In this paper, corn - based polylactic acid (PLA) biological packaging plastic is selected for the life cycle assessment-LCA. Taking Tianjin, China as an example, the PLA bio-package plastic is analyzed from four aspects: raw material acquisition, processing, use and final treatment. Produce costs, energy consumption, and greenhouse gas (GHG) emissions (equivalent carbon dioxide in this paper) over the entire life cycle of biological packaging plastic were calculated, and compared with traditional petroleum based Polyethylene (PE) plastic products in terms of environmental impacts. Based on LCA results, this paper puts forward corresponding suggestions and countermeasures from the perspective of sustainable development. The study found that the CO 2 emissions of biological materials are reduced by 61.25% compared with that of PE.

Because of people's increasing demand for water resources and excess usage of existing water, water shortage exists in many countries. Accordingly, the research on how to solve the water scarcity is of great value. Considering the dynamic influence of time on water resource supply and demand and the two factors including the degree of water resource exploitation and per capita availability of water, the water resource supply and demand model is built to measure the capacity of the region to offer clean water. Building up the grey prediction model to predict the following 15years' population situation and the total water resource supply in north China. By combining the model in before, the result that the demand for water resource is greater than the supply is concluded, which means severe water scarcity. The water scarcity causes the decrease of agricultural planting output, the change of planting structure, the reduction of industrial agglomeration and the residents' daily usage of water not reaching the living standard.

The living environment of human beings worsens, particularly the water scarcity is becoming more serious. It heavily affects the development of the nation and the survival of human beings. Firstly, this paper analysed the problem and developed a model that a region has the ability to provide clean water for its population, then predicted the future water resources and offered some measures to solve the problem. Firstly, we designed 5 influential principle indexes for water source and identified the controllable factors, then analysed the relationship between the various indexes. After that we developed the dynamic model to measure the water utilization rate and annual per ca-pita the surplus amount of water. First, analysed the pressure of world's water resources and selected India where water is heavily overloaded as the chosen country for the aim of research. Second, it analysed the reasons of water scarcity from the aspects of physical scarcity and physical scarcity. First of all, according to the development of environmental factors of India, we built the prediction model of population and GDP, then applied the models of water utilization rate and annual per capita the surplus amount of water to predict the situation of water resources in the next 15 years in India. In the next 15 years, water scarcity worsens gradually and the increasing rate of water utilization comes up and annual per capita availability of water falls, which dramatically affects the stability of economy, society and environment in India. Firstly, we developed the policy intervention model, then set up multi-objective model based on the minimum of water utilization and the maximum of annual per capita the surplus amount of water, predicted the two situations that applied the intervention or not.

The objective of this study is to explore the relationship between earthquake exposure and the incidence of PTSD. A stratification random sample survey was conducted to collect data in the Longmenshan thrust fault after Lushan earthquake three years. We used the Children's Revised Impact of Event Scale (CRIES-13) and the Earthquake Experience Scale. Subjects in this study included 3944 school student survivors in local eleven schools. The prevalence of probable PTSD is relatively higher, when the people was trapped in the earthquake, was injured in the earthquake or have relatives who died in the earthquake. It concluded that researchers need to pay more attention to the children and adolescents. The government should pay more attention to these people and provide more economic support.

Mechanical strong intelligent hydrogels have drawn the increasing attention in recent decades. We have designed a novel mechanical strong biocompatible dual pH- and temperature-responsive carboxymethyl chitosan (CMCTs)/graphene oxide (GO)/poly (N-isopropylacrylamide) (PNIPAM) nanocomposite double network hydrogel by a simple, one-pot in situ free radical polymerization initiated by the ultraviolet light, with the GO nanosheets as the crosslink centers instead of toxic common organic crosslinkers. CMCTs, EDC/NHS, or GO nanosheets are the pivotal factors for fabricating the mechanical strong dual responsive hydrogel. By adjusting the above factors, the optimal mechanical strong hydrogel displayed a high compressive strength of 0.792 MPa at the breaking strain of 0.836. Besides, we also investigated the relationship between the swelling and deswelling behaviors of the synthesized hydrogel and the above mentioned factors. Owing to this outstanding performance, they may have the potential application in drug delivery system and chemical valves in the future.

Multi-components electrical equipment has multiple failure modes. In the context of condition-based maintenance, it is inefficient if executing maintenance for a particular failure mode. Based on analysis of economic independence, opportunistic maintenance is a special preventive maintenance which can coordinate different maintenance for multiple failure mode. Furthermore, steady availability of equipment was quantified with inspection frequency and opportunistic maintenance strategy. Finally, maximizing steady availability of equipment with inspection frequency constraints to construct model. Feasibility and validity of the model are investigated through case study.