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In this paper, we present a novel physical unclonable function (PUF) based on dual entropy sources of a 2-transistor voltage reference (2T-VR) and a four-stage diode-clamped comparator. Featuring excellent stability over wide range of supply voltage and temperature, the proposed 2T-VR is constructed with one native transistor plus one PMOS transistor that are compensated to minimize its temperature coefficient. Moreover, different from most previous PUF implementations where a digital comparator with offset-cancellation is needed for digitizing the mismatched voltages/currents from the prior entropy stage, in this work, the customized diode-clamped comparator's offset is well-exploited as an additional entropy source, which can be superposed on the above 2T-VR-based entropy to significantly elevate the whole PUF structure's reliability. Besides, a near zero-overhead in-cell entropy sign based stabilization (ESS) scheme is proposed to further enhance the reliability by stabilizing the scenario with the dual entropy sources having opposite signs. The designed dual-entropy-superposed PUF is fabricated using a 65-nm standard CMOS process, and its excellent randomness is validated using the widely-accepted National Institute of Standards and Technology (NIST) PUB 800-22/800-90B and autocorrelation function (ACF) test tools. With the test chips repeatedly challenged at normal condition up to 4000 times, the measured native bit error rate (BER) and unstable bits are reported to be 0.16% and 1.3%, respectively. Moreover, with the operating temperature changing from -50°C to 130°C and the supply voltage changing from 0.8 V to 1.4 V, the native BER's VT sensitivities without stabilization are measured to be 0.195%/10°C and 0.651%/0.1 V, respectively, which can be further reduced by 4.5x and 1.5x with the proposed ESS scheme applied.

Modified biochar was used to remove Mn2+ from water with principal adsorption functions of precipitation and cation exchange. The MnCO3 and Al–Si–O–Mn mainly driven precipitation and Na+, Mg2+ and Ca2+ primarily contributed to the cation exchange.

In this article, we report a wafer-level packaged Pirani vacuum gauge using the proprietary InvenSense CMOS MEMS technology. The micro Pirani vacuum gauge features three serpentine-shaped molybdenum thermistors on the suspended silicon-on-insulator (SOI) bridges, while the wiring gap of each serpentine-shaped silicon microbridge is 1.6 ${ {\mu }}\text{m}$ . For the vacuum range of $5\times 10^{-{4}}$ –760 Torr, the CMOS MEMS Pirani gauge configured with a constant temperature interface circuit achieves a sensitivity of 0.414 V/Torr in a very fine vacuum regime, while its heating power is less than 21.3 mW. Moreover, the measured output of the micro Pirani gauge shows good agreement with a semi-empirical model, while the model predicts that the proposed Pirani gauge can measure a vacuum pressure as low as $2.6\times 10^{-{4}}$ Torr. The performance achieved by this Pirani vacuum gauge combined with its high level of integration makes it a promising Internet of Things (IoT) sensing node for vacuum monitoring in the industry.

Highly stretchable and robust strain sensors are rapidly emerging as promising candidates for a diverse array of wearable electronics and sensing devices. Conductive hydrogels represent a unique class of materials for bioelectronic applications due to their electrical and mechanical adaptability to human body. A common material engineering strategy is thus combining rigid electronic and/or ionic conductors with hydrogels to form conductive and stretchable composites. However, there exist trade-offs between high conductivity and excellent mechanical properties. To address this limitation, we designed a highly conductive yet highly stretchable hybrid hydrogel by simply encapsulating the liquid metal into polyacrylamide-alginate double networks. The resultant hydrogel simultaneously exhibits high conductivity (up to 22 S m-1), low elastic modulus (23 kPa), and ultrahigh stretchability (1500%) with excellent robustness (consistent performance against 12, 000 mechanical cycling), overcoming the traditional trade-off between electrical and mechanical properties. To demonstrate the potential impact of our technology on wearable electronics, a motion monitoring system with Self-Organizing Map was developed to achieve hand gesture monitoring and sign-to-speech translation. The use of our liquid metal-embedded hydrogels could be integral to the development of wearable electronics and human-machine interfaces.

