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Essential trace metals (ETMs) may play important roles in the pathophysiology of benign and malignant breast cancers. Our study aimed to find associations between ETMs and benign and malignant breast cancers. We recruited 146 patients with benign (n = 73) and malignant (n = 73) breast tumors and 95 healthy controls (HCs) from Peking University Third Hospital, Beijing, China. The serum concentrations of seven ETMs (Zn, Mn, Cu, Fe, Co, Ni, and Mo) were evaluated using inductively coupled plasma mass spectrometry (ICP-MS). The serum concentrations of Zn were significantly lower in the malignant group than in the HC group, whereas the concentrations of Cu (p

The large opacity fluctuations in the $z > 5.5$ Ly$\alpha$ forest may indicate inhomogeneous progress of reionization. To explain the observed large scatter of the effective Ly$\alpha$ optical depth ($\tau_{\rm eff}$) of the intergalactic medium (IGM), fluctuation of UV background ($\Gamma$ model) or the IGM gas temperature ($T$ model) have been proposed, which predict opposite correlations between $\tau_{\rm eff}$ and galaxy density. In order to address which model can explain the large scatter of $\tau_{\rm eff}$, we search for Ly$\alpha$ emitters (LAEs) around two (J1137+3549 and J1602+4228) quasar sightlines with $\tau_{\rm eff}\sim3$ and J1630+4012 sightline with $\tau_{\rm eff}\sim5.5$. Using a narrowband imaging with Subaru/Hyper Suprime-Cam, we draw LAE density maps to explore their spatial distributions. Overdensities are found within 20 $h^{-1}$Mpc of the quasar sightlines in the low $\tau_{\rm eff}$ regions, while a deficit of LAEs is found in the high $\tau_{\rm eff}$ region. Although the $\tau_{\rm eff}$ of the three quasar sightlines are neither high nor low enough to clearly distinguish the two models, these observed $\tau_{\rm eff}$-galaxy density relations all consistently support the $\Gamma$ model rather than the $T$ model in the three fields, along with the previous studies. The observed overdensities near the low $\tau_{\rm eff}$ sightlines may suggest that the relic temperature fluctuation does not affect reionization that much. Otherwise, these overdensities could be attributed to other factors besides the reionization process, such as the nature of LAEs as poor tracers of underlying large-scale structures., Comment: 13 pages, 14 figures, accepted for publication in MNRAS

As we already know, Rheumatoid arthritis (RA) cannot be excluded when the rheumatoid factor (RF) or anti-cyclic citrullinated peptide antibody (anti-CCP) is negative. Here, we determined the application value of 14-3-3η protein, anti-carbamylated proteins antibodies (anti-CarP), as well as their potential role to diagnose RA together with RF or anti-CCP.Serum levels of anti-CCP, RF, 14-3-3η and anti-CarP antibodies were detected in 291 RA patients, 223 patients with autoimmune diseases except RA, and 156 healthy subjects recruited from Han population of Northern China. We examined the differences in the levels of these indicators among groups and compared the correlations between any two of the indicators. At the same time, a total of 12 testing strategies were established for comparison to maximize the diagnostic value.The levels of RF, anti-CCP, anti-CarP and 14-3-3η were significantly higher in RA patients (12.5;[9.36-15.7], 30.7;[25.7-35.6], 1.90;[1.70-2.01], 15.8;[10.8-20.8], respectively) compared with either interference-control group (1.24;[1.07-1.41], 0.64;[0.42-0.86], 0.51;[0.46-0.57], 0.33;[0.23-0.44], respectively) (p 0.0001) or healthy-control group (1.03;[0.99-1.08], 0.49;[0.38-0.59], 0.28;[0.21-0.35], 0.55;[0.27-0.85], respectively) (p 0.0001). Among all 12 detection strategies, the YI and κ value of a novel strategy that either double-positive of any 2 markers or single-positive of anti-CCP can be diagnosed as RA had the highest diagnostic value.The results of our study demonstrated that in Han population of Northern China, anti-CarP antibodies and 14-3-3η protein can be treated as valuable indicators of RA, especially when combined with RF and anti-CCP, the detection value is maximized.

