构建更加灵活的土地管理政策体系

当下,我国社会主要矛盾发生变化,经济从高速增长阶段转向高质量发展阶段,土地管理体制、理念发生深刻变化。适应这些变化,在更高起点、更高层次、更高目标上推进管理制度改革,增强管理灵活性,对解决市场激励不足、要素流动不畅等问题,推进自然资源治理体系和治理能力现代化具有重要意义。深入学习领会党中央、国务院有关精神,加强和改善土地管理制度供给,构建更加灵活的管理政策体系,是摆在面前的重大课题和迫切任务。增强管理的灵活性,做好放活土地要素这篇大文章,根本出路在于深化“放管服”改革,在实践中彻底破解管理体制机制上的主要问题,创新管理方式和服务方式。     

中心城市产业结构对腹地城市人口增长及区域城市体系演化的影响

从产业异质性的角度,实证分析区域中心城市产业结构对周边城市人口增长的作用过程和机制,并进一步探究了产业结构对于区域城市体系的极化和均衡演化的影响。结果表明：(1)制造业强化了中心城市的溢出效应,促进了周边城市人口的增长,而服务业则弱化了溢出效应,对周边城市的增长具有抑制作用;(2)以制造业为主的区域中心城市由于相对较小的城市规模和较强的溢出效应,更容易形成相对均衡的区域城市体系,而以服务业为主的区域中心城市,更倾向形成相对极化的区域城市体系;(3)产业结构与周边城市人口增长呈现倒“U”型关系,即中心城市制造业或服务业占比过低或过高都不利于周边城市的人口增长。     

东北三省城乡结构演变及其经济增长效应

基于2003—2019年东北三省34个地级市面板数据,构建包括经济结构、要素结构、社会结构和公共服务结构的城乡结构协调度指标体系,运用全局熵值法和空间计量模型,探究城乡结构演变格局及其经济增长效应。研究发现：(1) 2003年来,东北三省城乡结构协调水平整体提升且空间集聚特征显著,但中心城市的城乡结构协调水平相对较低,要素资源分布较为集中。(2)城乡结构各指标变化率呈现“点状+面状集聚”空间格局,其中经济结构和要素结构演变类型主要为增长型,公共服务结构演变类型主要为降低型,社会结构演变类型省际差异明显。(3)空间计量分析结果表明,经济结构和公共服务结构协调度提高、要素结构和社会结构协调度降低对经济增长产生促进作用,且城乡结构、经济结构和公共服务结构协调度提高具有正向溢出作用。(4)城乡结构演变对经济增长的影响存在区域异质性特征。     

新疆农牧业碳排放及其与农业经济增长的脱钩关系研究

研究基于农地利用、畜牧养殖两方面15类碳源,测算了新疆1993-2011年以及各地州2011年的农牧业碳排放量,并运用Tapio脱钩模型对1994-2011年间新疆农牧业碳排放与农业经济增长之间的脱钩关系进行分析。结果显示:(1)2011年新疆农牧业碳排放总量为778.73×104t,比1993年增加了50.12%,年均增长2.28%,呈现出明显的"持续上升——波动上升"两阶段特征,碳排放强度和结构的空间差异明显;(2)农牧业碳排放与农业经济增长呈现出"弱脱钩与扩张连接交替—弱脱钩平稳—强脱钩转型"的演进过程。     

城市化、房地产投资与经济增长关系的研究——以河南省为例

在对城市化、房地产投资和经济增长之间相互作用机制进行分析的基础上,应用协整理论和格兰杰因果性检验研究了1990—2012年河南省城市化、房地产投资与经济增长之间的关系。协整检验表明:城市化、房地产投资与经济增长之间存在长期稳定的均衡关系。格兰杰因果性检验表明:城市化是促进经济增长的长期原因,而房地产投资并不是促进经济增长的长期原因;城市化是房地产投资增加的长期原因,房地产投资对城市化没有明显的推动作用。基于此,应采取措施加快城市化进程,完善房地产投资结构,合理调控房价,使城市化、房地产投资与国民经济协调发展。     

未来几十年煤炭仍是最主要能源

<正>必和必拓总裁安德鲁·麦肯齐表示,经济飞速增长的亚洲获取煤炭资源比获取天然气更容易一些。在未来相当长一段时间,煤炭还将是亚洲地区最主要的能源。近日,在休斯敦举行的一次能源高层论坛上,麦肯齐称,未来20年能源需求量将在现有基础上增长30%,其中一半增长来自于中国和印度。这些新兴经济体如何满足它们经济增长的需求,将对全球经济产生重大影响。     

