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Silicoaluminophosphate zeotypes with -CLO structure (SAPO-CLO) were ionothermally synthesized in 1-ethyl-3-methyl imidazolium ([emim]+) ionic liquid in the presence of tetrapropylammonium hydroxide. The physicochemical properties of SAPO-CLO with different silicon content were comparatively studied using several characterization techniques including XRD, SEM, XRF, NMR, BET, NH3-TPD, in situ DRIFTS etc. Notably, 29Si MAS NMR results revealed the incorporation of Si in the structure that was mainly in the form of SMII and SMIII combination. NH3-TPD and in situ DRIFTS results demonstrated that SAPO-CLO exhibited higher acid amount than AlPO-CLO as a result of the formation of new Bronsted acid sites Si–OH–Al in addition to structural P–OH in the framework. N2 physisorption results showed SAPO-CLO compared with AlPO-CLO exhibited higher BET surface area and microporous volume with the presence of extra-large-pore of about 1.2 nm. Finally, the catalytic performance of SAPO-CLO was evaluated in both methanol-to-olefin and propene oligomerization reactions to elucidate its activity, shape-selectivity and hydrothermal stability. SAPO-CLO showed improved catalytic activity in comparison to AlPO-CLO in both reactions, and lower selectivity of light olefins in the former reaction and higher selectivity of C3n oligomers in the latter reaction in comparison to small-pore SAPO-LTA. The deactivated catalyst was unrecoverable in MTO reaction due to structure degradation by water produced during the reaction, whereas recoverable in oligomerization reaction after the removal of coke by high temperature calcination.

In this work, a facile aqueous synthesis strategy was used (complete in 5 min at room temperature) to produce large-size Pd, PdCu, and PdPtCu nanomeshes without additional organic ligands or solvent and the volume restriction of reaction solution. The obtained metallic nanomeshes possess graphene-like morphology and a large size of dozens of microns. Abundant edges (coordinatively unsaturated sites, steps, and corners), defects (twins), and mesopores are seen in the metallic ultrathin structures. The formation mechanism for porous Pd nanomeshes disclosed that they undergo oriented attachment growth along the ⟨111⟩ direction. Owing to structural and compositional advantages, PdCu porous nanomeshes with certain elemental ratios (e. g., Pd87 Cu13 ) presented enhanced electrocatalytic performance (larger mass activity, better CO tolerance and stability) toward ethanol oxidation.

Polyoxometalate-based organic-inorganic hybrid compounds (POIHCs) have been greatly developed due to their wide application prospects, but the pursuit of their directed synthesis via molecular design still remains a challenge. Herein, we demonstrate that the coordination modes of the Keggin-type [ZnW12O40]6- anion can be tuned, which leads to different semiconductor characteristics. Using the same building block, ligand, and metal ion (ZnW12, phen, Cu2+), we synthesized three new POIHCs with different bonding patterns by means of different coordination modes of ZnW12. The three POIHCs (H2phen){ZnW12O40[Cu(phen)2]2}·3H2O (1), {ZnW12O40[Cu(phen)(H2O)2]2[Cu(phen)(H2O)]}n·3H2O (2), and (Me4N)2{ZnW12O40[Cu(phen)(H2O)]2}n·5H2O (3) (phen = 1,10-phenanthroline) have been structurally characterized by single-crystal X-ray diffraction. Compound 1 appears as a zero-dimensional coordination complex cluster, while compounds 2 and 3 are both 1D chain structures with different Cu2+ bridge linkages. Although these three POIHCs possess the same chemical components, their semiconductor properties are different, which is demonstrated by measurements of transient photocurrent and band gap (Eg) values. Furthermore, we carried out comparative experiments on the photoconductivity performance of compounds 1-3 and their photocatalytic reduction from O2 to H2O2, indicating the significant influence of the energy level matching on the photocatalytic activity.

Traditional denoising methods based on fixed transforms are not suited for exploiting their complicated characteristics and attenuating noise due to their lack of adaptability. Recently, a novel method called morphological component analysis (MCA) was proposed to separate different geometrical components by amalgamating several irrelevance transforms. For studying the local singular and smooth linear components characteristics of seismic data, we propose a novel method that excels particularly in attenuating random and coherent noise while preserving effective signals. The proposed method, which combines MCA, dictionary learning (DL), and deep noise reduction consists of three steps: first, we separate the local singular and smooth linear components from the seismic signal using MCA. Second, we apply a DL method on these two components to suppress noise and obtain the denoised signal and noise. In the final step, we apply the DL method to the noise to obtain a little of the seismic signal. Afterwards, we integrate the two seismic signals to obtain the final denoised seismic signal. Numerical results indicate that the proposed method can effectively suppress the undesired noise, maximally preserve the information of geologic bodies and structures, and improve the signal-to-noise ratio (S/N) of the data. We also demonstrate the superior performance of this approach by comparing with other novel dictionaries such as discrete cosine transforms (DCTs), undecimated discrete wavelet transforms (UDWTs), or curvelet transforms. This algorithm provides new ideas for data processing to advance quality and S/N of seismic data.

In this study, a new adaptive morphological filter is developed based on the mathematical morphology algorithm and characteristics of the subtle differences in the waveform morphology in seismic data. The algorithm improves the traditional morphological dilation and corrosion operations. In this study, we propose a multiscale adaptive operator based on the principle of morphological structural “probes” and present the corresponding mathematical proof. Simulation experiments and actual seismic data processing results show that compared with traditional morphological filters, the constructed OCCO-based multistructure adaptive morphological filter can suppress noise to the greatest extent. Moreover, it can effectively improve the SNR of the images, and offers great application prospects.

