Search

Purpose Single-incision laparoscopic surgery (SILS) has been validated as a safe approach for bariatric surgery. However, as the utilization of SILS in bariatric surgery is still limited by its disadvantages, this study analyzes the outcomes of symmetric three-port laparoscopic Roux-en-Y gastric bypass (STLGB). Methods The medical records of patients who underwent STLGB between January 2018 and February 2021 were analyzed retrospectively using an institutional database. The patients were divided into four groups according to their baseline body mass index (BMI). The primary endpoints were operative time, length of stay, complication rate, and weight loss 12 months after surgery. Results We analyzed the records of 101 patients who underwent STLGB. There was a slight predominance of women (n = 61; 60.4%). The mean operative time was 97.16 ± 38.79 min and the length of stay in the hospital after surgery was 2.79 ± 1.4 days. One patient (0.99%) suffered a gastrojejunal anastomosis leak within 30 days of surgery. There were no significant differences in LOS, complication rate, or cosmetic score among the four groups. The mean BMI reduction was 8.67 kg/m2 and the % total weight loss (%TWL) was 24.37%. Weight loss measured 12 months after surgery was significantly different among the four groups. Conclusions STLGB is safe, effective, and feasible for all kinds of patients. It is reproducible with standardization of the procedure.

The production of ancient glass is the crystallization of the wisdom of the majority of ancient working people in China. The differences in fluxes and the differences in the burial environment during weathering have a great impact on its chemical composition content. In this paper, a relevant classification model is established based on the data of various properties of glass. In this paper, Fisher linear discriminant model and random forest classification model were established according to the content of different chemical components, and Fisher linear discriminant model, which is easier to test for sensitivity analysis, was selected. Next, the clustering results were obtained by systematically clustering high potassium glass and lead-barium glass, and the classification basis was determined by drawing a line graph and then establishing a subclass classification model to classify high potassium glass into low potassium subclasses and high calcium subclasses. Sensitivity analysis was performed by changing the values of key parameters to check the reasonableness and stability of the subclass classification model. A discriminant model was established to initially determine the categories of eight unknown classified glass artifacts. Sensitivity analysis was performed by changing the key variables through the gradient descent method, and the model was obtained to have good sensitivity.

This study constructs a multi-player evolutionary game of local governments, tourism enterprises, and residents to analyze the stability strategies of game players in ecotourism protective development. The results show that the evolutionary game system of ecotourism conservation development can form four kinds of stable strategies under different conditions. The marginal influence of restrictive factors on the players’ strategic choice is more significant than that of incentive factors. Government penalties and incentives promote tourism enterprises to choose protective development strategies, and residents to choose supervision strategies. When higher protective development rewards exceed the government’s support capacity, the probability of local governments choosing active supervision strategies will decrease. Tourism enterprises will also reduce the probability of choosing protective development strategies due to the lack of effective supervision. The research results can help decision-makers to formulate ecotourism protection and development policies, and promote the sustainable development of ecotourism.

Grassland degradation has become one of the most important ecological and environmental problems in the world, affecting the ecological balance of grassland and the welfare of residents. To reveal the impact mechanism of herders’ livelihood constraints on grassland degradation, and to explore the comprehensive management methods to ensure herders’ livelihoods and grassland ecological restoration, this paper constructed an evolutionary game model considering local governments and herders. It is found that the ideal stable equilibrium game can be achieved when certain conditions are met, that is, when the local governments actively regulate and herders moderate grazing, the grassland degradation caused by overgrazing can be reduced. The livelihood differentiation of herders significantly affects the stable equilibrium state of the evolutionary game. The local government’s regulation is the key to promoting moderate grazing of herders. The effect of incentive measures on the moderate grazing of herders is limited, while punishment measures can significantly restrict the excessive grazing behavior of herders. Policy support for household livelihood differentiation can effectively motivate herders to moderate grazing and achieve their survival and development needs to a greater extent through a non-grazing livelihood. The research results help decision-makers to formulate policies to combat grassland degradation, and promote the improvement of herders’ lives.

