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Capital is the most basic element of production organization, and green bonds are important financing sources for the green industry. Financingcosts directly affect the steady development of the green industry. In order to verify whether third-party certification can reduce the financing cost of green bonds and whether the nature of property rights has an impact on the reduction, 285 green bonds issued from 2016 to 2019 are taken as samples, and then a hierarchical multiple statistical regression analysis method is adopted to conduct a quantitative study. The results show that third-party certification, as a unique credit enhancement method for green bonds, can significantly reduce green bond spreads. In addition, it isgreater that the effect on non-state-owned enterprises’ green bonds is. Since bond spread isamain part of financing costs, the above means that third-party certification can reduce the financing costs of green bonds, especiallyfor non-state-owned enterprises. In this regard, starting from reducing the cost of green bonds, the paper proposes to improve the green bond evaluation and certification standards as soon as possible, non-state-owned enterprises particularly should actively carry out third-party certification, and the government needs to further increase the implementation of third-party certification as well as strengthen multi-party cooperation.

An approach, i.e., atmospheric-pressure nonequilibrium oxygen plasma jet technology, has been reported for the first time to in situ prepare ultrathin nonstoichiometric nickel oxide layers with mix...

A plasma assisted phosphorization method has been developed for preparation of multi-phase materials with rich crystalline interfaces and oxygen vacancies. Specifically, P-NiMoP nanorods (NRs) comprising tri-phases of MoP2, Ni3P and MoO2 have been synthesized by plasma-assisted phosphorization of NiMoO4 NRs. The specific features of the plasma technique provide P-NiMoP NRs with rich crystalline interfaces and oxygen vacancies in MoO2. P-NiMoP NRs are demonstrated to be a stable and efficient catalyst for the hydrogen evolution reaction (HER). They only need overpotentials of 3 and 162 mV to drive current densities of 10 and 150 mA cm−2, both of which are lower than those of Pt/C. The DFT calculations indicate that the tri-phase structure with rich crystalline interfaces and oxygen vacancies plays an important role in the high catalytic activity of P-NiMoP NRs. It promotes a strong electronic coupling between MoP2, Ni3P and MoO2, which facilitates H2O adsorption and dissociation and reduces the |ΔGH*| value.

Over the past decades, controversial and conflict-laden water allocation issues among competing domestic, industrial and agricultural water use as well as urban environmental flows have raised increasing concerns (Huang & Chang, 2003); Particularly, Such competition has been exacerbated by the growing population, rapidly economic growth, deteriorating quality of water resources, and shrinking water availability due to a number of natural and human-induced impacts. A sounding strategy for water resources allocation and management can help to reduce or avoid the losses which are caused by water resources scarcity. However, in the water management system, many components and their interactions are uncertain. Such uncertainties could be multiplied not only by fasting changes of socioeconomic boundary conditions but also by unpredictable extreme weather events which caused by climate change. Thus, water resources management should be able to deal with all challenges above. Therefore, an effective integrated approach is desired for urban water adaptive management. Many methods, such as stochastic, fuzzy, and interval-parameter programming techniques, have been employed to counteract uncertainties in different fields of water management and have made great progresses in managing uncertainties in model scale. Water resource is an integral part of the socio-economic-environmental (SEE) system, which is a complex system dominated by human. In order to reach a sounding decision, it is necessary for decision-makers to obtain a better understanding of the significant factors that shape the urban and the way the water resources system reacting to certain policy. Therefore, study of sustainable water resource management should be based on general system theory that addresses dynamic interactions amongst the related social-economic, environmental, and institutional factors as well as non-linearity and multi-loop feedbacks. System dynamics (SD) aims at solving of complex systems problems by simulating development trends of the system and identifying the interrelations of each factor in the system. This will help to explore the hidden mechanism and thus improve the performance of the whole system. Hence, after proposed by W. Forrester (Forrester, 1968), SD model has been widely used in global, national, and regional scales for sustainability assessment and system development programme (Meadows 1973; Mashayekhi, 1990; Saeed, 1994). Due to