he correlation between neutral hydrogen (H i) in the intergalactic medium (IGM) and galaxies attracts great interest. We select four fields that include several coherently strong Lyα absorption systems at z ∼ 2.2 detected using background quasars from the whole SDSS/(e) Baryon Oscillation Spectroscopic Survey (BOSS) database. Deep narrowband and g-band imaging are performed using the Hyper Suprime-Cam on the Subaru Telescope. We select 2642 Lyα emitter (LAE) candidates at z = 2.177 ± 0.023 down to the Lyα luminosity of LLyα ≈ 2 × 1042 erg s−1 to construct the galaxy overdensity maps, covering an effective area of 5.39 deg2. Combining the sample with the Lyα absorption estimated from 64 (e) BOSS quasar spectra, we find a moderate to strong correlation between the LAE overdensity δLAE and the effective optical depth τLoS in lines of sight, with P value = 0.09% or

We present the environmental properties around high-$z$ radio galaxies (HzRGs) at $z\sim4$, which have been poorly investigated because of their rarity. We use the largest samples of HzRGs and $g$-dropout galaxy overdense regions at $z\sim4$, which were constructed from Hyper Suprime-Cam Subaru Strategic Program, to characterize the HzRG environments statistically. We measure the $g$-dropout galaxy overdensities around 21 HzRGs whose rest-frame 1.4 GHz radio luminosities ($L_{1.4\mathrm{GHz}}$) are $10^{26-27}$ W Hz$^{-1}$. We find that the overdensities around the faint HzRGs with $L_{1.4\mathrm{GHz}}\sim10^{26.0-26.5}$ W Hz$^{-1}$ tend to be higher than that of the $g$-dropout galaxies. On the other hand, no significant difference of density environments is found between the luminous HzRGs with $ L_{1.4\mathrm{GHz}}\sim10^{26.5-27.0} $ W Hz$^{-1}$ and the $g$-dropout galaxies. The HzRGs are found to occupy more massive halos than $g$-dropout galaxies through a cross-correlation between the HzRGs and $g$-dropout galaxies. This trend is more pronounced in the faint HzRGs. These results are consistent with a scenario where HzRGs get older and more massive as the radio-luminosity decreases. The HzRGs are expected to trace the progenitors of local cluster halos from their calculated halo mass. In addition, we find that surrounding galaxies tend to distribute along the radio-jet major axis of the HzRGs at angular distances less than $\lesssim500$ physical kpc. Our findings imply the onset of the filamentary structures around the HzRGs at $z\sim4$., Comment: 22 pages, 8 figures, accepted in ApJ

Characterizing high-z quasar environments is key to understanding the co-evolution of quasars and the surrounding galaxies. To restrict their global picture, we statistically examine the g-dropout galaxy overdensity distribution around 570 faint quasar candidates at z ~ 4, based on the Hyper Suprime-Cam Subaru Strategic Program survey. We compare the overdensity significances of g-dropout galaxies around the quasars with those around g-dropout galaxies, and find no significant difference between their distributions. A total of 4 (22) out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are found to be associated with the > 4 sigma overdense regions within an angular separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at this epoch. This is similar to the fraction of g-dropout galaxies associated with the > 4 sigma overdense regions. This result is consistent with our previous work that 1.3_{-0.9}^{+0.9} % and 2.0_{-1.1}^{+1.1} % of luminous quasars detected in the Sloan Digital Sky Survey exist in the > 4 sigma overdense regions within 1.8 and 3.0 arcmin separations, respectively. Therefore, we suggest that the galaxy number densities around quasars are independent of their luminosity, and most quasars do not preferentially appear in the richest protocluster regions at z ~ 4. The lack of an apparent positive correlation between the quasars and the protoclusters implies that: i) the gas-rich major merger rate is relatively low in the protocluster regions, ii) most high-z quasars may appear through secular processes, or iii) some dust-obscured quasars exist in the protocluster regions., 12 pages, 4 figures

