31 research outputs found
Net-Mediated Pubic Opinion Analysis of China’s Real Estate
With the development of Internet technology, the analysis of net-mediated public opinion based on text mining, has become increasingly concerned by the academic community in recent years. In this paper, we do research on net-mediated public opinion of China\u27s real estate in the second quarter of 2015empirically with the association rules, text tendency analysis and other technology of data mining and visualization. On the basis of the demonstration, a basic framework of net-mediated public opinion analysis is constructed. According to the analysis of this paper, the distribution and association of hot topics in this quarter were found, and the overall tendencies of the topics were reviewed, also some relevant policy recommendations were given
Surface Modulation of Graphene Oxide for Amidase Immobilization with High Loadings for Efficient Biocatalysis
As a type of important and versatile biocatalyst, amidase immobilization on solid materials has received broad attention with its relatively easy procedure and available reusability. However, current porous supports have suffered from limited loadings, and it is highly desired to develop a new type of material with abundant space so as to ensure a high loading of amidase. Here, graphene oxide was adopted as the support for amidase immobilization, which showed the highest loading capacity for amidase (~3000 mg/g) to date. To the best of our knowledge, it is the first case of amidase immobilized on graphene oxide. Through surface modulation via reducing the contents of oxygen-containing functional groups, activity recovery of immobilized amidase increased from 67.8% to 85.3%. Moreover, surface-modulated graphene oxide can efficiently uptake amidase under a wide range of pH, and the maximum loading can reach ~3500 mg/g. The resultant biocomposites exhibit efficient biocatalytic performance for asymmetric synthesis of a chiral amino acid (i.e., L-4-fluorophenylglycine, an intermediate of aprepitant)
Inference for the Process Performance Index of Products on the Basis of Power-Normal Distribution
The process performance index (PPI) can be a simple metric to connect the conforming rate of products. The properties of the PPI have been well studied for the normal distribution and other widely used lifetime distributions, such as the Weibull, Gamma, and Pareto distributions. Assume that the quality characteristic of product follows power-normal distribution. Statistical inference procedures for the PPI are established. The maximum likelihood estimation method for the model parameters and PPI is investigated and the exact Fisher information matrix is derived. We discuss the drawbacks of using the exact Fisher information matrix to obtain the confidence interval of the model parameters. The parametric bootstrap percentile and bootstrap bias-corrected percentile methods are proposed to obtain approximate confidence intervals for the model parameters and PPI. Monte Carlo simulations are conducted to evaluate the performance of the proposed methods. One example about the flow width of the resist in the hard-bake process is used for illustration
Electrocortical correlates of hypersensitivity to large immediate rewards in sensation seeking
Sensation seeking and delay discounting are strong predictors of various risk-taking behaviors. However, the relationship between sensation seeking and delay discounting remains elusive. Here, we addressed this issue by examining how high sensation seekers (HSS; NÂ =Â 40) and low sensation seekers (LSS; NÂ =Â 40) evaluated immediate and delayed rewards with low and high amounts during a behavioral task and an EEG task of delay discounting. Although HSS and LSS exhibited comparable discounting preference at the behavioral level, HSS relative to LSS was associated with a greater delay discounting effect at the neural level when earned rewards were large. This abnormality of reward magnitude was further corroborated by an electrocortical hypersensitivity to large immediate rewards and a stronger neural coding of reward magnitude for HSS as compared to LSS. Our findings support both the hyperactive approach theory and the optimal arousal theory in sensation seeking and have implications for the prevention and intervention targeting sensation seeking to reduce maladaptive risk-taking behaviors
Transport-Mediated Photocatalysts for Selective Conversion of Methane to Methanol and Other Oxygenates
The high activation barrier of the C-H bond in methane, combined with the high propensity of methanol and other liquid oxygenates toward overoxidation to CO2, have historically posed significant scientific and industrial challenges to converting methane directly and selectively to energy-dense fuels and chemical feedstocks. Here, we report a unique photocatalyst architecture, silica encapsulated titania decorated with AuPd nanoparticles (TiO2@SiO2-AuPd), that prevents methanol overoxidation on its surface and possesses high selectivity and yield of oxygenates even at high UV intensity. This room-temperature approach achieves high selectivity for oxygenates (94.5%) with oxygenate yield of 15.4 mmol/gcat·h at 9.65 bar total pressure of CH4 and O2. The underlying working principles of the photocatalyst system were further elucidated by tracking the photogenerated radicals and systematically varying the reaction conditions. The catalyst design principle was demonstrated to be generalizable for selective oxidation of other alkanes
Research and Mechanism of Two-step Preparation of Acetamide from Microalgae under Hydrothermal Conditions
A two-step synthesis of acetamide under hydrothermal condition from microalgae, is presented. results showed that the best yield of acetamide and selectivity of acetic acid were 9.5 % and 60.1 % at 320 ℃ for 8 min with a NH3 supply of 30. Algae such as spirulina, cyanobacteria and autotrophic chlorella could also acquire acetamide, and lactic acid was found to be an important intermediate during the exploration of reaction pathways. These results demonstrated that it is possible to develop a process for conversion of microalgae biomass into acetamide
Prognostic Value of ctDNA Mutation in Melanoma: A Meta-Analysis
