基于TOPSIS和灰色关联投影法的区域碳效率动态综合评价——以泛珠三角为例

为弥补传统碳效率评价偏向绝对量指标或者少数几个指标的单点式评价的不足,选取相对量指标,从经济、人口、福利多个维度并兼顾地区发展实际与公平原则,构建区域碳效率评价指标体系。将TOPSIS法与灰色关联投影分析相结合,并利用时间序列平均算子二次加权以实现对泛珠三角9省(自治区)2011—2020年碳效率的动态综合评价。静态与动态评价研究结果显示:该区域碳效率发展水平存在差异,其中海南省碳效率总体水平较高,为0.530;贵州省碳效率相对较低,为0.162;海南省比贵州省高出227%。福建省碳效率呈上升趋势,由2011年的0.327上升至2020年的0.498,增长了52.3%。研究认为,应该制定差异化减排策略、加大技术经费投入、增强社会福利、引进人才以实现低碳经济发展。

文化产业上市公司绩效评价——基于超效率DEA和Malmquist指数

运用超效率DEA模型和Malmquist指数法对30家文化产业上市公司进行了绩效评价。从DEA结果来看，30家文化产业上市公司只有8家上市公司达到DEA有效，上市公司整体绩效一般；从Malmquist全要素生产率（ TFP）指数看，文化产业上市公司的全要素生产率指数2011～2012年窗口期间的增长率为-4.8％，技术进步率下降是造成TFP负增长的重要原因，因此应加大技术研发投入，重视技术进步。

中国西部地区省际全要素能源效率研究——基于超效率DEA模型和Malmquist指数

本文基于超效率DEA模型，测算出2000～2011年中国西部11个省考虑环境效应的全要素能源效率，并运用Malmquist指数法将全要素能源效率指数分解为技术进步指数和技术效率指数，最后利用Tobit模型对全要素能源效率影响因素进行了分析。结果表明：西部各省能源效率差距较大，其中，内蒙古、重庆和青海的能源效率较高，广西、贵州、云南和甘肃的能源效率比较低；样本期间，西部地区平均全要素能源效率下降了0.4％，技术进步是能源效率变动的主要因素；第二产业和第三产业发展对西部地区能源效率提升有促进作用，能源价格、煤炭消费以及区际产业转移的上升对西部地区能源效率提升有抑制作用。

江苏旅游业发展效率及对策研究——基于超效率DEA和Malmquist指数分析

文章利用超效率DEA模型和Malmqulst指数模型分别测算了江苏13市2001-2012年旅游业发展的静态效率与动态效率。结果显示:江苏旅游业静态效率保持先降后升的态势,从2001年的0.848下降到2006年的0.611,后又上升到2012年的0.824,12年间效率均值为0.726。各市旅游业效率存在显著的地区差异,且呈现逐步扩大的趋势。江苏旅游业动态效率(TFP)年均变化值-0.6%,增长主要来源于技术进步而不是规模效率的作用。在以上研究的基础上,提出提升江苏旅游业效率的对策,为旅游业持续、高效、健康发展提供理论参考。

A study on the simulation of carbon and water fluxes of Dangxiong alpine meadow and its response to climate change

The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.

Performance improvement in stepped solar still modified by sponge layer

In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional device and increase the evaporation rate.All the parameters,including the temperature on the glass surface,the water temperature inside the evaporation zone,and the amount of water produced in both conventional and modified stepped solar stills are measured and compared.The efficiency of two devices and their exergy efficiency have been calculated.Finally,the economic analysis of both devices has been done to check the economic feasibility of the modified device.The amount of freshwater generated during one day was 2244.4 and 3076.2 mL/m^(2),respectively for the conventional and modified stepped solar stills.As a result,the amount of water produced in one day by modified stepped solar still is 35.5% more than the conventional one.Also,the costs for the conventional and modified stepped solar stills have been calculated as 0.0359 and 0.029$/(L·m^(-2)),respectively.

