中国地方保护主义及其治理机制

该文分析了中国地方保护主义的制度根源,并探讨了保护主义的界定标准及其防治机制。笔者认为,要保证大国的法治统一并防止地方保护主义,必须划分中央和地方的权力界限,中央和地方各司其职;中央不再包揽全部的立法权,但是必须将其分内的事情管好。因此,只有在限制中央立法权的基础上,才可能在有限的权力范围内无条件地实施中央至上原则,从而保证国家法治统一并防止地方保护主义。

试论胎儿权益的民法保护

胎儿的权利保护在我国立法中很不充分,导致现实生活中胎儿权益受损时无法得到应有的补偿。适值民法典立法之时,有必要重新反思胎儿的法律地位以及我国目前立法对胎儿保护的妥当性,确认其享有的权利范围。文章认为,在采取附条件保护主义对胎儿权益进行保护的同时,还应扩大对胎儿民事权利的保护范围,应当对胎儿在健康权、继承权、抚养损害、受遗赠权以及程序法上作为诉讼主体的权利等方面予以确认。此外,立法上应对胎儿民事权利保护的方式作出较为详细的规定。

试论胎儿权益的民法保护

胎儿的权益保护在我国立法中很不充分,以致现实生活中胎儿权益受损时无法得到应有的补偿。适值民法典立法之时,有必要重新反思胎儿的法律地位以及我国目前立法对胎儿权益保护的妥当性,以确认其享有的权利范围;应当在采取附条件保护主义对胎儿利益进行保护的同时,扩大对胎儿民事权利的保护范围,对胎儿在健康权、继承权、抚养损害、受遗赠权以及程序法上作为诉讼主体的权利等方面予以确认。此外,立法上还应对胎儿民事权利保护的方式作较为详细的规定。

A novel model-based multivariable framework for aircraft gas turbine engine limit protection control

Control technologies are innovated to satisfy increasingly complicated control demands of gas turbine engines.In terms of limit protection control,a novel model-based multivariable limit protection control method,which is achieved by adaptive command reconstruction and multiplecontrol loop selection and switch logic,is proposed in this paper to address the problem of balancing smaller thrust loss and safe operations by comparing with widely-used Min-Max logic.Five different combination modes of control loops,which represent the online control loop of last time instant and that of current time instant,is analyzed.Different command reconstructions are designed for these modes,which is based on static gain conversion of amplitude beyond limits by using an onboard model.The double-prediction based control loop selection and switch logic is developed to choose a control loop appropriately by comparing converted amplitude beyond limits regardless of one or more parameters tending to exceed limits.The proposed method is implemented in a twin-spool turbofan engine to achieve limit protection with direct thrust control,and the loss of thrust is improved by about 30% in comparison with the loss of thrust caused by Min-Max logic when limit protection control is activated,which demonstrates the effectiveness of the proposed method.

A micro-power LDO with piecewise voltage foldback current limit protection

To achieve a constant current limit,low power consumption and high driving capability,a micro-power LDO with a piecewise voltage-foldback current-limit circuit is presented.The current-limit threshold is dynamically adjusted to achieve a maximum driving capability and lower quiescent current of only 300 nA.To increase the loop stability of the proposed LDO,a high impedance transconductance buffer under a micro quiescent current is designed for splitting the pole that exists at the gate of the pass transistor to the dominant pole,and a zero is designed for the purpose of the second pole phase compensation.The proposed LDO is fabricated in a BiCMOS process. The measurement results show that the short-circuit current of the LDO is 190 mA,the constant limit current under a high drop-out voltage is 440 mA,and the maximum load current under a low drop-out voltage is up to 800 mA. In addition,the quiescent current of the LDO is only 7μA,the load regulation is about 0.56%on full scale,the line regulation is about 0.012%/V,the PSRR at 120 Hz is 58 dB and the drop-out voltage is only 70 mV when the load current is 250 mA.

Limit protection design in turbofan engine acceleration control based on scheduling command governor

A new limit protection method based on Scheduling Command Governor(SCG) is proposed for imposing multiple constraints on a turbofan engine during acceleration process. A Gain Scheduling Controller(GSC) is designed for the transient state control and its stability proof is developed using Linear Matrix Inequalities(LMIs). The SCG is an add-on control scheme which manages engine limits effectively based on reference trajectory optimization. Unlike the traditional min–max architecture with switching logic, the SCG method utilizes the Linear Parameter Varying(LPV) closed-loop model to form a prediction of future constraint violation and per instant solves a constraint-admissible reference within an approximate Maximal Output Admissible Set(MOAS).The influence of the variation of engine dynamic characteristics and equilibrium points during transient state control is handled by the design of contractive sets. Simulation results on a turbofan engine component-level model show the applicability and effectiveness of the SCG method. Compared to the traditional min–max method, the SCG method has less conservativeness. In addition,the design of contractive sets makes conservativeness tunable.

