地勘单位转制后税务风险识别与控制

结合“减税降费”的政策背景,以陕西省某转制地勘单位为例,引入风险控制相关理论并应用层次分析法,构建了税务风险评估指标体系,对转制地勘单位面临的税务风险进行了识别、分析、评估。研究结果表明:针对不同的税收类型,应着重关注不同方面的风险,排序前6位的风险依次为企业所得税扣除类风险、增值税决策环节风险、增值税销售环节风险、房产税计税依据风险、企业所得税税收优惠类风险、增值税采购环节风险;并对上述风险的控制机制进行了分析,从企业管控、政策优化两方面分别提出了相关对策和建议。     

Bootstrap procedures for detecting multiple persistence shifts in heteroskedastic time series

This article proposes new bootstrap procedures for detecting multiple persistence shifts in a time series driven by non-stationary volatility. The assumed volatility process can accommodate discrete breaks, smooth transition variation as well as trending volatility. We develop wild bootstrap sup-Wald tests of the null hypothesis that the process is either stationary [I(0)] or has a unit root [I(1)] throughout the sample. We also propose a sequential procedure to estimate the number of persistence breaks based on ordering the regime-specific bootstrap p-values. The asymptotic validity of the advocated procedures is established both under the null of stability and a variety of persistence change alternatives. A comparison with existing tests that assume homoskedasticity illustrates the finite sample improvements offered by our methods. An application to OECD inflation rates highlights the empirical relevance of the proposed approach and weakens the case for persistence change relative to existing procedures.     

Carbon,nitrogen and phosphorus recovery from liquid swine wastes: a review

Due to the pollution characteristics of the wastewater generated in piggeries, these waste streams have to be treated before discharging into the environment. These wastes have a high content of organic matter, nitrogen and phosphorus that can be converted or recovered into valuable products. The valuation of swine waste by anaerobic digestion has already been assessed, but no systematic review on the technologies used for recovering nutrients from this waste has been reported to date. Therefore, the present work has the goal of presenting the most studied technologies to different scales of recovery of carbon (i.e. organic matter), nitrogen and phosphorus from swine waste. The main characteristics and parameters of the processes involved in these technologies (mainly air stripping, membrane, enhance biological phosphorus removal and struvite formation) are also highlighted, pointing out its advantages and disadvantages and posing some final feasibility considerations on the subject addressed. Experiments reported in the literature proved that technologies used for nutrient recovery from swine waste are mostly applied to the effluents previously treated by anaerobic digestion as a primary treatment, and greater effort is required for the future implementation of these technologies in large scale. © 2020 Society of Chemical Industry     

基于最近邻与神经网络融合模型的软测量建模方法

软测量建模能够有效地解决生产过程中在线分析仪表测量滞后大、价格昂贵、维护保养复杂等问题。目前，基于数据驱动的神经网络是软测量建模的主要工具之一。而在建模数据的采集过程中，主导变量的采集相对辅助变量要困难得多，由此产生了大量缺失标签的数据。但传统的软测量建模方法却忽视了这些无标签数据，只利用少量的有标签数据建模，从而影响了模型的预测精度。为了解决标签缺失的问题，采用最近邻算法对无标签数据进行伪标记，同时设计了由卷积操作与门限循环单元神经网络（GRU）结合的网络结构来进一步利用无标签数据，提取不同时刻数据中的动态特征，提高神经网络的预测精度。最后将该方法应用于丙烯精馏塔塔顶丙烷浓度的预测，实验结果表明该模型能有效处理非线性动态系统的标签缺失问题，具有更高的预测精度。     

Supramolecular Chemistry in Molten Sulfur: Preorganization Effects Leading to Marked Enhancement of Carbon Nitride Photoelectrochemistry

Here, a new method for enhancing the photoelectrochemical properties of carbon nitride thin films by in situ supramolecular‐driven preorganization of phenyl‐contained monomers in molten sulfur is reported. A detailed analysis of the chemical and photophysical properties suggests that the molten sulfur can texture the growth and induce more effective integration of phenyl groups into the carbon nitride electrodes, resulting in extended light absorption alongside with improved conductivity and better charge transfer. Furthermore, photophysical measurements indicate the formation of sub‐bands in the optical bandgap which is beneficial for exciton splitting. Moreover, the new bands can mediate hole transfer to the electrolyte, thus improving the photooxidation activity. The utilization of high temperature solvent as the polymerization medium opens new opportunities for the significant improvement of carbon nitride films toward an efficient photoactive material for various applications.     

Lagrangian relaxation hybrid with evolutionary algorithm for short-term generation scheduling

Short-term generation scheduling is an important function in daily operational planning of power systems. It is defined as optimal scheduling of power generators over a scheduling period while respecting various generator constraints and system constraints. Objective of the problem includes costs associated with energy production, start-up cost and shut-down cost along with profits. The resulting problem is a large scale nonlinear mixed-integer optimization problem for which there is no exact solution technique available. The solution to the problem can be obtained only by complete enumeration, often at the cost of a prohibitively computation time requirement for realistic power systems. This paper presents a hybrid algorithm which combines Lagrangian Relaxation (LR) together with Evolutionary Algorithm (EA) to solve the problem in cooperative and competitive energy environments. Simulation studies were carried out on different systems containing various numbers of units. The outcomes from different algorithms are compared with that from the proposed hybrid algorithm and the advantages of the proposed algorithm are briefly discussed.     

重整装置首次开工关键因素探讨

阐述了做好重整装置首次开工的几个关键因素：做好预处理开工工作，确保重整进料合格；做好重整催化剂的处理工作；把好重整进油后480℃温度关；遵守操作规程，平稳操作。     

A propane water-to-water heat pump booster for sanitary hot water production: Seasonal performance analysis of a new solution optimizing COP

Electrical heat pumps for sanitary hot water production achieve a high performance with a good matching of water and refrigerant temperature profiles during the heat rejection stage, as it happens in CO₂ systems. This work considers the thermodynamic possibility to adapt the condenser pressure of a propane heat pump to maximize the COP, while producing sanitary hot water up to 60 °C from a heat sink equal to 15 or 25 °C. The performance of the heat pump is calculated through specific models which, in combination with a TRNSYS model of the whole system, allowed to assess its seasonal performance for a hotel in Strasbourg, also varying the control logic and the size of the storage tank. Results obtained led to the conclusion that, for achieving a high seasonal performance, the control logic of the tank has the largest influence.