The spatial inhomogeneity is one of the important features for understanding the reionization process; however, it has not yet been fully quantified. To map this inhomogeneous distribution, we simultaneously detect Ly$\alpha$ emitters (LAEs) and Lyman break galaxies (LBGs) at $z \sim 6.6$ from the Subaru/Hyper Suprime-Cam (HSC) large-area ($\sim1.5\,\mathrm{ deg}^2 = 34000\,\mathrm{cMpc}^2$) deep survey. We estimate the neutral fraction, $x_\mathrm{HI}$, from the observed number density ratio of LAEs to LBGs, $n(\mathrm{LAE})/n(\mathrm{LBG})$ based on numerical radiative transfer simulation, in which model galaxies are selected to satisfy the observed selection function. While the average $x_\mathrm{HI}$ within the field of view is found to be $x_\mathrm{HI} < 0.4$, which is consistent with previous studies, the variation of $n(\mathrm{LAE})/n(\mathrm{LBG})$ within the field of view for each $140\,\mathrm{pMpc}^2$ is found to be as large as a factor of three. This may suggest a spatially inhomogeneous topology of reionization, but it also leaves open the possibility that the variation is based on the inherent large-scale structure of the galaxy distribution. Based on the simulations, it may be difficult to distinguish between the two from the current survey. We also find that LAEs in the high LAE density region are more populate high $\mathrm{EW}_0$, supporting that the observed $n(\mathrm{LAE})/n(\mathrm{LBG})$ is more or less driven by the neutral fraction, though the statistical significance is not high., Comment: 20 pages, 22 figures, accepted for publication in ApJ

Text clustering is a fundamental task that finds groups of similar texts in the corpus. Deep learning based models can capture the semantic and syntactic information in local word sequences to represent the texts but may ignore global text structures in the corpus. Recently, Graph Convolutional Networks (GCNs) have achieved the state-of-the-art performance in many applications, which may facilitate the text clustering task by exploiting the graph structures between texts via words and phrases. However, GCNs are vulnerable to adversarial attacks, e.g., small perturbations in graph structures and node attributes lead to poor performance. To address this issue, we propose a Robust Text Clustering (RTC) approach which consists of both autoencoder and GCN modules to exploit the local text features and global text structures respectively in one unified framework. We generate two types of adversarial perturbations targeting text structure and graph structure, and develop an adversarial training method to improve the robustness and generalization of the RTC framework. Extensive experiments on two real-world datasets demonstrate the effectiveness of our proposal in text clustering.

GN-z11 was photometrically selected as a luminous star-forming galaxy candidate at redshift z > 10 based on Hubble Space Telescope (HST) imaging data. Follow-up HST near-infrared grism observations detected a continuum break that was explained as the Ly-alpha break corresponding to z = 11.09 (+0.08-0.12). However, its accurate redshift remained unclear. Here we report a probable detection of three ultraviolet (UV) emission lines from GN-z11, which can be interpreted as the [C III] 1907, C III] 1909 doublet and O III] 1666 at z = 10.957+/-0.001 (when the Universe was only ~420 Myr old, or ~3% of its current age). This is consistent with the redshift of the previous grism observations, supporting GN-z11 as the most distant galaxy known to date. Its UV lines likely originate from dense ionized gas that is rarely seen at low redshifts, and its strong [C III] and C III] emission is partly due to an active galactic nucleus (AGN) or enhanced carbon abundance. GN-z11 is luminous and young, yet moderately massive, implying a rapid build-up of stellar mass in the past. Future facilities will be able to find the progenitors of such galaxies at higher redshift and probe the cosmic epoch in the beginning of re-ionization., Published in Nature Astronomy on Dec 14, 2020; 21 pages; authors' version