Purpose. Melanoma is the most aggressive form of skin cancer. Circulating tumor DNA (ctDNA) is a diagnostic and prognostic marker of melanoma. However, whether ctDNA mutations can independently predict survival remains controversial. This meta-analysis assessed the prognostic value of the presence or change in ctDNA mutations in melanoma patients. Methods. We identified studies from the PubMed, EMBASE, Web of Science, and Cochrane databases. We estimated the combined hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) using either fixed-effect or random-effect models based on heterogeneity. Results. Sixteen studies including 1,781 patients were included. Both baseline and posttreatment detectable ctDNA were associated with poor OS (baseline detectable vs. undetectable, pooled HR = 1.97, 95% CI = 1.64–2.36, P<0.00001; baseline undetectable vs. detectable, pooled HR = 0.19, 95% CI = 0.11–0.36, P<0.00001; posttreatment detectable vs. undetectable, pooled HR = 2.36, 95% CI = 1.30–4.28, P=0.005). For PFS, baseline detectable ctDNA may be associated with adverse PFS (baseline detectable vs. undetectable, pooled HR = 1.41, 95% CI = 0.84–2.37, P=0.19; baseline undetectable vs. detectable, pooled HR = 0.43, 95% CI = 0.19–0.95, P=0.04) and baseline high ctDNA and increased ctDNA were significantly associated with adverse PFS (baseline high vs. low/undetectable, pooled HR = 3.29, 95% CI = 1.73–6.25, P=0.0003; increase vs. decrease, pooled HR = 4.48, 95% CI = 2.45–8.17, P<0.00001). The baseline BRAFV600 ctDNA mutation-positive group was significantly associated with adverse OS compared with the baseline ctDNA-negative group (pooled HR = 1.90, 95% CI = 1.58–2.29, P<0.00001). There were no significant differences in PFS between the baseline BRAFV600 ctDNA mutation-detectable group and the undetectable group (pooled HR = 1.02, 95% CI = 0.72–1.44, P=0.92). Conclusion. The presence or elevation of ctDNA mutation or BRAFV600 ctDNA mutation was significantly associated with worse prognosis in melanoma patients
Roles of magnetic coagulation in black-odor water restoration: An insight into dissolved organic matters
The black-odor water body restoration is an unfinished business in protecting and maintaining the ecological functions of natural water systems in China. Magnetic coagulation (MC) had found a vast application prospect for its high-efficient separation. In this work, the performance of MC was analyzed to explore its role in natural water protection, with a focus on identification and removal mechanisms of the dissolved organic matters (DOM) by absorption and fluorescence spectroscopy in terms of the spectroscopic indices, two-dimensional correlation spectroscopy (2D-COS), and parallel factor analysis (PARAFAC) methods. MC presented an excellent performance for suspended and colloidal matters, phosphorus, and DOMs, and showed high adaptability in pollution interception and water restoration. Tryptophan-like, tyrosine-like, and humics were identified as the key components in the wastewater, which were mainly recently produced or microbial-derived. The targeted pollutants were DOMs with high molecular weight, hydrophobicity, polarity, and aromaticity for the high affinity with the hydrolyzed Al species. Polyaluminum chloride (PAC) was the key in dissolved pollutants removal, while the mix stage is crucial for DOMs with low MW or humic-like substances as PAM facilitated the flocs formation and the absorption process. However, the residual PAM and the redissolved DOMs from the recycled magnetic seeds also act as the DOM source. This work identified the DOM composition and removal mechanism in MC, which would promote its application in natural water protection
Chromosome-level assemblies of cultivated water chestnut Trapa bicornis and its wild relative Trapa incisa
Abstract Water chestnut (Trapa L.) is a floating-leaved aquatic plant with high edible and medicinal value. In this study, we presented chromosome-level genome assemblies of cultivated large-seed species Trapa bicornis and its wild small-seed relative Trapa incisa by using PacBio HiFi long reads and Hi-C technology. The T. bicornis and T. incisa assemblies consisted of 479.90 Mb and 463.97 Mb contigs with N50 values of 13.52 Mb and 13.77 Mb, respectively, and repeat contents of 62.88% and 62.49%, respectively. A total of 33,306 and 33,315 protein-coding genes were predicted in T. bicornis and T. incisa assemblies, respectively. There were 159,232 structural variants affecting more than 11 thousand genes detected between the two genomes. The phylogenetic analysis indicated that the lineage leading to Trapa was diverged from the lineage to Sonneratia approximately 23 million years ago. These two assemblies provide valuable resources for future evolutionary and functional genomic research and molecular breeding of water chestnut
Promising Approach for High-Performance MoS<sub>2</sub> Nanodevice: Doping the BN Buffer Layer to Eliminate the Schottky Barriers
Reducing the Schottky
barrier height (SBH) of metal–MoS<sub>2</sub> interface with
no deteriorating the intrinsic properties of MoS<sub>2</sub> channel
layer is crucial to realize the high-performance MoS<sub>2</sub> nanodevice.
To realize this expectation, a promising approach is present in this
study by doping the boron nitride (BN) buffer layer between metal
electrode and MoS<sub>2</sub> channel layer. Results demonstrate that
no matter the types of concentrations and dopants the intrinsic electronic
structure, low electron effective mass of MoS<sub>2</sub> channel
layer, and the weak Fermi level pinning effects of metal/BN–MoS<sub>2</sub> interfaces are preserved and not deteriorated. More importantly,
the n- and p-type SBHs of metal/BN–MoS<sub>2</sub> interfaces
are significantly reduced by the electron-poor and -rich dopants,
respectively, when the doped BN buffer layer spreads all over the
nanodevice, which is in contrast to the traditional doping rule. Moreover,
both the n- and p-type SBHs are further decreased and even eliminated
when the concentrations of dopants increase. The n-type SBH of doped
Au/B<sub><i>x</i></sub>N–MoS<sub>2</sub> interface
and the p-type SBH of doped Pt/BN<sub><i>x</i></sub>–MoS<sub>2</sub> interface can be reduced to −0.21 and −0.61
eV by doping with high concentrations of Li and O, respectively. This
theoretical work provides an effective and promising method to realize
high-performance MoS<sub>2</sub> nanodevices with negligible SBHs