, and alkali-hydrolyzable nitrogen were the three most important factors affecting the SQI. Compared with the WR rotation, the soil organic matter, total nitrogen, and alkali-hydrolyzable nitrogen contents in the RR rotation were 24.1%, 16.8%, and 39.7% higher, respectively. With the increase in the SQI value, the optimum N application rate decreased. In soils with the same SQI value, the RR rotation required less N fertilizer input to achieve the same rice yield, and the optimum N application rate was 18.9 kg ha-1 lower than that in the WR rotation, especially in low-SQI soils. Therefore, rapeseed as a previous crop in rotation could enhance soil fertility and consequently improve rice yield, ultimately reducing N fertilizer application. • The rice yield of RR rotation was higher than that of WR rotation. • Compared with WR rotation, RR rotation improved the soil quality index. • The soil quality index can be used to evaluate the soil N supply capacity. • Rapeseed, as a previous crop in rotation, can reduce the input of N fertilizer for rice. [ABSTRACT FROM AUTHOR]

An Occupant Protection System (OPS) has very important applications in an automobile accident, which can save an occupant from fateful hurt or death. To provide a feasible framework for decreasing occupant injury degree, this paper presents a practical approach of the Reliability-based Design Optimization (RBDO) for vehicle OPS performance development based on the ensemble of metamodels. The weight factors of the ensemble associated with each metamodel are determined using a heuristic method. The comparative result shows that the prediction accuracies of the ensemble of metamodels exceed all individual one. Generally, the deterministic optimum designs without considering the uncertainty of design variables frequently push design constraints to the limit of boundaries and lead objective performance variation to largely fluctuate. So, the RBDO is presented and aims to maintain design feasibility at a desired reliability level. The First Order Reliability Method (FORM) and Second Order Reliability Method (SORM) are used to calculate the reliability index, and the results are checked by Monte Carlo (MC) simulation respectively, from which the failure probability of the OPS performance design is obtained. The result demonstrates that the reliability design is more reliable than the deterministic optimization in real engineering application. Finally, the reliability-based design optimization result is validated by the simulation result, which shows that the proposed RBDO approach is very effective in obtaining an optimum design. [ABSTRACT FROM AUTHOR]

Highlights: [•] First, we have shown that upregulated of the Loc554202 in breast cancer tissues. [•] Second, we demonstrated the function of Loc554202 in breast cancer cell. [•] Finally, we demonstrated that LOC554202 knockdown could inhibit tumor growth in vivo. [ABSTRACT FROM AUTHOR]

Highlights: [•] Straw mulching improved soil water and temperature conditions. [•] Straw mulching increased dry matter and N uptake of oilseed rape at seedling stage. [•] Effects of straw mulching on oilseed rape growth decreased after seedling stage. [•] Yield response of oilseed rape to straw mulching was different in two seasons. [•] Straw mulching led to more topdressing N loss through ammonia volatilization. [ABSTRACT FROM AUTHOR]

Straw application can not only increase crop yields, improve soil structure and enrich soil fertility, but can also enhance water and nutrient retention. The aim of this study was to ascertain the relationships between straw decomposition and the release-adsorption processes of K+. This study increases the understanding of the roles played by agricultural crop residues in the soil environment, informs more effective straw recycling and provides a method for reducing potassium loss. The influence of straw decomposition on the K+ release rate in paddy soil under flooded condition was studied using incubation experiments, which indicated the decomposition process of rice straw could be divided into two main stages: (a) a rapid decomposition stage from 0 to 60 d and (b) a slow decomposition stage from 60 to 110 d. However, the characteristics of the straw potassium release were different from those of the overall straw decomposition, as 90% of total K was released by the third day of the study. The batches of the K sorption experiments showed that crop residues could adsorb K+ from the ambient environment, which was subject to decomposition periods and extra K+ concentration. In addition, a number of materials or binding sites were observed on straw residues using IR analysis, indicating possible coupling sites for K+ ions. The aqueous solution experiments indicated that raw straw could absorb water at 3.88 g g−1, and this rate rose to its maximum 15 d after incubation. All of the experiments demonstrated that crop residues could absorb large amount of aqueous solution to preserve K+ indirectly during the initial decomposition period. These crop residues could also directly adsorb K+ via physical and chemical adsorption in the later period, allowing part of this K+ to be absorbed by plants for the next growing season. [ABSTRACT FROM AUTHOR]

A 5-DOF dynamic model of vehicle shimmy system with clearance in universal joint of steering handling mechanism is presented. The sub model of cross shaft universal joint with clearance is built based on Hertz' theory, and two-state model is applied to describe the contact force. The sub model of the universal joint is combined with the simplified dynamic model of steering system, and a 5-DOF dynamic model of vehicle shimmy system with consideration of assembling clearance in universal joint of steering handling mechanism is presented. Based on this model, numerical analysis is carried out to evaluate the influence of clearance in universal joint on the dynamic behavior of the vehicle shimmy system. The results show that the clearance and some other parameters, such as vehicle speed, have coupled contribution to the dynamic behavior of the vehicle shimmy system. The conclusions provide theoretical basis for effective attenuation of vehicle shimmy, especially for those in-service vehicles. [ABSTRACT FROM AUTHOR]