Natural disasters occur when environmental systems have a disruptive effect on the socio-economic system. In recent years, particular unreasonable human behaviours have amplified losses from natural disasters as result of the increasing complexity of human systems. Because of the lack of both quantitative calculation of this amplification, and analysis of the root cause of these behaviours, existing risk assessment and management research rarely includes unreasonable human behaviour as a critical factor. This study therefore creates three simulation scenarios, each based on a twenty-first-century catastrophe in China, and calculates the disaster losses that are amplified when such behaviour increases exposure (the 2008 Wenchuan earthquake), vulnerability (the 2014 Ludian earthquake) and hazard (the 2021 Zhengzhou rainstorm) levels. In doing so, it intuitively demonstrates the amplification effect caused by unreasonable human behaviour. The results show that these behaviours amplified disaster losses significantly: increased exposure due to unscientific planning nearly doubled the death toll in the Wenchuan earthquake; high vulnerability caused by the low economic level of residents increased the disaster losses of the Ludian earthquake more than tenfold; and the elevated hazard intensity caused by anthropogenic climate change resulted in a 1.44-times expansion of the area severely affected by the Zhengzhou rainstorm. These behaviours have become an important cause of disasters, and the main driving factors behind them—such as neglecting disaster risk; the inability to cope with disasters; and a lack of certainty about how to deal with extreme events—are the inevitable outcomes of societal development. On this basis, we constructed an extended risk framework that included unreasonable behavioural factors and a disaster mechanism, to analyse in depth the relationship between human behaviours and disaster risk prevention in different developmental stages. The results provide an important reference for the development of risk management policies to control these unreasonable behaviours.

This study aimed to investigate the prevalence of anemia and related nutrient deficiencies after sleeve gastrectomy (SG). Four online databases were searched for relevant articles. Thirty-one studies with 7639 patients were included in the meta-analysis. The pooled anemia prevalence was 7%, 6%, 9%, 10%, 12%, 25%, 20%, and 18% at baseline, 3 months, 6 months, 12 months, 24 months, 36 months, 48 months, and 60 months, respectively. Although the prevalence of vitamin B12 and folate deficiencies remained low postoperatively, the prevalence of ferritin deficiency steadily increased from 6% at baseline to 27% at 60 months. The prevalence of serum iron deficiency decreased from 13% at baseline to 6% at 24 months and increased to 20% at 60 months. Anemia and ferritin deficiency were strongly correlated (Pearson correlation coefficient = 0.774, p = 0.041). Subgroup analysis suggested that age ≤40 years, preoperative anemia, and insufficient iron supplementations were high-risk factors for postoperative anemia. SG is associated with an increased risk of anemia and decreased iron storage over long-term observation. Routine iron supplementations may reduce anemia after SG; however, the dosages recommended by current guidelines may be insufficient. More strict monitoring schedules and supplementation strategies should be established for the timely detection and management of postoperative anemia.

Background: Long noncoding RNAs (lncRNAs) X inactivate-specific transcripts (XIST) have been found to be dysregulated in breast cancer (BC). Nevertheless, the influence and mechanism of XIST on BC progression remain largely undefined. Methods: The expression levels of XIST, miR-362-5p, and ubiquitin-associated protein 1 (UBAP1) mRNA were detected by quantitative real-time polymerase chain reaction. Cell proliferation, apoptosis, migration, and invasion abilities were determined using MTT assay, flow cytometry, and transwell assay, respectively. Targeted relationship between miR-362-5p and XIST or UBAP1 was validated by the dual-luciferase reporter assay. Western blot was performed to evaluate UBAP1 protein level. Xenograft mice model was established for the investigation of XIST in tumor growth. Results: The authors' data indicated that XIST and UBAP1 were downregulated in BC tissues and cells. XIST overexpression weakened BC cell proliferation, migration, invasion, and facilitated the apoptosis, and XIST silencing exerted opposite effect. Mechanistically, XIST directly interacted with miR-362-5p and miR-362-5p mediated the regulatory effects of XIST overexpression on BC cell malignant behaviors. UBAP1 was a direct target of miR-362-5p. MiR-362-5p exerted its regulatory effects on BC cell behaviors by UBAP1. Moreover, XIST modulated UBAP1 expression through acting a competing endogenous RNA of miR-362-5p. XIST overexpression mediated antiproliferation, antimigration, anti-invasion, and proapoptosis effects were abated by the restored expression of UBAP1 in BC cells. Furthermore, the upregulation of XIST hindered tumor growth in vivo. Conclusion: The current study suggested that XIST overexpression hampered BC cell progression in vitro and in vivo at least partially by targeting the miR-362-5p/UBAP1 axis, illuminating XIST as a promising therapeutic agent for BC management.