Grazing is a traditional grassland management technique and greatly alters ecosystem nutrient cycling. The effects of grazing intensity on the nutrient dynamics of soil and plants in grassland ecosystems remain uncertain, especially among microelements. A 2‐year field grazing experiment was conducted in a typical grassland with four grazing intensities (ungrazed control, light, moderate, and heavy grazing) in Inner Mongolia, China. Nutrient concentration was assessed in soil and three dominant plant species (Stipa krylovii, Leymus chinensis, and Cleistogenes squarrosa). Assessed quantities included four macroelements (carbon (C), nitrogen (N), phosphorus (P), and magnesium (Mg)) and four microelements (copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn)). Soil total C, total N, total P, available N, and available P concentrations significantly increased with grazing intensity but soil Mg, Cu, Fe, Mn, Zn concentrations had no significant response. Plant C concentration decreased but plant N, P, Mg, Cu, Fe, Mn, and Zn concentrations significantly increased with grazing intensity. In soil, macroelement dynamics (i.e., C, N, and P) exhibited higher sensitivity with grazing intensity, conversely in plants, microelements were more sensitive. This result indicates macroelements and microelements in soil and plants had asymmetric responses with grazing intensity. The slopes of nutrient linear regression in C. squarrosa were higher than that of S. krylovii and L. chinensis, indicating that C. squarrosa had higher nutrient acquisition capacity and responded more rapidly to heavy grazing. These findings indicate that short‐term heavy grazing accelerates nutrient cycling of the soil–plant system in grassland ecosystems, elucidate the multiple nutrient dynamics of soil and plants with grazing intensity, and emphasize the important function of microelements in plant adaptation in grazing management., The nutrient dynamics of macroelements and microelements in plants and soil displayed opposite responses to grazing. The slopes of nutrient linear regression in Cleistogenes squarrosa were higher than that of Stipa krylovii or Leymus chinensis, indicating that C. squarrosa had higher nutrient acquisition capacity and responded more rapidly to grazing.

Vegetation maps are important sources of information for biodiversity conservation, ecological studies, vegetation management and restoration, and national strategic decision making. The current Vegetation Map of China (1:1000000) was generated by a team of more than 250 scientists in an effort that lasted over 20 years starting in the 1980s. However, the vegetation distribution of China has experienced drastic changes during the rapid development of China in the last three decades, and it urgently needs to be updated to better represent the distribution of current vegetation types. Here, we describe the process of updating the Vegetation Map of China (1:1000000) generated in the 1980s using a “crowdsourcing-change detection-classification-expert knowledge” vegetation mapping strategy. A total of 203,024 field samples were collected, and 50 taxonomists were involved in the updating process. The resulting updated map has 12 vegetation type groups, 55 vegetation types/subtypes, and 866 vegetation formation/sub-formation types. The overall accuracy and kappa coefficient of the updated map are 64.8% and 0.52 at the vegetation type group level, 61% and 0.55 at the vegetation type/subtype level and 40% and 0.38 at the vegetation formation/sub-formation level. When compared to the original map, the updated map showed that 3.3 million km2 of vegetated areas of China have changed their vegetation type group during the past three decades due to anthropogenic activities and climatic change. We expect this updated map to benefit the understanding and management of China’s terrestrial ecosystems.

We focus on a relaxed version of the classic forward–backward splitting method in the context of finding a zero point of the sum of two monotone operators, and derive its linear convergence rate. T...

A cokriging model using three variables is developed to estimate bare-surface soil moisture content based on multi-temporal synthetic-aperture radar (SAR) data. This model utilizes cross-semivariogram function to take into account spatially varied correlation among multiple variables. Here, five sentinel-1 SAR scenes were acquired on different dates using the interferometric wide-swath (IW) mode and a mean incidence angle of 39.02° to build the backscatter temporal-ratio in VV polarization. This algorithm is generally based on the assumption of contributions of soil moisture and surface roughness to the backscattering coefficient under the given radar configurations. In this study, soil moisture is the target variable, and the surface roughness and backscatter temporal-ratio in VV polarization are the auxiliary variables. A cross-semivariogram relationship is formulated among those three spatial variables; then ordinary cokriging is used, based on that cross-semivariogram formula, to estimate the spatial distribution of bare soil moisture content. The root mean square error (RMSE) of soil-moisture retrieval ranges from 2.62 to 2.66 vol%. The new empirical model described in this paper will provide new insights into the study of soil environments.

The criteria used by International Union for Conservation of Nature (IUCN) for its Red List of Ecosystems (RLE) are the global standards for ecosystem-level risk assessment, and they have been increasingly used for biodiversity conservation. The changed distribution area of an ecosystem is one of the key criteria in such assessments. The Stipa bungeana grassland is one of the most widely distributed grasslands in the warm-temperate semi-arid regions of China. However, the total distribution area of this grassland was noted to have shrunk and become fragmented because of its conversion to cropland and grazing-induced degradation. Following the IUCN-RLE standards, here we analyzed changes in the geographical distribution of this degraded grassland, to evaluate its degradation and risk of collapse. Past (1950-1980) distribution areas were extracted from the Vegetation Map of China (1:1,000,000). Present realizable distribution areas were equated to these past areas minus any habitat area losses. We then predicted the grassland’s present and future (under the Representative Concentration Pathway 8.5 scenario) potential distribution areas using maximum entropy algorithm (MaxEnt), based on field survey data and nine environmental layers. Our results showed that the S. bungeana grassland was mainly distributed in the Loess Plateau, Hexi Corridor, and low altitudes of the Qilian Mountains and Longshou Mountain. This ecosystem occurred mainly on loess soils, kastanozems, steppe aeolian soils and sierozems. Thermal and edaphic factors were the most important factors limiting the distribution of S. bungeana grassland across China. Since 56.1% of its past distribution area (4.9×104 km2) disappeared in the last 50 a, the present realizable distribution area only amounts to 2.2×104 km2. But only 15.7% of its present potential distribution area (14.0×104 km2) is actually occupied by the S. bungeana grassland. The future potential distribution of S. bungeana grassland was predicted to shift towards northwest, and the total area of this ecosystem will shrink by 12.4% over the next 50 a under the most pessimistic climate change scenario. Accordingly, following the IUCN-RLE criteria, we deemed the S. bungeana grassland ecosystem in China to be endangered (EN). Revegetation projects and the establishment of protected areas are recommended as effective ways to avert this looming crisis. This empirical modeling study provides an example of how IUCN-RLE categories and criteria may be valuably used for ecosystem assessments in China and abroad.

Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized under the optimized reaction conditions. Biological assays conducted at Syngenta showed the designed derivatives displayed an altered pattern of biological activity, of which 5h was identified as the most promising compound with strong activity against Pythium dissimile and also a broad antifungal spectrum in primary screening. Further structural optimization of pimprinine and streptochlorin derivatives is well under way, aiming to discover synthetic analogues with improved antifungal activity. Two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized through diversity-oriented synthesis strategy under the optimized conditions. Biological assays showed the designed derivatives exhibited potential activity.