We report the rest-frame ultraviolet luminosity function of $g$-dropout galaxies in 177 protocluster candidates (PC UVLF) at $z\sim4$ selected in the Hyper Suprime-Cam Subaru Strategic Program. Comparing with the UVLF of field galaxies at the same redshift, we find that the PC UVLF shows a significant excess towards the bright-end. This excess can not be explained by the contribution of only active galactic nuclei, and we also find that this is more significant in higher dense regions. Assuming that all protocluster members are located on the star formation main sequence, the PC UVLF can be converted into a stellar mass function. Consequently, our protocluster members are inferred to have a 2.8 times more massive characteristic stellar mass than that of the field Lyman break galaxies at the same redshift. This study, for the first time, clearly shows that the enhancement in star formation or stellar mass in overdense regions can generally be seen as early as at $z\sim4$. We also estimate the star formation rate density (SFRD) in protocluster regions as $\simeq 6-20\%$ of the cosmic SFRD, based on the measured PC UVLF after correcting for the selection incompleteness in our protocluster sample. This high value suggests that protoclusters make a non-negligible contribution to the cosmic SFRD at $z\sim4$, as previously suggested by simulations. Our results suggest that protoclusters are essential components for the galaxy evolution at $z\sim4$., Comment: 22 pages, 16 figures, Accepted for publication in ApJ

To determine the dominant sources for cosmic reionization, the evolution history of the global ionizing fraction, and the topology of the ionized regions, we have conducted a deep imaging survey using four narrow-band (NB) and one intermediate-band (IB) filters on the Subaru/Hyper Suprime-Cam (HSC), called Cosmic HydrOgen Reionization Unveiled with Subaru (CHORUS). The central wavelengths and full-widths-at-half-maximum of the CHORUS filters are, respectively, 386.2 nm and 5.5 nm for NB387, 526.0 nm and 7.9 nm for NB527, 717.1 nm and 11.1 nm for NB718, 946.2 nm and 33.0 nm for IB945, and 971.2 nm and 11.2 nm for NB973. This combination, including NB921 (921.5 nm and 13.5 nm) from the Subaru Strategic Program with HSC (HSC SSP), are carefully designed, as if they were playing a chorus, to observe multiple spectral features simultaneously, such as Lyman continuum, Ly$\alpha$, C~{\sc iv}, and He~{\sc ii} for $z=2$--$7$. The observing field is the same as that of the deepest footprint of the HSC SSP in the COSMOS field and its effective area is about 1.6 deg$^2$. Here, we present an overview of the CHORUS project, which includes descriptions of the filter design philosophy, observations and data reduction, multiband photometric catalogs, assessments of the imaging quality, measurements of the number counts, and example use cases of the data. All the imaging data, photometric catalogs, masked pixel images, data of limiting magnitudes and point spread functions, results of completeness simulations, and source number counts are publicly available through the HSC SSP database., Comment: 17 pages, 6 figures, PASJ open access (https://academic.oup.com/pasj/advance-article-abstract/doi/10.1093/pasj/psaa100/5959796), all the data products are available at https://hsc-release.mtk.nao.ac.jp/doc/index.php/chorus

We present a comparison of the spatial distributions of Lyα emitters (LAEs) and massive star-forming and quiescent galaxies (SFGs and QGs) at 2 < z < 4.5. We use the photometric redshift catalog to select SFGs and QGs and an LAE catalog from intermediate/narrow bands obtained from the Subaru Telescope and Isaac Newton Telescope in the Cosmic Evolution Survey (COSMOS). We derive the auto-/cross-correlation signals of SFGs, QGs, and LAEs and the galaxy overdensity distributions at the position of them. Whereas the cross-correlation signals of SFGs and QGs are explained solely by their halo mass differences, those of SFGs and LAEs are significantly lower than those expected from their autocorrelation signals, suggesting that some additional physical processes are segregating these two populations. Such segregation of SFGs and LAEs becomes stronger for rest-frame ultraviolet faint LAEs (M UV > -20). From the overdensity distributions, LAEs are located in less dense regions than SFGs and QGs, whereas SFGs and QGs tend to be in the same overdensity distributions. The different spatial distributions of LAEs compared to those of massive galaxies may be attributed to assembly bias or large amounts of neutral hydrogen gas associated with massive halos. These results reinforce the importance of exploring multiple galaxy populations in quantifying the intrinsic galaxy environment of the high-z universe.

