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This paper describes an approach to achieve low parts per billion (ppb) concentration level detection using a reversed-phase ultrahigh-performance liquid chromatographic ultraviolet absorbance detection method with large-volume feed injection (FI) for analytes in dichloromethane (DCM). FI is a novel technology that allows sample injection at a defined speed into the LC mobile phase. We demonstrate this approach for a mixture of bisphenol A and its diglycidyl ether derivatives in DCM. DCM is a very strong injection solvent at reversed-phase LC conditions and is typically immiscible with a starting reversed-phase gradient mobile phase containing a high percentage of water. As a result, reduced separation performance and even peak splitting are seen with classic flow-through injection. The method setup comprised an octyl-bonded core–shell stationary phase (150 × 4.6 mm i.d., 2.7 μm particle size) with a water/acetonitrile mobile phase gradient and an exceptionally high injection volume of 45 μL of DCM solution using FI. Optimization of feed speed (1%) and isocratic hold duration (4 min) was crucial for final separation conditions. FI delivered more than a 20-fold improvement in the limit of detection (LOD) compared to standard flow-through injection while maintaining peak resolution. The LOD of the final method ranged between 1 and 10 ppb in the polymer resin. This methodology has high potential for trace analysis in a large variety of applications that suffer from the “strong solvent effect”.

This brief presents a 14-bit 4 GS/s time-interleaving ADC design using two interleaved sub-ADCs. The sub-ADC achieves 2 GS/s conversion rate in 28 nm CMOS technology and uses pipelined structure to have high resolution at the same time. In the adopted sample-and-hold amplifier-less (SHA-less) pipeline, a comparator-based correction method is proposed to solve the associated aperture error in the frontend stage where input is sampled at the latch node. By tunning the path bandwidth, rather than using delay line in comparator clock path, the output spreading related to aperture error is reduced by the proposed tunning method to offset-limited level up to 4 GHz input frequency. The modified reference buffer in the ADC reuses the existing transconductance and improves its power efficiency when driving the pipeline stages. Buffers and digital calibrations are implemented on-chip to help wideband high-speed operation and to correct non-idealities in analog circuits. The fabricated ADC chip achieves 59.7 dB SNDR, 60.3 dB SNR and 69.3 dBc SFDR at 1.95 GHz input frequency. The input bandwidth is above 5 GHz. ADC power consumption is 782 mW, resulting in 247.8 fJ/conv.-step ${\rm FoM_{W}}$ and 153.7 dB FoMS.

Recently, many deep learning-based models have been successfully applied to click-through rate prediction. However, most previous models focus only on feature-level interactions between a single user behavior and the target item or only treat the user’s historical behavior as a sequence to uncover the hidden interests behind it when mining user interests. This can lead to user interest that evolves over time dynamically being ignored or the interest shown by a single user’s behavior not being exploited. Based on the above problems, we propose evolving interest with feature co-action network (EIFCN). Specifically, we first design user dynamic interest network to treat the user’s historical behavior as a sequence of information, and tap into the user’s hidden interests over time. In this part, we use a multi-head self-attention mechanism to initially process the data and then pass it into the deep learning network. Then a feature co-action network is designed to mine the user’s single behavior and the displayed feature-level interactions of the target item. Experimental results show that the EIFCN model performs better than other models.

The development of polymerization methods that install weak links or degradable bonds in the backbone of otherwise all-carbon chains could accelerate the design and commercialization of new classes of recyclable, upcyclable, or biodegradable polymers. Cyclic ketene acetals including widely studied 2-methylene-1,3-dioxepane (MDO) can be used as comonomers in conventional free-radical polymerizations to insert labile ester bonds into addition polymer backbones. However, the key obstacle in deploying MDO in water-borne, industrially relevant processes is hydrolysis of the monomer itself. Optimized conditions including relatively low temperatures, mildly alkaline pH, and consistent radical flux lead to high in-process conversions, a rapid rate of polymerization, and a low degree of MDO hydrolysis. Although MDO hydrolysis competes strongly with copolymerization, degradation can be minimized during aqueous emulsion polymerization with vinyl acetate to give robust incorporations of ∼90% MDO. The methods and quantitative analysis tools reported here provide principles for the copolymerization of MDO in aqueous media and will drive innovations in the circular polymer economy.

