Does information and communications technology affect economic growth? Empirical evidence from SAARC countries

ABSTRACT

This study investigates the impact of Information and Communications Technology (ICT) on economic growth (gross domestic product) for member countries of South Asian Association for Regional Cooperation (SAARC) using annual data for the period 1990–2014. The study has employed augmented Cobb–Douglas production function by incorporating ICT along with capital and labor. We have taken teledensity (number of fixed and mobile phones per 10,000 people) as the proxy of ICT. This study has included only four SAARC countries (Bangladesh, India, Sri Lanka, and Pakistan) due to data constraints. Our findings reveal a positive and statistically significant effect of ICT on economic growth using panel data techniques. However, the impact of ICT on economic growth is highest for India followed by Sri Lanka, Bangladesh, and Pakistan respectively. This study has crucial policy implications for SAARC countries as they have started giving due significance to the issues related to ICT these years.     

中亚高山区云下与地表降水氢氧稳定同位素时空分布特征及其水汽来源分析

基于中亚高山区7个站点的降水稳定同位素观测数据,利用Stewart雨滴蒸发模型及HYSPLIT模型,分析了云下与地表降水稳定同位素的时空分布特征及其与气象因子、地理环境和水汽来源之间的关系。结果表明:研究区地表与云下降水的δ²H和δ¹⁸O均表现出明显的季节波动,春夏富集,秋冬贫化；氘盈余则呈现相反的季节变化趋势;云下大气降水线斜率和截距均大于地表大气降水线,说明地表大气降水线受蒸发影响更显著；云下与地表降水的δ²H、δ¹⁸O和高程呈显著的负相关关系,而地表氘盈余呈现反高程效应；云下与地表降水δ¹⁸O与温度呈正相关关系,氘盈余与温度呈负相关关系,而降水量效应在云下与地表降水中均不显著；水汽输送轨迹显示,夏半年水汽主要源自西伯利亚大陆气团及局地再蒸发水汽,冬半年水汽主要源自西风带输送的北大西洋水汽,且在西风控制下的氘盈余值显著偏高。     

亚洲地区黑碳气溶胶外场在线观测研究进展

黑碳气溶胶是化石燃料和生物质不完全燃烧的产物之一, 不仅影响着空气质量和人体健康, 还通过吸收太阳 辐射改变辐照平衡从而影响区域乃至全球气候。亚洲地区作为世界七大洲中人口最多、面积最广的地区, 黑碳气溶 胶排放量占全球排放量二分之一以上。对当前黑碳气溶胶观测所用主要仪器与方法, 以及亚洲地区从上世纪九十年 代至今有关黑碳气溶胶的观测结果进行了系统性总结。通过总结发现亚洲地区大气黑碳浓度分布特征与人口分布特 征相一致, 中国地区黑碳浓度分界线与胡焕庸线大致吻合, 佐证了黑碳主要受人为活动影响的结论；并进一步分析了 亚洲地区黑碳排放来源及影响因素,以及黑碳光学性质的最新研究成果；最后总结了当前研究中存在的不足, 并对黑 碳气溶胶未来研究方向提出了展望。     

A seasonal forecasting procedure for reservoir inflows in Central Asia

This study develops a procedure for seasonal forecasting river discharge from headwaters above strategically important hydropower plants in Kyrgyzstan and Tajikistan. The El Niño Southern Oscillation, North Atlantic Oscillation, and Indian Ocean Dipole indices were used as inputs. Predictability was evaluated for average summer inflows conditional on the tercile of the preceding winter climate mode. We find that the winter Niño 3.4 index was significantly positively correlated with following summer inflows to Nurek, Andijan, and Toktogul reservoirs during the period 1941–1980. Kruskal–Wallis and Kolmogorov–Smirnov tests show significant differences in the distributions of summer inflows depending on previous winter Niño 3.4 for all three reservoirs. At Nurek, summer inflows were on average 19% greater following a winter El Niño. During 1941–2016, mean summer inflows to Nurek reservoir linked to previous November–December Niño 3.4 achieved a Heidke Hit Proportion of 51–59% (compared with 33% expected by chance). Acceptable predictions of summer inflow volume were made 44% of the time. Higher inflows are explained by a south‐westerly moisture flux that brings above average precipitation to Central Asia during winter El Niño conditions. Our procedure requires limited data, technical or computing resources—all considerations in data sparse, low capacity regions. Given planned developments of other large, headwater impoundments in Central Asia, early outlooks of discharge could contribute to improved dam safety, economic performance, and transboundary water sharing around such projects.     

