The spatial-temporal differentiation of green land use in Beijing-Tianjin-Hebei urban agglomeration

As the space carrier of the construction of ecological civilization, land's green and efficient utilization is an important guarantee for realizing national sustainable development. Based on traditional land evaluation, this paper scientifically defines the green land use, puts land as one of the production factors, and brings energy consumption, environmental pollution, etc. into the input-output system to measure the green land utilization efficiency of the urban construction land of Beijing-TianjinHebei Urban Agglomeration from 2006 to 2016. The study shows that the overall efficiency variation of the urban agglomeration is related with the land and environment policies. Efficiency of 2016 is higher than that of 2006, and energy and environment are the principal factors affecting the green land use. The efficiency of each city is positively correlated with its economic development, negatively correlated with the construction land expansion. Efficiency gaps in different cities are expanding.There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.

A Meta-analysis on the clinical efficacy and safety of optic capture in pediatric cataract surgery

AIM： To evaluate the clinical efficacy and safety of optic capture in pediatric cataract surgery.·METHODS： Searches of peer-reviewed literature were conducted in Pub Med, Embase and the Cochrane Library. The search terms were ＂optic capture＂ and ＂cataract＂. The retrieval period ended in December 2014.Relevant randomized controlled trials（RCTs）, case-control studies and cohort studies were included. Meta-analyses were performed. Pooled weighted mean differences and risk ratios with 95% confidence intervals were estimated.· RESULTS： Ten studies involving 282 eyes were included, 5 of which were RCTs involving 194 eyes. The application of optic capture significantly reduced both opacification of the visual axis（RR： 0.12; 95% CI： 0.02 to0.85; P =0.03） and occurrence of geometric decentration（RR： 0.09; 95% CI： 0.02 to 0.46; P =0.004）. But it did not significantly affect best corrected visual acuity（BCVA）（WMD：-0.01; 95% CI：-0.07 to 0.05; P =0.75） and influence the occurrence of posterior synechia（RR： 1.53;95% CI： 0.84 to 2.77; P =0.17）. Deposits in the anterior intraocular lens were significantly increased in the optic capture group early after surgery（RR： 1.40; 95% CI： 1.05 to 1.86; P =0.02） and at the last follow-up（RR： 2.30;95% CI： 1.08 to 4.92; P =0.03）. The quality of the evidence was assessed as high.· CONCLUSION： The application of optic capture significantly reduces opacification of visual axis and occurrence of geometric decentration but do not significantly improve BCVA with notable safety.

Evaluation and welfare effect of coordinated ecological development of the Beijing-Tianjin-Hebei region

Regional coordinated ecological development is a new form of regional coordinated development that aims to construct an ecological civilization in the“new normal”period.The coordinated ecological development of the Beijing-Tianjin-Hebei(BTH)region is especially significant because this region is leading the overall coordinated development and reform in China.Based on complex system theory,synergetics,and the ecological civilization and green development ideas of the“new normal”period,we constructed a regional ecological synergy measurement model that scientifically evaluates the dynamic evolution of the BTH ecological synergy level from 2006 to 2018.Using an econometric model,we also analyzed the welfare effect and the regional heterogeneity of ecological synergy in regional development.First,it was found that in general,the degree of ecological synergy in BTH increased yearly up to 2018 with a strong development trend.The speed of ecological synergy in the Tianjin-Hebei and Beijing-Hebei subsystems was accelerating during that period,but the development potential of the ecological synergy in Beijing-Tianjin was insufficient and slow-growing.Second,whereas Beijing had entered the stage of moderate coordinated ecological development,Tianjin and Hebei remained in the low level of coordinated development;moreover,the coordinated development was unstable.The uneven development of the internal subsystems in BTH restricted the development of the cooperative effect and the overall development of the region.Third,improving the degree of ecological synergy significantly benefited the social and economic welfare in BTH.Finally,the welfare effect of the degree of ecological synergy showed a significant regional heterogeneity,being significantly higher in Tianjin and Hebei than in Beijing.This result indicates that improving the ecological synergy can narrow the development gaps between Tianjin,Hebei,and Beijing.To further improve the level of regional ecological synergy,we should innovate the coordinated model of regional development,implement the collaborative ecological development model,generate new growth drivers for the green development of BTH based on a reasonable division of labor,difference positioning,and active integration,create a soft environment for an innovation ecosystem that promotes regional ecological synergy,and build a regional innovation ecosystem led by Beijing and Xiongan.Next,we should establish a balanced regional-interest mechanism with ecological environmental protection that supports regional green and high-quality development.

Separating Citizenization and Land Requisition: New Urbanization in Beijing's Rural-Urban Fringe Area

Through rapid urbanization, Beijing is entering into the advanced stage of industrialization and urbanization, while it, like many other cities, is faced with issues of low-quality urbanization and citizenization. Under the infl uences of both urbanization and suburbanization, the sprawling rural-urban fringe area becomes a tough issue to resolve. The reconstruction of 50 key villages in Beijing's rural-urban fringe area that was started in 2010 has initially changed the citizenization-land requisition coupling model through recombining land use right, household registration, and social security to make farmers become new-type citizens with land use right. The practice in Beijing reveals that the fringe issues are caused by the new and old dual structures which are formed as a result of the urban-rural dual land system, and that the path to new urbanization in China is to separate citizenization from land requisition, so as to achieve the transformation towards a proactive urbanization.