Formation mechanism of nanopores in dense films of anodic alumina

Constant-current anodization of pure aluminum was carried out in non-corrosive capacitor working electrolytes to study the formation mechanism of nanopores in the anodic oxide films.Through comparative experiments,nanopores are found in the anodic films formed in the electrolytes after high-temperature storage(HTS)at 130°C for 240 h.A comparison of the voltage-time curves suggests that the formation of nanopores results from the decrease in formation efficiency of anodic oxide films rather than the corrosion of the electrolytes.FT-IR and UV spectra analysis shows that carboxylate and ethylene glycol in electrolytes can easily react by esterification at high temperatures.Combining the electronic current theory and oxygen bubble mold effect,the change in electrolyte composition could increase the electronic current in the anodizing process.The electronic current decreases the formation efficiency of anodic oxide films,and oxygen bubbles accompanying electronic current lead to the formation of nanopores in the dense films.The continuous electronic current and oxygen bubbles are the prerequisites for the formation of porous anodic oxides rather than the traditional field-assisted dissolution model.

Agricultural Eco-efficiency:Progress,Challenges,and Prospects

Agricultural eco-efficiency is a vital indicator for assessing the sustainability of agriculture.Conducting evaluations of agricultural eco-efficiency can provide critical information for policymaking,resource allocation,and the advancement of agricultural sustainable development.While there exists a substantial body of research on the evaluation of agricultural eco-efficiency,its influencing factors,and improvement paths,there remains a paucity of systematic reviews,evaluations,and prospective analyses in this area.This study employed the literature search method to analyze relevant scholarly articles.Chinese literature was sourced from the CNKI(China National Knowledge Infrastructure)database,while international literature was obtained from the Web of Science database.The literature search was conducted from 1998 to 2023.The study reviewed the progress of research on agricultural eco-efficiency and outlined the challenges and prospects that lie ahead.The findings of this study indicate that the primary challenges in the field of agricultural eco-efficiency research include refining the evaluation system,integrating macro and micro influencing factors,and ensuring the suitability of models employed.In the future,the research could expand in areas such as deepening the application of artificial intelligence technology in evaluation methods,clarifying the driving factors of agricultural eco-efficiency,and promoting the green transformation of agriculture.This study provides a comprehensive systematic review and could provide critical information for related research expansion.

A hybrid ventilation scheme applied to bidirectional excavation tunnel construction with a long inclined shaft

The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the hybrid ventilation system applied in bidirectional excavation tunnels with a long inclined shaft,this study has established a full-scale computational fluid dynamics model based on field tests,the Poly-Hexcore method,and the sliding mesh technique.The distribution of wind speed,temperature field,and CO in the tunnel are taken as indices to compare the ventilation efficiency of three ventilation systems(duct,duct-ventilation shaft,duct–ventilated shaft-axial fan).The results show that the hybrid ventilation scheme based on duct-ventilation shaft–axial fan performs the best among the three ventilation systems.Compared to the duct,the wind speed and cooling rate in the tunnel are enhanced by 7.5%–30.6%and 14.1%–17.7%,respectively,for the duct-vent shaft-axial fan condition,and the volume fractions of CO are reduced by 26.9%–73.9%.This contributes to the effective design of combined ventilation for bidirectional excavation tunnels with an inclined shaft,ultimately improving the air quality within the tunnel.

Supported Ziegler-Natta catalysts from MgCl_(2)·nROH precursors and its catalytic behaviors for diene copolymerization

Heterogeneous TiCl4/MgCl_(2) type Ziegler-Natta(Z-N)catalysts with unique advantages like low cost,high activity,high stereoregularity and pretty particle morphology,contribute to more than 130 Mt polyolefin large-scale production.However,most researches related with heterogeneous Z-N catalysts focused onα-olefin polymerizations like ethylene,propylene,etc.

