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Grazing exclusion using fences is a key policy being applied by the Chinese government to rehabilitate degraded grasslands on the Tibetan Plateau (TP) and elsewhere. However, there is a limited understanding of the effects of grazing exclusion on alpine ecosystem functions and services and its impacts on herders’ livelihoods. Our meta-analyses and questionnaire-based surveys revealed that grazing exclusion with fences was effective in promoting aboveground vegetation growth for up to four years in degraded alpine meadows and for up to eight years in the alpine steppes of the TP. Longer-term fencing did not bring any ecological and economic benefits. We also found that fencing hindered wildlife movement, increased grazing pressure in unfenced areas, lowered the satisfaction of herders, and rendered substantial financial costs to both regional and national governments. We recommend that traditional free grazing should be encouraged if applicable, short-term fencing (for 4–8 years) should be adopted in severely degraded grasslands, and fencing should be avoided in key wildlife habitat areas, especially the protected large mammal species.

Abstract Indole alkaloids extract (IAAS) was prepared from leaves of Alstonia scholaris (L.) R. Br., an evergreen tropical plant widely distributed throughout the world. This plant has been used historically by the Dai ethnic people of China to treat respiratory diseases. This study evaluated the genotoxicity and safety pharmacology of IAAS to support clinical use. The bacterial reverse mutation (Ames) test, in vitro mammalian chromosomal aberration test, and in vivo mammalian erythrocyte micronucleus (MN) test were performed to evaluate genotoxicity. Mice were administered IAAS (240, 480, or 960 mg/kg bw) once orally to observe adverse central nervous system effects. Furthermore, beagle dogs were administered IAAS (10, 30, 60 mg/kg bw) once via the duodenum to evaluate its effects on the cardiovascular and respiratory systems. IAAS with or without S9-induced metabolic activation showed no genotoxicity in the Ames test up to 500 μg/plate, in the mammalian chromosomal aberration test up to 710 μg/mL, or in the MN test up to 800 mg/kg bw. No abnormal neurobehavioral effects were observed in mice following treatment with up to 960 mg/kg bw of IAAS. Moreover, blood pressure, heart rate, electrocardiogram parameters, and depth and rate of breathing in anesthetized beagle dogs did not differ among the IAAS doses or from the vehicle group. These data indicated that IAAS did not induce mutagenicity, clastogenicity, or genotoxicity, and no pharmaco-toxicological effects were observed in the respiratory, cardiovascular, or central nervous systems. Our results increased understanding of safety considerations associated with IAAS, and may indicate that IAAS is a possible drug candidate. Graphic Abstract

Leaf nitrogen (N) and phosphorus (P) stoichiometry covary with many aspects of climatic and edaphic factors, yet the effects of solar radiation (SR) on leaf stoichiometry are still unclear. In the Tibetan Plateau, the high level of SR can induce the plants to reach their light saturation point easily, which causes photoinhibition of photosynthesis. Here, the leaf N and P concentrations across the alpine meadow of the Tibetan Plateau were measured to explore the response of leaf N and P stoichiometry to SR. Our results showed that the concentrations of both leaf N and leaf P were negatively correlated with SR under the high SR level (SR > 15,000 KJ m−2 d-1). The structural equation model demonstrated that SR plays a vital role in leaf N and P stoichiometry, and SR has direct effects on leaf N and P stoichiometry through a physiological process (path coefficient =-0.293 and -0.343, respectively). In addition, the high SR level lowered the level of precipitation (path coefficient =-0.615) and temperature (path coefficient =-0.047), then changed the soil organic carbon, soil nitrogen and phosphorus content. Furthermore, precipitation, temperature, soil organic carbon, soil nitrogen and phosphorus also regulated leaf N and P stoichiometry, which caused the SR to have indirect effects on leaf N and P stoichiometry (path coefficient =-0.072 and -0.053, respectively). As a consequence, we highlighted that SR regulates leaf N and P stoichiometry across alpine meadows of the Tibetan Plateau, and the results provide guidance on grassland management.

Biomass pyrolysis is a promising method and often used to reduce hexavalent chromium Cr(VI) residue. However, the pyrolysis reduction mechanisms of Cr(VI) remain unclear, particularly regarding which tar compositions help the Cr(VI) reduction. In the present study, on-line MS analysis suggests that yields of CO and CH4 from biomass pyrolysis can principally represent the rate of Cr(VI) reduction. FT-ICR MS results indicate that high-molecular-weight compounds in tar (m/z > 350) located in the lignin/CRAM-like structure region or saturated (H/C = 0.7–1.5) and oxidized (oxygen number >6) compounds preferentially crack by catalysis of Cr(VI) to produce CO via decarbonylation reaction, further promoting the reduction of Cr(VI). Pyrolysis material with low stability (low aromaticity) can release more reducing gases and more easily cracks tar to promote Cr(VI) reduction. Lastly, chromite slag from a polluted site was successfully remediated by pyrolysis of a hydrochar sample. An extremely low leaching Cr concentration from remediated chromium slag can be obtained due to the carbon layer coating on Cr element. This study provides a novel perspective on the pyrolysis remediation mechanism of Cr(VI) and is highly significant for developing thermal remediation techniques for polluted sites.

Due to breakthroughs in the Lower Silurian Longmaxi Formation in the Sichuan Basin and multiple strata around the basin, the northern part of Guizhou adjacent to the Sichuan Basin has become a key area for shale gas exploration. Compared with the Longmaxi Formation, the Niutitang Formation displays greater TOC (total organic carbon) content, depositional thickness and distribution area, but the details remain undetermined. In the study area, the Lower Cambrian Niutitang Formation typically has high TOC content, maturity and brittle mineral content. The study area has experienced multiple periods of tectonic movement, which have great influence on the fracture and pore characteristics. The fractures are mainly structural fractures and have obvious zoning. The primary types of pores are intraparticle pores, organic matter pores, and interparticle pores. Further, macropores and mesopores less than 50 nm contribute most of the pore volume, while pores less than 2 nm contribute most of the specific surface area. Many factors affect the pore-fracture system, such as tectonism, TOC content, mineral composition, and sedimentary environment. Tectonic movements produce fractures based on the changing stress field, but the degree of fracture development does not agree well with the degree of pore development. The TOC content has good positive correlations with the development of fractures and micropores, especially for nanoporosity, while clay minerals show a negative correlation with the development of fractures but a strong positive correlation with the growth of micropores. Quartz displays a positive correlation with the development of fractures but no good correlation with pore development. Finally, the lithofacies, lithologies and mineral compositions under the control of sedimentary environments are internal factors that can impact the development of pore-fracture systems.