In this brief, we present an ultracompact physical unclonable function (PUF) based on the resistive random access memory (RRAM) with the in-cell salicide-blocked (SAB) contact. Different from most previously reported RRAM PUFs with only the RRAM cell’s high-resistance state (HRS) utilized as the static entropy, its low-resistance state (LRS) is enabled with the proposed SAB contact resistance as a novel entropy source. Concretely, by adding a photolithography mask of “SAB” that widely exists in standard CMOS process to the source/drain contact of the mainstream one-transistor-one-resistor (1T1R) RRAM cell’s access transistor, an SAB contact featuring large resistance stochasticity can be formed with zero design overhead of silicon area. With the SAB contact resistance connected in series, both HRS and LRS can be well-exploited to generate much more challenge–response pairs (CRPs), leading to significantly extended CRP space. In addition, the proposed RRAM PUF with in-cell SAB contact is validated using 0.18- $\mu \text{m}$ standard CMOS process plus postprocessing steps for RRAM devices, and the normalized bitcell area is reported to be $77~{F}^{{2}}$ /bit. By varying the operating temperature from −50 °C to 150 °C, the worst case bit error rate (BER) is measured to be 0.13% at 150 °C. Moreover, the excellent randomness of the proposed implementation is verified by passing both the National Institute of Standards and Technology (NIST) test and the autocorrelation function (ACF) test.

In this study, we have designed and synthesized a low-bandgap polymer, DPP-Qx, using quinoxaline (Qx), a non-alkylated weak acceptor, with diketopyrrolopyrrole (DPP) as an electron donor. The incorporation of Qx into DPP leads to the highest occupied molecular orbital level at −5.1 eV with a narrow optical bandgap (1.25 eV). The synthesized polymer is utilized in photovoltaics, and the photovoltaic properties are studied. This DPP-Qx with fullerene acceptors in polymer solar cells (PSCs) exhibits efficiency of 3.26%. Moreover, a minimum energy loss of 0.57 eV along with high extended external quantum efficiency is achieved with the DPP-Qx electron donor. The thermal, electrical and optical properties, energy levels and hole mobility of the synthesized polymer are studied and discussed.

The secondary fermentation stage is critical for stabilizing composting products and producing various secondary metabolites. However, the low metabolic rate of mesophilic bacteria is regarded as the rate-limiting stage in composting process. In present study, two indoleacetic acid (IAA)-producing bacteria (Bacillus safensis 33C and Corynebacterium stationis subsp. safensis 29B) were inoculated to strengthen the secondary fermentation stage to improve the plant-growth promoting potential of composting products. The results showed that the addition of IAA-producing bacteria promoted the assimilation of soluble salt, the condensation and aromatization of humus, and the accumulation of dissolved organic nitrogen (DON) and dissolved organic carbon (DOC). The bioaugmentation strategy also enabled faster microbial community succession during the medium-late phase of secondary fermentation. However, the colonization of Bacillus and Corynebacterium could not explain the disproportionate increase of IAA yield, which reached up to 5.6 times compared to the control group. Deeper analysis combined with physicochemical properties and microbial community structure suggested that IAA-producing bacteria might induce the increase of salinity, which enriched halotolerant bacteria capable of producing IAA, such as Halomonas, Brachybacterium and Flavobacterium. In addition, the results also proved that it was necessary to shorten secondary fermentation time to avoid IAA degradation without affecting composting maturity. In summary, enhancing secondary fermentation of composting via adding proper IAA-producing bacteria is an efficient strategy for upgrading the quality of organic fertilizer.

In this study, the finite-time formation control of multi-agent systems with region constraints is studied. Multiple agents have first-order dynamics and a common target area. A novel control algorithm is proposed using local information and interaction. If the communication graph is undirected and connected and the desired framework is rigid, it is proved that the controller can be used to solve the formation problem with a target area. That is, all agents can enter the desired region in finite time while reaching and maintaining the desired formation shapes. Finally, a numerical example is given to illustrate the results.