Responses to two-way selection on growth in mass-spawned F1 progeny of Argopecten irradians concentricus (Say)

A bstract In the present study,the effect of one-generation divergent selection on the growth and survival of the bay scallop(Argopecten irradians concentricus)was examined to evaluate the effi cacy of a selection program currently being carried out in Beibu Bay in the South China Sea.A total of 146 adult scallops were randomly selected from the same cultured population of A.i.concentricus,and divided into two groups in shell length(anterior-posterior measurement): large(4.91–6.02 cm,n=74)and small(3.31–4.18 cm,n=72).At the same time,a control group was also randomly sampled(4.21–4.88 cm,n=80).Mass-spawned F 1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases.The effects of two-way(or upward-downward)selection on fertilization rate,hatching rate,survival rate,daily growth in shell length and body weight were assessed in the three size groups.Results show that signifi cant differences(P0.01)were found in hatching rate,survival rate and daily growth of F 1 progenies,but not in fertilization rate(P0.05),among the three groups.The hatching rate,survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group(P0.05),which in turn were larger than those of small-sized group(P0.05).Responses to selection by shell length and body weight were 0.32±0.04 cm and 2.18±0.05 g,respectively,for the upward selection,and-0.14±0.03 cm and-2.77±0.06 g,respectively,for the downward selection.The realized heritability estimates of shell length and body weight were 0.38±0.06 cm and 0.22±0.07 g for the upward selection,and 0.24±0.06 cm and 0.37±0.09 g for the downward selection,respectively.The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.     

Influence of stocking density on growth,body composition and energy budget of Atlantic salmon Salmo salar L. in recirculating aquaculture systems

Atlantic salmon Salmo salar were reared at four stocking densities—high density D 1(final density ~39 kg/m 3), medium densities D 2(~29 kg/m 3) and D 3(~19 kg/m 3), and low density D 4(~12 kg/m 3)—for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight(SGR w) but did affect specific growth rate in terms of energy(SGR e). Stocking density significantly influenced the ration level(RL w and RL e), feed conversion ratio(FCR w and FCR e) and apparent digestibility rate(ADR). Ration level and FCR w tended to increase with increasing density. Fish at the highest density D 1 and lowest density D 4 showed lower FCR e and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.     

A Study of Resource Curse Effect of Chinese Provinces Based on Human Developing Index

Traditional opinion considers that natural resources play an important positive role in economic development, while resource curse theory holds that natural resources usually obstruct economic increase. This debate needs further exploration. In most of empirical studies on resource curse theory, the economic development of an area is mainly evaluated by the Gross Domestic Product （GDP）, however, the social and cultural contents of economic development are seldom considered. Thus, the Human Developing Index （HDI） was chosen to describe the comprehensive developing situation of an area in our study. Based on the panel data from the year of 2000 to 2011, the relationship between Human Developing Index and resource exploitation degree （RED） of 30 provinces in China （Tibet, Tai- wan, Hong Kong and Macao were not included because of the restriction of data acquisition） was investigated by correlation coefficient analysis and regression analysis. We found that resource curse did exist over the entire country and its effect on 30 provinces were not exactly the same. According to the effects of resource curse, these provinces could be classified into four types： no resource curse prov- inces, slight resource curse provinces, severe resource curse provinces, and extreme resource curse provinces. Testing from two short time periods 2000-2005, and 2006-2011, the resource curse effect was not prominent. However, testing from the entire period of 2000-2011, the effect was obvious among each province.     

河南省地理信息导航产业园奠基

正2月18日,河南省地理信息导航产业园举行奠基仪式。河南省国土资源厅党组书记、厅长盛国民,省测绘地理信息局局长贾志伟,省测绘地理信息局副局长禄丰年、王进福,郑州市委常委、统战部长王跃华等领导参加奠基仪式。随着3S技术应用领域的不断拓展,特别是新一代互联网、物联网和云计算等高新技术的融合与发展,地理信息产业已成为全球成长性最好、产业链最长、拉动效应最强的朝阳产业,也是国家城镇化建设、信息化建设、调整产业结构、转变经济增长方式和改善民生的战略性新兴产业。面对这一历史机遇和日趋激烈的国际竞争,如何迅速