脑电可穿戴无线射频发射芯片系统的研究

针对脑电EEG (electroencephalograph)传感网络近距离无线传输与可穿戴应用的需要,给出了一款无线射频电路控制系统:集成了模拟电路(8通道低噪声脑电放大器与中速SAR-ADC模数转换)、信道编码EEG-DSP加速器、射频发射芯片。在ISM-2.4 GHz波段,射频物理层使用射频直接上变频架构,通过FSK/OOK (on-off-keying)的数据调制方式;重点优化基于PLL的频率综合器(PLL-FS)与可开关的E类功率放大器(PA-E);PLL-FS具有低相位噪声(?119 dBc/Hz@1 MHz)、锁定时间短(28~60 us)、环路特性好的特点;PA优化了输出功率(4~5 dBm)、功率增加效率PAE(25%)、S-参数等。流水EEG-DSP负责整体系统控制、数据缓存、精简无线信道编码以及输出码流调制射频电路。设计利用Cadence Co.的SpecterRF软件、Synopsys Co.的系列数字软件/Caliber软件进行了功能仿真/物理版图验收,设计使用SmicRF180 nm数模混合工艺进行了加工,流片回来的测试结果表明EEG-DSP与射频发射芯片可以满足实际应用。

Bio-templated formation of defect-abundant VS2 as a bifunctional material toward high-performance hydrogen evolution reactions and lithium-sulfur batteries

Transition metal chalcogenides have nowadays garnered burgeoning interest owing to their fascinating electronic and catalytic properties,thus possessing great implications for energy conversion and storage applications.In this regard,their controllable synthesis in a large scale at low cost has readily become a focus of research.Herein we report diatomite-template generic and scalable production of VS2 and other transition metal sulfides targeting emerging energy conversion and storage applications.The conformal growth of VS2over diatomite template would endow them with defect-abundant features.Throughout detailed experimental investigation in combination with theoretical simulation,we reveal that the enriched active sites/sulfur vacancies of thus-derived VS2 architectures would pose positive impacts on the catalytic performance such in electrocatalytic hydrogen evolution reactions.We further show that the favorable electrical conductivity and highly exposed sites of VS2 hold promise for serving as sulfur host in the realm of Li-S batteries.Our work offers new insights into the templated and customized synthesis of defect-rich sulfides in a scalable fashion to benefit multifunctional energy applications.

Non-precious metal electrocatalysts for two-electron oxygen electrochemistry: Mechanisms, progress, and outlooks

Hydrogen peroxide (H_(2)O_(2)) is a valuable chemical for a wide variety of applications. The environmentally friendly production route of the electrochemical reduction of O_(2)to H_(2)O_(2) has become an attractive alternative to the traditional anthraquinone process. The efficiency of electrosynthesis process depends considerably on the availability of cost-effective catalysts with high selectivity, activity, and stability.Currently, there are many outstanding issues in the preparation of highly selective catalysts, the exploration of the interface electrolysis environment, and the construction of electrolysis devices, which have led to extensive research efforts. Distinct from the existing few comprehensive review articles on H_(2)O_(2) production by two-electron oxygen reduction, the present review first explains the principle of the oxygen reduction reaction and then highlights recent advances in the regulation and control strategies of different types of catalysts. Key factors of electrode structure and device design are discussed. In addition,we highlight the promising co-production combination of this system with renewable energy or energy storage systems. This review can help introduce the potential of oxygen reduction electrochemical production of high-flux H_(2)O_(2) to the commercial market.

Petrogenesis of volcanic rocks from Eastern Manus Basin: indications in mineralogy and geochemistry

