Crosstalk-free achromatic full Stokes imaging polarimetry metasurface enabled by polarization-dependent phase optimization

Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis. To date, most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk, leading to detrimental effects on imaging quality and measurement accuracy. Here, we propose a crosstalk-free broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses, implemented by the principle of polarization-dependent phase optimization. Compared with the single-polarization optimization method, the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9 μm to 12 μm, which guarantees the measurement of the polarization state more precisely. The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk. The measured average relative errors are 7.08%, 8.62%, 7.15%, and 7.59% at 9.3, 9.6, 10.3, and 10.6 μm, respectively. Simultaneously, the broadband full polarization imaging capability of the device is also verified. This work is expected to have potential applications in wavefront detection, remote sensing, light-field imaging, and so forth

Seasonality of suicide in Shandong China, 1991-2009: Associations with gender, age, area and methods of suicide

Backgrounds Whether suicide in China has significant seasonal variations is unclear. The aim of this study is to examine the seasonality of suicide in Shandong China and to assess the associations of suicide seasonality with gender, residence, age and methods of suicide. Methods Three types of tests (Chi-square, Edwards' T and Roger's Log method) were used to detect the seasonality of the suicide data extracted from the official mortality data of Shandong Disease Surveillance Point (DSP) system. Peak/low ratios (PLRs) and 95% confidence intervals (CIs) were calculated to indicate the magnitude of seasonality. Results A statistically significant seasonality with a single peak in suicide rates in spring and early summer, and a dip in winter was observed, which remained relatively consistent over years. Regardless of gender, suicide seasonality was more pronounced in rural areas, younger age groups and for non-violent methods, in particular, self-poisoning by pesticide. Conclusions There are statistically significant seasonal variations of completed suicide for both men and women in Shandong, China. Differences exist between residence (urban/rural), age groups and suicide methods. Results appear to support a sociological explanation of suicide seasonality

Exploration of the molecular structure of Escherichia coli cytochrome bo ubiquinol oxidase by genetic approach

Cytochrome bo ubiquinol oxidase is one of the two terminal ubiquinol oxidases in the aerobic respiratory chain of Escherichia coli. By deleting the intergenic region between the cyoA and cyoB and one base in the overlapping sequence between cyoB and cyoC, in-frame fusions are made between all three subunits (II-I-III), the resulting gene product still assembles as part of a functional oxidase. The fused subunit (II-I-III) contains 22 transmembrane spans. These data support the previously proposed topology of the subunits. The purified cytochrome bo oxidase contains four subunits. The observed molecular weight of subunit II by mass spectroscopy is considerably less than the calculated value from the deduced amino acid sequence of its corresponding gene cyoA. The similarity of the N-terminal signal sequence of subunit II with those of known lipoproteins suggest that it is modified by lipids. This is proved by demonstrating that subunit II incorporates radioactive palmitic acid.A series of partial deletion mutants on subunit II have been constructed. Removal of the redundant C-terminal tail has no influence on the structure and function of the oxidase, whereas other deletion mutants are totally non-functional. Both the low-spin heme and the high-spin heme sites are severely disturbed, as manifested by the misincorporation of heme B into the binuclear center and the abnormal $\alpha$-peak in the reduced minus oxidized difference optical spectra. Some deletion mutants have not shown any ubiquinol oxidase activity. It is likely that subunit II is involved in quinol binding. Site-directed mutagenesis has been conducted on all the highly conserved residues in subunit II and certain residues that are conserved in the quinol oxidase but not in cytochrome c oxidase. Replacement of the charged Glu89 with neutral residues gives rise to non-functional mutant oxidases. Of the total 33 site-directed mutants constructed in this work, only the mutant W136A shows an unusually high K\rm\sb{M} value when compared to the wild-type. The data suggest that Trp136 is involved in the quinol binding.Cytochrome bo oxidase is able to incorporate heme B and heme O. Comparison of oxidases purified from various strains with different proportions of heme B and heme O has led to the conclusion that the bo\sb3-type oxidase is much more active than the oo\sb3-type oxidase, and the bb\sb3-type is the least active form. Finally, it has been found that deletion of the genes for subunits III and IV leads to a weak interaction between subunit I and subunit II. When cyoC (subunit III) or cyoD (subunit IV) is deleted, the mutant oxidases inserted into the cytoplasmic membrane have no detectable ubiquinol-1 oxidase activity. It seems that subunit III and subunit IV are required for the assembly of a functional cytochrome bo oxidase.U of I OnlyETDs are only available to UIUC Users without author permissio

