Screening of Drought Resistance Identification Indexes for Rice(Oryza sativa L.) Cultivars in Ningxia

The morphological characters, physiological characters, yield traits and yield per plant of total 49 rice cultivars from Ningxia were investigated under conditions of water stress and non-water stress so as to determine the relationship between each trait and yield per plant under water stress and the relationship between each relative character and drought resistance coefficient under water stress and non-water stress. The correlation, grey correlation, stepwise regression and path analyses showed that the tiller number per plant, plant height, grain density, effective panicle number per plant and grain number per panicle, total 5 traits, were significantly correlated with the drought resistance of rice, and they could be used to identify the drought resistance of rice in Ningxia. In addition, the drought resistance of rice was graded qualitatively according to the subordinate function value of corresponding drought resistance coefficient. The results showed that among the 49 rice cultivars from Ningxia,6 rice cultivars were highly drought resistant, and 9 rice cultivars were moderately drought resistant, suggesting that the evaluation method was feasible and effective.

IMPROVED COVARIANCE DRIVEN BLIND SUBSPACE IDENTIFICATION METHOD

An improved covariance driven subspace identification method is presented to identify the weakly excited modes. In this method, the traditional Hankel matrix is replaced by a reformed one to enhance the identifiability of weak characteristics. The robustness of eigenparameter estimation to noise contamination is reinforced by the improved Hankel matrix, in combination with component energy index （CEI） which indicates the vibration intensity of signal components, an alternative stabilization diagram is adopted to effectively separate spurious and physical modes. Simulation of a vibration system of multiple-degree-of-freedom and experiment of a frame structure subject to wind excitation are presented to demonstrate the improvement of the proposed blind method. The performance of this blind method is assessed in terms of its capability in extracting the weak modes as well as the accuracy of estimated parameters. The results have shown that the proposed blind method gives a better estimation of the weak modes from response signals of small signal to noise ratio （SNR）and gives a reliable separation of spurious and physical estimates.

Water quality characteristics and assessment of Yongding New River by improved comprehensive water quality identification index based on game theory

The Yongding New River is essential for the water supplies of Tianjin.To date,there is no comprehensive report that assesses the year-round water quality of the Yongding New River Main stream.Moreover,little attention has been given to determining a combined weight for improving the traditional comprehensive water quality identification index(ICWQII)by the game theory.Seven water quality parameters were investigated monthly along the main stream of the Yongding New River from May 2018 to April 2019.Organic contaminants and nitrogen pollution were mainly caused by point sources pollution,and the total phosphorus mainly by non-point source pollution.Dramatic spatio-temporal variations of water quality parameters were jointly caused by different pollutant sources and hydrometeorological factors.In terms of this study,an improved comprehensive water quality identification index(ICWQII)based on entropy weight or variation coefficient and traditional CWQII underestimated the water qualities,and an ICWQII based on the superstandard multiple method overvalued the assessments.By contrast,water qualities assessments done with an ICWQII based on the game theory matched perfectly with the practical situation.The ICWQII based on game theory proposed in this study takes into account not only the degree of disorder and variation of water quality data,but also the influence of standard-exceeded pollution indicators,whose results are relatively reasonable.All findings and the ICWQII based on game theory can provide scientific support for decisions related to the water environment management of the Yongding New River and other waters.

Contrastive Study of the Circular Economy of Coal Resource City Based on Ecological Efficiency and C Model

Being a developing country, the evaluation of Chinese circular economy should have its particular crite- rion that suits for specific national conditions. With the growth of economy, Chinese environmental loads should be permitted to increase at an appropriate speed. Based on this concept, this paper divides the process of evaluation into two parts which include evaluation of development level and evaluation of development performance. Firstly, this paper sets up a reference system which includes Zaozhuang City of Shandong Province, Jiaozuo City of Henan province, Shizuishan City of Ningxia Hui Autonomous Region and China that is regarded as a region respectively, analyzes the development level of circular economy of coal resource cities based on the evaluation indicator of ecological efficiency, and puts forward the future direction of circular economy of coal resource cities. Secondly, based on C Model of Circular Economy, this paper constructs the measurement model of development perform- ance in which study regions are analyzed in a particular period that is from 2000 to 2020, and evaluates the de- velopment performance of circular economy for study regions according to the relationship of growth multiples between economic scale and environmental loads. We can draw several main conclusions： firstly, the development pathways of all four study regions belong to type I[ which resource efficiency is preferred. Secondly, the com- prehensive energy consumption efficiencies of coal resource cities were left far behind by China＇s average level. Thirdly, the circular economies of all study regions have achieved remarkable progress. Fourthly, the development level of circular economy can be evaluated from two dimensions which consist of horizontal comparison method and vertical comparison method. Fifthly, C model is an appropriate development model that suits for Chinese na- tional conditions and could be selected as an important method to evaluate regional development performance of circular economy.