Mortality in relation to changes in physical activity in middle-aged to older Chinese:An 8-year follow-up of the Guangzhou Biobank Cohort Study

Background:Physical activity(PA)is generally encouraged.Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk.It is unclear whether these associations apply to an older Chinese population.Hence,we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks.Methods:Metabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated.Participants were divided into 3 groups related to PA level,and changes in PA were classified into 9 categories.Information on vital status and causes of death from March 2008 to December 2012(the first repeated examination)until December 31,2017,was obtained via record linkage with the Death Registry.Results:Of 18,104 participants aged 61.21±6.85 years(mean±SD),1461 deaths occurred within 141,417 person-years.Compared to participants who maintained moderate PA,those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality(hazard ratio(HR)=1.47,95%confidence interval(95%CI):1.11-1.96).Participants who maintained a high level of PA(HR=0.83,95%CI:0.70-0.98)or increased PA from low to high levels(HR=0.71,95%CI:0.52-0.97)showed lower all-cause mortality risks.Those who maintained low PA levels showed a higher all-cause mortality risk,whereas those who increased their PA levels showed a non-significantly lower risk.Similar results were found for cardiovascular disease risk.Conclusion:Even at an older age,maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks,suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA.The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians.

Property changes of anchor grout calcined ginger nuts admixed with fly ash and quartz sand after accelerated ageing tests

Calcined ginger nuts admixed by fly ash and quartz sand (CGN-(F+S)) has been validated to be basically compatible to earthen sites as an anchor grout. Accelerated ageing tests including water stability test, temperature and humidity cycling test, soundness test and alkali resistance test are conducted with the objective to further research the property changes of CGN-(F+S) grout. Density, surface hardness, water penetration capacity, water permeability capacity, soluble salt, scanning electron microscopy (SEM) images and energy dispersive spectrometry (EDS) spectrum of these samples have been tested after accelerated ageing tests. The results show that densities of samples decrease, surface hardness, water penetration capacity and water permeability capacity of samples increase generally. Besides, soluble salt analysis, SEM and EDS results well corroborate the changes. Based on the results it can be concluded that property changes are most serious after temperature and humidity cycling test, followed by water stability, soundness and alkali resistance test in sequence. But in general, CGN-(F+S) still has good durability.

Structural evolution of carbon aerogel microspheres by thermal treatment for high–power supercapacitors

In this work, a series of carbon aerogel microspheres（CAMs） with tailored pore structures were successfully prepared via a sol-gel method and subsequent heat-treatment at various temperatures from 600 to 1600 ℃. The effects of heat-treatment temperature（HTT） on the CAM microstructure were systematically investigated by physical and chemical characterization. The electrical conductivity increased by up to 250 S/cm and mesopores with high electrolyte accessibility developed in the CAM with increasing HTT. However, the specific surface area（SSA） decreased for HTTs from 1000 to 1600 ℃. The results show that these two factors should be finely balanced for further applications in high power supercapacitors.The CAMs carbonized at 1000 ℃ had the highest SSA（1454 m^2/g）, large mesoporous content（20%） and favorable conductivity（71 S/cm）. They delivered a high energy density of 38.4 Wh/kg at a power density of 0.17 kW/kg. They retained an energy density of 25.5 Wh/kg even at a high power density of 10.2 kW/kg,and a good rate capability of 84% after 10,000 cycles. This performance is superior to, or at least comparable to, those of most reported carbon materials.

Soil Organic Carbon Pools in Particle-Size Fractions as Affected by Slope Gradient and Land Use Change in Hilly Regions,Western Iran

