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Reconfigurable intelligent surface (RIS) is a new technique that is able to manipulate the wireless environment smartly and has been exploited for assisting the wireless communications, especially at high frequency band. However, it suffers from hardware impairments (HWIs) in practical designs, which inevitably degrades its performance and thus limits its full potential. To address this practical issue, we first propose a new RIS reflection model involving phase-shift errors, which is then verified by the measurement results from field trials. With this beamforming model, various phase-shift errors caused by different HWIs can be analyzed. The phase-shift errors are classified into three categories: (1) globally independent and identically distributed errors, (2) grouped independent and identically distributed errors and (3) grouped fixed errors. The impact of typical HWIs, including frequency mismatch, PIN diode failures and panel deformation, on RIS beamforming ability are studied with the theoretical model and are compared with numerical results. The impact of frequency mismatch are discussed separately for narrow-band and wide-band beamforming. Finally, useful insights and guidelines on the RIS design and its deployment are highlighted for practical wireless systems.

Intelligent reflecting surface (IRS) has been considered as a revolutionary technology to enhance the wireless communication performance. To cater for multiple mobile users, adjusting IRS beamforming patterns over time, i.e., dynamic IRS beamforming (DIBF), is generally needed for achieving satisfactory performance, which results in high controlling power consumption and overhead. To avoid such cost, we propose a new architecture based on the static regulated IRS for wireless coverage enhancement, where the principle of distributed multiple-input multiple-output (D-MIMO) is integrated into the system to exploite the diversity of spatial directions provided by multiple access points (APs). For this new D-MIMO empowered static IRS architecture, the total target area is partitioned into several subareas and each subarea is served by an assigned AP. We consider to maximize the worst-case received power over all locations in the target area by jointly optimizing a single set of IRS beamforming pattern and AP-subarea association. Then, a two-step algorithm is proposed to obtain its high-quality solution. Theoretical analysis unveils that the fundamental squared power gain can still be achieved over all locations in the target area. The performance gap relative to the DIBF scheme is also analytically quantified. Numerical results validate our theoretical findings and demonstrate the effectiveness of our proposed design over benchmark schemes., Comment: Submitted to IEEE WCL for possible publication

In the cell-free massive multiple-input multiple-output (CF mMIMO) system, the centralized transmission scheme is widely adopted to manage the inter-user interference. Unfortunately, its implementation is limited by the extensive signaling overhead between the central process unit (CPU) and the access points (APs). To solve this problem, we propose a distributed downlink transmission scheme in this letter. First, the null space-based precoding is used to cancel the interference to partial users, where only a portion of channel state information (CSI) needs to be shared among the AP cluster. Based on this, the dual decomposition method is adopted to jointly optimize the precoder and power control, where the calculation can be performed independently by each AP cluster with closed-form expression. With very few iterations, our distributed scheme achieves the same performance as the centralized one. Moreover, it significantly reduces the information exchange to the CPU.

Immunothrombosis is a mechanism of defense of the organism against pathogenic microorganisms that increases their recognition, limitation, and clearance and is part of the innate immune defense. Physiological immunothrombosis is beneficial to the body against the invasion of pathogenic microorganisms, but when immunothrombosis is out of control, it is easy to cause thrombotic diseases, thus, causing unpredictable consequences to the body. Neutrophils play a pivotal role in this process. Understanding the mechanism of neutrophils in immune thrombosis and out-of-control is particularly important for the treatment of related thrombotic diseases. In this review, we studied the role of neutrophils in immune thrombosis and each link out of control (including endothelial cell dysfunction; activation of platelets; activation of coagulation factor; inhibition of the anticoagulation system; and inhibition of the fibrinolysis system).

