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Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.

Fluid Catalytic cracking (FCC) unit is one of the means to lighten heavy oil in refineries, and its regenerated flue gas is also the main source of air pollutants from refinery. However, it is not clear about the type and amount of pollutants discharged from FCC units. The emissions of regenerated pollutants in the stack flue gases of three typical FCC units in China were investigated in this study, including a partial regeneration unit without a CO boiler (U1), a partial regeneration unit with a CO boiler (U2) and a full regeneration unit (U3). Different monitoring methods were used to analyze the concentration of sulfur dioxide (SO2) and nitrogen oxides (NOx), and the results showed that Fourier Transform Infrared Spectroscopy (FTIR) monitoring results of SO2 and NOx are approximately 10 times and 5 times larger than that of the Continuous Emission Monitoring System (CEMS) data, respectively. Also, the contents of characteristic pollutants such as NH3, C6H6, HCN, C8H8, C2H4, CH4 and CO were also monitored by FTIR, and the emission factors based on coke burn-off rate and throughput were investigated. The pollutants in U1 exhibited relatively higher contents with the NH3, HCN and C6H6 of 116.99, 71.94 and 56.41 mg/Nm3 in flue gas, respectively. The emission of regenerated pollutants in U2 and U3 are significantly different from U1. Regeneration processes (including coke properties, operating modes and presence or absence of CO boilers) affected pollutants emission factors in varying degree. At last, reasonable emission factors based on the different FCC regeneration processes contributes to the prediction, assessment and control for the pollutants emission.

A commercial albumin-bound paclitaxel nano-formulation has been considered a gold standard against breast cancer. However, its application still restricted unfavorable pharmacokinetics and the immunogenicity of exogenous albumin carrier. Herein, we report an albumin-bound tumor redox-responsive paclitaxel prodrugs nano-delivery strategy. Using diverse linkages (thioether bond and disulfide bond), paclitaxel (PTX) was conjugated with an albumin-binding maleimide (MAL) functional group. These pure PTX prodrugs could self-assemble to form uniform and spherical nanoparticles (NPs) in aqueous solution without any excipients. By immediately binding to blood circulating albumin after intravenous administration, NPs are rapidly disintegrated into small prodrug/albumin nanoaggregates in vivo, facilitating PTX prodrugs accumulation in the tumor region via albumin receptor-mediated active targeting. The tumor redox dual-responsive drug release property of prodrugs improves the selectivity of cytotoxicity between normal and cancer cells. Moreover, disulfide bond-containing prodrug/albumin nanoaggregates exhibit long circulation time and superior antitumor efficacy in vivo. This simple and facile strategy integrates the biomimetic characteristic of albumin, tumor redox-responsive on-demand drug release, and provides new opportunities for the development of the high-efficiency antitumor nanomedicines., Graphical abstract The paclitaxel–maleimide prodrugs nanoparticles integrate the biomimetic characteristic of albumin, tumor redox-responsive on-demand drug release and pave the way for designing targeted delivery nano-platform for tumor therapy.Image 1

Fluid catalytic cracking (FCC) unit emits a large amount of flue gas, which is a major concern of environmental protection supervision. Wet flue gas desulfurization (WFGD) technologies have been widely used to control the emissions of SO2 in refineries. In this study, stack tests for pollutants emission of a typical FCC unit were conducted. The emission characteristics of the FCC unit indicated that WFGD would cause a large amount of water vapor in the flue gas, which indirectly leads to large quantities of salt pollutants entrained in the flue gas including ammonium sulfite ((NH4)2SO3) and ammonium sulfate ((NH4)2SO4). A strong correlation among the concentrations of SO2, NH3, and H2O was observed, and factor analysis shows that these concentrations are dominated by a common factor. It was also found that a mass quantity of NH4+ and SO32- existed in the condensate water of the flue gas. The TG-MS analysis shows that (NH4)2SO3 could be decomposed at 94.1 °C, and NH3, SO2, and H2O are released as reaction products in the form of gas. Therefore, a part of the NH3 and SO2 obtained by Fourier transform infrared spectroscopy (FTIR) monitoring may be derived from the decomposition of (NH4)2SO3 in the flue gas due to the high temperature during the sampling process, which was also confirmed in a lab experiment. The hot and wet sampling process will lead to overestimation of NH3 and SO2 emissions rather than FTIR method itself when monitoring the high-humidity FCC flue gas. Thus, the concentration of H2O in the flue gas and the type of sampling process need to be taken into consideration during the monitoring process.

Zn(bdc)(ted)0.5 was synthesized for methane storage application. The effects of various factors such as the mole ratio of reactants and crystallization time on the methane adsorption capacity were ...

A new sulfolane/secondary amine biphasic absorbent, sulfolane/2-methylaminoethanol (MAE) solution, was developed for postcombustion CO2 capture (PCC). Surprisingly, using a 4M/5M sulfolane/MAE solu...

This work investigated the full design, startup, operation, and control of a Kaibel divided-wall column (KDWC) for a laboratory-scale KDWC. The KDWC is designed to separate mixtures of methanol, et...

We investigate a family of dinuclear dysprosium metallocene single-molecule magnets (SMMs) bridged by methyl and halogen groups [Cp'2 Dy(μ-X)]2 (Cp'=cyclopentadienyltrimethylsilane anion; 1: X=CH3- ; 2: X=Cl- ; 3: X=Br- ; 4: X=I- ). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.3°) due to the stronger equatorial interactions between DyIII and methyl groups. Moreover, its magnetic axes show a temperature-dependent shifting, which is caused by the competition between exchange interactions and Zeeman interactions. Studies of fluorescence and specific heat as well as ab initio calculations reveal the significant influences of the bridging ligands on their low-lying exchange-based energy levels and, consequently, low-temperature magnetic properties.