Shales are widely developed in the strata of the Carboniferous-Permian coal measures in the Qinshui Basin, and these shales have great potential for shale gas exploration. In this paper, the shales of the Taiyuan Formation in the eastern Qinshui Basin are studied. The shales of the Taiyuan Formation in the study area are investigated through field investigation, organic geochemical testing, X-ray diffraction, scanning electron microscopy, high pressure mercury injection, low temperature liquid nitrogen adsorption and PetroMod simulation and through other tests to study the reservoir characteristics, such as organic geochemistry, mineralogy, petrology, pore permeability, and gas burial history. The results show that the shales of the Taiyuan Formation are well developed over the whole area with a thickness of more than 60 m. The average organic matter content is 2.95%, and the kerogen type is type III. The shale maturity (average value is 2.45%) corresponds to the stage of high maturity evolution, indicating that a large amount of shale gas has been generated in this area. A high content of quartz and clay minerals indicates a high fracturability. The nanopores in the shale reservoir are well developed at pore sizes between 2˜10 nm and greater than 1000 nm; however, the pores at the other pore sizes are poorly developed, resulting in weak pore connectivity in the reservoir. According to the results of the PetroMod simulation, the shale of the Taiyuan Formation has undergone two subsidence and two uplift processes. The Yanshanian magmatic intrusion is the key factor for the rapid increase in gas production. In addition, the geological structure of the area is relatively simple, and the burial history and caprock thickness are also the main controlling factors of gas generation and preservation. The shale-sandstone-shale combination and shale-coal-shale combination are the main models of shale gas preservation. This comprehensive study suggests that the shale gas of the Taiyuan Formation in the eastern Qinshui Bain has good potential for exploration and development.

The utilization of biomass pyrolysis volatile-derived water-dissolved organic matter (WOM, often called wood vinegar) determines sustainable recycling of biomass. Further, pyrolysis temperature significantly controls the cracking of biomass components, resulting in various molecular compositions and biological responses of WOM. Although it has been widely used in the agriculture, the relationship between molecular compositions and biological responses affected by heating temperature is still unclear. Here, it was observed that the WOM concentration increased with increasing temperatures and the pyrolysis of 1 g biomass can generate ~ WOM with 36.24 mg C. Moreover, with increasing pyrolysis temperatures, the generated WOM consisted of more phenols but fewer alcohols, furans, acids, and ketones, and demonstrated characteristics of higher aromaticity and lower m/z molecular weight. Due to the enhanced polarity, high temperatures promoted the solubility of WOM. Germination tests show that low pyrolysis temperatures-derived WOM ( 400 °C) with small-molecular-weight and high oxygen-containing (high O/Cwa) inhibited growth. These results suggest that WOM can be separately collected at different pyrolysis temperatures to achieve sustainable recycling of pyrolysis volatile.

With the aim to develop optimized biochar with minimal contaminants, it is important significance to broaden the understanding of biochar. Here, we disclose for the first time, a highly toxic substance (metal cyanide, MCN, such as KCN or NaCN) in biochar. The cyanide ion (CN−) content in biochar can be up to 85,870 mg/kg, which is determined by the inherent metal content and type in the biomass with K and Na increasing and Ca, Mg and Fe decreasing its formation. Density functional theory (DFT) analysis shows that unstable alkali oxygen-containing metal salts such as K2CO3 can induce an N rearrangement reaction to produce for example, KOCN. The strong reducing character of the carbon matrix further converts KOCN to KCN, thus resulting biochar with high risk. However, the stable Mg, Ca and Fe salts in biomass cannot induce an N rearrangement reaction due to their high binding energies. We therefore propose that high valent metal chloride salts such as FeCl3 and MgCl2 could be used to inhibit the production of cyanide via metal interactive reaction. These findings open a new point of view on the potential risk of biochar and provide a mitigation solution for biochar’s sustainable application.

Brevicaudosaurus jiyangshanensis, gen. et sp. nov., a new nothosauroid, is established on the basis of two nearly complete skeletons from the Middle Triassic (Ladinian) of China. Its skull is diagnostic in having a wide and constricted snout, a large supratemporal fossa slightly larger than the orbit, and a parietal table strongly constricted posteriorly. Postcranial specializations include a short trunk with 14 dorsal vertebrae, a short tail shorter than the skull-neck region in length, a stout anterolateral process on the clavicle, an extremely massive and broadened mid-diaphysis of the humerus, a strongly expanded proximal head of the ulna, seven ossified carpals, and a phalangeal reduction in the pes. In addition, the strongly pachyostotic postcranial skeleton may indicate a slow mode of swimming underwater and a benthic carnivorous feeding habit for B. jiyangshanensis. Phylogenetically, it is the sister taxon of the Nothosaurus-Lariosaurus clade within Nothosauroidea. The discovery of this new nothosauroid not only contributes to local faunal diversity and expands the known range of sauropterygian life styles during the late Middle Triassic, but also provides a chance to test the phylogenetic relationships of the Eosauropterygia hypothesized by previous studies. http://zoobank.org/urn:lsid:zoobank.org:pub:026D8680-CC71-47BD-A681-F5B6F140B84

Future climate warming is expected to have a significant effect on the operation of Earth and Ecological systems. A key concern in the future is water resource availability. In regions such as the Tibet Plateau (TP) lakes and glaciers appear to be highly sensitive to climate forcing and variations in the size and extent of these system will have profound socio-economic and environmental consequences in South and Central Asia. Although the variety of glaciers and lake son the TP is a heavily researched and discussed topic the interaction between glaciers/lakes and climate change has not be thoroughly investigated. Here we present, through a review of existing studies and original remote sensing analysis, a reconstruction of changes in the spatial coverage of glaciers and lakes on the TP from 1990 to 2015 along with an analysis of climate data for the same period. The results revealed that these systems responded to changes in both temperature and precipitation but the nature of this response, and the controlling factor, was spatially diverse. During this interval the total number of lakes increased from 868 to 1207, thus a large number of new lakes (n = 339) formed. The total water surface area of the lakes increase from 38,823.3 km(2) in 1990 to 48,793.0 km(2) in 2015, at a rate of 383.5 km(2) yr(-1). Over this period intensive glacial shrinkage occurred, primarily driven by increasing average temperature, except in the Karakoram Mountains where a slight increase in glacier extent was explained by low and stable temperatures along with increasing precipitation. The expansion of lakes in the central and northeastern TP can, therefore, be explained by a trend of increasing precipitation and the accelerated melting of glaciers associated with rising temperatures, both of which contributed to the enhanced total basin runoff. The shrinkage of lake areas along the Himalayan Mountains is accounted for by low precipitation coupled with high evaporation and limited basin space. The lakes within the Qaidam Basin express a complex pattern of response in association with fluctuating precipitation and strong evaporation. The pattern of shrinking glaciers and expanding lakes indicate that water cycle processes on the TP have been accelerating during the past 25 years. Under current climates, and future climate change, the shrinkage of glaciers and the enlargement of lakes may be expected to continue to accelerate until a "tipping point" is reached when the meltwater of declining glaciers can no longer sustain the enhanced lake levels. Such a scenario would have severe socio-economic and ecological consequences for this region making the continued study of water-cycle activity across the TP an urgent priority.