This study was conducted to explore the effects of topography and land use changes on particulate organic carbon(POC),particulate total nitrogen(PTN),organic carbon(OC) and total nitrogen(TN) associated with different size primary particle fractions in hilly regions of western Iran.Three popular land uses in the selected site including natural forest(NF),disturbed forest(DF) and cultivated land(CL) and three slope gradients(0-10 %,S1,10-30 %,S2,and 30-50%,S3) were employed as the basis of soil sampling.A total of 99 soil samples were taken from the 0-10 cm surface layer in the whole studied hilly region studied.The results showed that the POC in the forest land use in all slope gradients was considerably more than the deforested and cultivated lands and the highest value was observed at NF-S1 treatment with 9.13%.The values of PTN were significantly higher in the forest land use and in the down slopes(0.5%) than in the deforested and cultivated counterparts and steep slopes(0.09%) except for the CL land use.The C:N ratios in POC fraction were around 17-18 in the forest land and around 23 in the cultivated land.In forest land,the silt-associated OC was highest among the primary particles.The enrichment factor of SOC,EC,was the highest for POC.For the primary particles,EC of both primary fractions of silt and clay showed following trend for selected land uses and slope gradients:CL> DF> NF and S3 > S2> S1.Slope gradient of landscape significantly affected the OC and TN contents associated with the silt and clay particles,whereas higher OC and TN contents were observed in lower positions and the lowest value was measured in the steep slopes.Overall,the results showed that native forest land improves soil organic carbon storage and can reduce the carbon emission and soil erosion especially in the mountainous regions with high rainfall in west of Iran.

Concrete Physics Method for Solving NP hard Problem

With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem——Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will always be very efficient for NP hard problem.

Worrying about Climate Change

It is becoming clear that Climate Change is getting severe. It was reported that the improved ocean heat measurements have a rate of warming upwards from 4 to 5 Hiroshima bombs liberated heat per second or 388,800 per day. It was reported also that our climate has accumulated the equivalent of a total of more than 2.8 billion Hiroshima bombs’ worth of heat since 1998. Despite this global concern about the effect of global change on environment, it is believed that the problem is much more severe and with greater impact on all facets of life. The effect of Climate Change, especially with a 1℃increase in global temperature (from 14℃to 15℃) is equivalent to the heat liberated from explosion of about 300 million Hiroshima of atomic bomb. This is why this CoP 26 becomes more serious and had targeted year 2060 as a year of zero CO2 emission. This paper discusses the impact of climate change on ten sectors;water, water desalination, energy, renewable energy supply, health, society, agriculture, economy, industry, and built environment.

Characterization of Polymer Aging:A Review

Polymer aging under environmental conditions causes deterioration of service properties.Understanding the aging behavior and mechanism is important not only for lifetime prediction,but also for material improvement and development.Therefore,comprehensive characterization of polymer materials during aging is crucial.In this review,various analytical methods for characterization of chemical changes,physical changes and service properties are introduced.Based on that,methods for stabilization evaluation and lifetime prediction,especially sensitive evaluation methods are reviewed.Chemical changes include molecular weight changes by chain scission and crosslinking,functional group changes on the surface and in the bulk,formation of free radicals,formation of small molecular species as the degradation products,and chemical distribution by heterogeneous aging and additives migration.Physical changes include crystallization changes (post-or chemi-crystallization)and morphology changes (cracking,debonding,etc.).Service property changes include deterioration of processability,mechanical properties,electrical properties and appearance.In the end,existing problems and future research perspective are proposed,including relationship between chemical/physical changes and service properties,introduction of modern mathematical and computer tools.

The effect of physical property change on the water flooding development in Changqing oilfield Jurassic low permeability reservoir

Changqing old oilfield Jurassic reservoir's average calibration recovery is 24.7%,with geological reserves recovery of 16.6%,water cut of 65.2%.And most of Jurassic reservoirs are in the middle and later field life,part of them has entered the high water cut and high recovery stage.Traditional water flooding way for improving oil recovery becomes more difficult,and new method has to be considered.Maling oilfield BS district is a typical representative,with high water cut of 90.8%,high recovery percent of 26.1%and low oil recovery rate of 0.25%.To explore the new way to improve oil recovery,the polymer and surfactant(SP for short)important pilot test has been developed.The low permeability reservoir indoor core data in high water cut stage and inspection well results indicate that the reservoir permeability,pore combination characteristics and pore type changed greatly after long-term water flooding development.These changes bring more difficulties to the continue development,especially the high injection pressure,which can cause other problems for well pattern infilling and EOR.This paper takes the high injection pressure problem of Maling BS district Jurassic reservoir for example,analyzes the physical property change law on the following aspects:the development mode in the past,core analysis,formation sensitivity,interstitial matter,well test interpretation results,in order to help to further effective development and provide important parameters for tertiary oil recovery technique for similar reservoirs and others.