The development of Qingzang national park cluster is part of China’s efforts to establish a major ecological civilization project in the Qingzang Plateau, in line with global sustainable development goals. Based on preliminary scientific investigation and research in the Qingzang Plateau, the construction of the park cluster will include 21 national parks. To mitigate the conflict between conservation of the national park cluster and the development of local communities, this study proposes an analysis framework to identify the spatial coupling features between the national park cluster and sustainable development of communities. Four elements were selected to construct the analysis framework, including natural conditions, geographic location, cultural background, and national policies. This framework was applied to the 457 township communities within the 21 national parks. Results show the weak influence of the construction of the national park cluster for approximately 304 township communities, without significant spatial coupling traits, while the remaining 153 communities demonstrated significant spatial coupling features. These latter townships had developed four types of spatial coupling with national parks, including eco-migrants, transportation hubs, characteristic cultures, and border development, which account for 17.4%, 35.3%, 19.8%, and 27.5% of the 153 townships respectively. A composite type with more than one spatial coupling feature was also found for 14 communities within the 153 townships. This provides a reference for policy making towards four major types of interactive modes between townships and the national park construction for the sustainable development of Qingzang Plateau.

Technological hazards induced by natural hazards have a significant impact on human life and economy. Their power exceeds the impact of the natural hazards that caused them. However, most of the multi-hazard risk maps failed to incorporate technological hazards when mapping multi hazard risk. To address this problem, we established a hybrid multi-hazard risk assessment methodology that calculates the risk caused by natural and technological hazards in a three-step process. First, the possible natural and technological hazards in a given region are identified by hazard-forming environment analysis and hazard source investigation respectively. A scenario simulation is adopted to analyze the intensity and impact scope of these hazards. Second, the triggered relationships among natural and technological hazards are analyzed by a hazard matrix. Then, the radar graph is adopted to calculate the multi-hazard intensity under the coupling effect of all possible hazards in this region. Third, the multi-hazard risk is calculated by aggregating land use data and multi-hazard intensity together. This methodology was applied in Huairou Science City (HSC), Beijing. The result shows that the joint action of earthquake and liquid ammonia leakage is the main reason for the high risk in the central area of HSC. The methodology developed in this study can clearly show the different impacts of each hazard on a given region under the action of hazard coupling, and the calculated results can better reflect the actual disaster situation.

Linking of ‘consumption-industrial production-surface water deterioration’ is essential for industrialised economies to understand the mechanism of industrial water pollution. However, such a connection may mislead policy decisions if sectoral details are lacking. This study investigated excess pollution discharge from 11,094 industrial enterprises comprising 22 economic sectors through setting discharge thresholds on 1338 water function zones in Jiangsu Province, the most industrialised province in China. We further evaluated the contribution of final consumption in Chinese provinces to excess pollution discharge in Jiangsu via a national multi-region input–output table. Notably, despite typically heavy polluting sectors contributing the maximum excess pollution discharge, high-tech manufacturing sectors had a higher level of risk for excess pollution discharge. This was attributed to the spatial agglomeration of these sectors, with enterprises typically located in industrial parks. The increasing final consumption of specific sectors in both Jiangsu and other provinces may further drive excess pollution discharge in Jiangsu.

Most slope collapse accidents are indicated by certain signs before their occurrence, and unnecessary losses can be avoided by predicting slope deformation. However, the early warning signs of slope deformation are often misjudged. It is necessary to establish a method to determine the appropriate early warning signs in sliding thresholds. Here, to better understand the impact of different scales on the early warning signs of sliding thresholds, we used the Fisher optimal segmentation method to establish the early warning signs of a sliding threshold model based on deformation speed and deformation acceleration at different spatial scales. Our results indicated that the accuracy of the early warning signs of sliding thresholds at the surface scale was the highest. Among them, the early warning thresholds of the blue, yellow, orange, and red level on a small scale were 369.31 mm, 428.96 mm, 448.41 mm, and 923.7 mm, respectively. The evaluation accuracy of disaster non-occurrence and occurrence was 93.25% and 92.41%, respectively. The early warning thresholds of the blue, yellow, orange, and red level on a large scale were 980.11 mm, 1038.16 mm, 2164.63 mm, and 9492.75 mm, respectively. The evaluation accuracy of disaster non-occurrence and occurrence was 97.22% and 97.44%, respectively. Therefore, it is necessary to choose deformation at the surface scale with a large scale as the sliding threshold. Our results effectively solve the problem of misjudgment of the early warning signs of slope collapse, which is of great significance for ensuring the safe operation of water conservation projects and improving the slope deformation warning capability.