In this work, an in situ plasma method is developed for the synthesis of Fe•Li-antisite-free LiFePO4 nanoparticles with full nitrogen-doped carbon coating (NC) and graphitic nanosheet support (LFP@NC/GNS). Briefly, plasma discharge promotes in-situ formation of graphitic nanosheets on LFP@NC via Fe0-catalyzed glucose pyrolysis and simultaneously removes Fe•Li antisites in LFP. The resultant LFP@NC/GNS shows enhanced reversible capacities as a cathode material for Li-ion batteries. Even at the super-high current rate of 150 C, LFP@NC/GNS still delivers a stable reversible capacity of 100.7 mAh g−1. Furthermore, LFP@NC/GNS exhibits a super-long cycling stability with no apparent capacity drop when charged/discharged at 10 C and 100 C for 1200 cycles. The absence of the Fe•Li antisites is expected to play a significant role in the high performance of LFP@NC/GNS because it provides further expedited Li+ diffusion paths in the LFP lattices, thereby allowing for ready migration of Li+ ions and better utilization of LFP. The full NC coating and GNS support also aid the performance of LFP@NC/GNS significantly because both can improve the Li storage kinetics and utilization of the active material.

Bifunctional catalyst, which presents excellent electrocatalytic activity for oxygen reduction/evolution reaction (ORR/OER), is the key factor to explore the rechargeable Zn-air batteries (ZABs) with excellent performance and high stability. Herein, the polyaniline is coated on the outer surface of N-doped graphene hollow spheres (NGHS), which can further form the N-doped carbide (CNx) through the high temperature calcination process. The prepared CNx decorated N-doped graphene hollow spheres (CNx-NGHS) could enhance the conductivity of substrate material caused by the doping of N atoms, and the stretchy 3D hollow structure can prevent the deformation and collapse of fabricated electrode catalyst during the charge/discharge processes. Furthermore, the doped N atoms, acting as active sites, could facilitate the nucleation and growth of the core/shell metals/oxides nanoparticles on the surface of the CNx-NGHS, and at the same time enhance the interaction between metals/oxides nanoparticles and CNx-NGHS, both of which are helpful for promoting the electrocatalytic activity. Based on the investigation results, it can be concluded that CNx-NGHS loaded Co/CoO core/shell nanoparticles (Co/CoO/CNx-NGHS) show obvious better bifunctional electrocatalytic performance than that of CNx-NGHS supported Ni/NiO core/shell nanoparticles (Ni/NiO/CNx-NGHS). The synthesized Co/CoO/CNx-NGHS presents the lowest ΔE (~0.728) (ΔE= Ej10-E1/2), which indicates the better bifunctional electrocatalytic activity. The ZAB equipped with the Co/CoO/CNx-NGHS catalyst can deliver a maximum power density of 117 mW cm−2, which is larger than that of commercial 10% Pt/C (95 mW cm−2). The specific capacity of the Co/CoO/CNx-NGHS at both 100 and 200 mA cm−2 can reach ~99% of the theoretical capacity (~824 mAh g−1). Moreover, a minimum visible voltage loss can be seen for the synthesized Co/CoO/CNx-NGHS after cycled for 100 h, indicating the good durability and stability. All investigated results demonstrated that the outperformance of the fabricated Co/CoO/CNx-NGHS catalyst makes it a potential choice to replace the noble metal/carbon-based materials.

This work reports a novel approach for the synthesis of FeCo alloy nanoparticles (NPs) embedded in the N,P‐codoped carbon coated nitrogen‐doped carbon nanotubes (NPC/FeCo@NCNTs). Specifically, the synthesis of NCNT is achieved by the calcination of graphene oxide‐coated polystyrene spheres with Fe3+, Co2+ and melamine adsorbed, during which graphene oxide is transformed into carbon nanotubes and simultaneously nitrogen is doped into the graphitic structure. The NPC/FeCo@NCNT is demonstrated to be an efficient and durable bifunctional catalyst for oxygen evolution (OER) and oxygen reduction reaction (ORR). It only needs an overpotential of 339.5 mV to deliver 10 mA cm−2 for OER and an onset potential of 0.92 V to drive ORR. Its bifunctional catalytic activities outperform those of the composite catalyst Pt/C + RuO2 and most bifunctional catalysts reported. The experimental results and density functional theory calculations have demonstrated that the interplay between FeCo NPs and NCNT and the presence of N,P‐codoped carbon structure play important roles in increasing the catalytic activities of the NPC/FeCo@NCNT. More impressively, the NPC/FeCo@NCNT can be used as the air‐electrode catalyst, improving the performance of rechargeable liquid and flexible all‐solid‐state zinc–air batteries., The FeCo alloy nanoparticles embedded in the N,P‐codoped carbon coated nitrogen‐doped carbon nanotubes (NPC/FeCo@NCNT) have been synthesized and demonstrated to be efficient and durable catalysts for oxygen evolution and reduction reactions. It is usable as the air‐electrode catalysts to improve the performance of rechargeable liquid and flexible all‐solid‐state zinc–air batteries.