In preparation for the IGM tomography study by Subaru Prime Focus Spectrograph (PFS) survey and other large future telescopes such as TMT/ELT/GMT, we present the results of our pilot study on Ly$\alpha$ forest and IGM tomography statistics using the GADGET3-OSAKA cosmological smoothed particle hydrodynamical simulation. Our simulation includes models for star formation and supernova feedback, which enables more realistic cross-correlation studies between galaxies, neutral hydrogen (HI) and metals in circumgalactic and intergalactic medium. We create a light-cone data set at $z=2-3$ from our simulations and generate mock Ly$\alpha$ forest data. As a first step, in this paper, we focus on the distribution of HI and galaxies, and present statistical results on 1D flux PDF, 1D power spectrum, flux contrast vs. impact parameter, HI$-$galaxy cross-correlations. Our results show overall agreement with current observational data, with some interesting discrepancies on small scales that are due to either feedback effects or varying observational conditions. Our simulation shows stronger HI absorption with decreasing transverse distance from galaxies. We find that the massive galaxies with $M_\star \ge 10^{10}\,M_\odot$ contribute strongly to the flux contrast signal, and that the lower-mass galaxies with $M_\star \sim 10^8-10^{10}\,M_\odot$ tend to dilute the flux contrast signal from massive galaxies. On large scales, the average flux contrast smoothly connects to the IGM level, supporting the concordance $\Lambda$ cold dark matter model. We also find an increase in the HI absorption toward the center of a protocluster., Comment: 26 pages, 16 figures. Published in ApJ (matched to the published version)

Background Laboratory tests play an important role in the diagnosis of syphilis. This study aimed to compare and assess the performance of the Abbott chemiluminescent microparticle immunoassay (CMIA) and the ChIVD light‐initiated chemiluminescent assay (LICA) in the detection of Treponema pallidum (TP) antibody. Methods A total of 10 498 serum samples were detected with two assays, and the Treponema pallidum particle agglutination assay (TPPA) and recombinant immunoblot assay (RIBA) methods were used for confirmation. The sensitivity, specificity, positive predictive value, and negative predictive value of the Abbott CMIA and ChIVD LICA were calculated. The coincidence rate between two assays was also evaluated. The causes of false positive and false negative of two assays were studied. Results For the Abbott CMIA and ChIVD LICA, the sensitivity was 94.44% and 98.15%, the specificity was 99.89% and 99.81%, the positive predictive value was 93.29% and 88.83%, and the negative predictive value was 99.91% and 99.97%, respectively. The coincidence rate between Abbott CMIA and ChIVD LICA was 99.26%, and κ value was .790. The disease of infertility, hypertensive disease, liver disease, and cancer were the common causes of false positive in both assays, while infertility was also the main reason lead to false negative. Conclusion Our results demonstrated that the Abbott CMIA and ChIVD LICA generally had high sensitivity and specificity and therefore may be suitable for the detection of TP antibody and screening for syphilis.