The classical proximal point algorithm (PPA) requires a metric proximal parameter, which is positive definite and symmetric, because it plays the role of the measurement matrix of a norm in the convergence proof. In this paper, our main goal is to show that the metric proximal parameter can be nonsymmetric if the proximal center is shifted appropriately. The resulting nonsymmetric PPA with moving proximal centers maintains the same implementation difficulty and convergence properties as the original PPA, while the nonsymmetry of the metric proximal parameter allows us to design highly customized algorithms that can effectively take advantage of the structures of the model under consideration. We present both the exact and inexact versions of the nonsymmetric PPA with moving proximal centers, and analyze their convergence including the estimate of their worst-case convergence rates measured by the iteration complexity under mild assumptions and their asymptotically linear convergence rates under stronger assumptions.

Urbanization and the ecological resource environment are mutually influential and interdependent, and their coordinated development is the key to the sustainable development of urbanizatio...

We consider a non-Abelian dark SU(2)$_{\rm D}$ model where the dark sector couples to the Standard Model (SM) through a Higgs portal. We investigate two different scenarios of the dark sector scalars with $Z_2$ symmetry, with Higgs portal interactions that can introduce mixing between the SM Higgs boson and the SM singlet scalars in the dark sector. We utilize the existing collider results of the Higgs signal rate, direct heavy Higgs searches, and electroweak precision observables to constrain the model parameters. The $\text{SU(2)}_{\text{D}}$ partially breaks into $\text{U(1)}_{\text{D}}$ gauge group by the scalar sector. The resulting two stable massive dark gauge bosons and pseudo-Goldstone bosons can be viable cold dark matter candidates, while the massless gauge boson from the unbroken $\text{U(1)}_{\text{D}}$ subgroup is a dark radiation and can introduce long-range attractive dark matter (DM) self-interaction, which can alleviate the small-scale structure issues. We study in detail the pattern of strong first-order phase transition and gravitational wave (GW) production triggered by the dark sector symmetry breaking, and further evaluate the signal-to-noise ratio for several proposed space interferometer missions. We conclude that the rich physics in the dark sector may be observable with the current and future measurements at colliders, DM experiments, and GW interferometers., Comment: 40 pages, 10 figures, 3 tables

Conditions for strong first-order phase transition and generation of observable gravitational wave (GW) signals are very restrictive to the profile of the Higgs potential. Working in the minimal extension of the SM with a new gauge singlet real scalar, we show that the production of signals relevant for future GW experiments, such as LISA, can favor depleted resonant and non-resonant di-Higgs rates at colliders for phenomenologically relevant regimes of scalar mixing angles and masses for the heavy scalar. We perform a comprehensive study on the emergence of these di-Higgs blind spot configurations in GWs and also show that di-boson channels, $ZZ$ and $WW$, can restore the phenomenological complementarities between GW and collider experiments in these parameter space regimes., Comment: 17 pages, 7 figures

In 2012, Censor et al. proposed the so-called two-subgradient extragradient method (TSEGM) in which both projections have an explicit-formula because the projections are just executed onto half-spa...

In hydrogen fuel cells, the sluggish oxygen reduction reaction (ORR) requires the catalysts used. Unfortunately, the precious platinum based catalysts still exhibit the best ORR activity in the commercial hydrogen fuel cells. Therefore, developing non-precious metal catalysts ORR become an important aspect for the utilization of hydrogen energy by using hydrogen fuel cells to develop non-precious catalysts and understand their active sites of ORR, herein the cobalt and nitrogen co-doped CNTs, nitrogen-doped CNTs and cobalt doped CNTs were prepared, respectively, and their catalytic properties toward ORR were tested and compared. The surface composition, microstructure and ORR performance of the samples were examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), pore/specific surface analyzer and electrochemical methods. The results demonstrate that as the catalyst, the cobalt and nitrogen co-doped CNTs owns the highest ORR limiting current density, the most positive ORR onset potential and the largest transfer electron number close to four, and thus exhibits the better ORR catalytic performance compared to the other two samples of the nitrogen-doped CNTs and the cobalt doped CNTs. The good ORR performance of cobalt and nitrogen co-doped CNTs can be attributed to its active sites of nitrogen containing functional groups, cobalt or cobalt oxides, Co-Nx structure, and the synergistic effect of these sites on ORR.

Fencing is an effective and practical method for restoring degraded grasslands in northern China. However, little is known about the role of excess litter accumulation due to long‐term fencing in regulating abiotic environment and driving changes in community structure and function. We conducted a three‐year field experiment in two fenced grasslands in Inner Mongolia, and monitored light quantity, soil temperature, and soil moisture continuously, and determined community height, community aboveground net primary productivity (ANPP), and the relative dominance of different plant functional groups. Litter accumulation reduced light quantity and soil temperature but increased soil moisture. The regulating effects of litter accumulation on soil temperature and soil moisture fluctuated temporally and gradually weakened over the growing season. Litter accumulation also altered community vertical structure and function by increasing community height and ANPP. The increase in soil moisture increased the relative dominance of rhizome grasses but suppressed bunch grasses, thereby shifting bunch grass grasslands to rhizome grass grasslands. Our findings provide a potential mechanism for community succession in the context of litter accumulation in fenced grasslands and indicate that the vegetation and ecosystem services of degraded grasslands are improved after appropriate fencing.

Health care services are the core elements of the urban public service system. Hospital accessibility network and its decision network system of health care services play a decisive role in the facilitation of medical treatment for urban residents. A distribution map of hospitals in the main city of Dalian is generated using ArcGIS software. The average reach time of medical treatment in each district is calculated using the network analysis module. The average time of arrival is denoted as the evaluation index to discuss the accessibility of public transportation and private cars during peak and non-peak hours, as well as the spatial distribution characteristics and differences of each district and hospital. Moran's I index and LISA local clustering model are used to explore areas of inadequate medical services. The minimum available time of each district is set as a standard, the hinterland of medical service in hospitals at all levels was delimited, and the reasons for its formation were analyzed. Research shows that (1) the overall accessibility of medical care in the downtown district of Dalian is better, and the accessibility of peak and peak hours is in a circle. Relative to private cars, public transport at peak hours has obvious advantages for medical treatment. Peak and non-peak hours are quite different, average peak time average peak area of 10-20 min in a larger proportion of the cell, reaching 68.1%; (2) The hospital accessibility level is generally good, with a coverage area of 96.53% in 30min.. From the core area to the peripheral area, the influence of traffic resistance on reachability gradually increases. (3) The level of equalization of medical services at the street level is obviously different, and the overall spatial autocorrelation is weak. (4) Within each medical hinterland, the number and distance of the hospital's medical services has a decisive influence on the ability hinterland, lack of health areas highly dependent causing residents to a hospital.This article provides some suggestions for the abovementioned problems.