Binderless zeolite X pellets were “one-pot” synthesized via in situ hydrothermal conversion of silica gel precursors in sodium aluminate solution. The conversion and crystallization kinetics were i...

A novel three-dimensional porous dysprosium coordination polymer {[Dy2L2(bpdo)2(H2O)(CH3OH)]·2ClO4·2CH3CN}n (1) has been successfully assembled by combining a superparamagnetic building block of [DyLCl(CH3OH)]2 with the organic ligand 4,4′-bipyridine-N,N′-dioxide (bpdo) (H2L = N′-(2-hydroxybenzylidene)picolinohydrazide). Interestingly, upon the release and/or absorption of different solvent molecules, 1 undergoes reversible single-crystal-to-single-crystal (SCSC) transitions, resulting in the formation of another layer compound of {[DyL(bpdo)(H2O)]·ClO4·2H2O}n (2). This structural transformation involves the breaking and reforming of coordination bonds and leads to significant changes in the relaxation behaviour expected for these coordination polymers, as evidenced by the increase in effective energy barriers from 133 K (1) to 264 K (2) and the slowdown of quantum tunnelling at low temperature. The theoretical calculations indicate that the distinct relaxation behaviours arise mainly from the variation in the coordination geometry around the dysprosium ions. Our work shows that guest molecules can reversibly induce remarkable structural changes in a porous dysprosium coordination polymer and significantly affect its dynamic properties.

The development of novel sustainable materials as plastic replacements has become an urgent task, because the increasing accumulation of nondegradable fossil-based plastic wastes on land and in oceans has led to serious long-term threats to the ecosystem. Herein, a novel type of cellulose-based sustainable material, paper–polyimine composites (PPCs), were developed via the functionalization of cellulose papers using polyimine covalent adaptable networks (CANs). The polyimine infiltrates into the porous structure of cellulose papers and non-covalently bonds to cellulose fiber networks via hydrogen bonding, forming interpenetrating networks. The tensile strength and Young's modulus of PPCs can reach 71 MPa and 3.2 GPa, which are significantly higher than those of most commercially available plastics. The PPCs exhibit good malleability, re-healability, weldability, and moldability. The closed-loop recycling of the polymer matrix and cellulose papers has also been demonstrated. The recycled materials can be 100% reused in the production of next generation composites. More importantly, such PPCs exhibit excellent waterproof performance, superhigh gas (oxygen and moisture) barrier capability, and excellent solvent resistance. Therefore, PPCs represent a novel class of highly green and sustainable materials that can be used as plastic replacements.

Transparent, flexible, and eco-friendly touch sensors are important components for next-generation green electronics such as wearable sensors and e-skins. However, most current touch sensors, which are based on plastics or glass substrates and indium tin oxide or metal microelectrodes, are not environmentally friendly, as well as being difficult to recycle and expensive. Here, we demonstrate that a green, transparent, flexible, and recyclable nanopaper-based touch sensor (NPTS) can be fabricated via inkjet printing a conductive polymer, poly(3,4-ethylene dioxythiophene)-doped polystyrene sulfonate (PEDOT:PSS), on cellulose nanofibril paper. The materials cost of a single-keypad NPTS with a size of 3.5 cm × 2.5 cm × 0.05 mm is only $0.060. Good printability, excellent transparency (80% at 400 nm), and high conductivity (1360 S cm−1) were achieved with the PEDOT:PSS microelectrodes when using a newly developed, eco-friendly water-based ink formulation. It takes only 3–4 weeks for the NPTS to degrade completely in natural soil. A four-keypad NPTS was demonstrated by interfacing with the Arduino UNO development board. Folding, bending, and multiple finger-touch trials caused only slight capacitive changes to the NPTS, with no loss of function. The facile fabrication of the NPTS will be invaluable for many practical applications where eco-friendly, transparent, flexible, durable, recyclable, and economical touch-control is required.

The sulfolane was, surprisingly, found to be a universal phase splitting solvent in a serial of aqueous primary alkanolamine solution for CO2 removal, the reaction product of carbamate and hydrophilicity of amine can be the key factor for CO2 triggering phase change, also the phase change can have significant effect on CO2 absorption performance. To comprehensively understand the effect of phase change on absorption, stripping and phase separation performance of primary alkanolamine solution for CO2 capture, MEA sulfolane-based solution was chosen as typical biphasic system for investigation. First, the experimental results revealed that phase change can dramatically decrease the absorption rate and lead to less CO2 capacity in an absorption process. Second, the enriched MEA in separated solution can substantially decrease the energy consumption for CO2 stripping, but exorbitant concentration of MEA can significantly reduce the CO2 removal efficiency in a quasi-cycle of absorption and desorption. Third, t...

Bacterial therapy, which targets the tumor site and aims at exerting an antitumor immune response, has displayed a great potential against malignant tumors. However, failure of the phase I clinical trial of Salmonella strain VNP20009 alone demonstrates that bacterial treatment alone can unsatisfy the requirements of high efficiency and biosafety. Herein, a strategy of both-in-one hybrid bacteria is proposed, wherein the chemotherapeutic drug doxorubicin (DOX) is integrated onto the surface of glucose dehydrogenase (GDH)-overexpressed non-pathogenic Escherichia coli (E. coli) strain, to potentiate the antitumor efficacy. Nicotinamide adenine dinucleotide phosphate (NADPH), which is produced by GDH from E. coli, promotes the generation of toxic reactive oxygen species (ROS) within the tumor, and ROS is then catalyzed by the DOX-activated NADPH oxidases. Importantly, the hybrid bacteria enhance stimulated systemic antitumor immune responses, thereby leading to effective tumor eradication. When this strategy is applied in four different tumor models, the hybrid bacteria significantly inhibited tumor metastasis, postsurgical regrowth, and primary/distal tumor relapse. The both-in-one ROS-immunity-boosted hybrid bacteria strategy provides knowledge for the rational design of bacteria-based synergistic cancer therapy.