We present the results of a survey of the brightest UV-selected galaxies in protoclusters. These proto-brightest cluster galaxy (proto-BCG) candidates are drawn from 179 overdense regions of $g$-dropout galaxies at $z\sim4$ from the Hyper Suprime-Cam Subaru Strategic Program identified previously as good protocluster candidates. This study is the first to extend the systematic study of the progenitors of BCGs from $z\sim2$ to $z\sim4$. We carefully remove possible contaminants from foreground galaxies and, for each structure, we select the brightest galaxy that is at least 1 mag brighter than the fifth brightest galaxy. We select 63 proto-BCG candidates and compare their properties with those of galaxies in the field and those of other galaxies in overdense structures. The proto-BCG candidates and their surrounding galaxies have different rest-UV color $(i - z)$ distributions to field galaxies and other galaxies in protoclusters that do not host proto-BCGs. In addition, galaxies surrounding proto-BCGs are brighter than those in protoclusters without proto-BCGs. The image stacking analysis reveals that the average effective radius of proto-BCGs is $\sim28\%$ larger than that of field galaxies. The $i-z$ color differences suggest that proto-BCGs and their surrounding galaxies are dustier than other galaxies at $z\sim4$. These results suggest that specific environmental effects or assembly biasses have already emerged in some protoclusters as early as $z \sim 4$, and we suggest that proto-BCGs have different star formation histories than other galaxies in the same epoch., Comment: 18 pages, 11 figures, Accepted for publication in ApJ

We have carried out deep and wide field imaging observations with narrow bands targeting 11 quasar fields to systematically study the possible photoevaporation effect of quasar radiation on surrounding low mass galaxies at $z\sim2-3$. We focused on Lyman alpha emitters (LAEs) at the same redshifts as the quasars that lie within the quasar proximity zones, where the ultra-violet radiation from the quasars is higher than the average background at that epoch. We found that LAEs with high rest-frame equivalent width of Ly$��$ emission ($EW_0$) of $\gtrsim 150$��$~$ with low stellar mass ($\lesssim 10^8 M_{\odot}$), are predominantly scarce in the quasar proximity zones, suggesting that quasar photoevaporation effects may be taking place. The halo mass of LAEs with $EW_0>150$��$~$ is estimated to be $3.6^{+12.7}_{-2.3}\times10^9 M_{\odot}$ either from the Spectral Energy Distribution (SED) fitting or the main sequence. Based on a hydrodynamical simulation, the predicted delay in star formation under a local UV background intensity with $J (��_L)\gtrsim10^{-21}$ erg s$^{-1}$ cm$^{-2}$ Hz$^{-1}$ sr$^{-1}$ for galaxies having less than this halo mass is about $>20$ Myr, which is longer than the expected age of LAEs with $EW_0>150$��. On the other hand, the photoevaporation seems to be less effective around very luminous quasars, which is consistent with the idea that these quasars are still in an early stage of quasar activity., 18 pages, 9 figures

To evaluate the clinical application value of electrochemiluminescence immunoassay analyzer (ECLIA) and chemiluminescent magnetic microparticle immunoassay (CMIA) in the detection of Treponema pallidum (TP). A total of 1225 patients in Peking University Third Hospital was enrolled from June 2014 to October 2014. ECLIA and CMIA were applied to detect the serum anti-TP. The positive rate was analyzed. RIBA was taken as a golden standard to evaluate the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy of ECLIA and CMIA. A correlation analysis between 2 assays was conducted, and that between assay and RIBA. We also evaluate the clinical value of TPPA in the detection of T pallidum. The positive rate of CMIA and ECLIA is 10.63% and 9.89%, respectively, showing no statistically significant difference (P > .05). For CMIA, ECLIA, and TPPA, the sensitivity is 99.16%, 99.16%, and 99.16%, the specificity is 98.99%, 99.82%, and 100%, the positive predictive value is 91.47%, 98.33%, and 100%, the negative predictive value is 99.91%, 99.91%, and 99.91%, the coincidence rate is 99.01% (Kappa = 0.895), 99.75% (Kappa = 0.997), and 99.92% (Kappa = 0.998), respectively. The result shows high correlation between ECLIA and CMIA. Both have high sensitivity and specificity and can be used as screening tests for the diagnosis of T pallidum in common condition.