To understand the petrogenesis and magma evolution history in the Eastern Manus Basin(EMB),geochemistry of pyroxene and plagioclase mineral phenocrysts in basaltic andesites and dacites were reported.The plagioclase-melt thermometry showed that,plagioclase in dacites crystalized in 1027.2–1028.5°C under 3.37–5.08 kbar,whereas in basaltic andesite was 1181.4–1187.0°C under 1.79–4.46 kbar.Pyroxene compositions and invariable La/Sm vs La values of whole rock powders indicate that lavas were erupted in rapid cooling rate and mainly controlled by fractional crystallization(FC).In addition,oscillatory zonings in plagioclase and pyroxene phenocrysts indicated small local perturbations and degassing episodes in the magma chamber.Some high Mg#clinopyroxene antecrysts were found in EMB lavas.The highest Mg#of parental EMB melts is 69,which falls into the range of initial partial melts from upper mantle peridotite source(68–75).In terms of isotopic compositions,the EMB lavas most likely originated from Indian-type MORB mantle which was infl uenced by subduction components.In details,the subduction components are mainly derived from the dehydration of a subducted altered oceanic crust,and the contribution of sediment infl uence is minor.The Pb isotopic compositions and end member modeling further suggest that the source of subduction components is more likely from the Pacifi c Plate instead of the Solomon Plate.

Construction of defect-containing UiO-66/MoSe_(2) heterojunctions with superior photocatalytic performance for wastewater treatment and mechanism insight

Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO-66/MoSe_(2) composite was prepared using the solvothermal method.The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe_(2).X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite,which may have affected its photocatalytic performance.The composite is composed of ultra-thin flower-like MoSe_(2) that wrapped around cubic UiO-66,a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers.The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation.Rhodamine B was decolorized completely in 120 min,and most of the Cr(VI)was reduced within 150 min.The photochemical mechanism of the complex was studied in detail.The existence of Mo^(6+)and oxygen vacancies,in addition to the Z-type heterojunction promote the separation of electrons and holes,which enhances the photocatalytic effect.

Hyperbranched magnetic polymer:highly efficient removal of Cr(Ⅵ)and application in electroplating wastewater

By using a two-step hydrothermal method and trithiocyanuric acid(TTCA),2,4,6-trihydrazino-1,3,5-triazine(THT),and Fe_(3)O_(4)as raw materials,a spherical magnetic adsorbent polymer(TTCA/THT@Fe_(3)O_(4))was synthesized to achieve the efficient removal of Cr(VI)from wastewater.Under optimal adsorption conditions,the maximum adsorption capacity of TTCA/THT@Fe_(3)O_(4)for Cr(VI)can reach 1340 mg∙g‒1.Notably,the removal efficiency can approach 98.9%,even at the lower concentration of 20 mg∙L^(‒1)Cr(VI).For actual wastewater containing Cr(VI),the Cr(VI)concentration was reduced from 25.8 to 0.4 mg∙L^(‒1),a remarkable 20%lower than the current industry discharge standard value.A mechanism for the high adsorption performance of Cr(VI)on TTCA/THT@Fe_(3)O_(4)was investigated using Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,and density functional theory.It can be plausibly attributed to the formation of Cr/N and Cr/S coordination bonds.Additionally,surface electrostatic adsorption,reduction effects,and the spherical polymer structure increase the contact area with Cr(VI),maximizing adsorption.The synergistic effect of adsorption and reduction enhances the adsorption performance of TTCA/THT@Fe_(3)O_(4)for Cr(VI)and total chromium in water.The resultant polymer has a simple preparation process,excellent adsorption performance,easy magnetic separation,and promising application for actual wastewater.

Degradation potential of ofloxacin and its resulting transformation products during Fenton oxidation process

The degradation of ofloxacin(OFX)in the aqueous solution by Fenton oxidation process was investigated in the present study.The optimum operating conditions for the degradation of OFX in our system was determined.More importantly,the degradation pathways on a basis of the identification of transformation products during the degradation of OFX were proposed,which revealed that the initial degradation step could be associated with the decarboxylation at the quinolone moiety.Moreover,the detachment of the F element during the Fenton oxidation process has also been detected.Since the carboxylic group within OFX has been considered as an important bridge for binding quinolones with the DNA gyrase target,the decarboxylation process would offer insights into the reduction of antibacterial potentials.