A promising technique to enhance absorption of light in organic solar cells, “ternary approach” represents an important function in improving the device performance. We combined one small molecule dye (5,8-di(benzofuran-2-yl)-2,3-diphenylquinoxaline) (DB-Qx) with [6, 6]-phenyl C71 butyric acid methyl ester (PC71BM) (as the electron acceptor) and poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiopheneco-3-fluorothieno[3,4-b]thiophene-2-carboxylate] (PTB7-Th)(as the electron donor polymer) to form ternary solar cells. The morphology of the active layer of the ternary blend and hole mobility was potentially enhanced by the addition of a molecular donor. The complementary absorption of the two donors and matching photo-luminesce overlapping of DB-Qx with PTB7-Th contributed to improving the device performance. This means that the molecular donor in the ternary blend has an active function in the morphology. The devices produced PCE of 8.64% in the ternary blend system relative to 5.98% in the binary blend system. And, since the emission of DB-Qx partially overlaps with the absorption of PTB7Th, the transfer of energy from DB-Qx to PTB7-TH can improve the exciton utilization efficiency and achieve enhanced overall power conversion efficiency in this ternary solar cell. In this study, we synthesized a small fluorescent molecule material and constructed efficient ternary blend PSCs. Remarkably, the inverted device DIO-free ternary solar cells boost PCE from 5.98 to 8.64% and also exhibit the combined improvement in JSC and the morphology compared to those of DIO-processed films.

Formation problem of multi-agents systems has been investigated studied by more and more scientists. This paper studies the formation problem of the first-order multi-agent systems with region constraint. Not only formation control but also the constraint area is considered. The state of each agent is constrained by a common convex set. A formation control protocol is proposed based on the local information of neighbourhood and region constraint. If the communication topology is connected, and the target framework is rigid, all agents would enter the target area while reaching the desired formation. The convergence of the formation control to the final formation is guaranteed as proven by Lyapunov framework. Compared with the leader follower controller, the controller does not depend on the leader and has good robustness. In addition, the controller can quickly and accurately control all agents to all agents to enter the constrained area. Finally, the results are illustrated by numerical simulations.

The safe handling of heavy metals and antibiotics during waste disposal has attracted wide attention. In the present study, hydrothermally treated sewage sludge was used for co-pyrolysis with different concentration ratios of pig manure at 600 °C for heavy metal immobilization and antibiotic removal. Heavy metals (except Cd) were mainly retained in the biochar samples due to a high degree of decomposition characteristic of organic matter. Pyrolysis significantly immobilized the heavy metals via converting unstable F1 + F2 + F3 fractions (acid-soluble fraction + reducible fraction + oxidizable fraction) to stable F4 fraction (residual fraction), and more pig manure addition led to improved immobilization performance. After co-pyrolysis, the potential environmental risk of feedstocks reduced significantly and the addition of 50 wt.% of pig manure gave a minimum potential ecological risk index of 10.36 with a low risk of contamination. In addition, six types of antibiotics in feedstocks were decomposed completely during pyrolysis. The co-pyrolysis process showed numerous advantages in the synthetic treatment of sewage sludge and pig manure by reducing the heavy metal toxicity and antibiotic levels.

Background Both obesity and subclinical hypothyroidism (SCH) have adverse effects on human body, but the relationship between these two conditions remains inconsistent. The presence of thyroid autoantibodies influences thyroid hormone levels, and may further mediate the interaction between obesity and SCH. This study aimed to explore the association among obesity, SCH and thyroid autoantibodies. Methods This study was a cross-sectional survey of 2505 subjects. Obesity was defined as a body mass index ≥28 kg/m2. Serum concentrations of thyroid hormones, thyroid peroxidase antibody (TPO-Ab) and thyroglobulin antibody (Tg-Ab) were examined. Logistic analysis was used to explore the relation among obesity, SCH and thyroid autoantibodies. Results A proportion of 11.54% (289/2505) subjects were obese, and 165 subjects had SCH. The positive rates of thyroid autoantibodies, TPO-Ab and Tg-Ab were 17.64% (442/2505), 11.02% (276/2505) and 14.13% (354/2505), respectively. The proportion of SCH was significantly higher in obese than nonobese subjects among those with positive thyroid autoantibodies [22.41% (13/58) vs. 11.72% (45/384), p = 0.025, χ2 test]. Moreover, obesity was significantly associated with SCH in the presence of thyroid autoantibodies after adjusting for confounding factors (OR 2.212, 95% CI 1.103 to 4.433, p = 0.025). A higher proportion of subjects with obesity had Tg-Ab positivity [17.99% (52/289) vs. 13.63% (302/2216), p = 0.045, χ2 test], and obesity remained significantly associated with Tg-Ab positivity by multiple logistic analysis (OR 1.504, 95% CI 1.077 to 2.101, p = 0.017). Conclusions Obesity was associated with SCH in the presence of thyroid autoantibodies. Examination of SCH is recommended in obese subjects with thyroid autoantibody positivity.

