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Microfluidics has been applied in the preparation of monodisperse droplets and microcapsules due to its high encapsulation efficiency, its ability to create uniform particle sizes, and its capacity to control core–shell ratio and structure. To bring to the fore methodologies for the fabrication and application of monodisperse microcapsules using microfluidics, we present a review of the design, structure, materials, and surface modification techniques of various microfluidic chips. The review also covers fabrication methods, operating parameters and regulation methods of single and multiple monodisperse emulsion droplets fabricated from various microfluidic devices. Our findings show that particle size of monodisperse droplets depend mainly on microchannel characteristic size and flow rate, with particle size increasing with larger microchannel but decreasing with higher continuous phase flow rate. We additionally reviewed and compared various fabrication methods for monodisperse microcapsules, such as interfacial polymerization, free-radical polymerization, ionic cross-linking, and solvent evaporation. We further reviewed and examined the application of monodisperse microcapsules in biology applications, food engineering, composite materials development, and pharmaceutical industry. We found that high-throughput microfluidics for scale-up monodisperse microcapsule preparation towards uniform degradation and targeted release properties of monodisperse microcapsules would be key innovative direction for future applications.

As an industrial solid waste, coal gasification fine slag (CGFS), which consists of many elements, such as silicon, aluminum, and carbon, could be used as an important resource. Therefore, this solid waste was used as a raw material to prepare high-value-added adsorption material for the treatment of industrial wastewater in this study. A hydrothermal synthesis method was applied to convert CGFS into a Y-type zeolite/carbon porous composite. The effects of time and temperature on the synthesis were studied. XRD, SEM, and other techniques were used to analyze the material and its physicochemical properties. Additionally, the adsorption performance of the material for phenol was studied. The results showed that the composite has better adsorption capacity for phenol than CGFS. The Freundlich model and pseudo-second-order kinetics well fitted the adsorption behavior of the composite, which demonstrated that the adsorption of phenol was dominated by chemical adsorption.

In non-air-conditioned buildings, opening or closing of windows is one of the most common behaviours that occupants tend to carry out to restore their thermal comfort. As an alternative approach to...

A key operation in modern genetic engineering is to deliver foreign substances (like modified subcellular organelles, DNA molecules, and drugs) into live cells. Compared with the traditional methods like polyethyleneimine (PEI), cationic liposomes, viral vectors, electroporation, gene gun, etc., microinjection is a rising star due to the advantages of excellent safety, full controllability, high precision, and high survival rate. This review focuses on the recent development of microinjection technology and its applications in animal cells, yeast, fungal cells, and plant cells. Guidelines are provided for selecting the most appropriate microinjection method and system configuration for different application scenarios. When the outer membrane of the host cell is difficult to break, the piezo-driven penetrator could assist the penetration significantly and causes less damage to the host cell during microinjection process. The major existing challenges in microinjection are also analyzed. Overall, microinjection could become a standard technology for modern genetic engineering and microbiology.

The general strain gradient theory of Mindlin is re-visited on the basis of a new set of higher-order metrics, which includes dilatation gradient, deviatoric stretch gradient, symmetric rotation gradient and curvature. A strain gradient bending theory for plane-strain beams is proposed based on the present strain gradient theory. The stress resultants are re-defined and the corresponding equilibrium equations and boundary conditions are derived for beams. The semi-inverse solution for a pure bending beam is obtained and the influence of the Poisson’s effect and strain gradient components on bending rigidity is investigated. As a contrast, the solution of the Bernoulli–Euler beam is also presented. The results demonstrate that when Poisson’s effect is ignored, the result of the plane-strain beam is consistent with that of the Bernoulli–Euler beam in the couple stress theory. While for the strain gradient theory, the bending rigidity of a plane-strain beam ignoring the Poisson’s effect is smaller than that of the Bernoulli–Euler beam due to the influence of the dilatation gradient and the deviatoric stretch gradient along the thickness direction of the beam. In addition, the influence of a strain gradient along the length direction on a bending rigidity is negligible.

Measuring myocardial contractility is of great value in exploring cardiac pathogenesis and quantifying drug efficacy. Among the biosensing platforms developed for detecting the weak contractility of a single layer of cardiomyocytes (CMs), thin brittle metal membrane sensors with microcracks are highly sensitive. However, their poor stability limits the application in long-term measurement. Here, we report a high stability crack sensor fabricated by deposition of a 105 nm thick Ag/Cr with microcracks onto a carbon nanotubes-polydimethylsiloxane (CNT-PDMS) layer. This brittle-tough bilayer crack sensor achieved high sensitivity (gauge factor: 108 241.7), a wide working range (0.01-44%), and high stability (stable period2 000 000 cycles under the strain caused by a monolayer of CMs). During 14-day continuously monitoring CMs culturing and drug treatment testings, the device demonstrated high sensitivity and stability to record the dynamic change caused by contractility of the CMs.

Defects are pivotal to endow metal oxide catalysts with an efficient catalytic oxidation ability. Here, a defect engineering strategy was developed by hand-milling Co3O4 with the aid of Na at room temperature. The facile mechanical–chemical process could kill two birds with one stone: on the one hand, shatter the bulk, and on the other hand create vast oxygen vacancies, which play an important role for surface exposure and intrinsic reactivity enhancement. The as-obtained defective Co3O4 catalyst delivered a remarkable activity for methane combustion with 50% methane conversion temperature (T50) of 383 °C and 90% methane conversion temperature (T90) of 459 °C, which are 47 °C and 35 °C lower than those of the pristine Co3O4 catalyst, respectively. The catalytic performance improvement could be due to the significantly increased amount of active surface oxygen and boosted oxygen mobility induced by the construction of defects. This study provides effective and convenient tactics to afford advanced catalysts for methane activation and other oxidative reactions.