For the capture of CO2 from flue gas and decarbonization of natural gas streams, an ideal adsorbent should have a high selectivity for CO2 over N2 and CH4. In this work, through adjusting the proportions of extra-framework K+ and Cs+ cations and varying the Si/Al ratios of the zeolite ZK-5, the small “molecular gate” adsorbent ZK-5-n-K has been prepared. An increase in the number of K+ cations prevents the ingress of the larger molecules CH4 and N2, while allowing entry of the smaller CO2; the net result is that CO2 capture from CH4 or N2 is achieved with unusually high selectivity, of the order of 1 × 105. Grand canonical Monte Carlo simulations show that the extra-framework K+ and Cs+ cations are positioned at different locations in the ZK-5; K+ locates near the 8-ring window, whereas Cs+ resides in the interior regions. The separation performances of 12 different K+- and Cs+-doped ZK-5 structures (with four different Si/Al ratios of 3.17, 3.36, 3.46, and 3.57) have been investigated. Transient breakthrough simulations have been used to quantify the CO2 capture performances in four sets of separations: 30%/70%, 5%/95%, and 2%/98% CO2/CH4 mixtures at a total pressure of 1 MPa, and a 15%/85% CO2/N2 mixture at a total pressure of 100 kPa. In all cases, the selectivities were sufficiently high to ensure that the separation performance was primarily governed by the CO2 uptake capacity. The overall conclusion to be drawn from this work is that ZK-5 is a suitable adsorbent for the decarbonization of natural gas.

Ethnopharmacological relevance Leaf of Alstonia scholaris (L.) R. Br. (Apocynaceae), a wide used ethic-medicine in many Asia and Africa counties, has also been recorded as the common traditional Chinese medicine for treatment of illnesses in respiratory system by Dai people. Aim of the study To provide experimental data of clinical adaption of total indole alkaloids (TA) from leaf of A. scholaris for treating post-infectious cough in phase II clinical trial. Materials and methods To model post-infectious cough, all animals except control group were instilled intra-tracheal with lipopolysaccharide (LPS) (80 μg/50 µL/mouse), followed by subsequent exposure to cigarette smoke (CS) for 30 min per day for a total of 30 days. Mice were orally given TA at dose of 10, 25, 50 mg/kg, and four main alkaloids (Sch: scholaricine, Epi: 19-epischolaricine, Val: vallesamine, Pic: picrinine) once daily. Cellular infiltration was assessed in the broncho-alveolar lavage fluid (BALF). Expression of interleukin-6 (IL-6) and C-reactive protein (CRP) in the serum was determined, the superoxide dismutase (SOD) activity as well as malondialdehyde (MDA) content in the serum and homogenate were examined. Finally, histopathological examination in the lungs was assessed by H. E. staining. Results After administration of TA and four major alkaloids respectively, the symptoms of cough in mice were obviously attenuated. Total white blood cells (WBC) and neutrophils (NEU) amounts in BALF were reduced obviously and the pathological damage of lung was also attenuated. There was also significant reduction in IL-6, CRP, MDA and a marked improvement in SOD. Conclusions The efficacy of indole alkaloids against post-infectious cough (PIC) was shown in the down-regulation of inflammatory cells, cytokines, and the balance of antioxidants. What's more, the pharmacological effects of TA were better than single indole alkaloid, which might be related to the synergic effect of four major alkaloids., Graphical abstract fx1

Nano-MgO carbon composites (MCs) demonstrated great potential in phosphate immobilization to resolve phosphorus reuse and eutrophication problems, but the mechanisms of phosphate immobilization are still unclear. In this study, MCs were fabricated via CO2 activation of hydrochar materials, and the activation mechanisms were first investigated through analysis of pyrolysis gases and porosity. The results indicate that MgO particles (pyrolysis products of MgCl2) catalyzed the consumption of the carbon matrix but blocked the development of carbon matrix pores. Furthermore, phosphate immobilization by MCs increased with the increase of MgO loading content. More importantly, XPS and TEM-EDX profiles demonstrate that solution and surface precipitations regulated phosphate immobilization by MCs. Solution precipitation mainly contributed to a MgHPO4 precipitate, while in surface precipitation the carbon matrix served as a bridge for H2PO4− transmission to MgO particles to produce a Mg(H2PO4)2 precipitate. Also, with the decrease of carbon content, surface precipitation became dominant due to the shortened distance. This contributes to the improvement of phosphate immobilization by MCs, which was found to be even higher than pure MgO. Compared with N2 activated MC, CO2 activated MC showed much higher phosphate immobilization potential attributed to the surface precipitation reaction. The results of this study will guide the development of more efficient MC materials for phosphate recovery.

The Si/Al ratio in zeolite will be altered and the porous structure will be diluted by the traditional silica/aluminum-based binder in the granulation process. Here, a novel zeolite/activated carbon monolith (Z/AC) was prepared by adding coal-tar pitch in silicalite-1 (Si/Al greater than 400), where the pure silica characteristic is well maintained and the coal-tar pitch transforms to porous carbon with a uniform pore structure, in comparison, the aluminum-based bonded silicalite-1 pellet (ABSP) shows a much lower Si/Al ratio of 4.1. As a result, the Z/AC-600 monolith demonstrates a competitive CH4 adsorption capacity of 23.45 cm3/g, outperforming silicalite-1 powder and ABSP pellet, and the CH4/N2 selectivity is higher than 4.0 at 298 K and 1 bar. The gas-mixture breakthrough experiments demonstrated that Z/AC-600 can effectively separate the CH4/N2 mixtures (20/80 and 50/50; v/v) with dynamic selectivity of 4.2 and 3.9, respectively. Pressure swing adsorption (PSA) simulations further indicate that, by one step enrichment, pristine 50% methane can be enriched to 80% with a recovery of 85%.

