Enhanced stability and rate performance of zinc-doped cobalt hexacyanoferrate (CoZnHCF) by the limited crystal growth and reduced distortion

Cobalt hexacyanoferrate (CoHCF) is a potential cathode for aqueous Na-ion batteries due to its high theoretical specific capacity (170 m Ah g^(-1));however,its lower rate capability and cyclability limit its applications.Structural distortion at a weak N-coordinated crystal field during cycling disintegrates Co,yielding an irreversible reaction.Different Zn amounts ranging 0–1 were added to the Co site to suppress the structural irreversibility of CoHCF,yielding Co_(1-x)Zn_(x)HCF powder;this Zn (x≤0.09) addition reduced the powder’s dimension because the lower four coordination of Zn–N,not the six coordination of Co–N,limits the powder growth.Simultaneously,a small lattice parameter and interaxial angle (~90°) are obtained,implying that a narrower Co_(1-x)Zn_(x)HCF inner structure is formed to accommodate Na ions.Moreover,the electronic conductivity of Co_(1-x)Zn_(x)HCF gradually increased within 0–0.09 range.A smaller particle size with a high surface area leads to a near-surface-limited redox process,similar to a capacitive reaction.Both the surface-limited reaction and electronic conductivity enhances the reversibility due to the smaller charge transfer resistance at the electrode/electrolyte interface caused by Zn addition.Replacing redox-active Co with non-active Zn amount of 0.07 (Co_(1-x)Zn_(x)HCF) slightly reduces the specific capacity from 127 to 119 mAh g^(-1)at 0.1 A g^(-1)due to the shrunken Co charging sites.Rate performance is enhanced by compromising the capacity and reduced distortion,resulting in 81%retention at a 20-times-faster charging rate.Notably,the Co_(1-x)Zn_(x)HCF sample exhibited the good stability while preserving 74%of the initial capacity at 0.5 A g^(-1)after 200 cycles.

Phosphate limitation of phytoplankton growth in the Changjiang Estuary

Laboratory experiments of bioassay with Pltaeodaetytum tricornutum, Chatoceros didymus, Chaetoreros calcitraus and Heterogtoea sp. sampled from the Changjiang Estuary in spring and summer, 1986, indicated that both N and P limit phytoplankton growth in the medium with N : P ranged between 8-30, and N limits phytoplankton production in the medium with N: P<8, while P is the limitary nutrient in the N : P>30. Generally, N : P in the Changjiang Estuary waters is 2 times higher than Redfield ratio. The bioassay experiments with high N : P water samples collected from Changjiang Estuary show that phytoplankton production is limited by P. Phytopiankton appears to give priority to the uptake of P at all periods of time. And the optimum N:P for phytoplankton growth is determined to be 18.

Effects of soil nitrate:ammonium ratio on plant carbon:nitrogen ratio and growth rate of Artemisia sphaerocephala seedlings

Can soil nitrate： ammonium ratios influence plant carbon： nitrogen ratios of the early succession plant？ Can plant carbon： nitrogen ratios limit the plant growth in early succession？ To address these two questions, we performed a two-factor （soil nitrate： ammonium ratio and plant density） randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate： ammonium ratios, the carbon： nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate： ammonium ratios and plant density influenced the carbon： nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate： ammonium ratios, with the increase of soil nitrate： ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon： nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate： ammonium ratios affected the carbon： nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate： ammonium ratios influenced the carbon： nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate： ammonium ratios can be a limiting factor for the growth of the early succession plant.

Infinitely many solutions of p-Laplacian equations with limit subcritical growth

We discussed a class of p-Laplacian boundary problems on a bounded smooth domain, the nonlinearity is odd symmetric and limit subcritical growing at infinite. A sequence of critical values of the variational functional was constructed after the general- ized Palais-Smale condition was verified. We obtain that the problem possesses infinitely many solutions and corresponding energy levels of the functional pass to positive infinite. The result is a generalization of a similar problem in the case of subcritical.

Economic Growth:Theoretical Arguments about Resources,Environment and the Limit Issue & the Choices Faced by the Human Being

The relationship between man and nature seems highly diverse during the evolving process of human society. Numerous destructive consequences incurring from the carly stage of the industrialization led to man＇s severe concern about ecological and environment issues. In 1972, a book entitled “The Limits To Growth” ushered in a worldwide argumentation campaign, and forced man to realize that the bearing capacity of ecological surroundings is finite, and the quantity of resources is numbered as well. Admittedly, the human advance in science and technology, from the long-term viewpoint, is capable of discovering new types of energy and resources. However, each specific period of human history is always endangered due to the crisis of energy and resources. Therefore the core of the retainable development lies in variation of the outdated pattern of economic growth as well as pursuit to the new substitutes.

Study on the Recycling Agricultural System Operation Mechanism Focusing on Pig Farming

According to the characteristics of circular agricultural mode focusing on pig farming and by dint of system dynamics mode-based analysis techniques to analyze the characteristics,the operation force for the recycling agricultural system focusing on pig farming was put forward.

Continuous flow synthesis of plasmonic gold patches and nearly-complete nanoshells on polystyrene core particles

We describe the development of a T-mixer based continuous flow process for the coating of 86-500 nm diameter spherical polystyrene particles with thin gold patches by heterogeneous nucleation and growth.After establishing a suitable flow rate for good mixing and sufficiently uniform product morphology we systematically investigate the main reaction parameters.This reveals a considerable tunability of the patch morphology and,by virtue of the localized surface plasmon resonance of gold,the optical properties of the product dispersions.In order to further widen the range of nanostructures accessible by our process,a second T-mixer was added.This introduced new gold precursor,leading to further growth of the patches that were formed after the first mixer.By this approach,nearly-complete gold nanoshells could be produced in high yield on both small and large core particles,without the unwanted production of free-standing gold nanoparticles.Due to the pronounced optical properties of nearly-complete gold nanoshells on small core particles,we could estimate from electrodynamic sim-ulations the equivalent shell thickness to be as low as 8.6 nm.This is significantly thinner than can be routinely achieved using the standard seeded growth approach to synthesise gold nanoshells.Our results are therefore highly promising for the gram-scale synthesis of plasmon resonant nanostructures with designed optical properties.

Resilient and Inclusive Prosperity within Planetary Boundaries

The current model of economic growth generated unprecedented increases in human wealth and prosperity during the 19th and 2Oth centuries. The main mechanisms have been the rapid pace of technological and social innovation, human capital accumulation, and the conversion of resources and natural capital into more valuable forms of produced capital. However, there is evidence emerging that this model may be approaching environmental limits and planetary boundaries, and that the conversion of natural capital needs to slow down rapidly and then be reversed Some commentators have asserted that in order for this to occur, we will need to stop growing altogether and, instead, seek prosperity without growth. Others argue that environmental concerns are low-priority luxuries to be contemplated once global growth has properly returned to levels observed prior to the 2008 financial crisis. A third group argues that there is no trade-off and, instead,, promotes green growth： the （politically appealing） idea is that we can simultaneously grow and address our environmental problems. This paper provides a critical perspective on this debate and suggests that asubstantial researc＇h agenda is required to come to grips with these challenges. One place to start is with the relevant metrics： measures of per-capitawealth, and, eventually, quantitative measures of prosperity, alongside a dashboard of other sustainability indicators. A public andpoliticalfocus on wealth （a stock）, and its annual changes, could realistically complement the current focus on market-based gross output as measured by GDP （a flow）. This could have important policy implications, but deeper changes to governance and business models will be required.