Aims The latest China Vegetation Classification System (China-VCS) for natural/semi-natural vegetation has eight hierarchical levels: Association < Association-group < Subformation < Formation < Formation-group < Vegetation-subtype < Vegetation-type < Vegetation-type-group. The classification is based on dominant species and their growth forms and has been completed at the formation level. The principal challenge today in Chinese vegetation classification is to develop the China-VCS at levels below the formation in a way that is consistent with current international standards. We explored the following question: how can existing vegetation plot data help develop the China-VCS and improve its compatibility with other international classification systems? Methods We compiled 401 plots having plant cover and/or aboveground biomass measurements collected in six Stipa steppe formations and divided them into those with cover data (299 plots) and/or biomass data (283 plots). We applied a combination of hierarchical clustering and ordination to partition the cover and biomass data sets into formations and constituent associations. We then used supervised noise clustering to improve the classification and to identify the core plots representing each association. Diagnostic species were also identified at both association and formation levels. Finally, we compared the classification results based on cover and biomass data sets and combined these results into a comprehensive classification framework for the six formations. Important Findings Our results using cover data were comparable with those using biomass data at both formation and association levels. Three Stipa formations were classified into associations based on cover data, two based on biomass data and one based on both biomass and cover data. Twenty-seven associations were defined and proposed within the six formations, using cover or biomass data as consistent classification sections (CCSs). Both dominant species in the dominant stratum and diagnostic species from multiple strata of the core plots were used to characterize vegetation types at both formation and association levels, improving the compatibility of our classification with the International Vegetation Classification. Temperature and precipitation were found to be important climatic factors determining the distribution pattern and species composition of Stipa-dominated vegetation. We propose a framework for plot-based vegetation classification in the China-VCS, using our work with Stipa-dominated steppe vegetation as an example. We applied the concept of CCS to make optimal use of available data representing both plant cover and biomass. This study offers a model for developing the China-VCS to the association level in a way that is consistent with current international standards.

A novel Fe(III) cluster formulated as [ $${\text{Fe}}^{\text{III}}_{8}$$ (schhz)4(Py)6(H2O)2]∙2H2O (1) was synthesized by the hydrothermal reaction of FeCl2 and a symmetrical diacylhydrazine ligand N,N′-bissalicyl-1,3-cyclohexanedicarbohydrazide (H6schhz) in the presence of pyridine (Py) and pyrazine (Pz). It displays a nano-sized [24-MC-8] azametallacrown (azaMC) structure that eight Fe(III) ions are linked together by N–N bridges from four schhz6− ligands. To the best of our knowledge, it is the second case of Fe(III) [24-MC-8] azaMC up to now. The magnetic investigations reveal that the N–N bridges convey antiferromagnetic couplings between the Fe(III) centers in the system.

The overall strategy for land-sea coordination is important for scientific and technological innovation efficiency in China's coastal areas. In this paper, the country's mixed land and sea regions were selected for study, including two land and ocean subsystems with input and output index systems. Based on the variation coefficient method, the global Malmquist–Luenberger (GML) index was used to calculate the scientific and technological development efficiency of coordinated plans for China's coastal land and sea areas from 2006 to 2015 and to analyze the regional differences among these plans. The conclusions are as follows. First, the total factor productivity growth rate of science and technology innovation efficiency in China's coastal areas is primarily larger than 1 and at the frontier of efficiency. The efficiency of mixed areas is higher than that of separated land and sea areas, and the differences in regional technological innovation efficiencies has gradually narrowed. The change in technical efficiency is consistent with changes in the GML index, and the financial crisis of 2008–2009 had a significant positive impact on pure technical efficiency. Second, the coordinated plans for land and sea areas are realized and spatial differences in scientific and technological innovation efficiency in China's coastal areas are classified according to scientific and technological innovation in China's coastal areas. Hebei and Liaoning are classified according to the land efficiency type; Jiangsu and Zhejiang are classified as the marine efficiency-driven type; and the Shandong, Tianjin, Shanghai, and Pan-Pearl River Delta regions are classified as the efficiency of mixed land and sea areas type. Drivers of regional differences mainly include economic development levels, differences in industry structure, the personnel structure of scientific and technological systems, and the state of production and the influence of the government.

Sweet potato is an important starch resource and has different colored root tubers due to different genotype backgrounds. However, it is unclear whether starch properties are related to the color of root tuber. In this study, 3 white, 3 yellow, and 3 purple sweet potato varieties were planted in the same environment. The dry root tubers of white varieties had the highest starch ranging from 61.5 to 67.5% and the lowest soluble sugar ranging from 13.1 to 18.0%, and those of yellow varieties had the lowest starch ranging from 45.8 to 53.1% and the highest soluble sugar ranging from 28.9 to 31.5%. Starches from different varieties had different granule sizes (D[4,3] 12.3–18.1 μm) and amylose contents (24.1–27.2%), but all exhibited CA-type crystalline structure. The relative crystallinity ranged from 22.3 to 25.5%, and the IR absorbance ratios of 1045/1022 and 1022/995 cm−1 ranged from 0.665 to 0.775 and from 0.846 to 0.944, respectively, among 9 varieties. The starches from the same or different colored varieties had differences in swelling power, water solubility, gelatinization temperature, pasting viscosity, and digestion properties. The cluster analysis based on starch property parameters indicated that starch properties of sweet potato had no relationship with the color of root tuber but were determined by the genotype background of variety.