While assembling superparamagnetic units in a controlled manner is crucial for future applications of molecular nanomagnets, optimizing their magnetic properties while achieving directional assembly of these units still remains a formidable challenge. Herein, we demonstrate how the assembly of two dysprosium chain complexes, namely, [Dy2(L)2Cl2(CH3OH)3]n·nCH3OH (1) and [Dy(L)Cl(DMF)]n (2) (H2L = N‘-(5-bromo-2-hydroxybenzylidene)pyrazine-N-oxide-carbohydrazide), can be successfully manipulated using an appropriate bridging ligand design. Both complexes contain similar dimeric units bridged by two alkoxido oxygens from an L2− ligand, but extended by its pyrazine-N-oxide group exhibiting two distinct coordination modes, namely, single and double pyrazine-N-oxide bridges, respectively. Magnetic studies reveal that both complexes display typical slow magnetic relaxation under zero direct-current field; however, the anisotropy barrier and the coercive field at 2 K for complex 2 are twice as much as that of 1. A further theoretical study indicates that switching the coordination mode from a single pyrazine-N-oxide bridge to double bridges can enhance both the magnetic anisotropy of dysprosium ions and magnetic coupling within the dimeric cores. The synergistic effect between the magnetic anisotropy of dysprosium ions and magnetic interactions among them directly contributes to the overall better performance of complex 2.

To give better guidance of tertiary alkanolamine selection with proper structures for postcombustion CO2 capture, effects of the alkanol chain structure and intramolecular hydrogen bond were invest...

New Ln-metal–organic frameworks (Ln-MOFs), {[Ln(2,7-NDS)(IP)(OH)(H2O)2]·mH2O}n [Ln = Sm 1, Eu 2, Gd 3, Tb 4, Dy 5, m = 0.5–0; 2,7-NDS = 2,7-naphthalenedisulfonate, and IP = 1H-imidazo[4,5-f][1,10]-...

The effect of nitrogen compounds in FCC gasoline on reactive adsorption desulfurization (RADS)was investigated over NiO/ZnO-Al2O3–SiO2 adsorbents. On the basis of ammonia temperature-programmed des...

Soil clay minerals are effective substrate adsorbents of polycyclic aromatic hydrocarbons (PAHs) in natural soil. The adsorbed PAHs result in long-term contamination of soils. In this paper, a typical PAH phenanthrene (Phe) and nine high purity clay minerals are selected as representative PAH pollutants and adsorbents, respectively. A series of experiments have been conducted to disclose the relationship between the Phe adsorption effect of these clay minerals and their physical properties, including specific surface area (SSA), cation exchange capacity (CEC) and contact angle (CA). Molecular simulation methods are performed to explore the mechanism of clay mineral structure on Phe adsorption at the molecular level. Density functional theory (DFT) calculation suggests that the adsorption of Phe on clay minerals is mainly due to the van der Waals effect. The strength of the O-H-π effect is greater than that of the hydrophobic effect of Phe adsorption. Molecular dynamic (MD) simulations imply that the hydration effect of cations hinders the Phe hydrophobic adsorption by occupying the adsorption sites. Based on the mechanism explored, a simple empirical model is proposed, and the adsorption distribution coefficient Kd of clay mineral and water phases can be precisely predicted by the three physical properties of clay minerals, without rigorous quantitative analysis of soil clay minerals.

The Ni/ZnO-Al2O3-SiO2 adsorbent is a widely used industrial adsorbent for reactive adsorption desulfurization (RADS) process. Metallic Ni and NiO are assumed as the main RADS active sites, and NiSx is the intermediate phase to transfer sulfur to ZnO. However, NiSx could also be the active center for RADS process. In this work, to conduct the desulfurization activity of NiSx, a novel NiSO4/ZnO-Al2O3-SiO2 adsorbent was prepared and examined through a serious experimental and theoretical study over the conventional adsorbents. Results showed that NiSO4 based adsorbents could first self-sulfide to NiSx phases, and then NiSx plays as main active sites for RADS. The NiSO4 phases improved the direct desulfurization selectivity of dibenzothiophene (DBT). By adjusting the content of nickel, the sulfur removal rate of adsorbent with 3 wt% Ni from NiSO4 could achieve the same level of adsorbent prepared with 18 wt% Ni from NiO. Moreover, NiSO4 based adsorbent performs excellent desulfurization activity, and its breakthrough sulfur capacity achieves 122.0 mgS/g. The evolution of Ni species on NiSO4 adsorbent has been studied, and a desulfurization mechanism that takes both NiO and NiSx as active phases has been carried out. NiO phase mainly promotes the hydrodesulfurization pathway, while NiSx phase prefers the direct desulfurization pathway. Finally, the mechanism of RADS on NiSx and the reaction pathways of DBT are also presented.

In this work, a series of amphiphilic hemicellulose-based grafting polymers are synthesized by homogeneous esterification with various hydrophobic chain fatty acids. With the flexible chain conformation of hemicelluloses, the hemicellulose-graft-fatty acid is self-assembled into hard sphere micelles in aqueous solution through hydrophobic interactions. The resultant micelles show apparent hydrodynamic radius (Rh) varying in the range of 34-57 nm and radius of gyration (Rg) varying from 30 to 44 nm. Moreover, the Rh, Rg, zeta potential and critical micelle concentration (CMC) of the micelles gradually decreases with the increasing hydrophobic chain length. The aggregation number of micelles can be tuned by varying alkyl chain lengths. Taking curcumin (Cur) as a model drug, the hemicellulose micelles were investigated as drug carriers, which exhibit a chain length-controlled drug release behavior. Taken together, structure and property tunable hemicellulose-based micelles were obtained, and showed potential of application in pharmaceutical, food, and cosmetics fields.

