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Livelihood capital is the core element of sustainable livelihood development for rural households. Based on the survey data of 615 growers in the main rubber-producing areas of Hainan and Yunnan province, this paper constructs an evaluation system of rubber growers' livelihood capital within the sustainable livelihood analysis framework and calculates key indicators, such as farmers' livelihood capital index, livelihood activity diversity index, and household income diversity index. The multiple regression model and the mediating effect model are used to explore the influence mechanism of livelihood capital on the sustainable livelihood of rural households. The following three conclusions are drawn: (1) The accumulation of livelihood capital of rural households is conducive to enriching the structure of household livelihood activities and income sources, especially the accumulation of financial capital, which is more likely to improve the diversity of household livelihood activities. Regional differences exist in the impact of livelihood capital structures on rural household livelihood outcomes. Natural capital endowment has a significant effect on the income diversification level in Hainan, but there may be a "curse" effect in Yunnan. (2) Geographical characteristics, production decisions, and farming household characteristics significantly impact sustainable livelihoods. The altitude of the village and the distance from the county seat pose certain challenges for farmers in diversifying their livelihoods. Although the law of rubber tapping production may weaken farmers' production and business activities, it can better stabilize farmers' incomes owing to its strong flexibility in labor arrangements, which may be beneficial for diversifying livelihoods; however, it does not necessarily lead to diversified incomes. While the characteristics of poor households can help rural households gain policy support, building capacity is the key to achieving a sustainable livelihood. (3) There are intermediary effects of livelihood capital on livelihood activities and household income, but the mechanisms of action are different. For the diversity of farmers' livelihoods, 52.70% of the catalytic effect of livelihood capital is achieved by improving the ability to integrate livelihood capital. Optimizing household employment strategies contributed to the promotion of livelihood capital on the income diversification index, with a mediating effect of 30.52%. The main contribution of this study is to clarify how livelihood capital can achieve the goal of diversifying household livelihood activities and income by coordinating livelihood capacity and employment strategies. Therefore, to enhance the comprehensive livelihood capacity of rural households, the coordination capacity of livelihood capital, livelihood capacity building should be enhanced, and employment information channels should be expanded.

Population urbanization is the core of new urbanization in China and is an important task in the long term. Based on mediation effect models, spatial panel data econometric models, and coupling coordination models, this study attempts to identify the direct and indirect effects of the proportion of rubber-planted areas and the indications of population urbanization using panel data of counties on Hainan Island, explaining the mechanism. The results show that rubber plantations dominated by state-owned farms weakly impacted farmers' income in 1992-2002 (first phrase), and the effects became positive in the period of smallholding expansions from 2003 to 2013 (second phrase) at a statistically significant level of 10%. However, the effects became negative between 2013 and 2020 (third phrase) due to the continuously low prices of natural rubber compared to the second phrase; the regions with higher share of rubber plantations had less local fiscal revenues per capita—especially in the third phrase—mainly because of the short industrial chain of rubber in producing regions. Shares of rubber-planted areas in the city or county (defined as rubber-planted intensity, RPI) were negatively related to proportions of staff in the non-private sector (SNS) and nonrural employees (NRE) compared to people with jobs and census registered population urbanization rates (PUR). The reversed connections between RPI and NRE became weaker over time; a 10-percentage point increase in PRI might have led to a 10.3-percentage point decrease in NRE in the first phrase, but it reduced to 3.3 percentage points in NRE with no statistical significance in the third phrase. Conversely, the negative correlation of RPI with SNS and PUR became stronger from the first to third phrase; the farmers' income and local fiscal revenue could ease the negative relationships between RPI and SNS or NRE, but they turned to enhance the relation of RPI with PUR in the second and third phrase. The evidence from Moran's I and Geary's c indices proved the existence of obvious spatial correlations in the distribution of natural rubber and farmers' income and indicated that GDP per capita and other variables are also spatially related. The estimated spatial panel data models with adjacent, geographical and economical distance matrices indicated that the direct influences of RPI on SNS, NRE, and PUR were almost negative in all phrases, but the spillover and total effects can be positive in some situations, such as in the second phrase with adjacent and geographical distance matrices of PUR; this means that an increase in rubber-planted areas may promote nonfarm job market of adjacent regions mainly due to rural labor mobility. The coupling coordination degrees between the intensity of rubber planted and population urbanization of Haikou and Sanya reach 0.96 and 0.87, respectively, in the second and third phrases—much higher than those of other regions. Compared to the first phrase, the margin of increases in the degrees of coupling coordination in the second and third phrases are reducing from the east to west in Hainan Island. The key routes to mitigate the negative links are to improve labor productivity and extend the industrial chain of natural rubber along with the nonfarm job creation, and Hainan's population urbanization should consider many other possible angles across the island.