The formed Fe oxides (minerals) in the magnetic biochar production process can facilitate its recovery and carbon retention rate. However, the influence of Fe oxides on pyrolysis volatile-derived water-soluble organic matter (PVWSOM, also called wood vinegar) has been largely overlooked. Results demonstrated that in-situ formed Fe oxides (α-Fe2O3 and Fe3O4) could obviously inhibit biomass cracking and accordingly reduce PVWSOM emissions, as indicated by decreased PVWSOM concentrations from 28.7 to 6.8 mg C/g biomass. FT-ICR MS results further indicated that Fe oxides suppressed the formation of large-molecular-weight PVWSOM compounds with high degree of unsaturation (DBE value > 5) and oxygen content (oxygen number > 5), leading to lower polarity and aromaticity. Therefore, the changes in PVWSOM molecular structures caused by Fe oxides relieved its toxicity on wheat seed growth, and reduced negative impact on soil microbial diversity and promoted soil bacterial Proteobacteria and Acidobacteria. These results indicate that molecular structures of PVWSOM from biomass pyrolysis also can be changed by Fe oxides to affect its application.

Organometal trihalide perovskite solar cells (PSCs) based on multiple-site alloyed perovskite currently attract a surge of research interests owing to their extreme high solar-to-electric power conversion efficiency (PCE). Additionally, perovskite single crystals, proven to possess lower defect density, are highly anticipated to realize the full potential of perovskite materials. Herein, we for the first time proposes a facile and operable cooling-induced crystallization method to fabricate dual-site alloyed FA x MA 1−x Pb(I x Br 1−x ) 3 single microcrystals with tunable bandgaps, which will later be employed as encouraging precursors to form high quality perovskite films with extended grain sizes and less grain boundaries. The corresponding solar cells showcase advanced charge transport and retarded recombination, leading to satisfying photovoltaic performance and heartening device stability (a champion PCE of 18.3% and a satisfying maintenance of ~83% initial PCE after 2000 h aging without encapsulation), indicating a promising protocol of fabricating miscellaneous single microcrystal perovskite precursors for highly efficient PSCs.

ABX3-type organic-inorganic hybrid halide perovskite materials have been recognized as promising candidates for optoelectronic applications. However, poor stability of organic-inorganic hybrid perovskite hinders their forward long-term utilization and hence an effective strategy is needed to replace the organic part with an inorganic cation. Herein, all inorganic CsPbI3 nanowires with a diameter of 50–100 nm are synthesized on fluorine-doped tin oxide glass via a simple solution-dipping process, which are further transformed into CsPbBr3 nanowires through a solution-phase halide exchange method. A phase change from non-perovskite to perovskite structure is observed during the ion substitution process of I− by Br−, which is elaborated by X-ray diffraction, absorption and photoluminescence spectra. We for the first time apply the as-formed CsPbI3 and CsPbBr3 nanowires into perovskite solar cells, yielding power conversion efficiency of 0.11% and 1.21%, respectively. The inorganic CsPbBr3 nanowire solar cell shows impressive stability which still remains 99% of the initial power conversion efficiency even after 5500 h aging.

A novel Al(III)-4-tert-butylpyridine (TBP) gel electrolyte is successfully achieved by a simple and facile in situ gelation method and applied as quasi-solid-state electrolyte for dye-sensitized solar cells (DSSCs). Through directly adding Al3+ into the TBP solution, the induced hydrolysis of Al3+ and the coordination interaction between Al3+ and TBP facilitates the formation of metal-organic gels(MOGs), in which such bi-functional TBP molecules will act as both gelators and active additives to tailor the performance of electrolytes. In addition, the gel electrolytes can largely preserve the properties of liquid electrolyte and penetrate well into the TiO2 photoanode film. Both Al3+ and TBP in the gel electrolytes affect the performance of cells. The Jsc of gel electrolytes decrease with the increasing concentration of gelators due to the enhanced strength and viscosity of the gel electrolytes, while the competition between Al3+ and TBP causes conduction band edge shift and electron recombination, leading to a variation of Voc. Herein, by tuning the molar ratio of Al3+/TBP, an impressive conversion efficiency of 8.25% is obtained, indicating a promising protocol of preparing MOGs not only to achieve high performance in solar cells, but also opens up extended scopes in other energy-related fields such as catalysis.

Cesium lead iodide perovskite (CsPbI3) has been proposed as an efficient alternative to modify the instability of methylammonium lead iodide (MAPbI3) under thermal and humidity stress. However, three-dimensional (3D) cesium lead iodide forms an undesirable non-perovskite structure with a wide bandgap at ambient atmosphere. Herein, dimension engineering is employed by introducing a bulky ammonium cation to form stable 2D cesium lead iodide perovskite BA2CsPb2I7 (BA = CH3(CH2)3NH3), which not only exhibits prominent optoelectronic properties, but also possesses superior structural and compositional stability to 3D CsPbI3 and MAPbI3 under the pressure of heat and humidity. The current 2D BA2CsPb2I7 shows excellent stability after exposure to 30% relative humidity for 30 days or upon heating at 85 °C for 3 days. In addition, the corresponding BA2CsPb2I7 based planar perovskite solar cells retain 92% of the initial power conversion efficiency (PCE) after aging for over 30 days without any encapsulation, demonstrating the up-scalability of 2D perovskite compounds as stable and efficient light-absorbing materials for perovskite solar cells and other optoelectronic applications.

Nowadays, obtaining a thin and large-area perovskite single-crystal (SC) is still challenging. Herein, we report a novel strategy to prepare a laminar MAPbBr3 SC with a controllable thickness of 16 μm and a size of 6 × 8 mm. Additionally, the SC solar cell achieves an intriguing efficiency of 7.11% with an impressive stability, maintaining 93% initial PCE after aging for 1000 h.