Surface defect-assisted non-radiative recombination is one of major detrimental factors limiting the development of efficient and stable perovskite solar cells (PSCs). The ionic characteristic of perovskite absorbers facilitates passivation of diverse defects through the interaction of specific ending functional groups of organic molecules. Here, the passivation mechanism of a bifunctional organic molecule, 4-methoxyphenylacetic acid (MPA), on the defects within perovskite absorbers is systematically investigated. Density functional theory and X-ray photoelectric spectroscopy confirm that the keto-oxygen atom of carboxylic acid in the MPA mainly passivates Pb–I antisite through Lewis base-acid interaction, while the O-donor of the methoxy group from MPA heals the undercoordinated Pb2+ on the perovskite absorbers surface via a coordination bond. The synergetic passivation of two functional groups significantly reduces the defect density and thus recombination loss, which is confirmed by the space charge limited current, time-resolved photoluminescence (PL) spectroscopy and PL mapping. The capacitance-voltage measurement proves that MPA treatment enhances the built-in potential to accelerate the separation of photogenerated charges within perovskite absorbers. As a result, MPA-treated PSCs achieve a champion efficiency of 22.32% (relatively to 20.97% of the control) coupled with improved environmental tolerance for PSCs on ITO/glass and 19.34% for PSCs on flexible ITO/polyethylene terephthalate.

The non-peripherally substituted 1,4,8,11,15,18,22,25-octa(butoxy)-phthalocyanine-involved unsymmetrical heteroleptic bis(phthalocyaninato) terbium double-decker, Tb(Pc){H[Pc(α-OC4 H9 )8 ]} (Pc=unsubstituted phthalocyanine) (1), was revealed to exhibit typical single ion magnet (SIM) behavior with effective energy barrier, 180 K (125 cm-1 ), and blocking temperature, 2 K, due to the severe deviation of the terbium coordination polyhedron from square-antiprismatic geometry. Fabrication of this double-decker compound into the novel tetrakis(phthalocyaninato) terbium pseudo-quadruple-decker Na2 {Tb(Pc)[Pc(α-OC4 H9 )8 ]}2 (2) single molecule magnet (SMM) not only optimizes the coordination polyhedron of terbium ion towards the square-antiprismatic geometry and intensifies the coordination field strength, but more importantly significantly enhances the molecular magnetic anisotropy in the unsymmetrical bis(phthalocyaninato) double-decker unit, along with the change of the counter cation from H+ of 1 to Na+ of 2, leading to an significantly enhanced magnetic behavior with spin-reversal energy barrier, 528 K (367 cm-1 ), and blocking temperature, 25 K. The present result is surely helpful towards developing novel tetrapyrrole lanthanide SMMs through rational design and self-assembly from bis(tetrapyrrole) lanthanide single ion magnet (SIM) building block.

For the purpose of engineering magnetic anisotropy, chiral binaphthyl substituents with slight electron-withdrawing ability and dibutylamino substituents with intense electron-donating nature are incoporated onto the periphery of each phthalocyanine ligand in the bis(phthalocyaninato) terbium double-decker compound, resulting in the chiral heteroleptic bis(phthalocyaninato) terbium complex (R)/(S)-[Pc(OBNP)4]Tb{Pc[N(C4H9)2]8} (R/S-1) {Pc(OBNP)4 = {tetrakis(dinaphtho[1,2-e:1′,2′-g]-1,4-dioxocine)[2,3-b;2′,3′-k;2′′,3′′-t;2′′′,3′′′-c′]phthalocyanine}; Pc[N(C4H9)2]8 = [2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyanine]}. Magnetic studies reveal the typical single-ion magnet (SIM) nature of this chiral bis(phthalocyaninato) terbium double-decker with spin reversal energy barrier of 638 K. A butterfly-shaped magnetic hysteresis loop was observed at even 25 K for R-1 under the sweep rate of 500 Oe s−1. The performance of this SIM is well rationalized on the basis of theoretical analysis of the electrostatic potential according to calculations using the density functional theory method.

A new three-dimensional porous lanthanide coordination polymer {[Dy(L)(μ2-bpdo)0.5(μ4-bpdo)0.5(CH3OH)]·ClO4·3CH3OH}n (2) featuring slow magnetic relaxation has been successfully assembled by reacting a superparamagnetic chain complex{[Dy(HL)(H2O)2(CH3OH)2]·2Cl·CH3OH}n (1) with an organic bridging ligand, namely, 4,4′-bipyridine-N,N′-dioxide (bpdo) (H2L = N′-(2-hydroxybenzylidene)-picolinohydrazide). Compared with 1, complex 2 has a higher magnetic anisotropy barrier, which arises from the variation of the ligand field around dysprosium ions and/or the existence of magnetic coupling between them induced by the bpdo ligand, leading to a thermal magnetic relaxation process through the second-excited doublet. Interestingly, complex 2 can undergo a reversible single-crystal-to-single-crystal conversion accompanying the desorption and adsorption of methanol molecules. The de-solvated phase, {[Dy(L)(μ2-bpdo)0.5(μ4-bpdo)0.5(CH3OH)]·ClO4}n (3), exhibits a slow magnetic relaxation process through the first-excited doublet, presenting the first example of reversible adjustment on the magnetic relaxation pathway regulated by guest molecules. This exciting finding offers a new perspective for enhancing the magnetic relaxation barrier.

A new centrosymmetric tetranuclear aggregate [Dy4(L)2(OAc)8(CH3OH)2] (1) was assembled using a unique symmetrical Schiff base ligand 1,5-bis(salicylidene)-carbohydrazide (H2L). Magnetic studies reveal ferromagnetic interactions between dysprosium ions and two obvious relaxation processes under zero dc field with effective energy barriers Ueff of 38 K and 223 K, the highest among the reported tetranuclear dysprosium molecular nanomagnets. To obtain further evidence on the origination of the slow magnetic relaxation, a diamagnetic yttrium analogue [Y4(L)2(OAc)8(CH3OH)2] (2) and a diluted sample [(Dy0.06Y0.94)4(L)2(OAc)8(CH3OH)2] (3) were synthesized. Further magnetic studies on the diluted sample combined with theoretical calculations indicate that the two-step magnetic relaxation processes in complex 1 originate from the single-ion magnetic behaviors of dysprosium ions with different coordination environments.

Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato) terbium single-ion magnets, which exhibit blocking temperatures as high as 15 K and 28 K, respectively, providing an alternative method towards enhancing the magnetic behavior.

An approximately equatorial three-coordinated dysprosium(iii) complex DyL2[N(SiMe3)2] (L = bis(2-(2,5-dimethyl-1H-pyrrol-1-yl)ethyl)amine) with an additional neutral auxiliary pyrrole ligand was synthesised and structurally characterized. The magnetic property measurement shows that it is an equatorial charge distributed field-induced single-molecule magnet. Ab initio calculations reveal that the neutral pyrrole ligand plays an important role in stabilizing the ground doublet and thus enhancing the magnetic anisotropy.

In order to describe the reaction network and investigate the conversion behavior of sulfur compounds in delayed coking process, a molecular-level reaction kinetic model was established with a reaction network consisting of 81,081 reactions based on the structure-oriented lumping method. A feed molecular matrix containing 2,944 structural vectors was constructed with 24 structural increments based on the characteristics of the vacuum residue molecular composition. The reliability of the model was verified by industrial data. Through the calculation of the SOL model, the sulfur compounds in gasoline were expressed as 57 structural vectors, which were divided into thiophenes, mercaptans and thioethers according to the discriminant rules. The conversion law of sulfur compounds was investigated by tracking the reaction path of molecules in the reaction network. The SOL model could calculate the distribution of sulfur compounds in coking gasoline. The contents of thiophene molecules increased with the carbon numbers. Ethyl mercaptan and propyl mercaptan had higher content in mercaptans. The SOL model can reveal the influences of reaction conditions on sulfur compounds conversion in delayed coking process at the molecular level, which contributes to the accurate control of sulfur content in coking gasoline.

Bulky and strong electron-donating dibutylamino groups were incorporated onto the peripheral positions of one of the two phthalocyanine ligands in the bis(phthalocyaninato) terbium complex, resulting in the isolation of heteroleptic double-decker (Pc)Tb{Pc[N(C4H9)2]8} {Pc = phthalocyaninate; Pc[N(C4H9)2]8 = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate} with the nature of an unsymmetrical molecular structure, a square-antiprismatic coordination geometry, an intensified coordination field strength, and the presence of organic radical-f interaction. As a total result of all these factors, this sandwich-type tetrapyrrole lanthanide single-ion magnet (SIM) exhibits an overall enhanced magnetic performance including a high blocking temperature (TB) of 30 K and large effective spin-reversal energy barrier of Ueff = 939 K, rendering it the best sandwich-type tetrapyrrole lanthanide SIM reported thus far.

This work was supported by the Taiwan Ministry of Science and Technology (Grant No. MOST 108-2112-M-005-012-MY3 and 109-2112-M-005-013-MY3), and also supported in part by the National Natural Science Foundation of China under Grant No. 61974070 and 61874074, 1311 Talent Plan, and Start-Up Fund from Nanjing University of Posts and Telecommunications under Grant No. NY219003, and Shenzhen Peacock Plan (Grant No. KQTD2016053112042971).

Reasonable design of hybrid graphene aerogels with low cost, high specific surface area (SSA), and excellent mechanical properties is of great significance for future large-scale energy storage applications. Herein, we report a composite aerogel of biomass carbon/reduced graphene oxide (rGO)/nanocellulose (CNF) by a one-step self-assembly method. In the hybrid aerogel, biomass carbon particles with low cost and high SSA are assembled into the framework of rGO effectively preventing the restacking of rGO nanosheets and resulting in high SSA and high conductivity. Negatively charged nanocellulose fibers act as the binder between biomass carbon particles and rGO sheets, facilitating the formation of a strengthening network. As a result, the hybrid aerogel with a high content of biomass carbon (76% mass ratio) demonstrates excellent mechanical strength (240 kPa), high SSA (1007.9 m2 g−1), and efficient MnO2 deposition capability (33.9 mg cm−2). Employing the composite aerogel as electrodes to fabricate a self-supporting supercapacitor, an admirable capacitive performance (4.8F cm−2) was achieved. This work provides an effective method to fabricate low cost hybrid graphene aerogel materials with excellent performances for wide applications.

Nuciferine, a major alkaloid found in Nelumbinis Folium, exhibits a broad spectrum of bioactivities, such as antiobesity, anti-diabetes and anti-inflammatory. However, many research regarding nuciferine focused on the extraction, isolation and biological activity, the metabolism is not comprehensively explained in vivo. Thence, the present of this paper is to establish a simple method for speculating metabolites of nuciferine. A total of 15 metabolites were detected and tentatively identified through ultra high performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QTOF-MS), including 7 new metabolites. Among them, we also discovered a previously unmentioned metabolically active site at the C1-OCH3 position. These metabolites suggested that demethylation, oxidation, glucuronidation and sulfation were major metabolic pathways. This study provided significant experiment basis for its safety estimate and valuable information about the metabolism of nuciferine, which will be advantageous for new drug development.

Diabetic retinopathy(DR)is one of the complications of diabetes which could cause severe vision loss. Retinal ganglion cell(RGC)injury has been confirmed prior to micro-vascular damage. Over the past few decades, a number of animal and clinical studies have confirmed that RGC impairment leads to an early deterioration of vision in DR. Inhibition of aldose reductase (AR), advanced glycation end product (AGE), oxidative stress, glutamate toxicity, and an inflammatory response may play important roles in protecting RGCs in DR. Furthermore, nicotinamide mononucleotide adenylyl transferase-1 (Nmnat1), neurotrophins and neurotrophic factors may become new therapeutic targets. Photobiomodulation (PBM) may be used as adjunctive therapy in protective treatment of RGCs. In this review, we highlight and discuss protective treatments and their targets which have shown great promise for treatment of RGC injury in DR.