Fertilizer use in Asian agriculture: implications for sustaining food security and the environment

This paper studies the role of chemical fertilizers in sustaining the growth in foodgrain production in the major rice growing countries in Asia. The trends in fertilizer consumption are reviewed, the yield response and change in policies in the fertilizer sector and their impact on fertilizer prices are assessed and factors affecting fertilizer demand are analyzed. The implications of sustaining food security and the environment on fertilizer use are critically examined, future projections on food and fertilizer demand are made and areas of research needed to achieve the targets are suggested.     

鄂尔多斯盆地东南缘地应力、储层压力及其耦合关系

采用水压致裂测量地应力方法,获得了鄂尔多斯盆地东南缘26口煤层气井地应力分布,通过统计分析,建立了二叠系山西组2煤储层地应力与煤层埋藏深度之间的相关关系和模型,揭示了现今地应力分布规律及受控机制。研究结果表明,本区二叠系山西组2煤层破裂压力梯度、闭合压力梯度和煤储层压力梯度的平均值分别为 1.96,1.69,0.71 MPa/100 m。煤储层最大水平主应力、最小水平主应力和垂直主应力以及储层压力均随着煤层埋藏深度增大呈线性规律增高。在 1 000 m 以浅煤储层地应力状态主要表现为σv＞σhmax ＞σhmin ,最小水平主应力小于16 MPa,现今地应力处于拉伸应力状态,煤储层有效应力系数K0 为0.48,且低于油气盆地页岩层中的有效应力系数值(K0 =0.80);在1 000 m以深煤储层地应力状态转化为σhmax ≥σv≥σhmin ,最小水平主应力大于16 MPa,现今地应力转化为挤压应力状态。本区现今地应力受华北区域构造应力场控制,最大水平主应力方向主要以NEE-SWW方向为特征。本区煤储层压力偏低,相同深度条件下鄂尔多斯盆地东南缘煤储层压力要比沁水盆地南部偏低0.73~0.93 MPa,且煤储层压力与地应力呈正相关关系,随着地应力的增加,煤储层压力增大。     

地脉与风土 # ——渝东南土家族传统民居院落类型与演化

土家族聚居的渝东南地区是山脉围合的山地生态单元及水系交汇的地缘空间,在地脉的沉积影响与风土的传播交融中,民居院落在组合结构、空间形制、内部场域呈现多元表征。民居院落的类型演化与地理空间呈现相关性,表现为以地理区系及移民路径为内核的演化趋势,反映了土家族民居院落的地域性与风土性。本文以宏观到微观、物质到精神的多维度视角梳理土家族传统民居院落类型,研究其生成演化的内在机制以建构“形制 - 文化”逻辑,为当下土家族民居多样性的识别与保护提供参考。     

典型渝东南土家族聚落夏季风环境及吊脚楼夏季热环境模 拟研究

渝东南土家族人民生活在气候湿 热的武陵山区,当地土家族的聚落在选址 布局、空间形态中反映出利用自然通风进行 除湿、降温的技术策略。本文以典型的渝东 南土家民居聚落——黔江后坝乡为例,利用 Ecotect与CFD软件进行通风模拟研究,分 析其利用自然通风进行除湿、降温的技术 经验,提出有利于组织通风的典型聚落空 间形态,以及其中典型单体——“吊脚楼” 的特殊作用。     

川东南地区震旦系――志留系下组合有效烃源岩综合研究

震旦系志留系是川东南地区油气勘探的新层系、新领域，具有较好的勘探前景，但勘探程度极低。以地表露头、钻井岩芯样品为基础，通过地球化学特征、气源和沥青源对比分析，明确了下寒武统牛蹄塘组、下奥陶统五峰组下志留统龙马溪组灰黑色泥岩、页岩为区内震旦系一志留系主要烃源岩，其中下志留统龙马溪组烃源岩最为发育，且其发育时期与大地构造格局或沉积盆地性质发生重大变革的转换时期相吻合，还明确了主要烃源岩横向展布特征及其构造沉积主控因素。     

Adjustable robust low-carbon dispatch for interconnected power systems in Northeast Asian countries

Interconnected power systems that link several countries and fully utilize their individual resources in a complementary manner are becoming increasingly important. As these systems enhance accommodation of renewable energy, they also represent a move toward low-carbon and low-emission power systems. In this paper, a low-carbon dispatch model is proposed to coordinate the generation output between several countries where the carbon emission constraint is a priority. An adjustable robust optimization approach is used to find the optimal solution under the worst-case scenario to address the uncertainties associated with renewable energy resources. A specific constraint is that the area control error for each country should be self-balanced. Furthermore, a reformation using participation factors is presented to simplify the proposed robust dispatch model. Simulation results for practical interconnected power systems in northeast Asian countries verify the effectiveness of the proposed model.