The extra-long chain (ELC) of amylopectin influences molecular compositions of starch. In this study, starches were isolated from 22 rice varieties with different ELCs. Molecular compositions of starch were determined, and their relationships with crystalline structure, gelatinization properties, pasting properties, and enzyme hydrolysis were analysed. The results showed that the starches with different ELCs had significantly different structural and functional properties. The ELC was significantly positively related to setback viscosity and negatively related to relative crystallinity, lamellar peak intensity, swelling power, gelatinization enthalpy, and rapidly digestible starch of retrograded starch. The true amylose content was significantly positively related to retrogradation and negatively related to peak viscosity and hydrolysis degree by α-amylase and amyloglucosidase. The short branch-chain of amylopectin was significantly positively related to lamellar peak intensity, swelling power, hydrolysis degree by α-amylase, and rapidly digestible starch of retrograded starch and negatively related to setback viscosity and resistant starch of retrograded starch. The ratio of short to long branch-chain of amylopectin was significantly positively related to swelling power and hydrolysis degree by α-amylase. The principal component analysis and partial least squares discriminant analysis demonstrated that the low-ELC starches were distinguished from the middle- and high-ELC starches, the middle-ELC starches basically clustered together, but the high-ELC starches were highly dispersed. The above results would provide some new information for rice quality breeding and starch applications by changing the ELC in starch.

The crystallization chemistry of silica-based zeolites in ionic liquids remains highly puzzling and interesting in the field of zeolite science. Herein, we report the successful ionothermal synthesis of germanosilicate zeolites. The ionothermal templating effect with respect to the structure, alkalinity and concentration of organic additives was comparatively studied. The results showed that a small amount of organic base could effectively aid the dissolution of silica source and facilitate the crystallization of germanosilicate zeolites with ionic liquid as template. Remarkably, STW and IRR structures constructed with double-four-ring (D4R) structure-building units were ionothermally prepared using 1-ethyl/butyl-3-methyl imidazolium and 1-benzyl-3-methyl imidazolium ionic liquids as template, respectively. Ionothermal synthesis tailored with organic base showed suitable chemistry for the formation of germanium-containing siliceous D4R units. This finding will be helpful for the rational exploration of novel extra-large-pore zeolitic structures.

The Krasnoselskii–Mann iteration plays an important role in the approximation of fixed points of nonexpansive mappings, and it is well known that the classic Krasnoselskii–Mann iteration is weakly convergent in Hilbert spaces. The weak convergence is also known even in Banach spaces. Recently, Kanzow and Shehu proposed a generalized Krasnoselskii–Mann-type iteration for nonexpansive mappings and established its convergence in Hilbert spaces. In this paper, we show that the generalized Krasnoselskii–Mann-type iteration proposed by Kanzow and Shehu also converges in Banach spaces. As applications, we proved the weak convergence of generalized proximal point algorithm in the uniformly convex Banach spaces.

Considering the biodegradation pathway of Microcystins, in this paper, we propose a model described by a system of ordinary differential equations. We firstly investigate the local stability of the positive equilibrium and the existence of Hopf bifurcations. Then, the global stability of the positive equilibrium and the permanence of the model are considered. Finally, numerical simulations are carried out to illustrate the obtained results and we also consider the control strategy by changing the parameters in the model.

Defect engineering can be a promising approach to improve the photocatalytic performance of metal–organic frameworks (MOFs). Herein, a series of defective NH2-UiO-66(Zr) materials were synthesized via simply controlling the synthesis temperature, with concentrated HCl as the modulator and then these as-prepared samples were used to systematically investigate the effects of their structural defects on photocatalytic CO2 reduction. Remarkably, these MOFs with defects exhibit significantly enhanced activities in photocatalytic CO2 reduction, compared with the material without defects. The defect engineering creates active binding sites and more open frameworks in the MOF, and thus facilitates the photo-induced charge transfer and restrains the recombination of photo-generated charges efficiently. The current work provides an instructive approach to improve the photocatalytic efficiency by taking advantage of the structural defects in MOFs, and could also inspire more work on the design of advanced defective MOFs.

Models of particle physics that feature phase transitions typically provide predictions for stochastic gravitational wave signals at future detectors and such predictions are used to delineate portions of the model parameter space that can be constrained. The question is: how precise are such predictions? Uncertainties enter in the calculation of the macroscopic thermal parameters and the dynamics of the phase transition itself. We calculate such uncertainties with increasing levels of sophistication in treating the phase transition dynamics. Currently, the highest level of diligence corresponds to careful treatments of the source lifetime; mean bubble separation; going beyond the bag model approximation in solving the hydrodynamics equations and explicitly calculating the fraction of energy in the fluid from these equations rather than using a fit; and including fits for the energy lost to vorticity modes and reheating effects. The lowest level of diligence incorporates none of these effects. We compute the percolation and nucleation temperatures, the mean bubble separation, the fluid velocity, and ultimately the gravitational wave spectrum corresponding to the level of highest diligence for three explicit examples: SMEFT, a dark sector Higgs model, and the real singlet-extended Standard Model (xSM). In each model, we contrast different levels of diligence in the calculation and find that the difference in the final predicted signal can be several orders of magnitude. Our results indicate that calculating the gravitational wave spectrum for particle physics models and deducing precise constraints on the parameter space of such models continues to remain very much a work in progress and warrants care., 43 pages, 16 figures, 1 table

We review topics in searches for axion-like-particles (ALPs), covering material that is complementary to other recent reviews. The first half of our review covers ALPs in the extreme environments of neutron star cores, the magnetospheres of highly magnetized neutron stars (magnetars), and in neutron star mergers. The focus is on possible signals of ALPs in the photon spectrum of neutron stars and gravitational wave/electromagnetic signals from neutron star mergers. We then review recent developments in laboratory-produced ALP searches, focusing mainly on accelerator-based facilities including beam-dump type experiments and collider experiments. We provide a general-purpose discussion of the ALP search pipeline from production to detection, in steps, and our discussion is straightforwardly applicable to most beam-dump type and reactor experiments. We end with a selective look at the rapidly developing field of ultralight dark matter, specifically the formation of Bose-Einstein Condensates (BECs). We review the properties of BECs of ultralight dark matter and bridge these properties with developments in numerical simulations, and ultimately with their impact on experimental searches., Invited review, submitted to IJMPD. 58 pages, 11 figures. Comments welcome