Effects of Collocational Congruency,Frequency and L2 Proficiency on the Processing of English Adjective-Noun Collocations

The present study investigates the effects of congruency and frequency on adjective-noun collocational processing for Chinese learners of English at two proficiency levels based on the data obtained in an online acceptability judgment task.The subject pool of this research included 60 English majors studying at a university in China;30 were selected as a higher-proficiency group and 30 as a lower-proficiency group according to their Vocabulary Levels Test(Schmitt et al.,2001)scores and their self-reported proficiency in English.The experimental materials were programmed to E-prime 2.0 and included six types of collocations:(1)15 high-frequency congruent collocations,(2)15 low-frequency congruent collocations,(3)15 high-frequency incongruent collocations,(4)15 low-frequency incongruent collocations,(5)15 Chinese-only items,and(6)75 unrelated items for baseline data.The collected response times(RTs)and accuracy rates data were statistically analyzed by the use of an ANOVA test and pairwise comparisons through SPSS 16.0 software.The results revealed that:(1)the adjective-noun collocational processing of Chinese English learners is influenced by collocational frequency,congruency and L2 proficiency;(2)the processing time is affected by the interaction of congruency and frequency;and(3)the interactive effect of L2 proficiency in conjunction with congruency and frequency also influences the processing quality.

Research on Automatic Test System of Engine Blade Natural Frequency

Blades are one of the important components on aircraft engines.If they break due to vibration failure,the normal operation of the entire engine will be offected.Therefore,it is necessary to measure their natural frequency before installing them on the engine to avoid resonance.At present,most blade vibration testing systems require manual operation by operators,which has high requirements for operators and the testing process is also very cumbersome.Therefore,the testing efficiency is low and cannot meet the needs of efficient testing.To solve the current problems of low testing efficiency and high operational requirements,a high-precision and high-efficiency automatic test system is designed.The testing accuracy of this system can reach ±1%,and the testing efficiency is improved by 37% compared to manual testing.Firstly,the influence of compression force and vibration exciter position on natural frequency test is analyzed by amplitude-frequency curve,so as to calibrate servo cylinder and fourdimensional motion platform.Secondly,the sine wave signal is used as the excitation to sweep the blade linearly,and the natural frequency is determined by the amplitude peak in the frequency domain.Finally,the accuracy experiment and efficiency experiment are carried out on the developed test system,whose results verify its high efficiency and high precision.

微管壳式换热器在能量转换循环中的应用

目前,超临界二氧化碳(S-CO_(2))布雷顿循环普遍采用印刷电路板换热器(PCHE)来保证其相对其他能量转换循环的紧凑性优势。PCHE芯体为整体结构,若内部出现泄漏或结垢等问题,很难进行维护与检修。本文提出了一种微管壳式换热器(MSTE),其结构与传统管壳式换热器类似,但其管径缩小至微通道级。由于MSTE的流道横截面积占总截面积之比较PCHE大,在典型的回热器与冷却器设计工况下,相对PCHE而言,采用MSTE可将体积与质量均减小30%以上。灵敏性分析结果显示,采用本文设计的MSTE结构的回热器与冷却器,回热器冷热流道入口温度升高20℃左右,压缩机入口温度变化均不超过1℃,说明该种结构换热器的换热能力足够支撑能量转换循环的一般工况波动。

Research progress of magnesium anodes and their applications in chemical power sources

Magnesium is a promising metal used as anodes for chemical power sources. This metal could theoretically provide negative discharge potential and exhibit large capacity during the discharge process. However, when the magnesium anode is adopted for practical applications, several issues, such as the discharge products adhered to the electrode surface, the self-discharge occurring on the anode material, and the detachment of metallic particles, adversely affect its inherently good discharge performance. In this work, the types of chemical power sources using magnesium as anodes were elaborated, and the approaches to enhance its anode performance were analyzed.

Effects of Different Water Stresses on Eco-physiological Characteristics of Hippophae rhamnoides Seedlings

In order to examine the effects of the decrease of future precipitation on the eco-physiological characteristics of sea buckthorn (Hippophae rhamnoides Linn.) in Huangfuchuan Watershed in Nei Mongol, a water gradient experiment was conducted based on the four specially designed water supply levels, including normal precipitation, slight drought, drought and extreme drought. Results of ANOVE showed that different water gradients had a significant effect on (1) microhabitat factors, such as soil water content and soil temperature; (2) gas exchange, such as net photosynthetic rate, stomatal conductance and transpiration rate; (3) resource use efficiency; and (4) leaf water potential. Water use efficiency of H rhamnoides could increase under moderate water stress, i.e. drought condition, while its net photosynthetic rate and transpiration rate decreased. All kinds of eco-physiological characteristics proved H. rhamnoides seedlings under all water supplies were affected by water stress more or less and that mechanism of intrinsic physiological regulation in seedlings under the extreme drought conditions had the appearance of turbulence to a certain extent. Therefore, H rhamnoides seedlings in Huangfuchuan Watershed could not acclimate to extreme drought conditions.