The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves have garnered significant attention. However, the challenge of large-scale manufacturing of uniform, well-aligned, and tunable plasmonic surfaces has hindered their industrialization. To address this, we present a groundbreaking tunable plasmonic platform design achieved through magnetic field (MF) assisted ultrafast laser direct deposition in air. Through precise control of metal nanoparticles (NPs), with cobalt (Co) serving as the model material, employing an MF, and fine-tuning ultrafast laser parameters, we have effectively converted coarse and non-uniform NPs into densely packed, uniform, and ultrafine NPs (∼3 nm). This revolutionary advancement results in the creation of customizable plasmonic ‘hot spots,’ which play a pivotal role in surface-enhanced Raman spectroscopy (SERS) sensors. The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energy enhancement. When the plasmonic nanostructures resonate with incident light, they generate intense local electromagnetic fields, thus vastly increasing the Raman scattering signal. This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10−10M. Notably, the plasmonic platform also demonstrates robustness, retaining its sensing capability even after undergoing 50 cycles of rinsing and re-loading of chemicals. Moreover, this work adheres to green manufacturing standards, making it an efficient and environmentally friendly method for customizing plasmonic ‘hot spots’ in SERS devices. Our study not only achieves the formation of high-density, uniform, and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation between plasmonic resonance and energy enhancement. The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-related applications, including photocatalysis, photovoltaics, and clean water, propelling us closer to a sustainable and cleaner future.

The liquid hold-up in a reactive distillation (RD) column not only has a significant impact on the extent of reactions, but also affects the pressure drop and hydraulic conditions in the column. Therefore, the liquid hold-up would be a critical design factor for RD columns. However, the existing design methods for RD columns typically neglect the influence of considerable amount of liquid hold-up in downcomers owing to the difficulties of solving a large-scale nonlinear model system by considering downcomer hydraulics, resulting in significant deviations from actual situation and even operation infeasibility of the designed column. In this paper, a pseudo-transient (PT) RD model based on equilibrium model considering tray hydraulics was established for rigorous simulation and optimization of RD plate columns considering the liquid hold-up both in downcomers and column trays, and a steady-state optimization algorithm assisted by the PT model was adopted to robustly solve the optimization problem. The optimization results of either ethylene glycol RD or methyl acetate RD demonstrated that assuming all the liquid hold-up of a stage belonged to the tray will cause significant deviations in the column diameter, weir height, and the number of stages, which leads to not meeting the separation requirements and even operation hydraulic infeasibility. The rigorous model proposed in this study which considers the liquid hold-up both on trays and in downcomers as well as hydraulic constraints can be applied to systematically design industrial RD plate columns to simultaneously obtain optimal operating variables and equipment structure variables.

It is urgent to pursue appropriate gate photoactive materials for gate-to-channel signal modulation to achieve superior transconductance performances of organic photoelectrochemical transistor (OPECT) sensors. Notably, a hole transfer layer (HTL) participant CdZnS/sulfur-doped Ti3C2MXene (S-MXene) gate was designed and developed in this work, which exhibited a remarkable signal modulation performance by up to 3 orders of magnitude. Because of the incorporation of S-MXene with an enhanced electrical conductivity as the effective HTL, the signal modulation capabilities of the CdZnS/S-MXene photoactive gate were superior to those of CdZnS and CdZnS/MXene. This incorporation inhibited the recombination of the interfacial charge and facilitated the transfer of photogenerated holes, thus enhancing the photoelectric conversion performance. This enhancement facilitated fast electron transfer with a larger effective photovoltage to augment the dedoping ability of channel ions. Based on these findings, an aptasensing platform that exhibited good performance was constructed using the proposed OPECT device, with ofloxacin as a model target and an aptamer for specific recognition. The developed OPECT aptasensor had various advantages, including a high sensitivity, good linear range (1.0 × 10–13to 1.0 × 10–6M), and low limit of detection (3.3 × 10–15M). This study provided a proof-of-concept for the generalized development of HTL participant gates for OPECT sensors and other related applications.