Computational Efficiency of Decoupling Approach in Solving Reactive Transport Model: A Case Study of Pyrite Oxidative Dissolution

Pyrite existed widely in nature and its oxidative dissolution might lead groundwater to become acidic, which was harmful to the environment and indeed to artificial building materials. The reactive transport model was a useful tool to predict the extent of such pollution. However, the chemical species were coupled together in the form of a reaction term, which might lead the equations to be nonlinear and thus difficult to solve. A decoupling approach was presented: linear algebraic manipulations of the stoichiometric coefficients of the chemical reactions for the purpose of reducing the number of equation variables and simplifying the reactive source were used. Then the original and decoupled models were solved separately, by both a direct solver and an iterative solver. By comparing the solution times of two models, it was shown that the decoupling approach could enhance the computational efficiency, especially in situations using denser meshes. Using a direct solver, more solution time was saved than when using an iterative version

Performance Evaluation of CO2 Huff-n-Puff Gas Injection in Shale Gas Condensate Reservoirs

When the reservoir pressure is decreased lower than the dew point pressure in shale gas condensate reservoirs, condensate would be formed in the formation. Condensate accumulation severely reduces the commercial production of shale gas condensate reservoirs. Seeking ways to mitigate condensate in the formation and enhance both condensate and gas recovery in shale reservoirs has important significance. Very few related studies have been done. In this paper, both experimental and numerical studies were conducted to evaluate the performance of CO2 huff-n-puff to enhance the condensate recovery in shale reservoirs. Experimentally, CO2 huff-n-puff tests on shale core were conducted. A theoretical field scale simulation model was constructed. The effects of injection pressure, injection time, and soaking time on the efficiency of CO2 huff-n-puff were examined. Experimental results indicate that condensate recovery was enhanced to 30.36% after 5 cycles of CO2 huff-n-puff. In addition, simulation results indicate that the injection period and injection pressure should be optimized to ensure that the pressure of the main condensate region remains higher than the dew point pressure. The soaking process should be determined based on the injection pressure. This work may shed light on a better understanding of the CO2 huff-n-puff- enhanced oil recovery (EOR) strategy in shale gas condensate reservoirs

Cause of death, trend and disease burden in Shandong province, China : the third retrospective sampling survey of cause of death report

This book describes the mortality for all causes of death and the trend in major causes of death since 1970s in Shandong Province, China

Comparison of Salt-Related Knowledge and Behaviors Status of WeChat Users between 2019 and 2020

In order to identify the status of salt-related knowledge and behavior of the residents who were active in WeChat software between 2019 and 2020, 10-day salt-related surveys were conducted in 2019 and 2020 based on the WeChat public platform of China Healthy Lifestyle for All Campaign. Distribution and scores of salt-related knowledge, salt reduction behavior and high-salt intake behavior between 2019 and 2020 were compared. Data of 2109 participants in 2019 and 12,732 participants in 2020 were left for analysis. Overall, 88.2% of participants in 2019 had a willingness to reduce the amount of cooking salt in their households, significantly lower than 90.2% in 2020 (p-value < 0.05). In 2019 and 2020, over 80% of the participants knew fine dried noodles contain salt, but less than 30% knew ice cream contains salt. Over 78% of participants chose 5 g or 6 g for the maximum daily salt intake of healthy adults, and about 98% of participants knew that excessive salt intake would increase the risk of hypertension in both years. The percentage of participants who used salt measuring spoons asked restaurants to use less salt, read the sodium content on the nutrition facts table, chose foods with low sodium content and regularly used low-sodium salt, were 36.1%, 45.0%, 44.1%, 40.3% and 35.8% in 2019, and the percentage increased significantly to 46.4%, 49.2%, 50.8%, 47.1% and 43.4% in 2020 (all p-value < 0.05). The percentage of people regularly eating pickled mustard tubers, salted vegetables and sauce foods or using high-salt condiments also increased from 2019 to 2020. The median of salt-related knowledge scores, salt reduction behavior scores and high-salt intake behavior scores were 11, 2, 5 points in 2019, and 10, 3, 5 points in 2020, respectively. Compared to 2019, the salt-related knowledge score was relatively lower, while the salt reduction behavior score and high-salt intake behavior score were relatively higher in 2020. Besides, the score of salt-related knowledge and behaviors differed in different gender, age and hypertension groups. The COVID-19 epidemic may have influenced the salt-related knowledge and behaviors status of WeChat users in China. Promotion and education of salt-related knowledge and online behavior intervention are still needed, particularly for male and hypertension patients in the future