电力工业的非参数效率测度分析

对资源优化配置的非参数模型在电力工业中的应用进行了研究.选择了国内部分电网的数据,从纯技术效率、规模效率以及投入可处置度、投入组合效率、投入综合效率的角度对部分电力企业的资源配置效率进行了横向分析,结果表明,不同的电力企业之间的资源配置效率差距较大,电力企业总体上生产性投资的要素组合比例不合理,利用率较低.     

含硅聚氨酯的制备及其动力学研究

以3-氨基丙基三乙氧基硅烷（KH550）、丙烯酸羟乙酯（HEA）、2,4-甲苯二异氰酸酯、对甲酚为原料,制备含硅聚氨酯。用红外光谱对反应合成过程进行跟踪测定,发现端-NCO的聚氨酯预聚物和对甲基苯酚的封端反应在无催化剂条件下为二级反应,当加入催化剂三乙胺后该反应在发生初期为一级反应。无催化剂条件下该反应的活化能为46.96 kJ/mol,催化剂加入量为0.1%时反应的活化能为30.28 kJ/mol,催化剂加入量为0.3%时反应的活化能为18.16 kJ/mol,反应的活化能随催化剂加入量的增加而降低。     

Ambient flash sintering of reduced graphene oxide/zirconia composites:Role of reduced graphene oxide

Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing costs.In this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO₂(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is reported.When the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 s.The role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the rGO.The work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.     

真空高温退火对锻态Ti-6Al-4V合金显微组织与超塑性性能的影响

退火处理是改善钛合金显微组织,提高力学性能及超塑成形性能的一种重要工艺。使用真空退火炉在850℃-950℃温度区间内对锻态Ti-6Al-4V合金的进行了高温退火处理,研究了退火态Ti-6Al-4V合金微观组织演变及其在温度为900℃,应变速率为0.01 s^-1时的超塑拉伸性能。结果表明,锻态Ti-6Al-4V合金的初生α晶粒尺寸随真空退火温度的升高而减小,β相比例随真空退火温度升高而增大。当真空退火温度为910℃时,Ti-6Al-4V合金的晶粒尺寸和α相与β相分布较为均匀,其超塑拉伸试验结果表明,该合金表现出最佳的超塑拉伸性能,其拉伸延伸率达到785%,峰值应力仅为26.8 MPa。     

The Main Progress of Perovskite Solar Cells in 2020–2021

Perovskite solar cells (PSCs) emerging as a promising photovoltaic technology with high efficiency and low manufacturing cost have attracted the attention from ...     

Electrolyte/Structure?Dependent Cocktail Mediation Enabling High?Rate/Low?Plateau Metal Sulfide Anodes for Sodium Storage

As promising anodes for sodium-ion batteries, metal sulfides ubiquitously suffer from low-rate and high-plateau issues, greatly hindering their application in f...     

四川沐川大口径地质调查井（川沐地2井）钻探施工技术

大口径页岩气地质调查井（川沐地2井）部署在四川盆地西南缘五指山—天宫堂构造带建全—龙华复向斜的核部,设计井深2500 m,完钻井深2406.00 m。钻探目的是主探须家河组陆相页岩气,兼探雷口坡组常规气。本文介绍了川沐地2井的钻探施工情况,针对侏罗系易垮塌的泥岩和三叠系可钻性差的砂岩,开展了高效提速复合钻进、复杂地层钻井液、下套管固井工艺等应用研究,解决了垮塌段下套管固井难题,提高了钻探效率,建成了一口可供地层含气性测试的合格井,获取了岩心等实物资料,查明了该井区的地层层序,在三叠系须家河组—雷口坡组钻遇37层油气显示,实现了钻探目的及油气发现,为页岩气地质调查评价奠定了基础,对巩固乌蒙山区脱贫攻坚成果具有重要意义。     

Modelling corn production in China using AVHRR‐based vegetation health indices

Weather‐related crop losses have always been a concern for farmers, governments, traders and policy makers for the purpose of balanced food supplies, demands, trade, and distribution of aid to nations in need. Therefore, early crop loss assessment in response to weather fluctuations is an important issue. This paper discusses the utility of Advanced Very High Resolution Radiometer (AVHRR)‐based vegetation health indices as a proxy for modelling corn yield and for early warning of drought‐related losses of agricultural production in China. The indices were tested in Jilin province on corn yield during 1982–2001 using correlation and regression analysis. A strong correlation between corn yield and the vegetation health indices were found during the critical period of corn growth, which starts 2–3 weeks before and 2–3 weeks after corn tassel. Following the results of correlation analysis, several regression equations were constructed where vegetation health indices were used as independent variables. The estimates of corn yield can be carried out well in advance of harvest and the errors of the estimates are 7–10%. The errors become smaller when the estimations are related to losses in corn yield due to drought.     

EFAST Method for Global Sensitivity Analysisof Remote Sensing Model’s Parameters

Sensitivity analysis for parameters of remote sensing physical models is a prerequisite for inversion.The EFAST(Extended Fourier Amplitude Sensitivity Test)as a global sensitivity analysis method,can analyze not only a single parameter’s sensitivity but also the coupling effects among parameters.It is usually applied to analyse parameters’ sensitivity of the high-dimensional nonlinear models.In this paper,the SAIL model is taken as an example,the EFAST method and the field measured data of winter wheat in Shunyi district in 2001 were applied to analyze the model parameters’ sensitivity throughout the growing season and in different growth stages respectively.The results are compared with those of the USM (Uncertainty and Sensitivity Matrix) method.The results show that either the EFAST or the USM method for parameters’ sensitivity analysis of the SAIL model is feasible;but the EFAST method,which takes into account of the coupling effects among all the parameters and the analysis result is global,compared to the USM method,is more objective and comprehensive.