Visible-light-driven heterostructured g-C_(3)N_(4)/Bi-TiO_(2) floating photocatalyst with enhanced charge carrier separation for photocatalytic inactivation of Microcystis aeruginosa

The increase in occurrence and severity of cyanobacteria blooms is causing increasing concern;moreover,human and animal health is affected by the toxic effects of Microcystin-LR released into the water.In this paper,a floating photocatalyst for the photocatalytic inactivation of the harmful algae Microcystis aeruginosa(M.aeruginosa)was prepared using a simple sol-gel method,i.e.,coating g-C_(3)N_(4) coupled with Bi-doped TiO_(2) on Al_(2)O_(3)-modified expanded perlite(CBTA for short).The impact of different molar ratios of Bi/Ti on CBTA was considered.The results indicated that Bi doping in TiO_(2) inhibited photogenerated electron-hole pair recombination.With 6 h of visible light illumination,75.9%of M.aeruginosa(initial concentration=2.7106 cells/L)and 83.7%of Microcystin-LR(initial concentration=100μg/L)could be removed with the addition of 2 g/L CBTA1%(i.e.,Bi/Ti molar ratio=1%).The key reactive oxygen species(ROSs)in the photocatalytic inactivation process are h+andOH.The induction of the Bi^(4+)/Bi^(3+)species by the incorporation of Bi could narrow the bandgap of TiO_(2),trap electrons,and enhance the stability of CBTA-1%in the solutions with coexisting environmental substances.

Efficient singlet oxygen generation by excitonic energy transfer on ultrathin g-C_(3)N_(4) for selective photocatalytic oxidation of methyl-phenyl-sulfide with O_(2)

Efficient generation of singlet oxygen(1 O_(2)) by an excitonic ene rgy transfer process is highly desired on a semiconductor photocatalyst for selective oxidation of methyl phenyl sulfide(MPS).Herein,it is demonstrated that a large amount of 1 O_(2) is produced on pristine graphitic carbon nitride(CN) nanosheet compared with bismuth oxybromide(BiOBr) and comme rcial P25 titanium dioxide(TiO_(2)).This leads to a certain photoactivity of CN for MPS oxidation.The observed ~77% selectivity for CN depends on the competitive results of excitonic energy transfer for 1 O_(2) formation and charge carrier separation for superoxide radical(O_(2)·) production,which are based on the phosphorescence spectra and electron paramagnetic resonance signals,respectively.Moreover,ultrathin CN nanosheets are synthesized by thermal treatment with the cyanuric acid-melamine hydrogen bonded aggregates as precursors.It is confirmed that the amount of produced 1 O_(2) could be increased by decreasing the thickness of resultant CN nanosheets.The optimized ultrathin CN nanosheet(~4 nm) exhibits excellent photoactivity with high selectivity(~99%).It is suggested that the excitonic energy transfer for 1 O_(2) formation is close related to the intrinsic exciton binding energy and the two-dimensional quantum confinement effect.This work establishes a basic mechanistic understanding on the excitonic processes in CN,and develops a feasible route to design CN-based photocatalysts for efficient 1 O_(2) generation.

In situ preparation of g-C_(3)N_(4)/polyaniline hybrid composites with enhanced visible-light photocatalytic performance

The graphic carbon nitride/polyaniline(g-C_(3)N_(4)/PANI)hybrid composites were successfully synthesized by a facile in situ polymerization process under ice water bath.The photocatalytic activities of the g-C_(3)N_(4)/PANI composites were evaluated by using oxytetracycline(OTC)as model pollutants.The optimal g-C_(3)N_(4)/PANI composite(5%PANI:the g-C_(3)N_(4)/PANI hybrid with 5 wt.%of PANI)showed an enhancement degradation rate of 5-fold compared to that of conventional g-C_(3)N_(4)under simulated-sunlight irradiation.In addition,the 5%PANI demonstrate significantly photocatalytic evolution H_(2)rate(163.2μmol/(g·hr))under the visible light irradiation.Furthermore,based on the results of optical performance and electrochemical testing,a possible mechanism was proposed,indicating that the incorporation of PANI into the traditional g-C_(3)N_(4)can effectively tune the electronic structures,improve the photo-generated electrons-holes separation and enhance extensive absorption of visible light.Such a g-C_(3)N_(4)/PANI hybrid nanocomposites could be envisaged to possess great potentials in practical wastewater treatment and water splitting.