The distributed optimization for multi-agent systems with time delay and first-order is investigated in this paper. The objective of the distributed optimization is to optimize the objective function composed of the sum of local objective functions, which can only be known by its corresponding agents. Firstly, a distributed algorithm for time-delay systems is proposed to solve the optimization problem that each agent depends on its own state and the state between itself and its neighbors. Secondly, Lyapunov-Krasovskii function is used to prove that the states of each agent can be asymptotically the same, and the states are optimal. Finally, an example is given for illustrating the analytical results and a comparison is also gave to illustrate the differences between the algorithm of this paper and other results.

In this paper, we present a novel physical unclonable function (PUF) design based on cascode current mirror array. By using a single-stage cascode amplifier for each PUF cell, the output impedance can be significantly elevated. Compared with a traditional single-stage amplifier-based current-mode PUF, the proposed structure is capable of generating more polarized voltage value for the output node. With an additional digital buffer, the temporal noise can be well-suppressed, and a rail-to-rail digital output can be provided with high native reliability. Moreover, through operating the transistors at the subthreshold region, the overall power consumption can be dramatically reduced. Featuring a compact footprint of $3.23~\mu \text{m}^{2}$ (i.e. 764 ${F}^{2}$ ) for each PUF cell, the proposed PUF implementation is validated using 65-nm standard CMOS process. The excellent randomness of the proposed PUF design is verified based on the test results with widely-accepted auto-correlation function and NIST suites. Meanwhile, the PUF’s uniqueness is measured with 10 chip prototypes and reported to be 49.94%. In addition, the fabricated PUF chips were also characterized with various environmental influences. With multiple readout (500 times) under the reference operating temperature of 27 °C and supply voltage of 1.2 V, the native unstable bit ratio is measured to be as low as 1.50%, which can be further improved to 0.79% by adopting the mainstream temporal majority voting (TMV)-based error correction scheme. Besides, we also evaluate the fabricated PUF chips’ reliability under varied operating temperature from −40 °C to 120 °C and supply voltage from 0.95 to 1.3 V. The averaged bit error rate (BER) per 10 °C and BER per 0.1 V are measured to be 0.86% and 1.02%, respectively. Compared with the state-of-the-art implementations, the reliability figure of merit (RFoM) is improved by $1.16\sim 4.29\times $ , with the influences of the temporal noise, the temperature/supply voltage variations and their ranges comprehensively considered.

Supplementing nano zero valent iron (nZVI) is an attractive technology for wastewater treatment due to its advantages in accelerating the hydrolysis, fermentation and anaerobic digestion (AD) process. In this present study, nZVI was added to investigate its effects on enhancing tetracycline (TC) wastewater anaerobic treatment and the changes of microbial community, especially for underestimated syntrophic-methanogenic associations. The TC concentrations were 1, 10, 30, 50, 80, 100 and 150 mg/L with 0.38 g nZVI (with iron g/g VS of 0.50) complemented into reactors. Results revealed that nZVI could enhance AD process in both control and TC dosed systems, and the promoting effect on methanogenesis was more significant in systems of high concentration TC, with 100 and 150 mg/L. In addition, cumulative CH4 production for all TC added systems without nZVI were higher than the control indicating TC had positive effect instead of expected negative effect on AD process, high TC concentration of 100 and 150 mg/L only affecting the increase factor rather than causing inhibitory effect. After digestion, TC was largely removed in with/without nZVI systems. And also, nZVI evidently altered the bacterial and methanogenic community structure, with an increase abundance of syntrophic-methanogenic associations (Syntrophobacterales and Methanosarcinales) and resulting in the enhancement of methane generation. This research provides an efficient method for TC wastewater anaerobic treatment.

