133 research outputs found
Evolution and Trend of Green Technology Innovation Research: Visual Analysis Based on CiteSpace
Systematically understanding the global characteristics of green technology innovation research and studying the hotspots and trends of international green technology innovation research can provide beneficial directional references for subsequent scholars’ research. Papers on green technology innovation published in the core database of Web of Science from 2007 to 2021 were selected as the research objects. Knowledge map analysis method and CiteSpace software were used for visual analysis, and the trend of published papers,research countries and institutions, authors and keywords of green technology innovation research was summarized. It is found that the research on green technology innovation is on the rise and is the focus of most scholars at present; The publication of papers mainly comes from China, and universities are the main force of research; The research is mainly gathered in technological innovation, environmental regulation and sustainable development, which has very important theoretical value and reference significance for the development of green technology innovation
Research on Emergency Management Ability Evaluation of Sudden Landslide Event
In recent years, landslides occur frequently in China, which has brought great harm to people’s life and social security. Based on the relevant literature on landslide events and emergency management ability evaluation, this study constructs a set of effective landslide emergency management ability evaluation index system. At the same time, this study also comprehensively uses quantitative analysis and qualitative research methods to construct the evaluation model of landslide emergency management ability, and takes the “7.23” Shuicheng landslide event in Guizhou as an example. The results show that our government’s ability to deal with sudden landslides still needs to be improved, and the government should strengthen and improve early warning and prediction, information management and public opinion supervision. This study has certain practical significance and guiding role for the research of emergency management of sudden landslide
Greenhouse Gas Inventory Accounting for Chinese Cities: A Preliminary Study
City Greenhouse Gas (GHG) inventory, a framework for measuring a city’s detailed emissions from all activities, provides scientific evidence for the purpose of policy-making. As one of the largest GHG emitters in the world, China aims to reduce CO2 emissions per unit of GDP to 60 to 65 percent below 2005 levels by 2030. However, city GHG inventories in China have not yet been published by the city governments. Furthermore, previous studies on city inventory accounting are neither complete nor globally comparable. Hence, a case study of Beijing was conducted for the purpose of reporting the city inventory completely and enabling data to be comparable internationally. This research quantifies Beijing’s latest emissions based on available data through multiple methods, including Community-Scale Greenhouse Gas emissions inventories (GPC), a method devised by the Japanese Ministry of Environment (Japanese Ministry of Environment, 2010) and a method from recent academic research on CO2 emissions in the Chinese iron and steel industry (Zhao, Y. Q., Li, & Li, 2012). According to these methods, Beijing’s GHG emissions were 373,558,617 t CO2 in 2012. Additionally, comparisons between Beijing and six other mega-cities of Shanghai, Tokyo, New York, Washington D.C., London and Paris show that Beijing’s 2012 GHG emission per capita and per 10,000 CNY GDP ranked the highest. This study creates a timely and relatively complete GHG emission inventory that can be widely applied for comparisons and presents recommendations for city inventory building
Impacts of microphysical parameterizations on banded convective system in convection-permitting simulation: a case study
The representation of cloud microphysical processes in models has always been a challenge leading to uncertainty in convective simulations. This paper evaluates the effect of cloud microphysical parameterizations on the simulation of mesoscale convective systems (MCSs) through a realistic banded convection process. A series of numerical simulation experiments are performed using the Weather Research and Forecasting (WRF) model at a convection-permitting scale with a 3Â km horizontal grid spacing. Specifically, four experiments considering different hydrometeor species within the WRF single-moment-microphysics schemes (WSMMPs) are conducted, and three additional sensitivity tests change the graupel particle properties. The results indicate that the significant differences in the times of convection initiation across the experiments reach 120Â min, and more hydrometeor species may lead to later convection initiation. Moreover, the frozen graupel hydrometeor characteristics can appreciably alter the simulated convective morphology, even more than other hydrometeor species. When the graupel becomes smaller (such as Graupel-like), the fall speed of the graupel particles decreases. Therefore, more numerous graupel particles reside in clouds for a longer time, and experience more atmospheric diabatic heating and cooling effects. As a result, the simulated convective systems exhibit strong banded convective echo characteristics, the surface 10-m wind gust increases, and the cold pools associated with additional melting and evaporation become stronger, accelerating the propagation of the system. In contrast, larger and less abundant graupels (e.g., Hail-like) have a faster fall speed, and the atmospheric diabatic heating and cooling decrease by shortening the duration of their residence time within the clouds, resulting in a weak quasi-linear convective system, weak surface 10-m wind gust, unobvious cold pool, and slower propagation. Comparisons of the experiments further demonstrate that the fall speeds of frozen graupel particles largely impact the vertical distribution of the hydrometeors and the related microphysical processes
Ultrafast field-driven monochromatic photoemission from carbon nanotubes
Ultrafast electron pulses, combined with laser-pump and electron-probe
technologies, allow for various forms of ultrafast microscopy and spectroscopy
to elucidate otherwise challenging to observe physical and chemical
transitions. However, the pursuit of simultaneous ultimate spatial and temporal
resolution has been largely subdued by the low monochromaticity of the electron
pulses and their poor phase synchronization to the optical excitation pulses.