We place constraints on the normalized energy density in gravitational waves from first-order strong phase transitions using data from Advanced LIGO and Virgo's first, second and third observing runs. First, adopting a broken power law model, we place $95 \%$ confidence level upper limits simultaneously on the gravitational-wave energy density at 25 Hz from unresolved compact binary mergers, $\Omega_{\rm CBC} < 6.1 \times 10^{-9}$, and strong first-order phase transitions, $\Omega_{\rm BPL} < 4.4 \times 10^{-9}$. The inclusion of the former is necessary since we expect this astrophysical signal to be the foreground of any detected spectrum. We then consider two more complex phenomenological models, limiting at 25 Hz the gravitational-wave background due to bubble collisions to $\Omega_{\rm pt} < 5.0\times 10^{-9}$ and the background due to sound waves to $\Omega_{\rm pt} < 5.8\times10^{-9}$ at $95 \%$ confidence level for phase transitions occurring at temperatures above $10^8$GeV., Comment: 7 pages, 3 figures, version published in Physical Review Letters

Quiescent hard X-ray and soft gamma-ray emission from neutron stars constitute a promising frontier to explore axion-like-particles (ALPs). ALP production in the core peaks at energies of a few keV to a few hundreds of keV; subsequently, the ALPs escape and convert to photons in the magnetosphere. The emissivity goes as $\sim T^6$ while the conversion probability is enhanced for large magnetic fields, making magnetars, with their high core temperatures and strong magnetic fields, ideal targets for probing ALPs. We compute the energy spectrum of photons resulting from conversion of ALPs in the magnetosphere and then compare it against hard X-ray data from NuSTAR, INTEGRAL, and XMM-Newton, for a set of eight magnetars for which such data exists. Upper limits are placed on the product of the ALP-nucleon and ALP-photon couplings. For the production in the core, we perform a calculation of the ALP emissivity in degenerate nuclear matter modeled by a relativistic mean field theory. The reduction of the emissivity due to improvements to the one-pion exchange approximation is incorporated, as is the suppression of the emissivity due to proton superfluidity in the neutron star core. A range of core temperatures is considered, corresponding to different models of the steady heat transfer from the core to the stellar surface. For the subsequent conversion, we solve the coupled differential equations mixing ALPs and photons in the magnetosphere. The conversion occurs due to a competition between the dipolar magnetic field and the photon refractive index induced by the external magnetic field. Semi-analytic expressions are provided alongside the full numerical results. We also present an analysis of the uncertainty on the axion limits we derive due to the uncertainties in the magnetar masses, nuclear matter equation of state, and the proton superfluid critical temperature., v1: 44 pages, 15 figures. Comments welcome v2: Updated version with uncertainty bands on ALP couplings coming from different choices of the nuclear equation of state, the mass of the magnetar, and the model of proton singlet superfluidity. Calculation of n+p-->n+p+a clarified. Version matches that published in JCAP

Axion-like-particles (ALPs) emitted from the core of a magnetar can convert to photons in its magnetosphere. The resulting photon flux is sensitive to the product of $(i)$ the ALP-nucleon coupling $G_{an}$ which controls the production cross section in the core and $(ii)$ the ALP-photon coupling $g_{a\gamma \gamma}$ which controls the conversion in the magnetosphere. We study such emissions in the soft-gamma-ray range (300 keV to 1 MeV), where the ALP spectrum peaks and astrophysical backgrounds from resonant Compton upscattering are expected to be suppressed. Using published quiescent soft-gamma-ray flux upper limits in 5 magnetars obtained with $CGRO$ COMPTEL and $INTEGRAL$ SPI/IBIS/ISGRI, we put limits on the product of the ALP-nucleon and ALP-photon couplings. We also provide a detailed study of the dependence of our results on the magnetar core temperature. We further show projections of our result for future $Fermi$-GBM observations. Our results motivate a program of studying quiescent soft-gamma-ray emission from magnetars with the $Fermi$-GBM., Comment: 14 pages, 4 figures. Version accepted in Physical Review D. More conservative benchmark core temperature assumed, details of production in the core provided, new constraints on ALP couplings based on spectral analysis presented. Extensive supplementary material added, future projections discussed, overall conclusions unchanged

Polyoxometalates containing titanium (Ti-POMs) related to semiconductor TiO2 have potential applications in photocatalysis, photovoltaics and semiconducting materials. In this paper, we synthesized a Ti-POM, Na2H10[Co4(H2O)2(TiW9O34)2]·48H2O (1), by one-pot self-assembly reaction. In its crystal architecture, sodium ions connect multiple monomer units to form a layered structure. The electrochemical properties of 1 were investigated by cyclic voltammograms. The semiconductor band gap (Eg) value of 1 was calculated through diffuse reflection UV-vis spectroscopy. Furthermore, 1 was used as a semiconductor material and applied to photoelectrochemical sensing to detect dopamine with different concentrations in aqueous solution. The above-mentioned results open up an opportunity to develop polyoxometalate-based, titanium-containing coordination complexes with functional properties and lay the foundation for detection of other biological targets.

Tropical and subtropical forest ecosystems play an important role in the global carbon regulation. Although positive relationships between biodiversity and soil organic carbon (SOC) storage have been found in experimental grasslands, biodiversity effects on SOC storage in natural forests remain debated. Based on a large dataset from 523 forest inventory plots across subtropical forests in China, we tested the relationship between biodiversity and SOC storage and examined whether environmental conditions (temperature, precipitation, soil properties) and litter quantity (leaf litter and root biomass) and quality (leaf litter carbon to nitrogen ratio [leaf litter C/N]) had effects on SOC storage. Furthermore, we used linear mixed-effects models to test the relative effects of biodiversity, environmental conditions, and litter quantity and quality on SOC storage. We used structural equation models to test how these variables directly or indirectly affected SOC storage. We found that species diversity, together with climatic factors (mean annual temperature and mean annual precipitation), leaf litter C/N and root biomass determined SOC storage in subtropical forests at a large spatial scale. SOC storage was most strongly affected by climatic factors, followed by leaf litter C/N. Species diversity had both direct and indirect (through root biomass and leaf litter C/N) effects on SOC storage after accounting for environmental conditions. We also found that the positive diversity–SOC storage relationships were stronger in low and medium mean annual precipitation. Our findings highlight that higher species diversity can lead to higher SOC storage and therefore the conservation of biodiversity could play an important role in climate change mitigation.