The aim of this multicenter study was to demonstrate the distribution pattern of atherosclerotic stenosis and its trend with aging between extracranial and intracranial arteries and its distribution between the anterior and posterior circulations in Chinese patients hospitalized with ischemic stroke. In addition, the risk factors for the distribution pattern were illustrated. From June 2015 to May 2016, 9,346 patients with ischemic stroke from 20 hospitals were enrolled. Carotid artery ultrasonography and transcranial color-coded sonography/transcranial Doppler were used to evaluate the extracranial and intracranial arteries. The distribution pattern of atherosclerotic stenosis and its trend with aging were analyzed. Logistic regression was used to analyze the risk factors for the distribution pattern. Among the 9,346 patients, 2,882 patients (30.8%) had at least one artery with a degree of stenosis ≥50%. Among patients with arterial stenosis, the proportion of patients with intracranial artery stenosis was higher than those with extracranial artery stenosis (52.6% vs. 27.6%), and the proportion of anterior circulation artery stenosis was higher than that in the posterior circulation (52.2% vs.26.2%). With aging, the proportion of intracranial artery stenosis alone decreased; at the same time, the proportion of extracranial artery stenosis and extracranial plus intracranial artery stenosis increased (trend χ2=6.698, P=0.001). Hypertension (OR 1.416, P=0.008) and family history of stroke (OR 1.479, P=0.014) were risk factors for intracranial artery stenosis. Male, aging, and smoking were factors more related to extracranial artery stenosis. Aging (OR 1.022, P

Acidic anaerobic digestion attracted much attention and interest due to its significant advantage in wastewater treatment. In the present study, methanogenic fermentation was successfully operated under acidic condition during treating wastewater containing oxytetracycline (OTC) in a scale up anaerobic baffled reactor (ABR). After start-up process, the pH value in the first compartment was 4.60 with high activity of methanogenesis. After stabilization, different OTC loading of 1.0, 3.3 and 5.0 g/m3/d was added in the influent for OTC removal. The resulted showed that OTC addition had little impact on the methane generation with whole COD and OTC removal rate of 95% and 60%, respectively. The microbial analysis, OTC addition could significantly influence the bacteria and archaea communities. To be more specific, Methanosaeta showed the highest relative abundance and tolerance to OTC under acidic condition. The present work supplied deeper insights into methane generation from acidic condition during wastewater containing OTC treatment.

Ciprofloxacin is the most commonly prescribed antibiotic, and its widespread use poses threat to environmental safety. The removal of ciprofloxacin from contaminated water has remained a major challenge. The present study investigated adding nanoscale zero-valent iron (NZVI) and activated carbon (AC) on high-level ciprofloxacin removal in hydrolysis-acidogenesis stage of anaerobic digestion. The results showed that the degradation rate of ciprofloxacin increased from 22.61% (Blank group) to 72.41% after adding NZVI/AC with concentration of ciprofloxacin in effluent decreasing from 8.25 mg L−1 to 3.48 mg L−1. The volatile fatty acids (VFAs) yield increased by 173.7% compared with the Blank group. In addition, the NZVI/AC group achieved the highest chemical oxygen demand (COD) removal rate and acidogenesis rate. The microbial community analysis presented that hydrolytic and acidogenic bacteria and microorganisms related to degrading ciprofloxacin were obviously improved in the NZVI/AC group. Moreover, eleven transformation products and the main degradation pathways were proposed based on mass spectrometry information. In summary, the NZVI/AC addition supplied promising approach for ciprofloxacin wastewater treatment.