Microplastics pollution has been threatening the global environmental security, in which agricultural activities are considered as a main source of microplastics occurrence in soils. However, little is known about the occurrence characteristics of microplastics in agricultural soils with long-term plastic film mulching. Therefore, the abundance, distribution, and composition of microplastics were investigated by analyzing 225 soil samples collected from typical maize (Zea mays L.) planting zones with and without long-term (>20 years) plastic film mulching in northern China. Microplastics abundance in mulched soils (754 ± 477 items kg–1) was significantly higher than that in non-mulched soils (376 ± 149 items kg–1), which indicated that plastic film mulching contributed half of microplastics in soils. Moreover, microplastics abundance was significantly positively related to the length of time with film mulching applied. The percentage of microplastics

The concept of an Earth’s Third Pole national park cluster has been proposed on the Qinghai-Tibet Plateau and preliminary research for this completed in the initial stage of the second scientific investigation on the plateau. Based on the theory of territorial function, it is realized that with the diversification of land use demand, limited land exerts stronger and stronger binding forces on the allocation of territorial functions. There will be more and more space with complex territorial functions, among which national parks will become a new territorial function for large-scale optimization of the development and protection pattern of land on the Qinghai-Tibet plateau. Currently, land development accounts for about 0.08%, of the total area in Tibet, whereas various nature reserves account for 33.9%. There are many problems in protected natural areas, such as overlapping, a large number of settlements there, and the poverty of local farmers and herdsmen. The Qinghai-Tibet plateau has become the only area of deep poverty in China. Because of these problems, four territorial functions of the proposed third pole national park cluster on the Qinghai-Tibet plateau are: Maintaining protection of the global ecological system and the diversity of human civilization and culture; reshaping the main body of the natural protection system; coordinating the human-land coupling system; and supporting sustainable livelihood and high-quality regional development. To fulfill the requirements of forming a national park cluster, this paper explores the selection conditions of potential sites and proposes some innovative evaluation ideas, such as the contribution of alternative sites to the formation of the national park cluster and the integrity of their uniqueness and interaction. Through preliminary evaluation of the representative regional space of different ecosystems provided by ecological and geographical zoning, a draft of the global third pole national park cluster is proposed. It includes 6 flagship national parks, composed of 2 transnational national parks, and 9 national parks. With a land coverage of more than 300000 square kilometers, it will be a focused, large national park cluster, with distinctive ecological characteristics, and outstanding scientific research value for recreation and tourism. Studying the reasonable capacity of national parks (cluster) is the key link in the construction feasibility study. Furthermore, the reasonable capacity calculation is expanded from the natural carrying capacity to that of the facility and the society. Carrying-capacity considerations include the dual requirements of national, and non-national park functions, and from this, a comprehensive carrying capacity calculation model is then established. The concept and algorithm of a comprehensive carrying capacity were initially applied to test the Selincuo-Puruogangri national park alternative. Preliminary results indicated that the daily capacity for tourism should not exceed 7000 people, and the annual capacity should not exceed 800000 people. Results obtained in the extremely fragile natural ecosystems of the Qinghai-Tibet Plateau in northern Tibet indicate that the establishment of national park cluster there has a high feasibility. The construction of a national park cluster will be a new model of sustainable development for the Qinghai-Tibet plateau region, which will help change the current “transfusion” development model relying on state financial subsidies to farmers and herdsmen. Through subsidizing projects in the construction of national parks, the degree of public participation, the level of services, and also subsidizing the contribution of ecological protection, a “hematopoietic” development model is proposed in which the more you do, the more benefit you get. Finally, a virtual circle of “ecological advantages + assets → ecological products + benefits → sustainable livelihood + development → ecological restoration + value-added” will be realized. With the intensifying of this proposition in the second scientific investigation on the Qinghai-Tibet Plateau, a scientific basis for the special sustainable development model of the Qinghai-Tibet Plateau will be achieved by the completion of a construction plan of the Earth’s Third Pole national park cluster.