Halide perovskite single crystal of cubic HC(NH2)2PbI3 (FAPbI3) having excellent optoelectronic properties, such as narrow bandgap, large absorption coefficient and superior thermal stability has caught a surge of attention as a promising material for production of high-performance optoelectronic devices. However, at room temperature, the self-transformation of cubic FAPbI3 perovskite phase to non-perovskite phase leaves a critical roadblock to its practical viability. Herein, a simple alloying strategy by mixing methylammonium with formamidinium is developed to stabilize the FAPbI3 perovskite phase, hence achieving a highly stable mixed cation MA0.45FA0.55PbI3 perovskite single crystal over a span of 14 months. The MA0.45FA0.55PbI3 single crystal exhibits exceptional optoelectronic properties like high carrier mobility of 271 ± 60 cm2 s−1 V−1 and long diffusion length up to 254 μm, which are twice the values for sole MAPbI3 or FAPbI3 crystals. In addition, the photodetector based on MA0.45FA0.55PbI3 single crystal exhibits low detection limit of about 1 nW cm−2, high ON–OFF ratio of ∼1000, short response time of less than 200 μs, and impressive stability under aging in dark for 4 months or continuous photo-switching test for 1000 s.

Designing and exploring efficient and stable non-noble bifunctional catalysts by nanostructure modification and chemical composition tuning for water splitting is of critical importance for sustainable resources. Herein, pure phase nickel molybdenum phosphide (NiMoP2) nanowires on carbon cloth are successfully synthesized through a simple and highly reproducible in situ P/O exchange process. Such a NiMoP2 nanowire catalyst requires low overpotentials of 199 and 330 mV to obtain a high current density of 100 mA cm−2 towards the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, and is among the most active HER and OER electrocatalysts yet reported. The bifunctional NiMoP2 is used as both anode and cathode catalysts in a two-electrode water electrolysis configuration, which delivers a current density of 10 mA cm−2 under a potential of 1.67 V. Furthermore, the overall water-splitting of the bifunctional NiMoP2 nanowire catalyst is further driven by a dry battery with a nominal voltage of 1.5 V which exhibits excellent performance and durability in a strong alkaline electrolyte.

Citrus grandis (L.) Osbeck is a popular fruit cultivated around the world, and its peels are sometimes used for the treatment of cough, abdominal pain, and indigestion in China. However, the peel is discarded after fruit consumption in most cases, and its chemical constituents and biological activities have not been validated before. The present study focused on evaluation of the chemical and pharmacological profile of coumarins from peels of C. grandis against inflammation. The extracts and phytochemicals from peels of C. grandis were prepared, and anti-inflammatory activities were carried out in vivo and in vitro, including inhibiting xylene-induced ear edema and carrageenan-induced paw edema in mice and the production of inflammatory cytokines (interleukin 1β, prostaglandin 2, and tumor-necrosis factor α) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Results indicated that methanolic extract, ethyl acetate fraction, and four major coumarins (compounds 7, 8, 13, and 16) inhibited swelling induced by xylene and carrageenan, separately, in vivo. Furthermore, 18 coumarins inhibited inflammatory factor secretion in macrophages primed by LPS, in which compounds 4, 6, 7, 10, 17 showed the most pronounced change, which were comparable to dexamethasone. In summary, peel of C. grandis showed an anti-inflammatory effect and coumarin compounds were responsible for regulating inflammatory mediators and cytokines, which might provide a novel nutritional strategy for inflammatory diseases.

The performance of a zeolite is often related to its crystal morphology. In this work, the relationship between the crystal morphology of zeolite L and its gas separation performance was evaluated. Cylindrical-L (C-L: 3 × 2 μm), disk-shaped-L (D-L: 0.2 × 1.2 μm), and nanosized-L (N-L: 40 × 25 nm) were synthesized. Various characterization methods, including X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and N2 adsorption–desorption isotherms at 77 K (BET), were employed to obtain complementary information. Due to its small crystal size, the BET specific surface area (427.2 m2/g) and total pore volume (0.382 cm3/g) of N-L are significantly higher than those of D-L (339.6 m2/g and 0.116 cm3/g) and C-L (279.8 m2/g and 0.098 cm3/g). The CO2 adsorption capacity on N-L (70.7 cm3/g) increases 20.9% than that on C-L (58.5 cm3/g). The shorter channel paths in N-L permit faster diffusion and mass transfer than in C-L or D-L, as confirmed by kinetic experiments. Furthermore, breakthrough experiments indicate that N-L has great application potential for separating and capturing CO2 from power-plant flue gas, biogas, or landfill gas.

Water-soluble organic compounds derived from bio-oil (WOCB) are regarded as potential risk sources of sludge thermochemical treatment. This study showed that 10.35 mg of water-soluble organic carbon and 1.32 mg of water-soluble organic nitrogen were released per gram of sludge when the final temperature of thermochemical treatment was 600 °C. WOCB was mainly formed at 300–500 °C. Furthermore, FT-ICR MS results indicated that high temperatures promoted deamination reactions, and low molecular weight (LMW) compounds with low oxygen number polymerized into aromatic compounds with increasing temperature. Noteworthily, WOCB released at 20–600 °C showed strong phytotoxicity to wheat. LMW compounds with lignin/carboxylic rich alicyclic molecules (CRAM)-like structures derived from low temperatures (200–400 °C) induced this inhibitory effect, but lipids containing nitrogen and sulfur from high temperatures (400–600 °C) can act as nutrients to promote wheat growth. This study provides theoretical support for the risk control and benefits assessments of sludge thermochemical treatment.

Down-sizing zeolite crystals to achieve enhanced gas adsorption and separation performances is largely unexplored and underestimated. Nano-sized zeolite can expose more adsorption sites and shorten the diffusion path compared to micro-sized counterparts; however, the synthesis of Nano-sized zeolite is still very challenging. Herein, nano-sized ZK-5 is successfully prepared for the first time via the regulation effects of β-cyclodextrin. The crystal size of ZK-5 can be reduced from micron-size (3 μm) to nano-size (50–100 nm), thus the nano-ZK-5 exhibits a superior surface area (370 cm2 g−1) and pore volume (0.22 cm3 g−1) than the micron-sized sample (149 cm2 g−1 and 0.07 cm3 g−1), which may be due to the reduction in crystal size, which in turn leads to more micropores being detected. The CH4 adsorption capacity on nano-sized sample increased by 64% compared to that of micron-sized ZK-5. Notably, the record-high CH4 adsorption capacity of 1.34 mmol g−1 at 298 K is obtained on the nano-ZK-5 among the commercial zeolites. The equilibrium adsorption selectivity of CH4/N2 (20/80, v/v) mixed gas is as high as 4.2 (IAST method) at 1 bar and 298 K. The adsorption kinetics experiments have illustrated the boosted gas diffusion and mass transfer rate. Furthermore, the breakthrough experiments have confirmed the practical feasibility of separating various gas-mixtures, such as CH4/N2 (20/80, v/v).