Fast recognition of flammable and toxic gas species within very short response time is a challenging task for the gas sensing devices adopted in a wide range of applications. The recognition accuracies of the previous implementations are always constrained by the limited feature or dynamic information extracted from the short transient gas response curves. In order to address this issue, in this paper, we propose a novel hybrid approach with both convolutional and recurrent neural networks combined, which is based on the long short-term memory module. Featuring the capability of learning the correlations of time-series data, the proposed deep learning method is well-suited for extracting the valuable transient feature contained in the very beginning of the response curve. As a result, within a response time as short as 0.5 s, the proposed implementation is capable of recognizing the gas species with an accuracy of 84.06%. In addition, the aforesaid accuracy can be further improved by increasing the response time with the step of 0.5 s. According to our extensive experimental results, the recognition accuracy can be elevated up to 98.28% at the response time of 4 s, where it typically needs 40 s for the response curve to achieve saturation. The reported accuracy dramatically outperforms the previous algorithms, including gradient tree boosting (GTB), random forest (RF), support vector machine (SVM), k-nearest neighbor (KNN), and linear discriminant analysis (LDA). Moreover, various standard drift related experiments are conducted, of which the results validate our proposed algorithm's superior robustness for the wide range of real-life applications.

In this paper, we present a novel one-dimensional deep convolutional neural network (1D-DCNN) with a multi-label-way-based algorithm for comprehensively and automatically extracting features and classifying mixture gases. Although a number of pattern recognition methods have been used to analyze the mixed gases, the performances of these methods highly depend on the hand-crafted feature engineering. By contrast, the proposed implementation, based on one-dimensional convolution, is capable of automatically extracting features and distinguishing the individual component of binary mixture gases composed of ethylene, CO, and methane. To the best of our knowledge, the proposed 1D-DCNN algorithm is first applied in the mixture gases’ recognition. In addition, the proposed 1D-DCNN with multi-label way not only significantly reduces the label dimension but also quantifies the probability of each component in mixed gases. Compared with the conventional pattern recognition algorithms including support vector machine, artificial neural network, k-nearest neighbor, and random forest, the proposed 1D-DCNN exhibits a higher recognition accuracy (96.30%) based on our extensive experimental results using ten-fold cross validation.

Physical structures of sludge are critical factors determining the performance of the anaerobic digestion process, especially for the rate-limiting step, methanogenesis. Thus, to evaluate the effect of granular physical structure on methanogenesis and methanogenic community variation, intact and disintegrated granules were applied as inocula with formate, hydrogen and acetate as sole substrates in batch reactors. Kinetics results revealed that the physical structure of sludge had little impact on methane yield potential from three substrates, while a significantly different impact on methanogenesis rates of formate, hydrogen and acetate. The methanogenesis rate of formate in disintegrated granules was higher than that in the intact granular system, the methanogenesis rate of H2/CO2 in the intact granular system was higher than that in the disintegrated granules and the methanogenesis rate of acetate was similar with the in intact and disintegrated granular systems. Besides, in both intact and disintegrated granular systems, methanogenesis rates of formate were the highest, then followed the H2/CO2 and acetate was the lowest, indicating formate consumption has an advantage over hydrogen in the studied system. A microbial assay indicated that Methanobacteriales, Methanosarcinales and Methanomicrobiales are dominant methanogens on the order level, and the physical structure of granular sludge has little influence on methanogenic communities on the order level but showed significant influence on the species level. It enlightens us that the physical structure of sludge could be considered for regulating the anaerobic digestion via influencing the methanogenesis rates.