Flood disasters are one of the most serious meteorological disasters in China. With the rapid development of information technology, individual monitoring tools could not meet the need for flood disaster monitoring. Therefore, a new integrated air-space-ground method, based on combined satellite remote sensing, unmanned aerial vehicle remote sensing and field measurement technology, has been proposed to monitor and assess flood disasters caused by a dam failure in Poyang County, Jiangxi Province. In this paper, based on an air-space-ground investigation system, the general flooded areas, severely affected areas, and more severely affected areas were 53.18 km2, 12.61 km2 and 6.98 km2, respectively. The size of the dam break gap was about 65 m and 34.7 m on 22 and 23 June. The assessment precision was better than 98%, and the root mean square error (RMSE) was 0.86 m. The method could meet the needs for flood disaster information at different spatiotemporal scales, such as macro scale, medium scale and local small scale. The integrated monitoring of flood disasters was carried out to provide the whole process and all-round information on flood evolution dynamics, the disaster development process for flood disaster monitoring and emergency assessment, and holographic information for emergency rescue and disaster reduction, as well as to meet the need for different temporal and spatial scales of information in the process of disaster emergencies.

Reducing ecological risks is important for promoting regional sustainable development. However, studies on the influence of impervious surfaces on ecological risks and risk control strategies in regions undergoing rapid urbanization are limited. Therefore, this study aimed to demonstrate the spatial-temporal dynamics of regional ecological risks using Beijing as a case study to reveal the influence of impervious surfaces and explore the controlling strategies of risks. We first characterized the ecological risks in Beijing based on the ecosystem service values and mapped the risk levels and temporal variations in risks. We then identified the ecological risk increases caused by impervious surface expansion and built linear regression models for impervious surface coverage (ISC) and risk index. Finally, we formulated ecological risk control strategies for the strategy categories identified based on the ISC thresholds. The results show that the mountainous areas mainly exhibited low ecological risk levels, and the plain areas mainly showed high levels. The expansion of impervious surface was the main cause of the relatively large temporal increase in ecological risks from 2005 to 2015. Moreover, the strategies for ecological risk control can be divided into four categories based on the division of ISC, with 30%, 70%, and 90% as the thresholds. For risk control strategies, reducing ISC is the most important measure to reduce ecological risks for the category with an ISC range of 90%-100%, and increasing the area proportions of forests and water bodies is the most effective measure for the category with an ISC range of 0%-30%. For the other two categories, controlling the ISC and other strategies are required. Our study can increase the understanding of the influences of impervious surfaces on ecological risks in rapidly urbanizing regions and help inform the formulation of strategies for controlling the ecological risks in Beijing.

The development of industries in China’s resource-rich regions is mainly affected by resource reserves, environmental protection, and industrial structural adjustment. The development of resource-oriented industries that can’t support a high-quality regional economy is large but not well developed. This article considers China’s resource product imports and exports, carbon emissions, and industrial structure ratio factors in recent years. It is believed that China’s resource-rich regions have macro-level development bottlenecks, and the general development of a resource-based industries path is proposed based on the perspective of “resources, assets, and capital”. Taking Guangxi Zhuang Autonomous Region as an empirical case, this article analyzes the pattern of regional industrial development by using the input-output method, calculates the degree of inter-industrial correlation, and constructs a regional industrial development system. The results show the following: 1. China’s overall industrial development pattern has undergone major changes, 2. emerging industries and service-oriented industries have risen in development status, and although resource-based industries have a weaker development momentum, they still have an important position, 3. the hierarchical industry development management model is helpful for forming a regional circular economy innovation development pattern. The results also indicate that the integrated management of “resources, assets, and capital” has a positive effect on the development of resource-based industries in resource-rich regions, which affects the overall industrial development pattern of the region and promotes economic development.

Many empirical typhoon economic loss models consider that the losses caused by typhoons mainly depend on the intensity of the hazards and the exposure in the affected areas. Few studies have attracted attention to the role of disaster-formative environmental factors in typhoon losses. In this study, we chose land use and land cover (LULC) as disaster-formative environmental factors together with typhoon wind speed, rainfall, and gross domestic product (GDP) as predictive factors for typhoon economic losses in Guangdong Province, China. The results showed that the intensity of wind speed was the most important factor, while LULC played weak roles in typhoon economic losses for 23 typical typhoons in terms of county level losses in Guangdong. Subregionally, typhoon economic loss models performed better in coastal areas than in noncoastal areas.

In order to solve the engineering problem that the bolt tail is often broken under the impact of rock pressure, mining stress and the damage to the support structure contribute to great hidden danger to the safety of mining and tunneling. A new anti-impact bolt support structure is designed that can absorb energy under pressure. The double laminated springs and the inner spring deform under the impact load to achieve the purpose of absorbing most of the impact energy. The composition and working principle of the energy-absorbing structure is introduced. The static axial compression tests of the single laminated springs with cone angles of 30°, 45°, and 60° are carried out. The mechanical characteristics of the laminated springs in the three stages of energy absorption are investigated. It is found that the 45° laminated spring has the best energy absorption effect. The simulation method was used to analyze and optimize the energy absorption effect of anti-scour composite components. Double laminated spring anti-shock composite components absorb the impact energy and avoid the damage to the bolt support structure, which reduces the roadway support cost and has important engineering application value for ensuring the safety of deep tunneling and mining.