With the increasing of network attacks, the traditional machine learning method can not solve the classification problem of massive intrusion data effectively. This paper proposes a Xgboost based on stacked sparse autoencoder network(SSAE-XGB) method to learn latent representation of original data. Due to inconsistent category distribution of training and test dataset, we use the sparsity constraint to enhance the generalization ability of the model. Stacked sparse autoencoder network is employed to reduce the dimension of high-dimensional and unlabeled original data, so as to obtain the deep feature representation of the original data. Due to the class imbalance of intrusion data, this paper proposes a novel hybrid classifier, which is constructed by using binary tree and ensemble method. Our experiments with all NSL-KDD dataset demonstrate that our proposed SSAE-XGB binary tree and ensemble method can achieve incredibly high performance in terms of F1 and it outperforms the previous work.

An approach to optimize the wheel reprofiling of a high-speed electric multiple unit (EMU) train is presented; it has three functions as objectives: the critical speed of the train, the contact stress that affects the contact fatigue of wheel/rail wear and the diameter of the nominal rolling circle of the wheel. The vertical coordinates of the control points on the curve of the wheel profile are used as design variables and the upper and lower values of each control point are utilized as additional limiting conditions of the curve, with the height, thickness and contact angle of the wheel flange as well as the derivative of the curve acting as constraints on the geometry parameters. A multi-objective optimization model is established for the wheel reprofiling of a high-speed EMU train; three models are created: standard, worn and optimized wheel profiles. Comparisons of wheel/rail contact, running stability and curving performance of the vehicle are performed. It is shown that the wheel profile obtained from the reprofiling optimization model satisfies the constraints and its corresponding dynamic performance has a good agreement with that of a standard wheel profile with a 30 mm thick wheel flange. A performance close to that of a standard wheel profile can be obtained even though the worn wheel is not reprofiled to have the standard profile. Also, the amount of diameter reduction in the direction of the nominal rolling circle is reduced and service life-time is extended by employing the proposed wheel reprofiling approach based on the multi-objective optimization strategy.

Establishing the 1/4 vehicle mathematical model based on the nonlinear model of semi-active suspension system for high speed trains, the PID controller and the fuzzy adaptive PID controller were set up respectively on the semi-active suspension system, and the simulations of the high-speed train were carried out under the condition of passive suspension and the semi-active suspension based on the algorithm of the fuzzy adaptive PID control to compare the stability of the high-speed vehicle under these two cases. Results of the simulation show that: the stability and the comfortableness of the high-speed can be improved effectively by using the semi-active suspension with fuzzy adaptive PID control method.

At normal temperature and pressure, pulse corona plasma was used as a new method for the dehydrogenative coupling of methane in the absence of oxygen. The effects of voltage polarity and input energy on the dehydrogenative coupling of methane were investigated. The parameter “energy efficiency” was introduced to examine the coupling of the input energy and the dehydrogenative coupling of methane. The experimental results show that positive corona gives higher energy efficiency than negative corona. When the positive corona was chosen, C2 yield per pass was 31.6% and acetylene yield per pass was 30.1% with 44.6% methane conversion at an input energy density of 1788kJ/mol and a pulse repetition frequency of 66Hz. The function of input energy density towards methane conversion may be expressed as a formula of-In(1-X) =k (PIF). In the range of input energy employed, C2 yield is proportional to input energy density, but energy efficiency drops off with increasing input energy density.

To investigate the influence of flexibility of wheelset in high-speed rotation on vehicle dynamics performance, the finite element model of wheelset was established and its unconstrained modal analysis was carried out correspondingly to obtain modal information using modal synthesis method. The flexible wheelset-rigid rail contact mechanics model was established according to multi-body system dynamics theory. Based on the flexible wheelset-rigid rail contact mechanics model, the vehicle-track coupled dynamics model containing high-speed rotating flexible wheelsets was established, and researches on influence of structural vibration of flexible wheelset on vehicle dynamics performance were performed when running on tangent and curved track. Results show that the structural vibration of high-speed wheelset has an obvious influence on the position of wheel-rail contact point, creepages, and creep forces and derailment coefficient. Thus, the more accurate flexible wheelset-rail coupled model is essential to be employed to research the interaction of wheel and rail, wheel-rail rolling contact fatigue and wheel-rail noise.