• The response of TBM performance parameters in typical stressed rock mass are revealed. • The database is established with a wide range of rock mass parameters and TBM data. • An index based on TBM tunneling to assess stress-induced failure in real-time is proposed. The initial stress of the surrounding rock mass will be redistributed during TBM tunneling in a deep tunnel. This process may induce brittle failure of the surrounding rock mass, which has a great impact on TBM construction. The southern section of the Yinhan Water Conveyance Tunnel is mainly composed of massive to intact granite, with a maximum overburden depth of nearly 2000 m. The paper discussed in detail the relationship between various brittle failure degrees at the typical tunnel faces and TBM performance. The typical patterns, such as undamaged, slabbing, and strain rockburst at the tunnel face, and the corresponding characteristics of the TBM performance parameters were revealed. As the severity of damage increases, the rock mass boreability is improved, the cutterhead thrust is reduced, and the penetration increases, but there is an upper limit. It is noteworthy that the field penetration index (FPI) fluctuation expressed by the coefficient of variation (CV) varies significantly in different stress states. Based on the excavation response of TBM, a Rockburst Warning Index (RWI) was proposed to assess the brittle failure degree of the excavated rock mass in real-time. The results of the study can provide some insights into the prediction of TBM performance and the early warning of rockburst in deep-buried hard rock grounds. [ABSTRACT FROM AUTHOR]

Lithium aluminosilicate glass-ceramics (LAS GCs) are ideal shell materials for mobile phones; however, the mechanical properties of LAS GCs are comparatively lower than that of other shell materials. In this work, the impact of TiO2/(TiO2 + ZrO2) ratio on properties of LAS GCs was studied and the ion-exchange methods were applied to improve the mechanical properties of LAS GCs. The results show that LAS GCs with TiO2/(TiO2 + ZrO2) = 1/2 exhibit the best flexural strength (109 MPa) and Vickers hardness (525 Kg/mm2). The as-prepared glass was nucleated at 560 °C for 1 h and crystallized at 720 °C for 0.5 h. The main crystalline phases of LAS GCs are β-quartz solid solution, β-spodumene solid solution, and Li2SiO3. Moreover, the flexural strength and Vickers hardness of LAS GCs with TiO2/(TiO2 + ZrO2) = 1/2 further increased to 356 MPa and 838 Kg/mm2 after an ion-exchange at 420 °C for 6 h in pure KNO3 molten salt. The LAS GCs with enhanced mechanical strength have the potential to be applied as mobile phone back panels. [ABSTRACT FROM AUTHOR]

Optimal potassium (K) fertilization is beneficial for oilseed-rape ( Brassica napus L.) yield and quality. However, the discrepancy between the high K demand of winter oilseed rape and low soil fertility and insufficient potassium input has limited the sustainable development of oilseed-rape production. A series of on-farm experiments in the key winter oilseed-rape domains of China was conducted from 2004 to 2010 to evaluate K-fertilizer management for winter oilseed rape. Currently, the average NH4OAc-extractable K content in the 0-20 cm soil layer is 89.1 mg kg-1 indicative of 'slight deficiency'. In addition, farmers in China usually fail to use sufficient K fertilizer in oilseed-rape production, the average mineral-potassium-fertilizer input in 2010 being only 35 kg K ha-1, far lower than the recommended rate of potassium for winter oilseed rape. Adequate potassium fertilization significantly raises seed yield. The average yield-increase rate for the major production regions due to K-fertilizer application was 18.5%, and the average K fertilizer-use efficiency 36.1%. Based on the negative correlation between yield response to potassium fertilization and available soil K content, a soil-K-test index was established for winter oilseed rape with a threshold value for NH4OAc-extractable soil K of 135 mg kg-1. When available soil K-content is below this threshold value, more K fertilizer should be applied to achieve high seed yield and to increase soil fertility. The major challenge for K-fertilizer management in winter oilseed-rape production in China will be to guide farmers in the different regions in making reasonable use of K fertilizer through soil K-testing technology in order to maintain both seed yield and soil fertility. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogen (N) is an essential nutrient that requires careful management in intensive rice systems, since insufficient amounts might result in yield losses, and excessive application might harm the environment. However, farmers often tend to apply a large excess of N fertilizer to ensure high rice yields, primarily because of the absence of reliable methods to estimate optimal N application rates. Therefore, a large-scale study comprising 514 field experiments for rice was conducted in seven rice regions (totaling 1.253millionha) in Hubei province, Central China. We (i) evaluated yield responses to different N application levels, (ii) established indigenous soil N supply (INS) classification systems for different rice regions by identifying and using the preferable predictor of INS, and (iii) determined the optimal N application rates for each region based on regional mean optimal N rates (RMONR) in combination with INS. In all of the rice regions, rice yields were significantly higher in plots receiving N than in plots without N (termed no-N plots). The highest yields were obtained in plots receiving medium nitrogen (MN) treatment, where the average partial factor productivity (PFPN) and agronomic efficiency (AEN) were 50.4kggrainkg−1 N and 12.5kggrainkg−1 N, respectively. Yield responses of rice to N fertilizer were different among different rice regions because of regional variations in climatic conditions and soil fertility. A significant positive relationship between grain yield with and without N fertilizer also proved an important effect of INS on yield response to N fertilizer. On the basis of regression models, relative yields of 90%, 80%, 70%, 60%, and 50% were used as the critical values to obtain INS classifications, which were estimated by the yield of the no-N treatment but not by alkaline hydrolyzable-N. An obvious increasing trend of economic optimum N rate (EONR) with decreasing INS (from Class 1 to Class 6) was found for each rice region. Averaged across all rice regions of Hubei province, EONR was 150kgha−1, which was lower than the N application rate for the MN treatment of 171kgha−1. The results indicated that the N application rate recommended by local rice technicians could be cut by 12% (1–18% in different rice regions) without any loss of yield. In conclusion, the recommended N fertilizer application, based on RMONR in combination with INS, is feasible for regional rice production in China and other countries that have large numbers of small farmland areas and where agricultural testing equipment is absent or less modern. [Copyright &y& Elsevier]

