89 research outputs found
Regression Analysis Research on the Impact of Urbanization on Farmersâ Consumption Structure
The status of research on the impact of urbanization on farmersâ consumption structure conducted by the domestic and international scholars is described in the paper; and the argument is supported by exploration and analysis that the urbanization has exerted an influence on farmersâ consumption structure. Furthermore, by concretely exploring the related data model constructed in the research, the following achievements are made: along with the advancement of urbanization, the proportion of three categories including food and clothing in farmersâ consumption structure turns on a downward trend, while the proportion of housing, transportation, and other five categories are in an upward trend; in the farmersâ consumption expenditure, the medical and health expenditure is significantly affected by urbanization, while urbanization only has a little influence on food expenditure. On the basis of the conclusion in this paper, suggestions are put forward which include promoting the urbanization rate, creating a better condition for the development of the rural residents, improving the basic social security system and perfecting a series of policies that stimulate rural consumption including the âhome appliances going to the countrysideâ, âmobile phones going to the countrysideâ, and âcars going to the countrysideâ etc.
Diversity Induced Environment Design via Self-Play
Recent work on designing an appropriate distribution of environments has
shown promise for training effective generally capable agents. Its success is
partly because of a form of adaptive curriculum learning that generates
environment instances (or levels) at the frontier of the agent's capabilities.
However, such an environment design framework often struggles to find effective
levels in challenging design spaces and requires costly interactions with the
environment. In this paper, we aim to introduce diversity in the Unsupervised
Environment Design (UED) framework. Specifically, we propose a task-agnostic
method to identify observed/hidden states that are representative of a given
level. The outcome of this method is then utilized to characterize the
diversity between two levels, which as we show can be crucial to effective
performance. In addition, to improve sampling efficiency, we incorporate the
self-play technique that allows the environment generator to automatically
generate environments that are of great benefit to the training agent.
Quantitatively, our approach, Diversity-induced Environment Design via
Self-Play (DivSP), shows compelling performance over existing methods
Influence of Temperature on Hydrolysis Acidification of Food Waste
AbstractFor two-phase anaerobic digestion process of food waste, degree of hydrolysis and products by acidification during hydrolysis and acidification phase directly affect the performance of methanogenesis phase. Temperature has great impact on hydrolysis and acidification of food waste. This paper monitored the dynamic change of biogas production, biogas composition, pH, soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFAs) during hydrolysis and acidification stage so as to investigate specific influence of temperature on food waste. With the same inoculum and 9 daysâ fermentation, three different temperatures (35, 55 and 70°C) were taken into consideration. The results showed that cumulative gas production was 4860mL at 70°C, which was 129.79% and 37.87% higher than that at 35 and 55°C. Besides, hydrogen content at 70°C was 45.34%, which was the highest among the three temperatures. Hydrolysis rate was proportional to the increase of temperature. Meanwhile, total VFAs yield and composition widely differed at three different temperatures. The hydrolysis and acidification products at 35°C were mainly ethanol and acetic acids and the highest concentrations of ethanol at 35°C were 3.28 and 3.65 times of that at 55 and 70°C, but more acetic, isobutyric and butyric acids were generated at 55 and 70°C. Among three temperatures, 70°C had the highest acetic acids concentration while 55°C had the highest isobutyric and butyric acids concentration
Effects of Alfalfa Saponin on Fermentation Functions and Protozoal Populations in the Rumen of Sheep
Validating quantum-supremacy experiments with exact and fast tensor network contraction
The quantum circuits that declare quantum supremacy, such as Google Sycamore
[Nature \textbf{574}, 505 (2019)], raises a paradox in building reliable result
references. While simulation on traditional computers seems the sole way to
provide reliable verification, the required run time is doomed with an
exponentially-increasing compute complexity. To find a way to validate current
``quantum-supremacy" circuits with more than qubits, we propose a
simulation method that exploits the ``classical advantage" (the inherent
``store-and-compute" operation mode of von Neumann machines) of current
supercomputers, and computes uncorrelated amplitudes of a random quantum
circuit with an optimal reuse of the intermediate results and a minimal memory
overhead throughout the process. Such a reuse strategy reduces the original
linear scaling of the total compute cost against the number of amplitudes to a
sublinear pattern, with greater reduction for more amplitudes. Based on a
well-optimized implementation of this method on a new-generation Sunway
supercomputer, we directly verify Sycamore by computing three million exact
amplitudes for the experimentally generated bitstrings, obtaining an XEB
fidelity of which closely matches the estimated value of .
Our computation scales up to cores with a sustained
single-precision performance of Pflops, which is accomplished within
days. Our method has a far-reaching impact in solving quantum many-body
problems, statistical problems as well as combinatorial optimization problems
where one often needs to contract many tensor networks which share a
significant portion of tensors in common.Comment: 7 pages, 4 figures, comments are welcome
Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements
This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mgâ
L â1 â
d â1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%-62.2% higher than with NaOH-pretreatment alone and 22.2%-56.3% higher than with untreated corn stover. The best combination was obtained 5-9 days shorter than T 90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production
Suggestions on the development strategy of shale gas in China
AbstractFrom the aspects of shale gas resource condition, main exploration and development progress, important breakthrough in key technologies and equipment, this paper systematically summarized and analyzed current situation of shale gas development in China and pointed out five big challenges such as misunderstandings, lower implementation degree and higher economic uncertainty of shale gas resource, and still no breakthrough in exploration and development core technologies and equipment for shale gas buried depth more than 3500Â m, higher cost and other non-technical factors that restrict the development pace. Aiming at the above challenges, we put forward five suggestions to promote the shale gas development in China: (1) Make strategies and set goals according to our national conditions and exploration and development stages. That is, make sure to realize shale gas annual production of 20Â ĂÂ 109Â m3, and strives to reach 30Â ĂÂ 109Â m3. (2) Attach importance to the research of accumulation and enrichment geological theory and exploration & development key engineering technologies for lower production and lower pressure marine shale gas reservoir, and at the same time orderly promote the construction of non-marine shale gas exploration & development demonstration areas. (3) The government should introduce further policies and set special innovation funds to support the companies to carry out research and development of related technologies and equipment, especially to strengthen the research and development of technology, equipment and process for shale gas bellow 3500Â m in order to achieve breakthrough in deep shale gas. (4) Continue to promote the geological theory, innovation in technology and management, and strengthen cost control on drilling, fracturing and the whole process in order to realize efficient, economic and scale development of China's shale gas. (5) Reform the mining rights management system, establish information platform of shale gas exploration and development data, and correctly guide the non-oil and gas companies to participate in shale gas exploration and development
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