A reliable and practical approach for the direct measurement of volatile oxygenated compounds in high pressure liquefied light hydrocarbons has been successfully developed. The approach incorporates the use of a pressurized liquid injection device for sample introduction, a highly selective and polar ionic sorbent column technology to achieve separation of the target oxygenated compounds, and the augmentation of a recently commercialized two-stage post-column microreactor to convert carbon compounds, first to carbon dioxide by combustion and subsequently to methane by methanation. This two-stage conversion strategy is highly advantageous as it enables carbon compound independent responses as well as sensitivity improvements, particularly for short-chain oxygenated compounds. Oxygenated compounds such as acetaldehyde, propanal, methanol, ethanol, iso-propanol, n-propanol, and acetone in light hydrocarbons were found to have a detection limit of at least 0.1 ppm (v/v), respectable linear range from 0.2 ppm (v/v) to 3000 ppm (v/v) with R2greater than 0.997 and relative precision of less than 10% RSD (n= 7). Considering the carbon compound independent response capability, one single carbon-containing compound can be used for calibration to measure any of the target analytes with a respectable accuracy of less than ±10% error. The unique feature of equimolar carbon responses also enables the possibility of determining the “total” concentration for the known volatile oxygenated compounds. Also, the need for multi-level calibration was eliminated over the range of interest. This novel concept enables new measurement capability and flexibility, enhances the analytical throughput, and substantially decreases the overall cost of ownership. The utility of the methodology was demonstrated with practical industrial applications.

A gas chromatographic strategy to advance the direct detection and quantification of volatile aliphatic aldehydes such as formaldehyde and acetaldehyde in gas phase matrices without the need for sample pretreatment or concentration has been successfully developed. The catalytic hydrogenolysis of aldehydes to alkanes is conducted in situ within the 3D-printed steel jet assembly of the flame ionization detector and without any additional hardware required. Reliable conversion efficiencies of greater than 90% with respectable peak symmetries for the analytes were attained at 400 °C. Quantification of formaldehyde and acetaldehyde at parts-per-million levels over a range of 0.5–300 ppm (v/v) for formaldehyde and 0.2–430 ppm (v/v) for acetaldehyde with a respectable precision of less than 5% RSD (n= 10) was achieved. The total analysis time was less than 10 min. Linearity with a correlation coefficient (R2) greater than 0.9997 and measured recoveries of >99% for spike tests under the specified conditions were achieved. The 3D-printed steel jet assembly was found to be reliable and resilient to matrices such as air, water, hydrocarbons, and aromatics. An additional benefit realized with this analytical strategy is that the slight restriction induced by the presence of the catalyst in the 3D-printed jet assembly enables backflush via the inlet split vent without the need for additional pressure control or intercolumn-connection devices. The utility of this technique was demonstrated with important aldehyde applications from various segments.

This work tackles the perennial problem of reproducible baselines in information retrieval research, focusing on bag-of-words ranking models. Although academic information retrieval researchers have a long history of building and sharing systems, they are primarily designed to facilitate the publication of research papers. As such, these systems are often incomplete, inflexible, poorly documented, difficult to use, and slow, particularly in the context of modern web-scale collections. Furthermore, the growing complexity of modern software ecosystems and the resource constraints most academic research groups operate under make maintaining open-source systems a constant struggle. However, except for a small number of companies (mostly commercial web search engines) that deploy custom infrastructure, Lucene has become the de factoplatform in industry for building search applications. Lucene has an active developer base, a large audience of users, and diverse capabilities to work with heterogeneous collections at scale. However, it lacks systematic support for ad hocexperimentation using standard test collections. We describe Anserini, an information retrieval toolkit built on Lucene that fills this gap. Our goal is to simplify ad hocexperimentation and allow researchers to easily reproduce results with modern bag-of-words ranking models on diverse test collections. With Anserini, we demonstrate that Lucene provides a suitable framework for supporting information retrieval research. Experiments show that our system efficiently indexes large web collections, provides modern ranking models that are on par with research implementations in terms of effectiveness, and supports low-latency query evaluation to facilitate rapid experimentation