Linear tetrapyrrole is the core structure of light-sensitive native cofactors such as phycocyanobilin, phytochromobilin and bile pigments, which attracts increasing attention in biomimetic chemistry, photochemistry and coordination chemistry. To decipher the relationship between structures and functions, in this work, we firstly reported the synthesis, isolation and characterization of three bilindione isomers (ZZZ, syn, syn, syn 1, EZE, syn, syn, anti 2 and EZE, anti, syn, anti 3) bearing meso-pentafluorophenyl groups. The structures were confirmed by X-ray diffraction and 2-D NMR spectroscopes. More importantly, the interconversion between three isomers under heating and light irradiation was investigated, and isomer 3 was found to be transformed to 1 and 2 more easily, which is in line with the results of DFT calculation. This work provides important insights for understanding the relationship between structures and functions and would be important to further construct metal complexes based on linear tetrapyrrole ligands, which are complementary to well-studied the cyclic analogs such as porphyrin and corroles.

“Configurational isomerism” is an important approach found in naturally occurring chlorophylls to modulate light harvesting function without significant structural changes; however, this feature has been seldom applied in design of antenna ligands for lanthanide (Ln) sensitization. In this work, we introduced a bioinspired approach by orientation of β-dilactone moieties on porphyrinates, namely cis-/trans-porphodilactones, to modulate the energy transfer process from the lowest triplet excited state of the ligand (T1) to the emitting level of ytterbium(III) (2F5/2, Yb*). Interestingly, near-infrared (NIR) emission of Yb(III) could be switched “on” by the cis-porphodilactone ligand, while the trans-isomer renders Yb(III) emission “off” and the ratio of quantum yields is ∼8. Analysis of the structure–photophysical properties relationship suggests that the significant emission difference is correlated to the energy gaps between T1 and Yb* (1152 cm–1 in the cis- vs −25 cm–1 in the trans-isomer). More interest...

Strong electron-donating dialkylamino groups were incoporated onto the phthalocyanine ligand in bis(phthalocyaninato) rare earth complexes for the first time to investigate their effects on the spectroscopic properties, electrochemistry, and electronic structure. The bis[2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate] rare earth complexes M{Pc[N(C4H9)2]8}2 {Pc[N(C4H9)2]8 = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyanine, M = Y, Tb} (1, 2) were isolated from the condensation reaction of the corresponding metal free ligand in a refluxing mixture of n-octanol/1,2,4-trichrolobenzene (TCB) (1 : 5) in the presence of M(acac)3·nH2O (M = Y, Tb) in relatively good yields, with their sandwich double-decker nature revealed on the basis of their mass, 1H NMR, electronic absorption, IR, and EPR spectroscopic results in addition to elemental analysis. Their electrochemistry was investigated by cyclic voltammetry (CV). In particular, magnetic studies reveal the typical slow relaxation of the terbium double-decker, indicating its typical single-ion magnet (SIM) nature with a blocking temperature of 25 K and a spin reversal energy barrier of 752 ± 8 K, representing the sole example of sandwich-type tetrapyrrole lanthanide-based SMMs reported thus far with a blocking temperature over 20 K. Theoretical calculations disclose the effect of the bulky and strong electron-donating peripheral dialkylamino groups, which create a square-antiprismatic coordination geometry and intensified coordination field strength for the central terbium ion, resulting in the excellent magnetic performance of this terbium double-decker SIM.

Two novel dysprosium complexes, namely, [Dy2L2(NO3)2(DMF)2]·2DMF (1) and [Dy4L4(OAc)4(DMF)2] (2), have been successfully synthesized by reacting a new pyridine-N-oxide-containing organic ligand N′-(8-hydroxyquinoline-2-carboxaldehyde)pyridine-N-oxide-carbohydrazide (H2L) with different dysprosium salts. The single-crystal X-ray diffraction study revealed that they show either one-dimensional (1D) or tetranuclear structure that is governed by the coordination anion used during the reaction. Within the 1D structure of 1, the nine-coordinated Dy3+ ions are bridged by two phenol oxygen atoms from the 8-hydroxyquinoline group to form Dy2 dimers and these dimers are further connected by pyridine-N-oxide groups. While in 2, the two octa-coordinated Dy3+ ions are bonded together by both phenol oxygen and acetate bridges to produce the Dy2 units and two adjacent Dy2 units are further linked by pyridine-N-oxide groups, resulting in a tetranuclear structure. Magnetic studies indicate that the anisotropic Dy3+ ions in 1 and 2 are ferromagnetically and anti-ferromagnetically coupled, respectively. The alternating current (ac) susceptibility measurements revealed slow magnetic relaxation with effective energy barriers of Ueff = 18.0 K under zero dc field in complex 1. However, under zero dc field, the ac data for 2 show negligible out-of-phase signals, excluding the existence of slow magnetic relaxation. Theoretical studies indicate that the different magnetic relaxation behaviors of both complexes were attributed to the different coordination environments around Dy3+ ions and the distinct magnetic coupling between them.

Several novel flavonoids nitrogen mustard derivatives were synthesized and evaluated for antiproliferative activity against seven human cancer cell lines (HeLa, A549, HepG2, MCF7, SH-SY5Y, PC-3, DU145) by the MTT assay in vitro. The resulting IC50 showed that most compounds exhibited better inhibitory activity against seven cell lines. IC50 values of some compounds were lower than well-known melphalan. In particular, compound 8b was the most promising compound which inhibited HeLa cells with IC50 value of 1.43 μM. It showed excellent antitumor activity against these seven cell lines. Besides, it could arrest cell cycle of HeLa in G2/M phase and induce cell apoptosis. The loss of mitochondrial membrane potential may be an apoptotic mediating factor.