Although extensive investigations of biogenic and geological calcium phosphate crystallization/dissolution and their phase transformations have been performed, the mechanisms of crystallization and dissolution of sparingly soluble calcium phosphates in geological settings have not been completely determined at the near-molecular level. In particular, an understanding of the physical-chemical processes at the earliest nucleation stage and the subsequent crystal surface dynamics in soil solutions is lacking. This review focuses on the earliest events in homo/heterogeneous nucleation from an initial supersaturated solution phase, the subsequent growth of calcium phosphate phases, and the relevant influences of the presence of additional inorganic and organic molecules in both geological and biological settings. These studies have implications for the understanding of the complex processes of calcium phosphate transformations in soils, and provide possible physical-chemical mechanisms for the biogeochemical behavior of phosphorus at the near-molecular level. [ABSTRACT FROM AUTHOR]

Abstract: The integrated structural design and noise attenuation of flexible linkage mechanism is studied in this paper. Based on wave-number analysis of the structures, the acoustic radiation performance of the flexible linkage mechanism can be valued with the vibration of a “virtual linkage mechanism”. The integrated structural design and control design is carried out to attenuate the acoustic radiation of the mechanism. In which, the thickness of the links and the parameters of control system are taken as independent design variables simultaneously. The weighted sum of structural mass, acoustic radiation energy of the mechanism, and energy cost of the control system is taken as the performance index, and optimization is carried out based on the modified constrained variable metric method. At last, simulation is carried out to verify the method presented. [Copyright &y& Elsevier]

Abstract: The sensitive composite material was prepared by loading Pt and La2O3 into ultrafine In2O3 matric material (8nm) synthesized by microemulsion method. A highly selective ethanol gas sensor was developed based on hot-wire type gas sensor, which was sintered in a bead (0.8mm in diameter) to cover a platinum wire coil (0.4mm in diameter). The gas sensor was operated by a bridge electric circuit. The influences of La2O3 and Pt additives on C2H5OH sensing properties of In2O3-based gas sensor were discussed. The addition of La2O3 resulted in a prominent selectivity for C2H5OH, and the addition of Pt improved the response rate to C2H5OH without affecting the sensitivity. The temperature and humidity characteristics of the sensor output were also investigated. The selective sensor had low power consumption, significantly minor humidity and temperature dependence, high selectivity and prominent long-term stability. [Copyright &y& Elsevier]

An active noise control method for flexible linkage mechanism systems with piezoelectric actuators and strain gauge sensors is studied. By employing a set of wave number transformations on the original equations of motion of the flexible linkage mechanisms, a new set of equations of motion is obtained, in which the unknown variables can describe the structural acoustic radiation level of the mechanism system directly. On the basis of the new equations, the active noise control of the flexible linkage mechanism system with piezoelectric actuators is discussed. Firstly, the optimal control forces are determined based on the optimal control theory. Secondly, the controller of the system that consists of the output feedback and the disturbance feed-forward control laws is presented. Simulations show that the method presented in this paper is valid. [Copyright &y& Elsevier]