Exploiting ingenious photoelectrodes and innovative signal amplification strategies has the potential to achieve high sensitivity in self-powered cathodic photoelectrochemical (PEC) analysis. In this work, a novel self-powered PEC sensing platform was constructed by integrating a synergistic signal amplification of an ingenious photocathode with a high light-harvesting photoanode. In the dual photoelectrode-based PEC system, the amplified photocurrent signals were induced by a synergistic enhancement: (1) the photocurrent of the BiOBr photocathode was improved by the incorporation of nitrogen-doped graphene; (2) the photocurrent of the self-powered sensor was activated by the high-light-harvesting Bi2S3–C3N4photoanode. Subsequently, the rational mechanism for synergistic signal amplification was investigated. For the construction of the sensing interface, an aptamer was introduced as the recognition element to specifically capture the streptomycin (STR) target. Under optimal conditions, the constructed self-powered aptasensor has the merits of good linear range (1 × 10–11to 5 × 10–7M), acceptable limit of detection (1.18 × 10–12M), and excellent stability and selectivity for STR detection. Additionally, the proposed self-powered aptasensor showed acceptable accuracy for the detection of STR in water. Hopefully, this might stimulate more interest in designing and constructing novel platforms for exquisite photocathodic monitoring of various contaminants in the environment.

Commercial C18columns packed with superficially porous particles of different sizes and shell thicknesses (Ascentis Express, Kinetex, and Poroshell 120) or sub‐2‐μm totally porous particles (Acquity BEH) were systematically compared using a small molecule mixture and a complex natural product mixture as text probes. Significant efficiency loss was observed on 2.1‐mm id columns even with a low dispersion ultra‐high pressure liquid chromatography system. The Kinetex 4.6‐mm id column packed with 2.6‐μm particles exhibited the best overall efficiency for small molecule separations and the Poroshell 120 column showed better performance for mid‐size natural product analytes. The Kinetex 2.1‐mm id column packed with 1.7‐μm particles did not deliver the expected performance and the possible reasons besides extra column effect have been proved to be frictional heating effect and poor column packing quality. Different column retentivities and selectivities have been observed on the four C18columns of different brands for the natural product separation. Column batch‐to‐batch variability that has been previously observed on the Ascentis Express column was also observed on the Kinetex and Poroshell 120 column.

Three HPLC columns packed with 3 μm, sub‐2 μm, and 2.7 μm Fused‐Core (superficially porous) particles were compared in separation performance using two natural product mixtures containing 15 structurally related components. The Ascentis ExpressTMC18 column packed with Fused‐Core particles showed an 18% increase in column efficiency (theoretical plates), a 76% increase in plate number per meter, a 65% enhancement in separation speed and a 19% increase in back pressure compared to the Atlantis T3TMC18 column packed with 3 μm particles. Column lot‐to‐lot variability for critical pairs in the natural product mixture was observed with both columns, with the Atlantis T3 column exhibiting a higher degree of variability. The Ascentis Express column was also compared with the AcquityTM BEH column packed with sub‐2 μm particles. Although the peak efficiencies obtained by the Ascentis Express column were only about 74% of those obtained by the Acquity BEH column, the 50% lower back pressure and comparable separation speed allowed high‐efficiency and high‐speed separation to be performed using conventional HPLC instrumentation.

The SWNTs/DDAB film modified glassy carbon electrode was successfully prepared to study the electrochemical behavior of hemoglobin (Hb). A better electrochemical response was observed than that on the DDAB or SWNTs film modified electrode. Cyclic voltammetry of Hb showed two pairs of well-defined and nearly reversible peaks. The electrochemical reaction of hemoglobin on the SWNTs/DDAB film modified electrode was controlled by absorption. Using the SWNTs/DDAB film modified electrode, the interaction between hemoglobin and tar was studied.

The SWNTs/DDAB film modified glassy carbon electrode was successfully prepared to study the electrochemical behavior of hemoglobin (Hb). A better electrochemical response was observed than that on the DDAB or SWNTs film modified electrode. Cyclic voltammetry of Hb showed two pairs of well‐defined and nearly reversible peaks. The electrochemical reaction of hemoglobin on the SWNTs/DDAB film modified electrode was controlled by absorption. Using the SWNTs/DDAB film modified electrode, the interaction between hemoglobin and tar was studied.