Considering that channel estimation plays a crucial role in coherent detection, this paper addresses a method of Recursive-least-squares (RLS) channel estimation with adaptive forgetting factor in wireless space-time coded multiple-input and multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. Because there are three different forgetting factor scenarios including adaptive, two-step and conventional ones applied to RLS channel estimation, this paper describes the principle of RLS channel estimation and analyzes the impact of different forgetting factor scenarios on the performances of RLS channel estimation. Simulation results proved that the RLS algorithm with adaptive forgetting factor (RLS-A) outperformed that with two-step forgetting factor (RLS-T) or with conventional forgetting factor (RLS-C) in both estimation accuracy and robustness over the multiple-input multiple-output (MIMO) channel, i.e., a wide-sense stationary uncorrelated scattering (WSSUS) and frequency-selective slowly fading channel. Hence, we can employ the RLS-A method by adjusting forgetting factor adaptively to track and estimate channel state parameters successfully in space-time coded MIMO-OFDM systems.

The synthesis and characterization of a novel polymerizable ionic liquid derived from polyfluorene, poly[3‐methyl‐1‐(4‐(9‐methyl‐fluorene)‐butyl)‐imidazolium hexafluorophosphate] (PFIL), are described.

The green supply chain management implementation including purchasing raw materials, product design, product manufacturing and product distribution, product circulation, user consumption and recycling, etc., the participants including suppliers, manufacturers, distributors and retailers, users and logistics business. The green supply chain management is still exist many obstacles, green supply chain management from design, procurement, production, marketing, consumption for the corresponding management.

The latest 3GPP LTE release enables coordinated multi-point (CoMP) operation in heterogeneous networks. In this context, a multitude of low power nodes can be deployed within the coverage area of a high-power macro node, allowing to configure different sets of network nodes for the uplink reception from and the downlink transmission to a target mobile terminal. The resulting asymmetry between the uplink composite channel for joint reception and the downlink channel for joint transmission precludes the mobile terminal to accurately estimate the uplink pathloss using standard estimation techniques based on measuring the signal strength of downlink reference signals. In this paper, we introduce the concept of virtual propagation loss for an uplink signal jointly received by multiple geographically separated points. We demonstrate how this new metric can readily be computed at a network controller (.g., the eNodeB in LTE systems), hence enabling a fast correction of the erroneous pathloss estimate at the mobile terminal side through a simple closed-loop feedback for power control. We evaluate our method with extensive system-level simulations, showing that the proposed power control scheme achieves 20% cell-average and 50% cell-edge throughput gain over the LTE Rel.-10.

Considering that channel estimation is crucial for coherent detection, a blind channel estimation method based on linear precoding for orthogonal frequency-division multiplexing (OFDM) systems is proposed in this paper. The proposed linear frequency-domain precoder is applied to each pair of blocks before they enter the OFDM system. Due to the introduced structure of precoder, the frequency-selective channel can be identified at the receiver based on cross-correlation operations, singular value decomposition (SVD) and resolving the scalar ambiguity. Because the linear frequency-domain precoder is creatively employed to channel estimation, the proposed blind method is computationally simple and requires no prior statistical information of channel or noise. And the proposed blind method has high spectral efficiency because it exploits no training sequence. Computer simulations have proved that this proposed blind method can identify the frequency-selective channels perfectly and have a good performance

Since accurate channel state information is essential to diversity combination, coherent detection and decoding in a wireless MIMO-OFDM system, this paper presents a channel estimation method using adaptive filters in wireless MIMO-OFDM systems. Though this method presupposes no prior knowledge of channel statistics, it can track or estimate time-varying channel parameters instantaneously with the help of pilot symbols and adaptive filters. Simulation results have proved this method using adaptive filters has better performance than another method based on a least-square (LS) algorithm. And the method using a least-mean-square (LMS) filter has lower computational complexity than that using a recursive-least-squares (RLS) filter. However, the channel estimation method using the RLS filter has better performance and faster convergence than that using the LMS filter. Therefore, we can select a fitter channel estimation method using different filters according to its characteristics