Floods that cause yearly economic losses and casualties have increased in frequency with global warming. Assessing the mortality risks of populations due to flooding is important and necessary for risk management and disaster reduction. Thus, this paper develops a method for assessing global mortality risks due to river flooding. Global historical annual death tolls are first estimated during the historical period 1986–2005 (T0) by using available mortality vulnerability functions of river flooding. Then, the best vulnerability function is selected according to lower root mean square errors (RMSE) and the differences in the multi-year mean (DMYM) values. Next, the adjustment coefficient K c for each country (region) is calculated to use in the revision of the selected vulnerability function. Finally, the mortality risks are estimated based on an adjusted vulnerability function. As a case, the paper assessed and analysed the global mortality risks due to river flooding during 2016–2035 (2030s) and 2046–2065 (2050s) for the combined scenario of the Representative Concentration Pathway 4.5 (RCP4.5) and the Shared Socioeconomic Pathway 2 (SSP2), and the RCP8.5-SSP5 scenario. The results show that the estimation errors of the death tolls in most countries (regions) decrease after adjusting the vulnerability function. Under the current defense capacity and vulnerability level, the average annual death tolls of RCP4.5-SSP2 and RCP8.5-SSP5 in the 2030s will increase by 1.05 times and 0.93 times compared with the historical period. They will increase 1.89 and 2.20 times, respectively for the two scenarios during 2050s. High-risk areas are distributed in the south-eastern Eurasia.

This paper explores the differences between public perceptions and existing monitoring indicators in environmental quality in Beijing. The results reveal, existing indicators do not accurately reflect public perceptions of the environment. Some environmental problems, such as fluffy catkins, are not reflected in the existing indicators, yet have a relatively large influence on public perception. The policymakers and public's variegated understanding of the environment, the lag period of public perceptions of environmental quality change, and lack of standards and monitoring for emerging problems are the three main reasons that resulted in a deviation of monitoring indicators from the public perceptions. Resultantly, to improve the level of environmental governance, it is necessary to take relevant measures that reduce the difference between public perceptions and monitoring indicators. Residents should be surveyed regularly to obtain their public perceptions, and the selection of indicators should not be limited to environmental pollution. In particular, some indicators based on public perception should be developed to complement the existing environmental monitoring protocol. In addition, due to the emerging environmental problems, quality standards and monitoring systems should be updated regularly.

Multi-hazard risk assessment is a major concern in risk analysis, but most approaches do not consider all hazard interactions when calculating possible losses. We address this problem by developing an improved quantitative model—Model for multi-hazard Risk assessment with a consideration of Hazard Interaction (MmhRisk-HI). This model calculates the possible loss caused by multiple hazards, with an explicit consideration of interaction between those hazards. There are two main components to the model. In the first, based on the hazard-forming environment, relationships among hazards are classified into four types for calculation of the exceedance probability of multiple hazards occurrence. In the second, a Bayesian network is used to calculate possible loss caused by multiple hazards with different exceedance probabilities. A multi-hazard risk map can then be drawn addressing the probability of multi-hazard occurrence and corresponding loss. This model was applied in northeast Zhejiang, China and validated by comparison against an observed multi-hazard sequence. The validation results show that the model can more effectively represent the real world, and that the modelled outputs, possible loss caused by multiple hazards, are reliable. The outputs can additionally help to identify areas at greatest risk, and allows a determination of the factors that contribute to that risk, and hence the model can provide useful further information for planners and decision-makers concerned with risk mitigation.

This paper develops a systematic hazard interaction classification based on the geophysical environment that natural hazards arise from – the hazard-forming environment. According to their contribution to natural hazards, geophysical environmental factors in the hazard-forming environment were categorized into two types. The first are relatively stable factors which construct the precondition for the occurrence of natural hazards, whilst the second are trigger factors, which determine the frequency and magnitude of hazards. Different combinations of geophysical environmental factors induce different hazards. Based on these geophysical environmental factors for some major hazards, the stable factors are used to identify which kinds of natural hazards influence a given area, and trigger factors are used to classify the relationships between these hazards into four types: independent, mutex, parallel and series relationships. This classification helps to ensure all possible hazard interactions among different hazards are considered in multi-hazard risk assessment. This can effectively fill the gap in current multi-hazard risk assessment methods which to date only consider domino effects. In addition, based on this classification, the probability and magnitude of multiple interacting natural hazards occurring together can be calculated. Hence, the developed hazard interaction classification provides a useful tool to facilitate improved multi-hazard risk assessment.