In this paper, fault tree analysis method and Bayesian network are introduced briefly. To overcome the restriction that fault tree analysis assumes the condition of an event as two-state, according to the mapping relationship between fault tree and Bayesian network, an event in fault tree is transformed to a node in Bayesian network, which will be divided into some sub-nodes corresponding to different states of an event. And connecting strength in Bayesian network corresponded to logical gate in fault tree will be expressed by conditional probability distribution. Taking foundation brake system as an example, reliability analysis on high-speed EMU bogie is presented. The research result shows that when multi-state characteristic of an event and uncertainty of logical relationship are considered, the calculation of probability distribution of bogie system fault can be more accurate. The reliability algorithm of high-speed EMU bogie based on fault tree analysis and Bayesian network is presented and developed.

The pilot plant of pulse corona for flue gas treatment has been put into operation some years ago, yet the apparent energy yield is still a key situation to be improved both in commercial and in bench-scale. Two approaches have been carried out by us to solve this problem, namely based upon high efficiency pulse generator/reactor system and plasma chemistry mechanism. In this paper, a thorough examination of the electrical parameters of the generator/reactor coupling system versus removal efficiency was conducted. Thereby an innovative circuit design for the high efficiency pulse generator was suggested. Moreover, the optimization of the coupling system led to an empirical relation between the capacitances of the two condensers C f = (7 −10) C L . The generator thus improved gives a fairly high efficiency of > 65%. Testing of its feasibility for laboratory simulated flue gas treatment showed promising results. With an initial concentration of 2000 ppm SO 2 and 200–300 ppm NO, when ammonia is injected, the removal efficiencies are of > 95% and 30–57% respectively, while the corresponding total energy input is only 4.2 Wh/Nm 3 as measured. The resulting apparent energy yield for SO 2 is as high as 1.3 g/Wh.

A new equivalent linearization method based on describing function approach was presented to do mathematical treatment on nonlinear dry friction shock absorber of heavy haul freight car, and respectively, the vertical and lateral non-linear friction force between the wedge and bolster were equivalent to the vertical and lateral linear damper, and after equivalent linearization, the dynamic performance analysis of linear vehicle model is carried out and compared with the corresponding dynamic results of nonlinear model, furthermore, the equivalent linearization model was applied to dynamic response analysis of heavy haul freight carthe existing bridge coupling system to study the effect of vibration of the existing bridge on dynamic performance of heavy haul freight car. The results show that, within a certain error range, equivalent linear model of nonlinear dry friction force in freight car based on describing function approach is correct, and can replace the complicated nonlinear model to study the dynamic response of freight car-existing bridge coupling, and it provides an effective way to analyze and predict dynamics performance of heavy haul freight car-existing bridge coupling system.

In Gao Ping Chang Ping mine 4305 working face the cross-section area of tired car transportation lane is large, the stress environment is complex, its reasonable supporting parameters and the supporting form are worth deeply further analysis. Based on the results of in-situ stress measurement and rock loose circle, in conjunction with the situation of the roadway, proposes bolt and cable support approach to control the deformation of surrounding rock. Using existing support experiences proposes Programs. In order to find reasonable supporting parameters using finite difference flac2d numerical simulation software to research. Through comparatively analyzing simulation results of the roof and floor support programs, determines a reasonable program. Rock mass strength improves, displacements of two sides and roof of the tunnel significantly reduce. Project improves good effect.

The mechanical power system model of 1:5 trial tilting bogie is established in the ADAMS, and it’s considered to predict the filtered acceleration (velocity or displacement) from the frame using neural network, and the tilting actuation systems is controlled in accordance with the signal and research will be proceeded on the effect of according control algorithms imposed on the performance of swing bolsters. The research results shows that: under a certain satisfaction, the reference input of 1:5 trial tilting bogie control system established by predictive signal can not only guarantee the accuracy of controlling the start and stop, but also ensure the real time of control, and realize the compensation of filter delay.