Fluid catalytic cracking (FCC) unit emits a large amount of flue gas, which is a major issue of environmental protection supervision. A spent FCC catalyst from a typical FCC unit was characterized by NMR, XPS, EA TGA and TPD-MS methods. XPS results presented that the nitrogen compounds in coke were pyridine nitrogen, pyrrole and quaternary nitrogen. Sulfur compounds in coke are in the form of thiophene and thiols. TGA and TPD-MS results indicated that the soft coke in the spent catalyst may decompose to small molecular such as NOx, SO2 and HCN. NH3 and HCN are mainly emitted due to the incomplete combustion. The flue gas from the FCC unit is monitored by different on-line monitoring instruments. Results showed that the existence of ammonia greatly affected the value of SO2 during the venting process or instruments’ inlet piping system, where saturated vapor in flue gas is partially condensed. The concentration of NH3 and HCN is more than 100 ppm, which should be paid more attention to. Taken together, fourier transform infrared method was more applicable for monitoring FCC flue gas than non-dispersed infrared method and ultraviolet fluorescence method.

The spin state transition from low spin to high spin upon substrate addition is one of the key steps in cytochrome P450 catalysis. External perturbations such as pH and hydrogen bonding can also trigger the spin state transition of hemes through deprotonated histidine (e.g. Cytochrome c). In this work, we report the isolated 2-methylimidazole Cobalt(II) [Co(TPP)(2-MeHIm)] and [Co(TTP)(2-MeHIm)], and the corresponding 2-methylimidazolate derivatives where the N−H proton of axial 2-MeHIm is removed. Interestingly, various spectroscopies including EPR and XAFS determine a high-spin state (S = 3/2) for the imidazolate derivatives, in contrast to the low-spin state (S = 1/2) of all known imidazole analogs. DFT assisted stereoelectronic investigations are applied to understand the metal-ligand interactions, which suggest that the dramatically displaced metal center allowing a promotion eg(dπ) → b1g(\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d_{x^2 - y^2}$$\end{document}dx2-y2) is crucial for the occurrence of the spin state transition., Studying the electronic structures and spin transitions of synthetic heme analogs is crucial to advancing our understanding of heme enzyme mechanisms. Here the authors show that a Co(II) porphyrin complex undergoes an unexpected spin state transition upon deprotonation of its axial imidazole ligand.

2D transition metal dichalcogenide (TMD) layered materials are promising for future electronic and optoelectronic applications. The realization of large-area electronics and circuits strongly relies on wafer-scale, selective growth of quality 2D TMDs. Here, a scalable method, namely, metal-guided selective growth (MGSG), is reported. The success of control over the transition-metal-precursor vapor pressure, the first concurrent growth of two dissimilar monolayer TMDs, is demonstrated in conjunction with lateral or vertical TMD heterojunctions at precisely desired locations over the entire wafer in a single chemical vapor deposition (VCD) process. Owing to the location selectivity, MGSG allows the growth of p- and n-type TMDs with spatial homogeneity and uniform electrical performance for circuit applications. As a demonstration, the first bottom-up complementary metal-oxide-semiconductor inverter based on p-type WSe2 and n-type MoSe2 is achieved, which exhibits a high and reproducible voltage gain of 23 with little dependence on position.

The reactive adsorption desulfurization (RADS) of a model gasoline n-hexane containing thiophene was carried out with a NiO/ZnO-Al2O3-SiO2 adsorbent in N2 and H2, respectively. A declining RADS trend has been observed in N2, without the presence of H2, indicating that NiO is sulfurized and exhibits activity for RADS. TPR and XPS results presented NiO in the adsorbent is hard to be reduced because of the powerful interaction between NiO and the support. The sulfurization of NiO into NiSx is a primary condition for the RADS process, the same as the presulfurization of hydrotreating catalyst, while metallic Ni is an intermediate reduction product of NiSx. Results of a low RADS temperature at 300 &deg, C, much lower than the reduction temperature of NiO, suggest that NiO plays an important role. Based on assumption of NiO as the main active component, the RADS could reduce the reaction temperature and energy consumption significantly. The participation of hydrogen and n-hexane in pretreatment conducted at 420 &deg, C contributes to the activation of adsorbent. Also, these methods of pretreatment improved the desulfurization performance under the reaction temperature of 300 &deg, C.

Although zinc dicarboxylic acids are highly effective β-nucleating agents (β-NAs), they lose their β-nucleating ability in isotactic polypropylene (iPP) upon the addition of calcium stearate (CaStr2). In this study, we investigated the failure mechanism of these β-NAs in terms of the chemical and physical interactions of zinc adipate (ZnAA) with CaStr2. No chemical reaction occurs between CaStr2 and ZnAA; rather, it is the physical interactions between this β-NA and CaStr2 that are responsible for the loss of β-nucleating ability. Based on the experimental findings and molecular dynamics (MD) simulations, we suggest a blocking effect of CaStr2 on nucleation as a possible failure mechanism. MD simulations confirmed that the aggregation of CaStr2 on the β-NA surface, observed experimentally using polarized optical microscopy and scanning electron microscopy, resulted from the binding energy for the interaction between ZnAA and CaStr2 being higher than that for iPP/CaStr2. Because the active nucleation sites on the surface of the β-NA were covered, lattice matching between ZnAA and the iPP chains was hindered. Therefore, the addition of CaStr2 weakens the β-nucleating ability of ZnAA, leading to inhibition of the epitaxial crystallization process, thereby decreasing the degree of β-crystal formation and, consequently, lowering the toughness of the resulting iPP.