Risk assessment plays an important role in disaster risk management. Existing multi-hazard risk assessment models are often qualitative or semi-quantitative in nature and used for comparative study of regional risk levels. They cannot estimate directly probability of disaster losses from the joint impact of several hazards. In this paper, a quantitative approach of multi-hazard risk assessment based on vulnerability surface and joint return period of hazards is put forward to assess the risk of crop losses in the Yangtze River Delta region of China. The impact of strong wind and flood, the two most prominent agricultural hazards in the area, is analyzed. The multi-hazard risk assessment process consists of three steps. First, a vulnerability surface, which denotes the functional relationship between the intensity of the hazards and disaster losses, was built using the crop losses data for losses caused by strong wind and flood in the recent 30 years. Second, the joint probability distribution of strong wind and flood was established using the copula functions. Finally, risk curves that show the probability of crop losses in this multi-hazard context at four case study sites were calculated according to the joint return period of hazards and the vulnerability surface. The risk assessment result of crop losses provides a useful reference for governments and insurance companies to formulate agricultural development plans and analyze the market of agricultural insurance. The multi-hazard risk assessment method developed in this paper can also be used to quantitatively assess multi-hazard risk in other regions.

A spherical robot will inevitably be affected by rolling resistance from the ground when it is used in an unstructured exploration environment. Because of the complex contact condition between the robot and the ground, it is very difficult to obtain the information about the rolling resistance correctly. This fact decreases the movement performances of spherical robots greatly. In this study, dynamic models of the sphere subsystem and the inner suspension subsystem are derived. By Lyapunov theorem, the sliding surface with integral element is applied to construct a new sliding-mode control scheme to track the desired velocity of the spherical robot. In the proposed controller, the sgn(x) function is replaced by the tanh(x) function, in order to reduce the inherent chattering phenomena of the sliding-mode algorithm. Because the rolling resistance is uncertain, an adaptive control scheme is applied to estimate the uncertain rolling resistance dynamically, which makes the robot more sensitive and adaptive in...

The inner suspension of spherical robot undergoes a kind of typical underactuated vibration when the mobile benchmark performs the longitudinal movement. The inherent vibration deteriorates the control performances such that it is difficult to obtain the satisfactory movement effects. Considered the fact that the state variables of a spherical robot and the uncertain rolling resistance moment are unavailable in practical implementation, an extended state observer is proposed with the aid of which some of the sensors can be replaced and the rolling resistance can be obtained to construct the controllers. Also, an adaptive hierarchical sliding mode control approach is presented based on the extended state observer. The proposed control methodologies can assure the robot rolling performances and realize the effective control of the inner suspension simultaneously. The numerical simulation results demonstrate that the designed closed-loop control system of the spherical robot possesses robust and adaptive capabilities to overcome the uncertain rolling resistance which is significant for a mobile robot in unstructured environment.

In recent years, greater attention has been given to advancing the theory and practice of assessing risk from multiple hazards. Most approaches calculate multi-hazard risk by aggregating risk scores for individual hazards and ignore the combined exceedance probability of multiple hazards. We address this problem by developing a simple and practicable multi-hazard risk assessment method that uses information diffusion theory to overcome the difficulty posed by a lack of historical or spatial data on natural hazard-induced loss. China’s Yangtze River Delta region is used as a demonstrative example, and the exceedance probability distribution of multi-hazard risk to human life was calculated using natural hazard disaster life loss data for 1950–2010. Multi-hazard risk to human life is mapped as exceedance probability at different mortality rates and loss at different risk return periods using a geographical information system. Results show that Hangzhou and Ningbo are at a relatively high risk from multiple natural hazards, and Shanghai is at a relatively low risk. For scenarios of 10-, 20- and 50-year risk return periods, there are no significant changes in the risk rank of the cities; Hangzhou, Ningbo and Zhoushan are at a relatively high risk, while Shanghai is at a relatively low risk.