Acute myocardial infarction (AMI) is the main cause of death from cardiovascular diseases. Thus, early diagnosis of AMI is essential for the treatment of irreversible damage from myocardial infarction. Traditional electrocardiograms (ECG) cannot meet the specific detection of AMI. Cardiac troponin I (cTnI) is the main biomarker for the diagnosis of myocardial infarction, and the detection of cTnI content has become particularly important. In this review, we introduced and compared the advantages and disadvantages of various cTnI detection methods. We focused on the analysis and comparison of the main indicators and limitations of various cTnI biosensors, including the detection range, detection limit, specificity, repeatability, and stability. In particular, we pay more attention to the application and development of electrochemical biosensors in the diagnosis of cardiovascular diseases based on different biological components. The application of electrochemical microfluidic chips for cTnI was also briefly introduced in this review. Finally, this review also briefly discusses the unresolved challenges of electrochemical detection and the expectations for improvement in the detection of cTnI biosensing in the future.

Toxic organic solvents are commonly used to disperse nanomaterials in the manufacturing of flexible conductive composites (e.g., graphene-PDMS). The dry-blended method avoids toxic organic solvent usage but leads to poor performance. Here, we proposed an innovative manufacturing method by adapting the traditional dry-blended method, including two key steps: minor CNT bridging and high-frequency electric field enhancement at the percolation threshold of graphene-PDMS. Significant improvement was achieved in the electrical conductivity (1528 times), the giant gauge factor (8767.54), and the piezoresistive strain range (30 times) over the traditional dry-blended method. Further applications in measurements of culturing rat neonatal cardiomyocytes and mouse hearts proved that the proposed method has great potential for the manufacturing of nontoxic flexible sensors.

Potassium carbonate was employed as an effective catalyst to explore the catalytic pyrolysis characteristics of Shenfu bituminous coal (SF). The online investigation on the effects of catalyst load...

The present study aims to explore the physico-chemical structure evolution characteristic during Yangchangwan bituminous coal (YCW) gasification in the presence of iron-based waste catalyst (IWC). The catalytic gasification reactivity of YCW was measured by thermogravimetric analyzer. Scanning electron microscope–energy dispersive system, nitrogen adsorption analyzer and laser Raman spectroscopy were employed to analyze the char physico-chemical properties. The results show that the optimal IWC loading ratio was 5 wt% at 1000 °C. The distribution of IWC on char was uneven and Fe catalyst concentrated on the surface of some chars. The specific surface area of YCW gasified semi-char decreased significantly with the increase of gasification time. i.e., the specific surface area reduced from 382 m2/g (0 min) to 192 m2/g (3 min), meanwhile, the number of micropores and mesopores decreased sharply at the late gasification stage. The carbon microcrystalline structure of YCW gasified semi-char was gradually destroyed with the increase of gasification time, and the microcrystalline structure with small size was gradually generated, resulting in the decreasing order degree of carbon microcrystalline structure. IWC can catalyze YCW gasification which could provide theoretical guidance for industrial solid waste recycling.

As special waste biomass, cow manure (CM) is also the main pollutant in agricultural production. The combination of cow manure and coal is conducive to the sustainable development of energy and the solution to pollution problems. This work aims to investigate the co-gasification reactivity and synergy of cow manure and Meihuajing (MHJ) bituminous coal blends at 800-1100 °C using a thermogravimetric analyzer, and the correlation between char gasification reactivity and its structural characteristics is performed. The results indicate that the sensitivity of gasification reactivity to temperature is gradually weakened with the proportion of CM increasing. The synergistic effect on reactivity was observed in the co-gasification process of CM/MHJ. The addition of CM promoted the synergistic effect obviously at the low carbon conversion level, and the inhibitory effect with the CM addition on the order degree of char carbon structure was enhanced during the co-gasification process according to Raman spectroscopy analysis. The addition of CM promoted the porous structure evolutions, which make the pore size distribution and the specific surface developed remarkable. The changes in carbon and pore structures can be well related to the gasification reactivity. The findings in this study would be helpful in the understanding of the co-gasification synergy mechanism of cow manure and coal blends.

Phase change material (PCM) selection for particular applications mainly depends on its phase change temperature and latent heat, which were commonly measured by the differential scanning calorimetry (DSC). However, the DSC instruments are not absolute measuring devices and calibration is extremely important to ensure the accuracy of determined data. Meanwhile, the PCM with melting temperature between 0 and 65 °C is the most common interest for energy saving in buildings. This study, therefore, calibrated the DSC produce (NanoTechnology Inc.) by the high-purity metals with various regression methods for low melting temperature PCM thermal properties analysis. In the end, the paraffin n-eicosane was introduced to evaluate the accuracy of the temperature and latent heat measurements of the DSC. The experimental results showed that the accuracy of calibration could be improved by higher-order and more reference materials in a broad temperature range. However, the measurement results of n-eicosane proved that the 0-order regression method could offer good accuracy with only one suitable calibrant in a particular temperature range. Therefore, this research suggests the selection of reference materials for DSC calibration should consider the target of measurement temperature range as well as the thermal stabilities of calibrants.

Fatigue crack fracture is one of the main reasons for the failure of a refractory lining in a coal-water slurry gasifier. To explore the fracture failure behavior of a refractory lining during the operation of a gasifier, the stress intensity factor (SIF) and