Composting, as an effectively bio-oxidative process, has been widely used for converting organic waste to organic fertilizer. However, the low fertilizer efficiency of composting product limited its application in agriculture. To improve the growth-promoting effect of composting product, the present study investigated the bioaugmentation strategy of inoculating indole-3-acetic-acid (IAA)-producing bacteria. Firstly, two IAA-producing bacteria (Bacillus safensis 33C and Rhodococcus rhodochrous YZ) were isolated from composting products with high IAA yields of 39.18 and 16.32 μg mL-1, respectively. Secondly, the microbial inoculants were prepared with 33C, YZ and a previously isolated IAA-producing strain Corynebacterium stationis 29B. To increase the accumulation of microbial secondary metabolites, microbial inoculants were amended at the secondary fermentation stage of composting. Physicochemical characterization showed that the maturity of composting product was significantly promoted by inoculating microbial inoculants prepared with 33C and 29B (single and combined inoculants). Finally, bioaugmentation with 33C and 29B increased the IAA contents of composting products by 2.9-5.2 times, which benefited the germination and early vegetative growth of plants. In summary, inoculating proper IAA-producing bacteria during secondary fermentation of composting could improve the quality of composting product and expand its application.

In this study, the performances of a conventional anaerobic baffled reactor (ABR) and an ABR combined with microbial electrolysis cells (MECs) for enhancing degradation of volatile fatty acids (VFAs) were evaluated in 55°C. The ABR-MECs system achieved a total chemical oxygen demand (COD) removal rate of 97.2% and a methane yield of 236 ± 5 mL g-1 CODremoved at organic loading rate (OLR) of 6.9 kg COD m-3 d-1, which were higher than those of the ABR with 77.6% and 207 ± 5 mL g-1 CODremoved, respectively, at OLR of 5.1 kg COD m-3 d-1. The pyrosequencing analysis confirmed that the introduction of MECs into ABR was conducive to establishing stable functional communities of syntrophic fatty acids oxidizing bacteria (SFOB), exoelectrogens and hydrogenotrophic methanogens, such as Syntrophobacter (5.4%), Thermodesulfovibrio (2.0%), Methanobacterium (43.8%), Methanolinea (20.4%). The content of unclassified bacteria increased from 12.4% in the ABR system to 52.3% in the ABR-MECs system. In contrast, the proportion of aceticlastic methanogens decreased from 50.1% in the ABR to 24.5% in the ABR-MECs system. The improved performance of the thermophilic ABR-MECs system resulted from phase separation, wide ecological niche and intensification of methanogenesis process via functional microbes, which significantly enhanced the degradation of propionic acid and acetic acid.

Conductive material assisted anaerobic digestion presented much interest and promising prospect in pollutant removal during wastewater treatment. The present study deeply investigated the effect iron/carbon in anaerobic digestion for dichlorophen (DCP) degradation and methane production in synthetic DCP wastewater treatment. Results showed that nano-zero valent iron/activated carbon (nZVI/AC) and zero valent iron/activated carbon (ZVI/AC) gave higher chemical oxygen demand (COD) conversion (42.18% and 42.61%) and DCP removal (98.49 wt% and 99.00 wt%) in acidification step with better methane production from anaerobic digestion of the pretreated effluent. Same phenomenon occurred in the direct anaerobic degradation process due to the formation of galvanic cells between iron and carbon. In comparison, applying iron/carbon in acidification as pretreatment strategy plus following effluent anaerobic degradation showed higher efficiency in methane production and DCP removal than that of direct anaerobic degradation. Specifically, the methane production was 253.70 mL and 253.41 mL in subsequent anaerobic digestion system after nZVI/AC and ZVI/AC acidification pre-treatment, which was higher than 224.37 mL and 246.31 mL in direct anaerobic digestion system. Microbial community analysis showed that Clostridium_sensu_stricto_1 was the dominated bacteria due to its important role in DCP wastewater treatment. Both acetoclastic and hydrogenotrophic methanogens were enhanced in iron/carbon added systems, which was also agreement with the strengthen in related genes involved in methanogenesis. In conclusion, the present work systematically investigated the enhancement role of iron/carbon system in anaerobic digestion for DCP wastewater treatment and paved way for future application.