State-of-the-art photon-driven sources have good monochromaticity but poor
phase synchronization. In contrast, field-driven photoemission has much higher
light phase synchronization, due to the intrinsic sub-cycle emission dynamics,
but poor monochromaticity. Such sources suffer from larger electron energy
spreads (3 - 100 eV) attributed to the relatively low field enhancement of the
conventional metal tips which necessitates long pump wavelengths (> 800 nm) in
order to gain sufficient ponderomotive potential to access the field-driven
regime. In this work, field-driven photoemission from ~1 nm radius carbon
nanotubes excited by a femtosecond laser at a short wavelength of 410 nm has
been realized. The energy spread of field-driven electrons is effectively
compressed to 0.25 eV outperforming all conventional ultrafast electron
sources. Our new nanotube-based ultrafast electron source opens exciting
prospects for attosecond imaging and emerging light-wave electronics
Tunable Interband Transitions in Twisted h-BN/Graphene Heterostructures
In twisted h-BN/graphene heterostructures, the complex electronic properties
of the fast-traveling electron gas in graphene are usually considered to be
fully revealed. However, the randomly twisted heterostructures may also have
unexpected transition behaviors, which may influence the device performance.
Here, we study the twist angle-dependent coupling effects of h-BN/graphene
heterostructures using monochromatic electron energy loss spectroscopy. We find
that the moir\'e potentials alter the band structure of graphene, resulting in
a redshift of the intralayer transition at the M-point, which becomes more
pronounced up to 0.25 eV with increasing twist angle. Furthermore, the twisting
of the Brillouin zone of h-BN relative to the graphene M-point leads to tunable
vertical transition energies in the range of 5.1-5.6 eV. Our findings indicate
that twist-coupling effects of van der Waals heterostructures should be
carefully considered in device fabrications, and the continuously tunable
interband transitions through the twist angle can serve as a new degree of
freedom to design optoelectrical devices
Career-Specific Parenting Practices and Career Decision-Making Self-Efficacy Among Chinese Adolescents: The Interactive Effects of Parenting Practices and the Mediating Role of Autonomy
This study examined the unique and interactive effects of various career-specific parenting practices (i.e., parental career support, interference, and lack of engagement) on Chinese high school students’ career decision-making self-efficacy (CDSE) as well as the mediating role of autonomy in such associations. Based on data from 641 Chinese high school students (47.6% male; mean age = 15.28 years old, SD = 0.49) in 2016, two moderated mediating effects were identified. Higher level of parental career engagement strengthened the positive association between parental career support and adolescents’ autonomy, which in turn, was associated positively with adolescents’ CDSE. Parental career interference related negatively with adolescents’ CDSE via autonomy when lack of parental career engagement was low, but related positively with adolescents’ CDSE via autonomy when lack of parental career engagement was high. These findings advance our understanding of the underlying processes between career-specific parenting practices and adolescents’ CDSE. Implications for practices were discussed
Alkaline stress reduces root waving by regulating PIN7 vacuolar transport
Root development and plasticity are assessed via diverse endogenous and environmental cues, including phytohormones, nutrition, and stress. In this study, we observed that roots in model plant Arabidopsis thaliana exhibited waving and oscillating phenotypes under normal conditions but lost this pattern when subjected to alkaline stress. We later showed that alkaline treatment disturbed the auxin gradient in roots and increased auxin signal in columella cells. We further demonstrated that the auxin efflux transporter PIN-FORMED 7 (PIN7) but not PIN3 was translocated to vacuole lumen under alkaline stress. This process is essential for root response to alkaline stress because the pin7 knockout mutants retained the root waving phenotype. Moreover, we provided evidence that the PIN7 vacuolar transport might not depend on the ARF-GEFs but required the proper function of an ESCRT subunit known as FYVE domain protein required for endosomal sorting 1 (FREE1). Induced silencing of FREE1 disrupted the vacuolar transport of PIN7 and reduced sensitivity to alkaline stress, further highlighting the importance of this cellular process. In conclusion, our work reveals a new role of PIN7 in regulating root morphology under alkaline stress
Locally advanced rectal cancer with dMMR/MSI-H may be excused from surgery after neoadjuvant anti-PD-1 monotherapy: a multiple-center, cohort study
ObjectiveExamine patients with locally advanced rectal cancer (LARC) with deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) who received neoadjuvant immunotherapy (nIT), and compare the outcomes of those who chose a watch-and-wait (WW) approach after achieving clinical complete response (cCR) or near-cCR with those who underwent surgery and were confirmed as pathological complete response (pCR).MethodsLARC patients with dMMR/MSI-H who received nIT were retrospectively examined. The endpoints were 2-year overall survival (OS), 2-year disease-free survival (DFS), local recurrence (LR), and distant metastasis (DM). The efficacy of programmed cell death protein-1 (PD-1) inhibitor, immune-related adverse events (irAEs), surgery-related adverse events (srAEs), and enterostomy were also recorded.ResultsTwenty patients who received a PD-1 inhibitor as initial nIT were examined. Eighteen patients (90%) achieved complete response (CR) after a median of 7 nIT cycles, including 11 with pCR after surgery (pCR group), and 7 chose a WW strategy after evaluation as cCR or near-cCR (WW group). Both groups had median follow-up times of 25.0 months. Neither group had a case of LR or DM, and the 2-year DFS and OS in each group was 100%. The two groups had similar incidences of irAEs (P=0.627). In the pCR group, however, 2 patients (18.2%) had permanent colostomy, 3 (27.3%) had temporary ileostomy, and 2 (18.2%) had srAEs.ConclusionNeoadjuvant PD-1 blockade had high efficacy and led to a high rate of CR in LARC patients with dMMR/MSI-H. A WW strategy appears to be a safe and reliable option for these patients who achieve cCR or near-cCR after nIT
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