The paper discussed the optimum uses of water resource in a city based on Social-Economic-Environmental (SEE) complex system by applying System Dynamic Model, which fully considered the interactions and interrelations amongst each element in the SEE complex system. The SD model can be used to estimate the overall development trends based on the current development status, and then relevant information of water supply-demand can also be available. Furthermore, by sensitivity analysis and running SD model on the current situations, the important parameters and variables (IPV) of could be identified, and different development modes could be designed through adjusting IPV value. Then through comparing and analyzing the simulation results of SD model, the optimal water resources utilization mode could be selected. As an example, Qinhuangdao water resource system dynamic (QinSD) model was set up to research the information of water supply and demand in different economic development mode which the paper framed, and then the sustainable water resources plan of Qinhuangdao was achieved

In this study the influences of Mo oxidation states and its configuration on both metathesis reaction and its competing side reactions, in particular carbon deposition, are described. Various oxidation states, namely Mo(VI), Mo(V) and Mo(VI), have been prepared by oxidation and reduction pretreatments of the silica-supported Mo catalysts. Molecular identifications of these species were obtained via XPS and ESR techniques. A combination of catalyst pretreatments, promoter effects and induction phenomena, together with the propene conversion suggests that the distorted square pyramidal Mo(V) species plays the decisive role in the metathesis function of the catalyst under study. Reduction pretreatments of the catalyst with H 2 in the temperature range 430–450 °C produce an abrupt increase in carbon deposition along with a marked drop in propene conversion. The results, associated with XPS and ESR characterisation of the oxidation states, suggest that the Mo(IV) species is principally responsible for the severe dehydrogenation and thereby coking out of the reacting olefin. Mo(VI) species in crystalline MoO 3 has no metathesis activity. However, it exerts a reducing effect on the reacting olefin to form undesired products, H 2 O and carbonaceous deposits. Hence, overloading of MoO 3 seems to be detrimental.

A hybrid mechanism is a configuration that combines the motions of two characteristically different electric motors by means of a mechanism to produce programmable output. In this paper, by means of establishing mathematic model for the influence of output accuracy of a planar hybrid five-bar mechanism affected by manufacturing error of link length, the sensitive coefficient of manufacturing error of link-length was determined and the law of influence on output accuracy of hybrid mechanism affected by manufacturing error of link length was analyzed. Living example of design shows that reasonable designed manufacturing tolerance of link length of hybrid five-bar mechanism could make the mechanism not only satisfy the requirement of accuracy but also achieve lower manufacturing cost.

Based on the Coulomb friction model, the frictional motion model of workpiece relating to the polishing pad was presented in annular polishing. By the dynamic analysis software, the model was simulated and analysed. The conclusions from the results were that the workpiece did not rotate steadily. When the angular velocity of ring and the direction were the same as that of the polishing pad, the angular velocity of workpiece hoicked at the beginning and at the later stage were the same as that of the polishing pad before contacting with the ring. The angular velocity of workpiece vibrated at the moment of contacting with the ring. After that the angular velocity of workpiece increased gradually and fluctuated at a given value, while the angular velocity of ring decreased gradually and also fluctuated at a given value. Since the contact between the workpiece and the ring was linear, their linear velocities and directions should be the same. But the angular velocity of workpiece was larger than that of the polishing pad on the condition that the radius of the workpiece was less than that of the ring. This did not agree with the pure translation principle and the workpiece surface could not be flat, either. Consequently, it needed to be controlled with the angular velocity of ring and the radii of the ring and the workpiece, besides friction to make the angular velocity of workpiece equal to that of the polishing pad for obtaining fine surface flatness of the workpiece.

Metathesis catalyst break-in, or extended induction period, for a series of silica-supported Mo catalysts during propene metathesis has been studied in a conventional flow reactor as well as by following the generation of Mov paramagnetic species by ESR spectroscopy. It is shown that two kinds of Mov centers, having entirely different metathesis reactivities, coexist in this transient period. Catalytically, only the distorted square pyramidal Mov site shows a fairly linear correlation between relative intensity and increasing metathesis conversion. By assuming the propene conversion to be proportional to the active site concentration, a first-order rate expression was deduced and verified experimentally. Hence, the intrinsic nature of the break-in phenomenon has been explored. A model is postulated to explain the roles of both Mov sites in catalyst break-in. It is apparent that the oxidation state (via the electronic effect) and coordination structure (via the geometric effect) are both critical in the creation of a site which is active for metathesis. Finally, the active site is characterised not only by its oxidation state and configurational modification, but also by assigned MO bonding coefficients on a molecular level. In summary, the stronger π-bonding covalency in the out-of-plane Mo species is related to the optimal activity of the Mov site in metathesis catalysis.