Isotactic polypropylene (PP) composites achieved high impact strength by melt mixing with complex titanate whiskers/multiwalled carbon nanotubes (MWCNTs). The complex fillers, obtained via coupling agent γ-aminopropyl triethoxysilane, triggered additional reinforcement with stiff backup of whiskers and strengthened interfacial adhesion generated from MWCNTs, forwarding positive synergy on the PP composites. In presence of compatibilizer maleic anhydride-grafted polypropylene, 5 wt% of the complex fillers brought about impact strength 6.3 ± 0.3 kJ/m2 to the composite, which was 103% higher than PP. Meanwhile, tensile strength was also improved with 34.8 ± 0.5 MPa as compared with that of PP (32.6 ± 0.3 MPa). Morphology witnessed by scanning electron microscope revealed that the complex fillers favored dispersion of MWCNTs in polymer matrix, fulfilling bridging for reinforcement. Detection of differential scanning calorimetry also indicated that the complex fillers facilitated crystallization of PP in the composites. Upon high impact strength and improved tensile property, the PP composites could find potentials with facile processing manipulation in applications.

We undertake a careful analysis of stochastic gravitational wave production from cosmological phase transitions in an expanding universe, studying both a standard radiation as well as a matter dominated history. We analyze in detail the dynamics of the phase transition, including the false vacuum fraction, bubble lifetime distribution, bubble number density, mean bubble separation, etc., for an expanding universe. We also study the full set of differential equations governing the evolution of plasma and the scalar field during the phase transition and generalize results obtained in Minkowski spacetime. In particular, we generalize the sound shell model to the expanding universe and determine the velocity field power spectrum. This ultimately provides an accurate calculation of the gravitational wave spectrum seen today for the dominant source of sound waves. For the amplitude of the gravitational wave spectrum visible today, we find a suppression factor arising from the finite lifetime of the sound waves and compare with the commonly used result in the literature, which corresponds to the asymptotic value of our suppression factor. We point out that the asymptotic value is only applicable for a very long lifetime of the sound waves, which is highly unlikely due to the onset of shocks, turbulence and other damping processes. We also point out that features of the gravitational wave spectral form may hold the tantalizing possibility of distinguishing between different expansion histories using phase transitions., 52 pages, 20 figures; v3: version published in JCAP

We study and reveal the relation between the electroweak sphaleron energy and the gravitational wave signals from a first-order electroweak phase transition. For the first time, we find that a larger sphaleron energy corresponds to a stronger gravitational wave signal for a sufficiently strong phase transition. We also present the correlation between the sphaleron and the properties of the gravitational waves, such as the signal-to-noise ratio, peak frequency, and amplitude, with the intention that traces of the sphaleron can be obtained with detailed measurement and studies of the stochastic gravitational wave at future space-based detectors. This study paves the way for a more practical revelation of the sphaleron which is otherwise unprobable at high energy colliders.

Molecular imaging is a powerful tool to visualize cellular processes and activity levels of biomarkers at the cellular and molecular level, in which a molecular probe is a prerequisite for the molecular imaging technique. The present work reports a bimodal probe for the fluorescence and magnetic resonance detection of fluoride ions (F−) in aqueous media and in vivo. The bimodal probe, EDTA–Gd–HF, was prepared by self-assembly of the EDTA–Gd complex with 3-hydroxyflavone (HF). In the system, HF plays the role of spectroscopic reporter and Gd(III) serves as a MRI signal output unit as well as the fluoride ion binding site. Upon addition of fluoride ions into an aqueous solution of EDTA–Gd–HF, the replacement of one coordinated water molecule and then liberation of HF led to remarkable spectroscopic recovery and distinct changes to the longitudinal relaxivity (r1), by which fluorescence/MRI bimodal fluoride ion sensing was achieved. In vivo magnetic resonance imaging (MRI) in mice indicates that EDTA–Gd–HF can be potentially used in biomedical diagnosis and therapy fields.

Utilizing the Georgi-Machacek model, we study the electroweak symmetry breaking mechanism with extra electroweak symmetry breaking contributions (eEWSB) that are bounded by the Fermi constant and limits from the related collider searches. The eEWSB is helpful to build a different zero temperature vacuum structure from the Standard Model (SM), and therefore leads to different electroweak phase transition patterns at the early Universe. We investigate the collider search prospects and gravitational waves (GW) predictions from the strongly firstly order phase transition (SFOEWPT) in this scenario. The Higgs pair searches at lepton colliders are found to be complementary with the GW searches of the SFOEWPT parameter spaces.

A Cu coordiantion polymer, namely, [Cu3(ovph)(Py)2Cl2] (1) [H4ovph = N,N′-bis(o-vanillidene)pyridine-2,6-dicarbohydrazide]; Py = Pyridine], was synthesized by solvothermal reaction of copper acetate and diacylhydrazone ligand H4ovhp. It was characterized by element analysis, FT-IR, thermogravimetric analysis, PXRD and single crystal X-ray diffraction. Structural analysis indicated that the N–N bonds of its ovph4− ligands bridge the Cu2+ ions to form quasi-linear [Cu3] cluster-based units, which were further linked together by in situ generated µ-Cl−, giving rise to a rare Cu chain structure containing two kinds of magnetic exchange pathways. Variable temperature magnetic measurements revealed that both N–N and Cl− bridges convey antiferromagnetic couplings, with the best fitting JN–N = − 99.95 cm−1, JCl = − 5.70 cm−1, zj = − 1.17 cm−1 and g = 2.00.

Growth responses of the moderately salt-tolerant velvet ash (Fraxinus velutina) and salt-sensitive poplar (Populus × euramericana) were investigated under heterogeneous root zone salinity. The salinity treatments imposed on the two root zones (lower-higher) were 137-137 (uniform), 103-171, 68-205, 34-239, and 0-273 mM NaCl for velvet ash, and 51-51 (uniform), 34-68, 17-85, and 0-103 mM NaCl for poplar. The leaf gas exchange of the plants was measured one month after these treatments were implemented, and the plants were sampled 75 d after treatment to measure other physiological parameters. Net photosynthetic rate, transpiration rate, total biomass, and fine root compensatory growth increased as the difference in salinity between the two root zones (i.e., salinity heterogeneity) increased in velvet ash. These parameters showed no significant difference among the treatments in poplar. The leaf Na+ content was lower under heterogeneous salinity than under uniform salinity in both tested species. The leaf proline content in velvet ash decreased under heterogeneous salinity compared to that under uniform salinity, whereas that of poplar increased. The soluble sugar content of velvet ash leaves increased under heterogeneous salinity, whereas no changes were observed in poplar. The increased fine root biomass in the lower salinity zone promoted velvet ash growth by decreasing the leaf Na+ and Cl- content under heterogeneous salinity. The poplar’s undifferentiated root distribution and gas exchange in response to the heterogeneous salinity were attributed to its salt sensitivity.

