高温红外吸收法测定水煤浆中可燃硫方法研究

研究采用高温红外吸收法直接测定水煤浆中可燃硫方法,确定了用浆状水煤浆试样或粉末固体试样的样品制备和红外测硫仪的炉温设定范围(900℃～950℃),通过与间接差减法测定结果对比分析,表明此法可行.     

What drives large South African corporations to invest in sub‐Saharan Africa? CEO's perspectives and implications for FDI policies

Foreign direct investment (FDI) flowing into Africa is highly diverse in terms of the origin of the investors, size of the firms, and the sectors of activity. The motivations and factors driving firms' decisions to invest in Africa are equally diverse. A direct survey of senior management in South African firms that are operating in sub-Saharan Africa reveals that the drivers of foreign investment as well as the risks and the strategies to overcome them differ markedly between sectors. A further finding is that there is a limited pool of FDI promotion policies and incentives that governments can institute that are effective in impacting South African corporations' investment decisions. As a consequence, broad-based FDI promotion policies aimed at attracting FDI across all investor groups are likely to have limited impact in attracting FDI from any particular investor group, or in attracting any FDI from multinational companies similar to the South African companies studied here. Such broad based policies probably need to be complemented with policies targeting those specific firms or sectors which countries hope to attract.     

石灰石与SO_2直接硫酸化反应宏观动力学的研究

温度、ＳＯ＿２浓度、颗粒大小、石灰石类型和样品的微观结构影响着直接硫酸化反应过程。这一反应过程能用缩芯模型来描述，并对ＳＯ＿２具有一级反应特征。本征反应和产物层扩散控制反应的活化能分别是８５．２ｋＪ／ｍｏｌ和４１．５ｋＪ／ｍｏｌ。在８００℃、２０００ｐｐｍＳＯ＿２和反应１０１ｍｉｎ的条件下，Ｉｇｚｌａｂｅｒｇａ和Ｆｏｒｓｂｙ石灰石的ＣａＣＯ＿３转化率分别可达８４％和７２％。在初始２ｍｉｎ内已煅烧石灰石（ＣａＯ）的硫酸化反应速率与石灰石的反应速率稍高，随后二者基本相同。     

Rapid karyotyping in ectopic pregnancies

The aim of this study was to determine the feasibility of karyotyping ectopic Fallopian tube pregnancies utilizing dividing cytotrophoblast cells. Villi from 78 ectopic conceptuses were processed by the direct chromosome technique and cytogenetic diagnosis was successful in 60 cases (76-9 per cent). The amount of villi obtained, as well as villus morphology, was correlated with cytogenetic success rate. Histological examination of the Fallopian tube was also carried out. A total of 47 cases were chromosomally abnormal (78-3 per cent), which is the highest frequency of cytogenetic abnormalities reported to date.     

微絮凝——直接过滤技术的研究与应用进展

对微絮凝—直接过滤技术在城市给水处理和城市废水的深度处理中的研究与应用现状做了概述 ,并对以后的研究工作提出一些建议。     

Sulfate aerosols forcing: An estimate using a three-dimensional interactive chemistry scheme

The tropospheric sulfate radiative forcing has been calculated using an interactive chemistry scheme in LMD-GCM. To estimate the radiative forcing of sulfate aerosol on climate, a consistent interaction between atmospheric circulation and radiation computation has been allowed in LMD-GCM. The model results indicate that the change in the sulfate aerosols number concentration is negatively correlated to the indirect radiative forcing. The model simulated annual mean direct radiative forcing ranges from −0.1 to −1.2 W m⁻², and indirect forcing ranges from −0.4 to −1.6 W m⁻². The global annual mean direct effect estimated by the model is −0.48 W m⁻², and that of indirect is −0.68 W m⁻².     

Does female plumage coloration signal parental quality? A male removal experiment with the bluethroat (Luscinia s. svecica)

Females in several sexually dimorphic species with conventional sex roles possess ornamental traits that resemble those found in males. The evolution of such traits, however, is still poorly understood. Bluethroats (Luscinia s. svecica) are socially monogamous, sexually dichromatic passerine birds, in which female throat patch coloration varies from near absence to near full expression of male-like coloration. A recent study, demonstrating that male bluethroats prefer colourful females, suggests that female coloration is subject to sexual selection through male choice. However, the benefits males may gain from mating with colourful females have not yet been identified. In this study we tested the hypothesis that female coloration signals parental quality (the good-parent hypothesis). During the course of the same day, we recorded female care both in the presence and the absence of the male mate. The latter was done to eliminate the confounding effect of variable male care by removing the male temporarily. Female coloration did not correlate with female feeding rates either in the presence or in the absence of the male. Female feeding rates in the absence and the presence of the male were positively, although weakly, correlated. Female coloration did not correlate with female ability to compensate for the loss of male care, or with the change in brood mass during male removal. Therefore, there is no evidence for the good-parent hypothesis to explain female plumage coloration in bluethroats. Received: 4 March 1999 / Received in revised form: 14 October 1999 / Accepted: 23 October 1999     

Frontier science and challenges on offshore carbon storage

● The main direct seal up carbon options and challenges are reviewed. ● Ocean-based CO₂ replacement for CH₄/oil exploitation is presented. ● Scale-advantage of offshore CCS hub is discussed. Carbon capture and storage (CCS) technology is an imperative, strategic, and constitutive method to considerably reduce anthropogenic CO₂ emissions and alleviate climate change issues. The ocean is the largest active carbon bank and an essential energy source on the Earth’s surface. Compared to oceanic nature-based carbon dioxide removal (CDR), carbon capture from point sources with ocean storage is more appropriate for solving short-term climate change problems. This review focuses on the recent state-of-the-art developments in offshore carbon storage. It first discusses the current status and development prospects of CCS, associated with the challenges and uncertainties of oceanic nature-based CDR. The second section outlines the mechanisms, sites, advantages, and ecologic hazards of direct offshore CO₂ injection. The third section emphasizes the mechanisms, schemes, influencing factors, and recovery efficiency of ocean-based CO₂-CH₄ replacement and CO₂-enhanced oil recovery are reviewed. In addition, this review discusses the economic aspects of offshore CCS and the preponderance of offshore CCS hubs. Finally, the upsides, limitations, and prospects for further investigation of offshore CO₂ storage are presented.     

Stimulation impact of electric currents on heterotrophic denitrifying microbial viability and denitrification performance in high concentration nitrate-contaminated wastewater

Electric current stimulation has been shown to have a positive influence on heterotrophic denitrifying microbial viability and has the potential to improve wastewater denitrification performance. This study investigated the effects of varying current densities on microbial activity and NO_3~- removal efficiency under heterotrophic conditions.NO_3~-removal rate was highest at an applied current density of 400 mA/m~2. However, the optimum removal efficiency of total inorganic nitrogen(TIN; 99%) was achieved when the current density was fixed at 200 m A/m~2. Accumulation of NH_4~+-N and NO_2~--N byproducts were also minimized at this current density. The activity of heterotrophic denitrifying microorganisms was much higher at both 200 and 400 mA/m~2. Moreover, the average adenosine-5′-triphosphate(ATP)content(an indicator of cell metabolism) at a current density of 1600 mA/m~2 was lower than that under no current, indicating heterotrophic denitrifying microbial activity can be inhibited at high current densities. Hence, direct electrical stimulation on the activity of heterotrophic denitrifying microorganisms in the developed system should be lower than 1600 mA/m~2. This study improves the understanding of electric current influence on heterotrophic denitrifying microorganisms and promotes the intelligent application of direct electrical stimulation on wastewater treatment processes.