SUMMARY Unlike the traditional underactuated mechanical system, the equilibrium point of the inner swing-up suspension of a spherical robot possesses stable and dynamic characteristics. The stable dynamic equilibrium position of the underactuated suspension must agree well with the uncertain rolling resistance in practice. To overcome this special underactuated problem with dynamic equilibrium, we present an adaptive control scheme to enhance the ground adaptability using hierarchical sliding mode approach. The control method can drive the spherical robot to a desired position, and at the same time, the suspension subsystem holds on their dynamic equilibrium points rapidly. The proposed control approaches are verified to be effective by numerical simulation for a spherical robot to achieve satisfactory control performances, such as ground adaptability, rapid convergence, and disturbance rejection. Copyright © 2013 John Wiley & Sons, Ltd.

In recent decades, society has been greatly affected by natural disasters (e.g. floods, droughts, earthquakes), and losses and effects caused by these disasters have been increasing. Conventionally, risk assessment focuses on individual hazards, but the importance of addressing multiple hazards is now recognised. Two approaches exist to assess risk from multiple hazards: the risk index (addressing hazards, and the exposure and vulnerability of people or property at risk) and the mathematical statistics method (which integrates observations of past losses attributed to each hazard type). These approaches have not previously been compared. Our application of both to China clearly illustrates their inconsistency. For example, from 31 Chinese provinces assessed for multi-hazard risk, Gansu and Sichuan provinces are at low risk of life loss with the risk index approach, but high risk using the mathematical statistics approach. Similarly, Tibet is identified as being at almost the highest risk of economic loss using the risk index, but lowest risk under the mathematical statistics approach. Such inconsistency should be recognised if risk is to be managed effectively, whilst the practice of multi-hazard risk assessment needs to incorporate the relative advantages of both approaches.

In this study, a double closed-loop control structure with a disturbance observer is reported. This combining structure could globally realize postures-tracking stabilization and have disturbance adaptive capability. On the outer loop, a new function having sinusoidal and inverse tangent characteristics, which are continuously differentiable, is applied to construct the velocity controller by using backstepping technology. Meanwhile, a disturbance-observer-based controller is applied to the inner loop to estimate the dynamic disturbances acting on the wheels; these disturbances are unavoidable and uncertain in an unstructured environment. To enhance the robustness of the system, sliding-mode control technology is applied to construct the system's dynamic controller. Finally, simulations are carried out to verify the effectiveness of the proposed control methods.

In this paper, the structural improved thermoacoustic cooler is discussed using numerical method. Firstly, the heat transfer Mathmatics model of porous medium is setup, and an improved shape of thermoacoustic cooler is designed. The heat transfer process is simulated roundly, and the detailed analysis focused on the parameters of heat transfer process, such as temperature, velocity, pressure, and density. It can be concluded that tube external shape changed has an obvious effect on refrigeration effect.

The inner suspension of a spherical robot undergoes an underactuated state which will be difficult for the underactuated system control, when the robot is rolling ahead. To resolve this underactuated control problem, an adaptive hierarchical sliding mode control scheme is proposed. The spherical robot system is separated as shell subsystem and inner suspension subsystem according to the movement. Then a pair of first layer sliding surfaces is defined for each subsystem, by which the equivalent control law is derived to ensure states of each subsystem approaching to their own sliding mode surface. Based on the first layer sliding surface, a second layer surface is defined correspondingly, through which a total control law is given to make sure that all states can converge to their desired value via Lyapunov stability theorem. Meanwhile, considering the unavoidable and uncertain disturbance in the unstructured exploration environment, an adaptive hierarchical sliding mode control scheme is adopted to estimate the uncertain disturbances in real-time. Finally, the simulation results demonstrate the controller's adaptability and validity.

With the development of minimally invasive surgical techniques, achieving cosmetic results and reducing surgical trauma to the greatest extent become the pursuit of the surgeon. Natural orifice transluminal endoscopic surgery (NOTES) was developed with “no scar,” was less invasive, and had a more esthetic effect. But NOTES is still difficult for broad clinical application because of the limitation of instruments and greater technical difficulty, with the risks of abdominal infection and organ perforation. Transumilical single incision laparoscopic surgery (TUSILC) hides bdominal operative scars by means of the umbilicus, a atural skin fold. The procedure achieves “no scar” in the bdominal wall and better cosmetic results and technical ifficulty and operative risk are greatly reduced. We find hat TUSILC has obvious advantages and is the most feaible NOTES operation. From February 2009 to October 2011, 254 patients with gallbladder disease were selected to undergo TUSILC.