MIMO-OFDM systems are considered as the solution scheme for future wideband wireless communication systems. And channel state information play a crucial role in data detection module. But Kalman filtering (KF) is a linear processing method which is not fit for processing nonlinear problem. While wireless channels have some nonlinear characteristics. Owing to the above reasons, this paper describes a channel estimation method based on extend Kalman filtering (EKF) for MIMO-OFDM systems. The proposed method based on EKF can exploit pilot symbols and an extended Kalman filter to implement channel estimation without the aid of any prior knowledge of channel statistics. In comparison with the channel estimation methods based on the least square (LS) and the least mean square (LMS) algorithms, the method base on EKF has better performances theoretically. Computer simulations also demonstrate the channel estimation method based on EKF outperforms the channel estimation methods based on LS and the LMS. Hence, the channel estimation method based on EKF can offer a dramatic system performance improvement at the cost of modest computational complexity

Since accurate channel state information is crucial for coherent detection in a wireless MIMO-OFDM system, the performance of the MIMO-OFDM system critically depends on the availability of accurate channel estimation. This paper presents a channel estimation method base on particle filtering for wireless MIMO-OFDM systems. Based on the concept of sequential importance sampling and the use of Bayesian theory, particle filtering is particularly useful in dealing with nonlinear and non-Gaussian problems such as wireless channel estimation. Although this method presupposes no prior knowledge of channel statistics, it can track time-varying channel parameters instantaneously with the help of pilot symbols and particle filters. Computer simulations confirm that this method base on particle filtering has better performance than the other methods which are based on extended Kalman filtering (EKF) and LMS filtering.

The synthesis and characterization of a novel polymerizable ionic liquid derived from polyfluorene, poly[3‐methyl‐1‐(4‐(9‐methyl‐fluorene)‐butyl)‐imidazolium hexafluorophosphate] (PFIL), are described.

Because channel estimation can play a crucial role on coherent detection of the information symbols in each data block, this paper proposes a redundant precoding assisted blind channel estimation approach for orthogonal frequency-division multiplexing (OFDM) systems. A redundant linear frequencydomain precoder is applied on each pair of blocks before they enter the OFDM system. Due to the introduced structure, the frequency-selective channel can be identified at the receiver based on autocorrelation operations, singular value decomposition (SVD) and resolving the scalar ambiguity. The proposed channel estimation method has low computational complexity and requires no prior statistical information of channel or noise. And the proposed blind method has high spectral efficiency owing to exploiting no training sequence. Computer simulations confirm that this proposed blind channel estimation method can identify the frequency-selective channels perfectly and have a good performance.

The synthesis and characterization of several new ionic liquid derivatives containing dithiocarbamate, i.e., 3‐methyl‐1‐[3‐N,N‐diethyldithiocarbamate‐propyl]‐ imidazolium hexafluorophosphate 5a, 3‐methyl‐1‐[3‐N,N‐dibutyldithiocarbamate‐propyl]‐imidazolium hexafluorophosphate 5b, 3‐methyl‐1‐[3‐N,N‐dioctyldithio‐ carbamate‐propyl]‐imidazolium hexafluorophosphate 5c, 3‐methyl‐1‐[3‐N,N‐diphenyl‐dithiocarbamate‐propyl]‐imidazolium hexafluorophosphate 5d, 3‐methyl‐1‐[3‐morpholinedithiocarbamate‐propyl]‐imidazolium hexafluorophosphate 5e, 3‐methyl‐ 1‐[3‐pyridinedithiocarbamate‐propyl]‐imidazolium hexafluorophosphate 5f, and 3‐methyl‐1‐[3‐imidazoledithiocarbamate‐propyl]‐imidazolium hexafluorophosphate 5g, are described.