SO2-4/TiO2-Al-MCM-41制备及其催化合成戊酸丁酯

选择硅酸四乙酯为硅源,在室温和pH=3.5条件下合成具有较低硅铝比的MCM-41型分子筛。以其为基础载体,采用浸渍和焙烧法制备含钛分子筛型固体超强酸。低温N₂吸附、IR、SEM和XRD分析表明,铝已进入分子筛的骨架中;Hammett指示剂测定表明,酸强度H₀<－14.52。以戊酸丁酯合成为探针反应,考察了催化剂的催化性能。结果表明,反应温度为138 ℃、催化剂用量为反应物总质量的1%、丁醇和戊酸的物质的量比为3∶1条件下,产品转化率达98.5%。     

Evaluating the regulator: Winners and losers in the regulation of Spanish electricity distribution

The principal aim of this study is to evaluate the regulation of electricity distribution in Spain. To this end, we begin by analyzing whether the changes introduced by the regulator led distribution companies to improve their efficiency; we then address whether the reimbursements paid to the distribution companies are linked to efficiency; lastly, we examine whether consumers benefited from the efficiency improvements. We focus on Spain because the electricity regulator in that country is a longstanding pioneer in the implementation of incentive-based regulatory models. Our analysis was implemented using the regulatory model proposed by Bogetoft (1997) as a benchmark. The results show that the Spanish electricity regulator did not establish a link between efficiency and the reimbursements paid to electricity companies; in addition, the electricity companies benefited to the detriment of consumers.     

高清电视电影后期制作问题研究

高清电视电影将凭借良好的解晰度、色彩还原以及丰富的艺术表现力而受到各类播出机构的青睐，影片在不同国家地区播出、发行及交流过程中会遇到要求影片提供不同格式的问题，在后期制作过程中如何具体解决上述问题是本文研究的主要方向。     

钻井风险评价方法与模型建立

提出了钻井风险的多因素多层次综合评价方法，以层次分析法建立模型，并求得了该模型的解。介绍了层次分析法，阐明了多因素多层次与风险的关系。通过实例分析，说明该方法可行，有助于钻井风险评价与防范，并提供了一个便于计算的风险定量化模型。     

The preparation and microwave properties of Ba3ZnZCo2-ZFe24O41/SiO2 microcrystalline glass ceramics by citrate sol-gel process

A series of Ba₃Zn_ZCo_2-ZFe₂₄O₄₁/SiO₂ microcrystalline glass ceramics with Z=0.0,0.4,0.8 and 1.2 were prepared by citrate sol-gel process. The result showed that Ba₃Zn_ZCo_2-ZFe₂₄O₄₁ hexferrite crystallites could be obtained by this process at 1200 °C in the system of BaO-Fe₂O₃-CoO-ZnO-SiO₂. The complex dielectric constant and complex permeability of Ba₃Zn_ZCo_2-ZFe₂₄O₄₁/SiO₂ microcrystalline glass ceramics calcined at different temperature were measured in the range of 200MHz-6 GHz by transmission/reflection coaxial line method. The complex dielectric constant and dielectric loss exhibited insignificant variety in the whole range of measuring frequencies for all samples. The real part of the permeability decreased as the measuring frequency increasing, and calcining temperature had a clear influence on the value of μ′ for Ba₃Zn_ZCo_2-ZFe₂₄O₄₁/SiO₂ microcrystalline glass ceramics, and so did the content of Zn²⁺ and Co²⁺. The natural resonance phenomenon was observed in μ′′ spectra for all the Ba₃Zn_ZCo_2-ZFe₂₄O₄₁/SiO₂ microcrystalline glass ceramics. The substitution of Zn²⁺ ion and annealing temperature closely affect the resonance frequency, the more the Zn²⁺ ion, the higher the annealing temperature and the lower the resonance frequency. Received: 23 July 2001 / Accepted: 24 July 2001     

C语言与汇编语言的接口技术在DSP芯片中的应用

对于DSP芯片的控制程序的开发,采用C语言和汇编语言混合编程具有较高的效率。该文阐述了两种语言的接口方式和接口协议,并给出了采用这种接口技术实现混合编程在DSP芯片TM320C24x中的几种典型应用实例。     

页岩气水平井生产套管变形机理及工程应对方案——以昭通国家级页岩气示范区黄金坝区块为例

针对四川盆地周缘昭通国家级页岩气示范区黄金坝区块2口页岩气水平井套管严重变形的情况,基于24臂井径套管变形测量、裸眼井径、电阻率电测、钻时及气测录井、固井CBL/VDL及CBL成像等资料,分析引起套管变形位置附近地层的地质与工程特征,利用三维成像分析软件分析24臂井径测量数据并进行三维成像,得到了变形套管的形态特征。研究结果表明:(1)极严重套管变形井段发生在构造裂缝发育区;(2)套管变形形态为上下方向为主的"S"形弯曲;(3)极严重套管变形呈现明显的遭受岩石高角度滑移挤压而横向剪切变形特征。据此提出建议:(1)该区应重点防范由岩石沿裂缝面滑移引起的剪切套管变形,利用产层段构造等值线图,设计井眼轨迹避开地下局部高陡构造的"脊部"或"谷底"位置;(2)利用产层段蚂蚁体分布图预测的裂缝带分布信息,使井眼轨迹沿裂缝带走向钻进;(3)推荐采用免钻磨大通径桥塞或全通径无限级完井工艺技术,避开压裂后常规桥塞钻磨工序,以确保压裂后的各级压裂层都能投产。     

The sources of the urban wage premium by worker skills: Spatial sorting or agglomeration economies?

We estimate the respective importance of spatial sorting and agglomeration economies in explaining the urban wage premium for workers with different sets of skills. Sorting is the main source of the wage premium. Agglomeration economies are in general small, but are larger for workers with skills associated with non‐routine job tasks. They also appear to involve human capital accumulation, as evidenced by the change in the wage of workers moving away from denser regions. For workers with routine jobs, agglomeration economies are virtually non‐existent. Our results provide further evidence of spatial density bringing about productivity advantages primarily in contexts when problem‐solving and interaction with others are important.     

一种高分辨率数据采集系统的设计

针对石油测井采集信号的特点,设计了一种高分辨率24位数据采集系统。给出了单片机和A/D转换器的接口电路,设计上位机控制软件。该采集系统采样最大频率为32ksps,可超前采集1s,采集数据以二进制文件形式保存。