Distributed machine learning (DML) over time-varying networks can be an enabler for emerging decentralized ML applications such as autonomous driving and drone fleeting. However, the commonly used weighted arithmetic mean model aggregation function in existing DML systems can result in high model loss, low model accuracy, and slow convergence speed over time-varying networks. To address this issue, in this paper, we propose a novel non-linear class of model aggregation functions to achieve efficient DML over time-varying networks. Instead of taking a linear aggregation of neighboring models as most existing studies do, our mechanism uses a nonlinear aggregation, a weighted power-p mean (WPM), as the aggregation function of local models from neighbors. The subsequent optimizing steps are taken using mirror descent defined by a Bregman divergence that maintains convergence to optimality. In this paper, we analyze properties of the WPM and rigorously prove convergence properties of our aggregation mechanism. Additionally, through extensive experiments, we show that when p > 1, our design significantly improves the convergence speed of the model and the scalability of DML under time-varying networks compared with arithmetic mean aggregation functions, with little additional computation overhead., 13 pages, 26 figures

Cell-free massive MIMO provides ubiquitous connectivity for multiple users, and implementation using radio stripes is very efficient. This paper proposes a parallel scheme for radio stripes to allow access point to do signal processing simultaneously. Simple maximum ratio (MR) processing works in this scheme, but its performance is bad. Therefore, this paper further proposes two efficient parallel schemes to gain better performance. The first is interference-aware MR processing with a tailored user-centric strategy. The second is distributed regularized zero-forcing (D-RZF) algorithm which derives from LMMSE. Simulation results show that the proposed parallel schemes gain better performance than existing works.

Background The Yi is the largest ethnic group in Yunnan Province (China), with a population of five million. The Yi people tend to live in mountainous areas, and their culture includes a unique dietary system for treating and protecting people against illnesses. Medicinal plants occupy an essential place in the Yi diet because they play a key role in health and the prevention and treatment of diseases. However, few studies have addressed these medicinal dietary plants and their importance in the Yi’s daily lives. The aim of this study was to (1) investigate the medicinal dietary plants used by the Yi in Mile City, (2) document the traditional knowledge held about these plants, (3) identify species with important cultural significance to the Yi in Mile City, and (4) analyze the special preparation methods and consumption habits of these plants. Methods Field investigations were performed in six villages in Mile City, Honghe Hani and Yi Autonomous Prefecture, Yunnan, from July 2017 to May 2018. Information was collected using direct observation, semi-structured interviews, key informant interviews, individual discussions, and focus group discussions. The use value (UV) and frequency of utilization index (FUI) of these plants were analyzed. Plant samples and voucher specimens were collected for taxonomic identification. Results This study documented 124 species belonging to 62 families and 102 genera. These plants included angiosperms (117 spp.), gymnosperms (3), pteridophytes (2), lichen (1), and fungus (1). The 20 species with the highest UV were noted as being particularly important to the Yi people’s daily life in Mile City. The primary medicinal preparation method for plants recorded in the study was decoction. The most commonly used plant parts were fruits and roots. The most frequently used edible parts were fruits, and the most frequently used medicinal parts were roots. The medicinal parts were used to treat diseases such as rheumatism, edemas, kidney deficiency, spleen deficiency, gastritis, parasites, and so on. Conclusion A wide variety of medicinal dietary plants are used by the Yi people in Mile City. Those plants, which have both rich nutritional and medicinal value, occupy an essential part of the Yi dietary and medicine culture. Ethnobotanical surveys of medicinal dietary plants provide a theoretical reference for the conservation and sustainable use of the plant resources and could contribute to the protection of the Yi food culture and traditional medicine in Mile City. In addition, this information provides a sound basis for developing and using Yi ethnic medicine and health products.

Two new benzoic acid derivatives, named methyl(S)-3-hydroxy-4-(2- hydroxy -6-methylheptan-2-yl)benzoate (1) and 2-hydroxy-3-(6- hydroxy-6-methylhept-1-en-2-yl)benzoic acid (2), were isolated from the ethanol extract of an endophytic fungus Aspergillus versicolor derived from the medicinal plant Euphorbia royleana. The structures of compounds (1–2) were elucidated using NMR and MS methods.