Liquid phase produced by the subcritical hydrothermal liquefaction (HTL) of livestock manure is extensively used in agronomic and environmental applications, but the potential risks caused by inherent pollutants (e.g., roxarsone, ROX) of the livestock manure have not been considered. This study shows that less toxic ROX is completely converted into highly toxic As(III) and As(V) in the HTL reaction with temperature more than 240 °C. Moreover, more than 81.5% of As is distributed in the liquid phase generated by the livestock manure HTL reaction. Notably, the hydrothermal products of livestock manure facilitate the conversion of As(V) to As(III). The resulting hydrochar and aldehydes act as electron donors for As(V) reduction, thus resulting in the formation of As(III). Furthermore, the dissociated As promotes the depolymerization and deoxygenation of the macromolecular compounds to produce more small oxygen-containing compounds such as aldehydes, further boosting the As(V) reduction to As(III). These results indicate that the liquid phase of the livestock manure has potential risks in applications as a fertilizer. Such findings have substantial implications in biomass utilization and redox reactions of envirotechnical and biogeochemical relevance.

Two-dimensional (2D) ZnO nanosheet arrays were prepared via vanadium (V)-doping assisted hydrothermal method, and then the nanosheet was successfully converted to a nanorod-on-nanosheet ZnO hierarchical structure by treating with Na2S solution and subsequent hydrothermal reaction. Hierarchical films with different nanorod growth time (1–8 h) were prepared and their photovoltaic properties were also investigated after electrodeposition of CdSe quantum dots. For the hierarchical nanorod-on-nanosheet ZnO films, increasing the ZnO nanorod growth time can enormously enlarge the length of branched nanorods and light-scattering ability, resulting in better light-harvesting efficiency and higher photo-generated electron concentration, which leads to higher short-circuit current density ( J sc) and open-circuit voltage ( V oc). However, further increasing nanorod growth time to 8 h leads to the over-dense coverage of nanorods, which is harmful for light-harvesting efficiency and leads to severe electron recombination, eventually diminishes the power conversion efficiency (PCE). With the optimized nanorod modification and Cu2S counter electrode, the PCE reaches a maximum value of 4.26%, which to the best of our knowledge, is among the highest PCE record for CdSe sensitized solar cells based on ZnO photoanodes.

Soil respiration (Rs) is the second largest carbon flux next to GPP between the terrestrial ecosystem (the largest organic carbon pool) and the atmosphere at a global scale. Given their critical role in the global carbon cycle, Rs measurement and modeling issues have been well reviewed in previous studies. In this paper, we briefly review advances in soil organic carbon (SOC) decomposition processes and the factors affecting Rs. We examine the spatial and temporal distribution of Rs measurements available in the literature and found that most of the measurements were conducted in North America, Europe, and East Asia, with major gaps in Africa, East Europe, North Asia, Southeast Asia, and Australia, especially in dry ecosystems. We discuss the potential problems of measuring Rs on slope soils and propose using obliquely-cut soil collars to solve the existing problems. We synthesize previous estimates of global Rs flux and find that the estimates ranged from 50 PgC/yr to 98 PgC/yr and the error associated with each estimation was also high (4 PgC/yr to 33.2 PgC/yr). Using a newly integrated database of Rs measurements and the MODIS vegetation map, we estimate that the global annual Rs flux is 94.3 PgC/yr with an estimation error of 17.9 PgC/yr at a 95% confidence level. The uneven distribution of Rs measurements limits our ability to improve the accuracy of estimation. Based on the global estimation of Rs flux, we found that Rs is highly correlated with GPP and NPP at the biome level, highlighting the role of Rs in global carbon budgets.

The power conversion efficiency (PCE) of a planar perovskite solar cell (PSC) is closely associated with the conduction band energy, conductivity and coverage of the compact layer. However, as the most widely used compact layer material, TiO2 has unfavorable electrical properties such as low electron mobility and conductivity; as a result, modifications such as elemental doping are of paramount importance. In this study, Nb-doped TiO2 with improved carrier density and conductivity was prepared via a facile one-pot solution process and applied successfully as a high-quality compact layer for planar PSCs. A positive shift in the flat-band potential (Vfb) and increased conductivity after Nb doping efficiently facilitated photogenerated electron injection and charge extraction from the perovskite film to the 2% Nb-doped TiO2 compact layer, contributing to impressive advances in photovoltaic performance compared with pristine TiO2. Ultimately, a PSC assembled using optimized 2% Nb-doped TiO2 and CH3NH3PbI3 yielded a power conversion efficiency of up to 16.3%.

In situ fabrication of an ordered macroporous perovskite semitransparent film on a FTO glass was successfully achieved via sacrificial polystyrene (PS) microsphere templates. The average visible transmittance of active layer from 20% to 45% can be tuned by simply changing the PS diameters and precursor concentrations. The ordered macroporous perovskite films show enhanced crystallinity and reduced recombination defects, superior to the island perovskite film. Transient photovoltage, transient photocurrent and electrochemical impedance spectra measurements proved the advanced charge transport and reduced recombination by importing macroporous structures. Herein, the optimized 400 nm MP CH3NH3PbI3 perovskite film with a high AL AVT of 36.5% achieved an impressive PCE of 11.7% compared to the island-like perovskite film (champion PCE = 5.6%), presenting a great potential for building integrated photovoltaic applications.

The fabrication of hierarchically structured photoanode materials is believed to be an effective way to obtain efficient dye-sensitized solar cells (DSSCs). In this paper, hierarchical TiO2–B/anatase core/shell heterojunction nanowire arrays on a titanium plate substrate are synthesized and used as novel photoanode materials for DSSCs. By using H2Ti3O7 nanowire arrays as the precursor template, anatase nanoparticle coated TiO2–B nanowire arrays are prepared via a hydrothermal reaction followed by a calcination process. Photoelectric measurements reveal that the anatase nanoparticle shell makes the pristine TiO2–B nanowire rougher for more dye adsorption and effective light scattering, which can enhance the light harvesting ability and thus the photocurrent density of the photoanode largely. Moreover, the dynamic electron transport and recombination study via electrochemical impedance spectroscopy (EIS) and intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS) measurements reveal that the TiO2–B/anatase composite photoanode based cell has a faster electron transport and higher electron collection efficiency than a TiO2–B based cell. As a consequence, the photoelectric conversion efficiency of the hierarchical composite photoanode was greatly enhanced to 4.88%, which is among the highest reported value for TiO2 nanowire array photoanodes grown on titanium plate substrate.