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a clinically common functional gastrointestinal disease, in which immune imbalance plays an important role. Related immune cells include innate immune cells and adaptive immune cells, and immune cytokines include immunoglobulin, interferon, interleukin, tumor necrosis factor, etc. Traditional Chinese medicine monomers/compounds or compound formulas can regulate immunotherapy for IBS-D through multi-pathway, multi-target. This article systematically reviews and sorts out relevant literature on targeted immunotherapy of IBS-D using traditional Chinese medicine monomers/compounds and compound therapies from the perspectives of immune imbalance and intestinal infection, dysbiosis of flora, brain-gut axis disorder, and endocrine disorders. At the same time, it confirms the similarities between the "spleen as the guard" and immunity, to provide ideas for traditional Chinese medicine to treat IBS-D and related diseases through immune-mediated pathways.

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a clinically common functional gastrointestinal disease, the "SCFAs-intestinal barrier" pathway plays an important role in the pathogenesis of IBS-D. Traditional Chinese medicine monomers/compounds or Chinese medicine compound can treat IBS-D by regulating the "SCFAs-intestinal barrier" through multiple pathways and multiple targets. This article takes the relationship between SCFAs and the four major intestinal barriers, as well as the mediating effect of IBS-D,as the starting point to systematically review and sort out the relevant literature on the targeted regulation of "SCFAs-intestinal barrier" in the treatment of IBS-D by Traditional Chinese medicine monomers/compounds and Chinese medicine compound; explores the theoretical basis of IBS-D caused by "SCFAs-intestinal barrier" from the perspective of "Large intes" tine dominating fluid", in order to provide ideas for Traditional Chinese medicine to establish a precision treatment system with Chinese medicine characteristics. [ABSTRACT FROM AUTHOR]

In this paper, a patch array antenna with wideband circular polarization and high gain is proposed by utilizing a hybrid metasurface (MS). A corner-cut slotted patch antenna was chosen as the source due to the possible generation of CP mode. The hybrid MS (HMS), consisting of a receiver MS (RMS) arranged in a 2 × 2 array of squared patches and a linear-to-circular polarization conversion (LCPC) MS surrounding it was then utilized as the superstrate driven by the source. The LCPC MS cell is a squared-corner-cut patch with a 45° oblique slot etched, which has the capability for wideband LCPC. The LCPC unit cell possesses wideband PC capabilities, as demonstrated by the surface current analysis and S-parameter simulations conducted using a Floquet–port setup. The LP EM wave radiated by the source antenna was initially received by the RMS, then converted to a CP wave as it passed through the LCPC MS, and ultimately propagated into space. To further enhance the LCPC properties, an improved HMS (IHMS) was then proposed with four cells cut at the corners, based on the original HMS design. To verify this design, both CMA and E-field were utilized to analyze the three MSs, indicating that the IHMS possessed a wideband LCPC capability compared to the other two MSs. The proposed antenna was then arranged in a 2 × 2 array with sequential rotation to further enhance its properties. As demonstrated by the measurements, the array antenna achieved an S11 bandwidth of 60.5%, a 3 dB AR bandwidth of 2.85 GHz, and a peak gain of 15.1 dBic, all while maintaining a low profile of only 0.09λ0. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Palladium‐catalyzed Mizoroki‐Heck reaction is a powerful and efficient method for construction of Csp2–Csp2 bonds. Herein, four palladium complexes (I—IV) with N,O‐bidentate ligands (L1—L4) based on N‐oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki‐Heck reaction of aryl bromides with electron‐deficient olefins. X‐ray diffraction analyses indicated the palladium(II) atom of II took the distorted square planar geometry and was four‐coordinated by nitrogen and oxygen atoms from two ligands (L2). Two free chloride ions were presented as counter anions in complex II. But the palladium(II) center of IV was coordinated by nitrogen and oxygen atoms from one ligand (L4) as well as two chlorine atoms, which exhibited the nearly square‐planar geometry. The study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other complexes. The coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2—5 mol% palladium complex II, giving the desired products in good to excellent yields. The advantages of this method such as good compatibility of functional groups, high yields, and short reaction times made it more attractive for constructing Csp2–Csp2 bonds in the synthesis of functional molecules and materials. [ABSTRACT FROM AUTHOR]