Esculentoside A (EsA) is a saponin isolated from the roots of Phytolacca esculenta. This study was designed to evaluate the pharmacological effects of EsA on lipopolysaccharide (LPS)-stimulated BV2 microglia and primary microglia cells. Our results indicated that EsA pretreatment significantly decreased LPS-induced production of Nitric Oxide (NO) and Prostaglandin E2 (PGE2) and impeded LPS-mediated upregulation of pro-inflammatory mediators' expression such as nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-12 (IL-12) and tumor necrosis factor-a (TNF-α) in both BV2 microglia and primary microglia cells. Moreover, EsA markedly suppressed nuclear factor-κB p65 (NF-κB p65) translocation by blocking IκB-α phosphorylation and degradation in LPS-treated BV2 cells. EsA also decreased phosphorylation level of mitogen-activated protein kinases (MAPKs) and inhibited NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome mediated caspase-1 activation in LPS-stimulated BV2 cells. Additionally, EsA decreased β-amyloid1-42 (Aβ1-42)-induced production of TNF-α, IL-1β and IL-6 in primary microglia. Thus, EsA might be a promising therapeutic agent for alleviating neuroinflammatory diseases.

Guanzhong narrow courtyard is a traditional architecture form of family house in Guanzhong area in China. This project will be dedicated to my grandmother. She used to live in such house for decades. Although she has moved to city long ago, she is still missing the life in such narrow courtyard house. Unfortunately the old house has been teared down just like most of them in Guanzhong area. So I would like to design a new house for her and explore a way to translate the traditional architecture form into a modern building.

We study the precoding for the high-rank MIMO in the LTE-A Pro systems. Unlike the low-rank precoding, layer mapping has a relatively large impact on the performance for high-rank precoding. First, we construct a model on the relationship between layer mapping and precoding. Then we derive the system throughput with the resulting model, so that the performance of the layer mapping and precoding can be evaluated. Further, we operate a sub-space optimization for the codebook-based precoding to maximize the system throughput. Simulation results show that after optimizing layer mapping, high-rank precoding achieves much better performance.

Massive MIMO is a promising technique to provide high data rate with good energy efficiency for the future wireless cellular communication. However, its performance benefit often can be realized only when accurate channel state information (CSI) is available at the transmitter to perform accurate beamforming. With large number of antennas, full CSI consumes too much overhead to feed back without compression. To reduce CSI feedback overhead, CSI feedback scheme with dual stage precoding structure is designed to quantize the long term spatial channel correlation information and short term linear precoder information. In this paper, we discuss how to optimize this dual stage precoding scheme in the typical dual-polarized massive MIMO system. The eigenvalues of spatial correlation matrix are used to improve feedback efficiency. By relaxing the constant modulus constraint in codebook design, more flexible long term precoding can be used and adapt to the channel. A specific structure of long term precoding matrix for dual-polarized MIMO system is proposed to ensure the orthogonality of the final precoder for multi-layer transmission.

Massive MIMO is one of the promising techniques to improve the spectral efficiency and network performance in future 5G networks. Compared to FDD, it is relatively easier to realize downlink massive MIMO for TDD as downlink channel information can be obtained via uplink-downlink channel reciprocity. This paper provides our field test results of massive MIMO system with a base station prototype equipped with 64 transmit antennas. Significant throughput gain is observed by performing 3D-beamforming to current LTE-Advanced handsets by using standard-transparent Multiuser(MU) MIMO techniques. With the massive MIMO base station prototype, MU-MIMO is realized by multiplexing maximum of eight handsets in spatial domain considering both azimuth and elevation directions. In addition to the field trial test results, future potential enhancements for TDD massive MIMO system are discussed. Evaluation results of evaluating some enhancements on uplink reference signal are provided.

The synthesis of hexa chlorocyclotriphosphazene was investigated. The results have showed that the reaction time was shorter to 3.5 hours and the purity of the product was 96%.