Nanostructural modification and chemical composition tuning are paramount to developing effective non-noble hydrogen evolution reaction (HER) catalysts for water splitting. Herein, we report a novel excellent porous molybdenum tungsten phosphide (Mo–W–P) hybrid nanosheet catalyst for hydrogen evolution, which is synthesized via in situ phosphidation of molybdenum tungsten oxide (Mo–W–O) hybrid nanowires grown on carbon cloth. The three-dimensional (3D) hierarchical hybrid electrocatalyst exhibits impressively high electrocatalytic activity with a low overpotential of 138 mV required to achieve a high current density of 100 mA cm−2 and a small Tafel slope of 52 mV dec−1 in 0.5 M H2SO4, which are significantly higher than those of single MoP nanosheets and WP2 nanorods. Such an outstanding performance of the Mo–W–P hybrid electrocatalyst is attributed to the 3D conductive scaffolds, porous nanosheet structure, and strong synergistic effect of W and Mo atoms in Mo–W–P, making it a very promising catalyst for hydrogen production. Our findings demonstrate that careful control over the morphology and composition of the electrocatalyst can achieve highly efficient hybrid electrocatalysts.

Solar water splitting by photoelectrochemical (PEC) cells is emerged as a promising route for H2 production. However, thus far no single component material can fulfill all the requirements for high efficiency PEC behavior, especially for the photoanode which conducts the water oxidation, while constructing a composite photoelectrode can result in improved performance. Herein, a simple wet-chemical treatment method is introduced to in situ fabricate ZnFe2O4 onto conductive Al:ZnO nanowire arrays for solar-driven water splitting. Benefiting from the high conductivity of Al:ZnO and the visible-spectrum absorption of ZnFe2O4, such a host–guest structure has finally led to an excellent photoelectrochemical performance with low onset potential (VRHE = 0.38 V) and a photocurrent density of 1.72 mA cm−2 (VRHE = 1.23 V). Notably, the low onset potential gives this structure great potential for application in unassisted light-driven tandem-type PEC cells.

In this work, we have studied high-silica (Si/Al = 200) zeolite silicalite-1 pellets sorbent for the separation of methane and nitrogen in a pressure swing adsorption (PSA) process. The pellet samples have well maintained similar adsorption and separation performances of the zeolite powder samples. The adsorption kinetic parameters were determined by actual breakthrough experiments on the pellet samples. The effects of feed flow and cycle time on methane product purity and recovery have been investigated. The accuracy of the numerical simulation method has been verified by the experiment data. In order to optimize the coalbed methane enrichment performance, the two-bed six-step PSA cycle was applied in the simulation. The simulation results revealed that 45% and 57% methane concentration could be achieved from 20% and 30% methane feedings with a recovery above 80%.

Small-pore zeolites have been a research hotspot in the field of gas adsorption and separation. Despite the high adsorption levels of these zeolites, the slow adsorption and desorption rate as well as desorption hysteresis are detrimental to the industrial applications. In this work, nano/micro-scale (~500 nm) K-KFI zeolite crystals were synthesized via hydrothermal and ultrasound-assisted (US) methods. The US-K-KFI zeolites obtained were characterized by means of X-ray diffraction, scanning electron microscopy, and nitrogen adsorption-desorption isotherms at 77 K. The effect of the ultrasonic treatment time on zeolite formation was investigated. The results revealed that the ultrasonic time had a significant effect on the morphology of the K-KFI zeolite, and the particle size was reduced from 1.5 μm to 500 nm. Furthermore, the sample ultrasonically treated for 3 h and crystallized for 1 day (US-K-KFI-3h/1d) exhibited the same high level of crystallinity as the sample hydrothermally crystallized for 3 days without ultrasonic treatment (HT-K-KFI-0h/3d). Compared with large-crystal (3 μm) zeolite (HT-K-KFI-0h/3d) at a given pressure, nano/micro-scale (500 nm) zeolite (US-K-KFI-10h/1d) was characterized by a shorter adsorption equilibrium time and exhibited enhanced mass transfer due to its shorter diffusion path. Moreover, compared with that of HT-K-KFI-0h/3d, the adsorption capacity of US-K-KFI-10h/1d for CO2, CH4, N2, and O2 was 31%, 24%, 18%, and 26% higher, respectively, at room temperature (298 K) and 1 bar. The results of this work showed that the ultrasound-assisted method represents a rapid and controllable means of synthesizing nano/micro-scale zeolites.

According to the correspondence relationship between the base coefficients of fitting curves and the functional data, this paper proposed a method of outlier detection for functional data. The principle is to use MCD algorithm in multivariate data to detect the outliers of the base coefficients of fitting curves, and then correspond the detection result with the functional data to realize the process of outlier detection of functional data. Since the base coefficients of the functional data can express most of the information of the original functional data, the outlier detection of the base coefficients of the functional data with MCD algorithm can take into account both the overall anomaly and the local anomaly of the functional data. In the simulation part, this method is applied to the outlier detection of functional data of air quality, and compared with the outlier detection method based on statistical depth. The results show that the proposed method is more appropriate for detecting outliers in air quality data.

The emission geometries, e.g. the emission region height, the beam shape, and radius-to-frequency mapping, are important predictions of pulsar radiation model. The multi-band radio observations carry such valuable information. In this paper, we study two bright pulsars, (PSRs B0329+54 and B1642-03) and observe them in high frequency (2.5 GHz, 5 GHz, and 8 GHz). The newly acquired data together with historical archive provide an atlas of multi-frequency profiles spanning from 100 MHz to 10 GHz. We study the frequency evolution of pulse profiles and the radiation regions with the these data. We firstly fit the pulse profiles with Gaussian functions to determine the phase of each component, and then calculate the radiation altitudes of different emission components and the radiation regions. We find that the inverse Compton scattering (ICS) model can reproduce the radiation geometry of these two pulsars. But for PSR B0329+54 the radiation can be generated in either annular gap (AG) or core gap (CG), while the radiation of PSR B1642-03 can only be generated in the CG. This difference is caused by the inclination angle and the impact angle of these two pulsars. The relation of beaming angle (the angle between the radiation direction and the magnetic axis) and the radiation altitudes versus frequency is also presented by modelling the beam-frequency evolution in the ICS model. The multi-band pulse profiles of these two pulsars can be described well by the ICS model combined with the CG and AG.

Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities and pulse width parameters of these pulsars are estimated. For eleven pulsars these are the first high-frequency observations and for a further four, our observations have a better signal-to-noise ratio than previous observations. For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed profiles. A comparison of 19 profiles with those at other frequencies shows that in nine cases the separation between the outmost leading and trailing components decreases with frequency, roughly in agreement with radius-to-frequency mapping, whereas in the other ten the separation is nearly constant. Different spectral indices of profile components lead to the variation of integrated pulse profile shapes with frequency. In seven pulsars with multi-component profiles, the spectral indices of the central components are steeper than those of the outer components. For the 12 pulsars with multi-component profiles in the high-frequency sample, we estimate the core width using gaussian fitting and discuss the width-period relationship., Comment: 33 pages, 49 figures, 5 Tables; accepted by ApJ

Quantifying forest carbon storage and its spatial distribution at regional scales is critical for the creation of greenhouse gases inventories, the evaluation of forest services and carbon-oriented forest management. The plot-based forest inventory (PBFI) and stand-based forest inventory (SBFI) collect extensive information on trees and stands respectively, and together, provide an opportunity to improve the regional estimates of forest carbon. In this study, we applied the SBFI to overcome the spatial extent limits of the PBFI in neighboring plots and improve the regional carbon estimation. We found that the forests in Sichuan Province reserved a total of 624.2 Tg C in biomass and featured a large spatial heterogeneity, with high values in natural forests and low values in plantations. We found that the solo use of PBFI derived a slightly higher (46.63 Mg C/ha) estimation on average compared with the integrated method (43.6 Mg C/ha). However, when considering the spatial distribution, the PBFI generated an overestimation of young forests located between 3000and 4000 m in elevation, and an underestimation in mature forests. The spatially explicit biomass carbon estimation could be helpful in guiding regional forest management and biodiversity conservation.

The valuation of ecosystem services is critical to understand the current status of ecosystems and to develop an effective planning strategy for ecosystem protection. This study aims to analyse the spatio-temporal changes in ecosystem services driven by land use changes from 1984 to 2013 in Dalian, China. The land use changes are characterized using remote sensing data and then ecosystem service values (ESVs) are assessed using the equivalent factor method, i.e., assigning value coefficients to different land use categories. The total ESV of Dalian reduced significantly by 44.3% from 1984 to 2013, primarily due to the reduction of forests, water and wetlands. Water and climate regulations are the two largest service functions, contributing about 43.6% of the total ESV on average. In addition, ESVs show a spatial variation in different administrative regions, with the central city area having the maximum decreasing rate. Further, ESV changes and distributions are found to have a strong link with city development policies. This study provides an enhanced understanding of the implications of urban policies on ecosystem services, which is essential for sustaining the provision of ecosystem services and achieving sustainable development goals.

Supernova 1987A is a core collapse supernova in the Large Magellanic Cloud, inside which the product is most likely a neutron star. Despite the most sensitive available detection instruments from radio to gamma-ray wavebands being exploited in the pass thirty years, there have not yet been any pulse signals detected. By considering the density of the medium plasma in the remnant of 1987A, we find that the plasma cut-off frequency is approximately 7 GHz, a value higher than the conventional observational waveband of radio pulsars. As derived, with the expansion of the supernova remnant, the radio signal will be detected in 2073 A.D. at 3 GHz.

PSR J1023+0038 is a known transitional pulsar, which switches between the accretion-powered X-ray pulsar state and the rotation-powered radio millisecond pulsar (MSP) state. Here, we study the conditions for its state transition by ascribing similar to GHz radio pulse emission to the plasma cutoff oscillation frequency at the magnetosphere, which depends on the plasma density or accretion rate. With the accretion X-ray luminosity declining fromhigh to low state (e.g., similar to 10(35) erg s(-1) to similar to 10(32) erg s(-1)), the magnetosphere boundary expands to the light cylinder, where the plasma density is low enough to permit the emission of radio waves at the several-GHz frequency band. Thus, for a sufficiently low accretion-rate state (similar to 1032 erg s(-1)), the radio emission at the several-GHz band is not blocked by the plasma, and the radio pulsar can be detected in the favored "observational windows," i.e., the L band (1-2 GHz), S band (2-4 GHz), and C band (4-8 GHz). Furthermore, to evaluate the penetration characteristics of the outgoing radio wave of low frequency, we calculate its skin depth, which is found to be a couple of centimeters for the low X-ray luminosity of 10(34)-10(32) erg s(-1), a scale that is much shorter than the light cylinder radius of about 100 km for MSPs.

Organometal trihalide perovskites have been attracting intense attention due to their enthralling optoelectric characteristics. Thus far, most applications focus on polycrystalline perovskite, which however, is overshadowed by single crystal perovskite with superior properties such as low trap density, high mobility, and long carrier diffusion length. In spite of the inherent advantages and significant optoelectronic applications in solar cells and photodetectors, the fabrication of large-area laminar perovskite single crystals is challenging. In this report, an ingenious space-limited inverse temperature crystallization method is first demonstrated to the in situ synthesis of 120 cm2 large-area CH3 NH3 PbBr3 crystal film on fluorine-doped tin oxide (FTO) glass. Such CH3 NH3 PbBr3 perovskite crystal film is successfully applied to narrowband photodetectors, which enables a broad linear response range of 10-4 -102 mW cm-2 , 3 dB cutoff frequency (f 3 dB ) of ≈110 kHz, and high narrow response under low bias -1 V.

The pulse profile of PSR B1133+16 is usually regarded as a conal-double structure. However, its multifrequency profiles cannot simply be fitted with two Gaussian functions, and a third component is always needed to fit the bridge region (between two peaks). This would introduce additional, redundant parameters. In this paper, through a comparison of five fitting functions (Gaussian, von Mises, hyperbolic secant, square hyperbolic secant, and Lorentz), it is found that the square hyperbolic secant function can best reproduce the profile, yielding an improved fit. Moreover, a symmetric 2D radiation beam function, instead of a simple 1D Gaussian function, is used to fit the profile. Each profile with either well-resolved or not-so-well-resolved peaks could be fitted adequately using this beam function, and the bridge emission between the two peaks does not need to be a new component. Adopting inclination and impact angles based on polarization measurements, the opening angle ({\theta}_{\mu}0) of the radiation beam in a certain frequency band is derived from beam-function fitting. The corresponding radiation altitudes are then calculated. Based on multi-frequency profiles, we also computed the Lorentz factors of the particles and their dispersion at those locations in both the curvature-radiation (CR) and inverse-Compton-scattering (ICS) models. We found that the Lorentz factors of the particles decrease rapidly as the radiation altitude increases. Besides, the radiation prefers to be generated in annular region rather than core region, and this needs further validation., Comment: 13 pages, 18 figures, ApJ, 816, 76