An adaptive limited wide area differential protection for power grid with microsources

The operation mode of power grids with intermittent distributed generations(DGs)changes frequently due to the bidirectional power flow.In comparison with the conventional grids,the protection relays in power grids with micro-sources are more difficult to set.To tackle this problem,this paper proposes an extended bus differential protection(EBDP)strategy based on the limited wide area(LWA).In this method,the micro-grids are divided into several protection areas at the core of the bus.The whole protection areas are protected by the wide area current differential relays,which are also configured to protect each component in this protection area.Moreover,the protection areas can be changed adaptively according to the power flow direction.Finally,a micro-grid model with multiple DGs is developed using the PSCAD/EMTDC platform.The simulation results indicate that the proposed adaptive limited wide area differential protection(LWADP)has better performance than the traditional relaying protection in detecting the faulty area in micro-grids and isolating the fault,and can be widely utilized in larger micro-grids.

The research and the development of the wide area relaying protection based on fault element identification

The urgent problem of the relaying protection in the modern AC/DC hybrid connected grid and the development of the wide area communication,the information process and the intelligent technology powerfully promotes the development of the technology of the wide area relaying protection(WARP),which has become a research hotspot that attracts extensive attention.Originated from the basic concept of the wide area relaying protection,this paper analyses the advantages,the effects and the functions of the wide area relaying protection.The two main approaches to realize the wide area protection,which are on-line adaptive setting(OAS)principle and fault element identification(FEI),are introduced in this paper.Aimed at improving the performance of the backup protection,the research content and the technology demand of the wide area protection are proposed,meanwhile,the basic principle and the algorithm of the fault element identification are introduced.At last,the scheme of the limited wide area relaying protection based on the existing pilot channel of the main protection is discussed.

中国农药最大残留限量标准的演变趋势及动因分析

农药最大残留限量标准既是各国政府保障公共食品安全的政策工具,也可能成为新的贸易保护政策工具。中国作为世界第一大农产品进口国,其农药最大残留限量标准是否具有保护性备受各界关注。本文运用历史数据,分析了中国农药最大残留限量标准发展趋势及其驱动因素。结果表明,中国农药最大残留限量标准正处于快速发展阶段,不仅总条目数增长迅速,其涵盖的食品类别和农药的种类都保持了持续扩大的趋势。中国农药最大残留限量标准的发展既坚持了"国际化"方向,以国际标准为基础,又体现出鲜明的中国"本土化"特色,充分反映了农业生产方式、粮食安全以及食品消费结构在内的社会经济发展的要求和变化。尽管中国农药最大残留限量标准中80%以上食品的比CAC标准更为严格,但整体水平不高。最重要的是,严格指数整体升高的根本动因不是关税的降低,而是随着公众食品安全意识的提高,相应更高的食品安全需求,以及中国政府对食品安全事件的积极应对。这意味着,中国农药最大残留限量标准并没有替代关税成为新的贸易保护政策工具,仅凭严格指数判断农药最大残留限量标准是否具有保护倾向具有误导性。

Neural network-based model predictive control with fuzzy-SQP optimization for direct thrust control of turbofan engine

A nonlinear model predictive control method based on fuzzy-Sequential Quadratic Programming(SQP)for direct thrust control is proposed in this paper for the sake of improving the accuracy of thrust control.The designed control system includes four parts,namely a predictive model,rolling optimization,online correction,and feedback correction.Considering the strong nonlinearity of engine,a predictive model is established by Back Propagation(BP)neural network for the entire flight envelope,whose input and output are determined with random forest algorithm and actual situation analysis.Rolling optimization typically uses SQP as the optimization algorithm,but SQP algorithm is easy to trap into local optimization.Therefore,the fuzzy-SQP algorithm is proposed to prevent this disadvantage using fuzzy algorithm to determine the initial value of SQP.In addition to the traditional three parts of model predictive control,an online correction module is added to improve the predictive accuracy of the predictive model in the predictive time domain.Simulation results show that the BP predictive model can reach a certain degree of predictive accuracy,and the proposed control system can achieve good tracking performance with the limited parameters within the safe range。