This paper presents a new type of miniaturized base station antenna array, which consists of a metal reflector, six upper-band dipoles, and a couple of ladder sidewalls, operating over 1.71-2.69 GHz (DCS/PCS/UMTS/LTE). Meanwhile, this paper also proposes a novel miniaturized phase shifter with one input and five outputs to enable the antenna array to achieve electrical downtilt (0°-10°) in the operating frequency band. Three different sidewalls are applied in the proposed antenna array to compare their performance. Simulated results demonstrate that the antenna array with ladder sidewalls can achieve an excellent performance, and this proposed phase shifter also has good electrical properties to help the proposed antenna array realize downtilt. The proposed antenna array and phase shifter are fabricated and measured, and the measured results show that the antenna array has good radiation characteristics, including low-voltage standing wave ratio (31 dB), low third-order passive intermodulation (3 30 dB), and high cross-polarization discrimination at ±60° azimuth (>11.5 dB) in all frequency bands and electrical downtilt angles. The proposed antenna array exhibits an acceptable gain of 15 ± 1.1 dBi across the operational frequency band.

This paper presents an energy-efficient level shifter design that is capable of converting an extremely low input voltage to the supply voltage level. Featuring a core area as compact as $32.99~\mu \text{m}^{2}$ , the proposed design comprises a front-end current mirror and an output cross-coupled structure. Concretely, the current mirror is used to boost the complementary input signals to a proper level, with the operations of pull-up and pull-down networks well-balanced. The cross-coupled structure is used at the second stage to achieve a full-swing output. In addition, multi-threshold CMOS transistors are employed and optimized to elevate the circuit performance. The prototype was fabricated using a commercial 65-nm CMOS process. Experiments show that a 90-mV low input voltage can be successfully converted to 1.2 V. The energy consumed per conversion is reported to be 31.47 fJ for converting a 0.2-V input to 1.2 V at 10 MHz, and the corresponding propagation delay is measured to be 23.98 ns.

In this study, anaerobic batch experiments were conducted to investigate the effect of carbon-based (biochar) and metal-based (nanoscale zero-valent iron, NZVI and zero valent iron, ZVI) mediators on the AD process treating phenolic wastewater. Fresh apricot shell- and wood-derived biochar (BiocharA, BiocharB) could remove the phenol efficiently (77.1% and 86.2%), suggesting that biodegradation cooperated with adsorption had advantage in phenol removal. BiocharB, NZVI and ZVI enhanced the methane production by 17.6%, 23.7% and 23.2%, respectively. Apart from serving as carrier for microbial growth, BiocharB might promote the direct interspecies electron transfer (DIET) since the Anaerolineaceae/Clostridium sensu stricto, which have potential for DIET, were enriched. NZVI and ZVI added systems mainly enhanced the abundance of Clostridium sensu stricto (24.5%, 37.6%) and Methanosaeta. Interestingly, BiocharA inhibited the methanogenesis completely. An inhibitory mechanism was proposed: the exposure of absorbed microbes on the BiocharA to the highly concentrated phenol in biochar' pores resulted in the inhibition of methanogens, especially for Methanosarcina. In conclusion, this study showed that suitable biochar (BiocharB) could serve as an alternative redox mediator for realizing simultaneously the efficient phenol removal and methane production.

Sludge filtrate is a kind of special organic wastewater generated from hydrothermally pretreated sewage sludge. The efficient treatment of sludge filtrate can promote the development of sludge recycling technology. Herein, the anaerobic baffled reactor (ABR) assisted by symbionts of short chain fatty acid-oxidation syntrophs (SFAS) and exoelectrogens was applied to treat the sludge filtrate. The influence of fermentation temperature and promotion of methanogenesis via symbionts were focused. The results showed that the COD removal efficiency and methane yield of the ABR system assisted by symbionts at 35 °C (R3) were 11.7% and 11.0% higher than the one at 55 °C (R2), respectively. And the COD removal efficiency and methane yield of the R2 system were 9.1% and 12.9% higher than the traditional ABR system at 55 °C (R1), respectively. Large abundances of exoelectrogens such as Thermincola and Geobacter were found in the R2 and R3 systems, respectively. Moreover, ample Syntrophobacter, Syntrophomonas and Methanobacterium were detected in both R2 and R3 systems. The present research revealed the importance of SFAS, exoelectrogens and hydrogenotrophic methanogens for the improvement of methanogenesis. Besides, the mesophilic condition is conducive to enhancing the methanogenesis rate of sludge filtrate.