To design a dialogue model and standard artificial programming interface (API), this paper designs an intelligent dialogue support for medical service systems and improving hospital intelligent serviceability, which combines patient pre-diagnosis, diagnosis, and post-diagnosis services with artificial intelligence depth. This is done via an intelligent man–machine dialogue support platform (MMDSP) suitable for medical services based on a multi-dimensional disease model and outpatient knowledge base with artificial intelligence. As a result of the intelligent service capability of the hospital service systems and platforms, patients’ medical experiences have significantly improved. The platform standardizes the multi-channel service process, improves patient service efficiency, and reduces the cost of human resources and business knowledge learning. In addition, the integration of intelligent multi-system service information provides data support for hospitals to serve patients accurately and has good application and promotion value. [ABSTRACT FROM AUTHOR]

Polypeptoids with well-designed structures have the ability to self-assemble into nanomaterials, which have wide potential applications. In this study, a series of diblock copolypeptoids were synthesized via ring-opening polymerization followed by click chemistry and exhibited both temperature and pH stimulation responsiveness. Under specific temperature and pH conditions, the responsive blocks in the copolypeptoids became hydrophobic and aggregated to form micelles. The self-assembly process was monitored using the UV-Vis and DLS methods, which suggested the reversible transition of free molecules to micelles and bigger aggregates upon instituting temperature and pH changes. By altering the length and proportion of each block, the copolypeptoids displayed varying self-assembly characteristics, and the transition temperature could be tuned. With good biocompatibility, stability, and no cytotoxicity, the polypeptoids reported in this study are expected to be applied as bionanomaterials in fields including drug delivery, tissue engineering, and intelligent biosensing. [ABSTRACT FROM AUTHOR]

The development of nontoxic and efficient antifreeze agents for organ cryopreservation is crucial. However, the research remains highly challenging. In this study, we designed and synthesized a series of peptoid oligomers using the solid-phase submonomer synthesis method by mimicking the amphiphilic structures of antifreeze proteins (AFPs). The obtained peptoid oligomers showed excellent antifreeze properties, reducing the ice crystal growth rate and inhibiting ice recrystallization. The effects of the hydrophobicity and sequence of the peptoid side chains were also studied to reveal the structure–property relationship. The prepared peptoid oligomers were detected as non-cytotoxic and considered to be useful in the biological field. We hope that the peptoid oligomers presented in this study can provide effective strategies for the design of biological cryoprotectants for organ preservation in the future. [ABSTRACT FROM AUTHOR]

The rock mass classification methods developed to evaluate rock mass stability and tunnel support design for blast and drill tunnels are not suitable to guide tunneling by tunnel boring machine (TBM), such as selection of TBM types, determination of construction scheme and so on. By comprehensively considering the rock mass boreability and stability, a modified rock mass classification system for TBM tunnels is proposed on the basis of the hydropower rock mass classification (HC) method of China. The input parameters are five rock mass parameters as the same as the HC method. In addition, the tunnel diameter is needed to estimate the TBM advance rate. The structure and parameter determination of the classification system are explained and statistically analyzed in details. This system can be applied to evaluate the feasibility of TBM construction and serve as the basis for selection of TBM types and design parameters in the pre-construction phase. Furthermore, it can also be applied to estimate TBM performance and guide tunnel support for a given ground condition in the design phase, and to optimize TBM operational parameters during the construction phase as well. An example is presented to illustrate the application of the proposed system. The limitations of the proposed system and further studies are also discussed. • A modified rock mass classification system for TBM tunnels and tunneling is developed. • The system has the characteristics of simple input parameters and structure. • The system can estimate the rock mass stability, boreability and TBM applicability. • The database is established with a wide range of rock types and rock mass parameters. [ABSTRACT FROM AUTHOR]

To determine the impact of K fertilization on crop yields and soil K supplying capacity in rice (Oryza sativa L.) and oilseed rape (Brassica napus L.) rotation, four field experiments were conducted with five K fertilizer rates: 0 (K0), 90–147 (K1), 180–210 (K2), 270–300 (K3) and 336–390 (K4) kg K2O ha−1 per rotation. Compared with K0, adding K increased the yield of rice and oilseed rape by 4.2–8.9% and 7.5–32.6%, respectively. Potassium fertilization increased K uptake at four sites, whereas yields remained stagnant in K2, K3, and K4 treatments despite increasing K uptake. Continuous K removal decreased soil K supplying capacity. For the 0 to 20 cm and 20 to 40 cm soil depths, the NH4OAc-K and boiling HNO3-K at the harvest were decreased in K0 and K1 treatments, whereas it maintained or increased in K2, K3, and K4 treatments, although negative K balances were recorded at all sites. It suggests that application 180–210 kg K2O ha–1 in rice-oilseed rape cropping systems improved crop yield and maintained soil potassium fertility. [ABSTRACT FROM AUTHOR]