Efficient removal of tetracycline by H_(2)O_(2) activated with iron-doped biochar: Performance, mechanism, and degradation pathways

In this study,novel iron-doped biochar(Fe-BC) was produced using a simple method,and it was used as an H_(2)O_(2)activator for tetracycline(TC) degradation.Generally,iron loading can improve the separation performance and reactivity of biochar(BC).In the Fe-BC/H_(2)O_(2)system,92% of the TC was removed within 30 min with the apparent rate constant(k_(obs)) of 0.155 min^(-1),which was 23.85 times that in the case of the BC/H_(2)O_(2)system(0.0065 min^(-1)).The effects of the H_(2)O_(2) and Fe-BC dosage,initial pH,and TC concentration on the TC removal were investigated.The radical quenching and electron paramagnetic resonance(EPR) measurements demonstrated that the removal of TC using the Fe-BC/H_(2)O_(2)process involved both radical(^(*)OH and O_(2)^(-)) and non-radical pathways(^(1)O_(2) and electron transfer).In addition,the performance of the catalyst was also affected by the persistent free radicals(PFRs) and defective sites on the catalyst.Moreover,the degradation pathways of TC were proposed according to the intermediate products detected by LC-MS and the ecotoxicity of intermediates was evaluated.Finally,the Fe-BC/H_(2)O_(2)showed high resistance to inorganic anions and natural organic matter in aquatic environments.Overall,Fe-BC is expected to be an economic and highly efficient heterogeneous Fenton catalyst for removing the organic contaminants in wastewater.

Micro EEG/ECG signal's chopper-stabilization amplifying chip for novel drycontact electrode

Facing the body＇s EEG（electroencephalograph, 0.5–100 Hz, 5–100 μV） and ECG＇s（electrocardiogram,〈 100 Hz, 0.01–5 mV） micro signal detection requirement, this paper develops a pervasive application micro signal detection ASIC chip with the chopping modulation/demodulation method. The chopper-stabilization circuit with the RRL（ripple reduction loop） circuit is to suppress the ripple voltage, which locates at the single-stage amplifier＇s outputting terminal. The single-stage chopping core＇s noise has been suppressed too, and it is beneficial for suppressing noises of post-circuit. The chopping core circuit uses the PFB（positive feedback loop） to increase the inputting resistance, and the NFB（negative feedback loop） to stabilize the 40 dB intermediate frequency gain. The cascaded switch-capacitor sample/hold circuit has been used for deleting spike noises caused by non-ideal MOS switches, and the VGA/BPF（voltage gain amplifier/band pass filter） circuit is used to tune the chopper system＇s gain/bandwidth digitally. Assisted with the designed novel dry-electrode, the real test result of the chopping amplifying circuit gives some critical parameters： 8.1 μW/channel, 0.8 μVrms（@band-widthD100 Hz）, 4216–11220 times digitally tuning gain range, etc. The data capture system uses the NI CO＇s data capturing DAQmx interface,and the captured micro EEG/ECG＇s waves are real-time displayed with the PC-Labview. The proposed chopper system is a unified EEG/ECG signal＇s detection instrument and has a critical real application value.

PDGFR kinase inhibitor protects against septic death via regulation of BTLA

Sepsis,defined as life-threatening organ failure caused by a dysregulated host response to severe infection,is a major cause of death among intensive care unit patients.Therapies targeting on immunomodulatory is a new research field in sepsis treatment.B-and T-lymphocyte attenuator(BTLA)is an inhibitory costimulatory factor molecule of B and T lymphocytes.Studies have shown that elevated expression of BTLA in lymphocytes can reduce mortality in sepsis,but its regulatory compounds and the underlying mechanism remains to be elucidated.Here,we show that treatment with CP-673451 significantly decreases mortality of septic mouse.CP-673451 is a PDGFR kinase inhibitor which can promote the expression of BTLA,inhibit the release of chemokines such as CXCL13,and reduce first the chemotaxis of B cells to the peripheral blood and vital organs.CP-673451 also inhibits both the release of cytokines and chemokines such as IL-1β,IL-6,IL-10,TNF-α,CCL1,CCL2 and CCL7 and reduces both the chemotactic ability of T cells.This suggests that CP-673451 may prevent septic death by inhibiting lymphocyte chemotaxis and alleviating“cytokine storm”.In conclusion,our study provides a new therapeutic target and an effective compound for sepsis treatment.