In this paper we investigate the phenomenology of the electron flavored Dirac dark matter with two types of portal interactions. We analyze constraints from the electron magnetic moment anomaly, LHC searches of singly charged scalar, dark matter relic abundance as well as direct and indirect detections. Our study shows that the available parameter space is quite constrained, but there are parameter space that is compatible with the current data. We further show that the DAMPE cosmic ray electron excess, which indicates cosmic ray excess at around 1.5 TeV, can be interpreted as the annihilation of dark matter into electron positron pairs in this model., Comment: 6 pages, 5 figures

Rocky desertification is currently the most serious ecological and environmental problem in karst region of southwestern China. Its negative consequences for both natural ecosystems and the human inhabitants of the karst region have created a need for effective ecosystem restoration strategies, but success in these efforts has been limited. We hypothesized that scarcity of mineral nutrients could be a crucial factor in vegetation recovery, but relatively little information is available about the limiting roles of various mineral elements. We investigated responses of aboveground biomass and nutrient concentrations of a degraded karst grassland to nitrogen (N), Phosphorus (P) and Potassium (K) additions over a period of three years. Nutrient additions significantly increased aboveground biomass and nutrient concentrations for both the plant community and individual plant functional groups. Total aboveground biomass was significantly increased by N (by 35.6%), P (by 35.3%) and K (by 11.7%) fertilization over three years of nutrient additions. The interaction effects of year × N and year × P on total biomass were significant. Additions of N and P increased the biomass of grasses by 39.2% and 15.0%, respectively, and additions of P increased the biomass of forbs by 69.3%. The biomass of shrubs was significantly increased by P (by 111.3%), K (by 45.3%) and N (by 38.5%), and there were strong interaction effects of N, P and K on shrub biomass. P and K additions significantly increased the relative biomass of shrubs but decreased that of grasses, especially under the NPK treatment. Our results suggest that the productivity of degraded grassland in the karst region of China is co-limited by N, P and K, with N and P being the primary limiting factors. Among functional groups, grasses are mainly limited by N and P, forbs by P, and shrubs by all 3 elements, with P being the most limiting factor overall. Mineral fertilization stimulates plant growth and may be a useful tool in efforts to restore woody vegetation in degraded grasslands, thus counteracting the process of rock desertification in the karst region of southwestern China.

Recently, the convergence of the Douglas–Rachford splitting method (DRSM) was established for minimizing the sum of a nonsmooth strongly convex function and a nonsmooth hypoconvex function under the assumption that the strong convexity constant $$\beta $$ is larger than the hypoconvexity constant $$\omega $$ . Such an assumption, implying the strong convexity of the objective function, precludes many interesting applications. In this paper, we prove the convergence of the DRSM for the case $$\beta =\omega $$ , under relatively mild assumptions compared with some existing work in the literature.

The ionothermal synthesis of extra-large-pore aluminophosphate zeotype with -CLO topological structure, DNL-1, was studied by using 1,6-hexanediamine and several quaternary ammonium compounds with different types of cations and anions as co-structure-directing agents (co-SDAs). The phase selectivity and crystallization process were investigated, and results showed that the crystallization of the -CLO and LTA structures correlated with the alkalinity and concentration, rather than with the structure of the co-SDA. By combining solid/solution 13 C NMR spectroscopy and other characterizations on DNL-1 obtained with different co-SDAs, it was demonstrated that the ionic-liquid cation was unalterably occluded in the structure, whereas occlusion of the co-SDA cation was not imperative. A plausible crystallization pathway was accordingly deduced, in which alkaline co-SDA, which acted as an acidity regulator in the ionothermal system, could facilitate the formation of the double-four-ring (d4r) unit (Al4 P4 O20 ), and influence their subsequent assembly mode around ionic-liquid cations, and thus, direct the crystallization of -CLO and LTA structures at different concentrations of co-SDA.

The issue that climatic change has great influence on species distribution is currently of great interest in field of biogeography. Six typical Kobresia species are selected from alpine grassland of Tibetan Plateau (TP) as research objects which are the high-quality forage for local husbandry, and their distribution changes are modeled in four periods by using MaxEnt model and GIS technology. The modeling results have shown that the distribution of these six typical Kobresia species in TP was strongly affected by two factors of “the annual precipitation” and “the precipitation in the wettest and driest quarters of the year”. The modeling results have also shown that the most suitable habitats of K. pygmeae were located in the area around Qinghai Lake, the Hengduan-Himalayan mountain area, and the hinterland of TP. The most suitable habitats of K. humilis were mainly located in the area around Qinghai Lake and the hinterland of TP during the Last Interglacial period, and gradually merged into a bigger area; K. robusta and K. tibetica were located in the area around Qinghai Lake and the hinterland of TP, but they did not integrate into one area all the time, and K. capillifolia were located in the area around Qinghai Lake and extended to the southwest of the original distributing area, whereas K. macrantha were mainly distributed along the area of the Himalayan mountain chain, which had the smallest distribution area among them, and all these six Kobresia species can be divided into four types of “retreat/expansion” styles according to the changes of suitable habitat areas during the four periods; all these change styles are the result of long-term adaptations of the different species to the local climate changes in regions of TP and show the complexity of relationships between different species and climate. The research results have positive reference value to the protection of species diversity and sustainable development of the local husbandry in TP.

LTA-type aluminophosphate zeotype (AlPO-LTA) was ionothermally prepared with the assistance of several tetraalkylammonium hydroxides (TAAOH) containing alkyl chains of different lengths. The shape of the TAA+ cations had no determinant effect on the product structure selectivity, but had some influence on the crystallization kinetics, resulting in the formation of cubic and rhombohedral AlPO-LTA with different crystallinities. Combining the results of 1H → 13C CP/MAS NMR and TG–DTA characterizations, it was demonstrated that tetramethylammonium (TMA+) was occluded in the LTA structure acting as co-template, whereas the other three TAA+ with longer alkyl chains were not occluded. The structure of AlPO-LTA after detemplation and hydration in moisture was carefully studied using XRD and 27Al MAS NMR characterizations, manifesting its high structural stability with reversible water-adsorption capability, irrespective of TAAOH used in the synthesis.