Measuring technical efficiency of Chinese nonferrous metals enterprises on a background of industry consolidation

Since 2009, Chinese nonferrous metals industry has been carried out industry consolidation with strong support by the central government. This work examined technical efficiency of Chinese nonferrous metals firms and its change during the period of 2007 and 2011. Based on financial data from nonferrous metals listed companies, technical efficiency of nonferrous metal minerals mining firms and nonferrous metal smelting, pressing and processing firms was estimated respectively using the data envelopment analysis （DEA） method. It was found that, in both sectors, number of pure technical and scale inefficient firms dominated over efficient ones. Overall, their technical and scale efficiency tended to be very low after 2009. In particular, efficiency scores of nonferrous metal smelting, pressing and processing firms fluctuated greatly during the research period. And a limited number of large leading firms were able to maintain 100% efficiency score in the industry, while efficiency of most of other leading firms has declined since 2009.

Effect of N Fertilization on Yield, N Absorption and Utilization of Two Species of Super High-Yielding Summer Maize

[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization.

Agrobacterium _mediated Transformation of Rice with Help of Bombardment

Oryza sativa L. ssp. japonica cv. Zhonghua 8, which is recalcitrant to infection of Agrobacterium tumefaciens (Smith et Townsend) Conn strain EHA105 with ordinary binary vector pCambia 1301, was transformed through Agrobacterium-mediated transformation with help of bombardment. The transformation efficiency can be raised greatly. Single copy of gene insertion in the genome of transgenic rice plants was proved by Southern analysis and the expression of GUS gene was observed. GUS gene and hygromycin-resistant gene show 3:1 segregation in progenies of the transgenic rice plants.

Effects of Different Irrigation Amounts on Water Consumption and Water Use Efficiency of Greenhouse Cucumber

[Objective] This study was to investigate the effects of different irrigation amount on water consumption and water use efficiency of greenhouse cucumber.[Method]Under the condition of drip irrigation with different water amounts in sunlight greenhouse of the arid areas in Ningxia,the soil water was measured and the water consumption of crop was calculated.[Result]When irrigation amount was 563 mm,the water consumption as a whole gradually increased with the delay of growth period,reached peak during the thriving stage of fruit setting,and then gradually declined;in each treatment,the daily water consumption increased with the increasing of irrigation amount during each growth period.However,the consumption of soil moisture reduced with the significant increase of irrigation.563 mm of irrigation amount could meet the water requirements of cucumber and began to add water to soil,and water utilization efficiency could reach 33.4 kg/m3.[Conclusion]The research had provided theoretical basis for water management in the production process of greenhouse cucumber.

Effect of oxide and fluoride addition on electrolytic preparation of Mg-La alloy in chloride molten salt

Mg-La alloys were prepared by constant voltage electrolysis in the molten salt system of MgC12-LaC13-KC1 at 750℃, with a graphite crucible as the anode and a tungsten rod as the cathode. The effect of oxide and fluoride addition on the electrolysis was investigated comprehensively. X-ray diffraction （XRD） was used to characterize some of the Mg-La alloy products and the sludges. As the content of MgO or La203 in the electrolyte increased, both the current efficiency and the mass of alloy product decreased, indicating that both MgO and La203 may take part in the reactions in the electrolyte. When the same mass of the oxide was added, compared with La203, MgO had a more pronounced effect on both the current efficiency and the mass of alloy product. XRD studies confirmed the formation of LaOC1 when MgO or LazO3 was added into the electrolyte. The formation of LaOCl sludge would be the main reason for the negative effect of the oxide addition on both the current efficiency and the mass of alloy. In the electrolytic system, the addition of CaF2 was not helpful to suppress the negative effect of MgO on the electrolysis, probably due to the complex reactions of the La compounds in the electrolyte.