Radiocarbon analysis plays an important role in studying the Quaternary geologic history of the East China Sea. More than 20014C dates have been published in various Chinese publications. The continental shelf of the East China Sea is one of the few large continental shelves in the world. Many low-lying flats and deltaic plains lie along the coast making it a favorable site for sea-level studies. Radiocarbon data from Neolithic sites, chenier ramparts, peaty deposits, and submarine sediments converge to suggest that oscillations of sea level have occurred: they also suggest that the lowest glacial sea levels probably occurred between 22,000 and 19,000 yr B.P. Calculation of the volume of the Yangtze River Delta, together with14C dates, indicates that more than 89% of the solid particles carried by the river were deposited in the delta. Due to the sedimentary load, the crust beneath the delta has subsided isostatically and tilted seaward. Marine shells provide many acceptable14C dates, but because they are easily transported, most samples from the continental shelf cannot be directly related to the history of sea-level changes.

More than forty calcrete and gypcrete samples from bore holes in the Curtin Springs area of the Amadeus Basin, Central Australia, have been dated by means of the 14 C and ESR techniques. The results indicate that the application of multiple dating techniques to samples from calcrete and gypcrete deposits enables age limits to be expanded and the number of datable material types to be increased with respect to Quaternary studies. The ability of the 14 C and ESR techniques to determine the approximate age of calcrete and gypcrete deposits has been demonstrated.

Sediment samples from a 17 m thick profile composed of clay, arkosic sand and calcrete have been dated by means of ESR spectrometry. The ESR signals of the clay sample are mainly from the feldspar. The E' signal is sensitive to γ radiation and thus it provides a reliable accumulated absorbed dose (AD) value for dating purposes. The tentative result gives the age of 200 ka for the clay samples from the lower part of the profile, 150–190 ka for the calcrete samples from the lower profile, and 120–130 ka for the clay samples from the upper part of the profile. The ESR ages are considered an order of magnitude younger than the geological age ( ∼1.8 Ma), estimated from geomorphological evidence. An inferred explanation for the underestimation in ESR ages is presented.

The groundwater discharge zone of central Australia is marked by a chain of playas extending 500 km from Lake Hopkins in Western Australia through Lake Neale, Lake Amadeus and numerous smaller playas to the Finke River in the Northern Territory. This great valley is devoid of surface drainage, and the playas and their associated landforms and chemical sediments are a result of groundwater transmission, and discharge from a large regional flow system. The valley contains extensive groundwater calcrete deposits, which are commonly silicified. The playas contain gypsum and glauberite deposits resulting from the evaporative concentration of discharging groundwater to 250 g/1total dissolved solids. Thin gypcrete crusts have developed on the playa margins and islands as a result of induration of bordering gypsum dunes. Diagenetic changes in the calcrete and gypcrete are caused by dissolution and reprecipitation through groundwater movement. Calcrete and gypcrete samples from playas near Curtin Springs, NT, date...

In order to assess the application of ESR to dating of authigenic chemical precipitates (including gypsum, phosphate and calcrete deposits), a wide variety of samples of different age, purity, mineralogy and geographical distribution were utilized. Observations of a number of radiation-induced signals indicate that the accumulated dose (AD) derived from individual signals may vary by one or two orders of magnitude. Thus the selection of an “appropriate” signal of the ESR spectrum is critically important in ESR dating. For this reason, the first stage of our investigation involved the irradiation of selected samples by a 60Co γ-ray source, with a known absorbed dose (100 or 400 Gy), to check the reliability of AD values obtained from the routine method. The results enable us to select a suitable signal for dating. A comparison of ESR and 14C ages of duplicate pedogenic calcrete from late Pleistocene sediment indicates that a valid method for the assessments of annual dose rate is of paramount importance. Based on our current experience, ESR appears to be a feasible technique for dating chemical precipitates such as gypsum, phosphate and calcrete deposits.

In order to assess the validity of routine AD-determination, more than 50 carbonate samples of various origin and known age or AD were investigated. Our results demonstrated that reliable chronological information indeed exists on the gamma-induced spectrum. Moreover, information relating to genesis, depositional environment and crystallization can be obtained simultaneously. The uncertainty in AD estimation is about 20% depending on the selection of signal and plotting method. Our study illustrates that the ESR dating method opens up new possibilities for Quaternary chronological studies.