Synthesis of two trans-dihydroxy platinum(IV) porphyrins (TPP, tetraphenylporphyrin and F[Formula: see text]TPP, tetrakispentafluorophenylporphyrin) by dimethyl dioxirane (DMD) oxidation of their Pt[Formula: see text] porphyrin precursors have been described. The oxidation state of Pt cation in such complexes was assessed by X-ray photoelectron spectroscopy and shown to be [Formula: see text]4. More importantly, proton was found to promote the formation and stabilization of the trans-dihydroxy platinum(IV) porphyrins, as revealed by UV-vis spectroscopic results and single crystal structures. In addition, these trans-dihydroxy Pt[Formula: see text] porphyrins were much easier to be reduced than their Pt(II) counterparts and capable to transfer oxygen atom to triphenylphosphine and thioanisol, which is important for further application of Pt(IV) complexes in catalytic reactions.

Two novel luminescent three-dimensional coordination polymers [Eu2(tpphz)(oba)3]·nH2O (n = 5.5 for 1, n = 3.5 for 2; H2oba = 4,4′-dicarboxydiphenyl ether) have been hydrothermally synthesized by in situ generation of tetrapyrido[3,2-a:2′,3′-c:3′′,2′′-h:2′′′,3′′′-j]phenazine (tpphz) ligand from 2-(4-pyridine)-imidazo-[4,5-f]1,10-phenanthroline precursor. Both complexes are rare examples of eight-connected self-penetrating networks. The porous nature of the structures is further supported by gas adsorption measurements.

In order to establish an integrative mass transfer coefficient (KGaV) model for CO2 absorption into blended monoethanolamine (MEA)/1-dimethylamino-2-propanol (1DMA2P) solution in packed column, the models of CO2 Henry’s law constants (HeCO₂-MEA/1DMA2P) and the equilibrium CO2 solubility (αeq) were constructed. The experimental produced data can be reasonably analyzed. In this work, the Arrhenius equation was employed to fit the values of HeCO₂-MEA/1DMA2P at different temperature with AARD of 4.06%; the Kent-Eisenberg prediction model and empirical polynomial prediction model were used to predict the data of αeq under different CO2 partial pressures and temperatures with AARDs of 2.64% and 0.83%, respectively; the empirical KGaV model proposed by Li, the empirical KGaV model proposed by Aroonwilas and new KGaV model were used to correlate the average values of KGaV with AARDs of 14.36%, 12.44% and 9.03%, respectively; the model for outlet CO2 concentration (yCO₂,out) in packed column was developed with AARD of 15.97%. Moreover, the heat of CO2 absorption in 6 kmol/m3 MEA/1DMA2P solution was estimated by Gibbs-Helmholtz equation which gave a value of −39.8 kJ/mol. The results show that the blended MEA/1DMA2P solution has advantages that make it a potential absorbent for CO2 capture.

To figure out the steric hindrance and its magnitude effects on CO2 absorption performance and Bronsted correlations of primary and secondary alkanolamines, the pKa values and kinetics data (second order reaction rate, k2) were investigated for nine alkanolamines at 293–313 K using pH meter and stopped-flow technique. The tested amines include monoethanolamine (MEA), diethanolamine (DEA), 2-methyl-ethynolamine (MAE), 2-ethyl-ethynolamine (EAE), 1-amino-2-propanol (1-AP), 3-amino-1-propanol (3-AP), 2-amino-2-methyl-1-propanol (AMP), 2-amino-1-propanol (2-AP) and 3-Amino-1,2-propanediol (3-APD). In addition, the equilibrium solubility of MEA, MAE, EAE, 2-AP and AMP were tested for evaluation of steric hindrance effect on carbamate’s stability. The comprehensive analysis of kinetics, solubility and Bronsted correlations indicated that the steric hindrance caused by alkyl group(s) attached to α-C atom has much significant effect on k2 and solubility than that caused by alkyl group connected to amino group. Moreover, the k2 and pKa values for sterically unhindered and hindered amines were separately fitted at 293–313 K, giving out an AARD of 5.2% and 16.5% between predicted and experimental k2, respectively. Finally, based on molecular structures and experimental results, mechanism of steric hindrance effect on reaction kinetics was proposed.

4-diethylamino-2-butanol (DEAB), as a novel tertiary amine, shows a promising potential for CO2 capture. In this study, the mass transfer performance of CO2 absorption into aqueous DEAB solution in a non-wetted and partially-wetted mode of hollow fiber membrane contactor (HFMC) was theoretically investigated in comparison with that of monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP). A 2D mathematical model based on finite element method (FEM) was established to solve the steady-state continuity equations for the shell, tube and membrane sides simultaneously. The influences of the operating parameters on the CO2 absorption flux in HFMC including liquid and gas velocity and CO2 partial pressure were comprehensively investigated. The numerical results show that the CO2 absorption flux can increase with the increasing liquid velocity and CO2 partial pressure, and slightly increases with the increasing gas velocity. Moreover, the CO2 absorption performance of aqueous DEAB solution was further compared with different amine solutions, which reveals that the CO2 absorption flux of DEAB is higher than those of DEA, MDEA and AMP, and is also comparable to MEA. The analysis on the mass transfer resistance indicates that the proportion of the membrane mass transfer resistance increased rapidly from 13.7% to 75.3% as membrane wetting ratio increased from 0% to 20%. Instead of the liquid phase, the mass transfer in wetted membrane phase becomes the rate-controlling step ultimately. The increase in the membrane wetting leads to the significant decrease in CO2 absorption performance with 49.4% and 80.5% decrease in CO2 absorption flux and the overall mass transfer coefficient at membrane wetting ratio of 5% and 50%, respectively. Based on the analysis on enhancement factor, it demonstrates that the chemical reaction between CO2 and DEAB for the non-wetted mode generally occurs in the intermediate fast-instantaneous regime and gradually transfers to the instantaneous regime with membrane wetting.