(1) Background--Natural rubber production is obviously different from other crops, rubber trees are a long-term biological asset, and rubber tapping production is a daily activity. The decision of rubber growers mainly focuses on the allocation of labor factors, and the technology adoption is not included in the analysis framework of the impact of non-agricultural employment on rubber tapping production in reviewed literatures. (2) Methods--The research data came from two rounds of questionnaire surveys of rural households in Hainan Province and Xishuangbanna Dai Autonomous Prefecture in Yunnan Province in 2013 and 2019. The least square method, logit model and intermediate effect model were used to discuss the influence transmission of rubber planting scale, non-agricultural employment, technology adoption and rubber tapping production. The least square method and logit model were used to quantitatively analyze the influence of rubber planting scale on non-agricultural employment, and the intermediate effect model was used to identify the effect of low-frequency rubber tapping technology on non-agricultural employment and rubber tapping production. (3) Results--The larger the scale of household rubber planting, the smaller the proportion of non-agricultural employment in the labor force. The increase of years of schooling and the non-agricultural employment of fathers could significantly increase the probability of part-time employment and out-migrating for work of young labor forces. Rubber planting area increased by 1%, and the proportion of household non-agricultural employment labor forces decreased by 0.6 percentage points, and the percentage of young labor forces in non-farm employment fell by 0.5 percent. Compared with the two rounds of survey data, the deterioration of natural rubber market conditions did not change the negative correlation between rubber planting scale and the proportion of mi grant workers, and the estimated coefficients were very close. In fact, the proportion of households with no labor forces out-migrating for work in the 2019 survey samples increased by 0.9 percentage points compared with that in the 2013 survey samples. The local employment market was buoyant, and only about one third of house holds were pure farmers, which was similar to the national situation. The increase of rubber planting area and non-agricultural employment labor forces would make the rubber growers change the production patterns of rubber tapping. Due to the specificity of rubber tree assets and rubber tapping technology, the increase of rubber planting area would inhibit non-agricultural employment, and further promote the rubber growers to maintain normal rubber tapping production. The contribution of low-frequency rubber tapping technology to the reduction of rubber tapping activities caused by the expansion of rubber planting area and the increase of non-agricultural labor forces was very small, less than 3%, indicating that the adaptability of low-frequency rubber tapping technology in private rubber plantations was very low. The main reason was that the low-frequency rubber tapping technology was difficult to master, the risk was large, and the rubber planting scale was small. (4) Conclusions and Discussions--In order to balance rubber tapping production and non-agricultural employment, the following policy recommendations are put forward: First, improve the labor productivity of rubber tapping, including the promotion of low-frequency rubber tapping technology, the development of rubber tapping machinery and equipment, and the promotion and publicity of relevant technologies. Second, strengthen the skills training of rubber growers, increase the effective supply of non-agricultural employment market, and at the same time increase the supply of jobs. Third, construct the trading platform for the rubber plantation and rubber tree resources to promote the scale management of the rubber plantations, pilot professional services for the rubber growers provided by state-owned farms, professional cooperatives, large growers, scientific research institutes and other entities, and establish a service standard system. [ABSTRACT FROM AUTHOR]

We propose a novel Fabry–Pérot (FP) antenna consisting of a checkered polarization-conversion metasurface (PCM), corner-cut square patch antennas, and sandwiched compounds. The proposed antenna achieves low radar-cross-section (RCS), high gain, and wideband circular polarization (CP). The corner-cut square patch antennas facilitate high reflectivity, satisfactory transmission magnitude, and the desired phase difference. An embedded metal between two rings of substrate contributes to reducing cross-polarization, improving transmission efficiency, enhancing bandwidth, and reducing RCS. Following simulations, we fabricated a prototype of the proposed antenna and tested its performance. Measurements from the simulation and prototype tests were similar within a reasonable margin of error. Compared with alternative antennas, our proposed FP antenna offers high gain, wideband CP, low cost, a low RCS, and a lower profile. [ABSTRACT FROM AUTHOR]

This research involves a compact wideband circularly-polarized antenna array, which consists of a sequential rotating phase feed network, 2 × 2 mushroom-type metamaterial (MTM) unit, and so on. Each antenna array unit contains a microstrip feedline, an L-shaped slot antenna, and so on. The MTM-based antennas were incorporated with a sequential-phase network of sequentially rotated series-parallel feed to achieve wideband operation. The operational bandwidth and the radiation model in the high-frequency area were improved through the adjustment of spacing between the L-shaped slots while maintaining the size and structure of the MTM. The proposed design had dimensions of 80 mm × 80 mm × 3.5 mm (~1.64 λ0 × 1.64 λ0 × 0.072 λ0 at 6.15 GHz), and it was simulated, fabricated, and tested. [ABSTRACT FROM AUTHOR]

Phase modulated metasurface (PMM) can control the transmission state of electromagnetic (EM) wave through phase modulation scheme on the interface. Orbital angular momentum (OAM) vortex wave is denoted by the helical phase distribution of the wave front. The interaction between OAM vortex wave and PMM is investigated in this paper. The mathematical model is firstly established according to the array theory. Whereafter, two typical PMMs of chessboard metasurface (CBM) and phase gradient metasurface (PGM) are exploited as examples to uncover the scattering characteristics under illumination of OAM vortex wave. For CBM, the phase cancellation scheme is found to be broken when the OAM order l equals to ±2 under both normal incidence and oblique incidence. It reveals that the OAM vortex wave is a promising approach for metasurface stealth target detection. For PGM, the scattered wave still keeps the OAM feature but is deflected to the non-specular direction, which reveals that the generalized Snell's law is also suitable to OAM vortex wave. The discoveries of this paper may find applications in radar detection fields using OAM vortex wave.