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The cooling capacity of a typical dilution refrigerator is mainly determined by the circulating flow of the He-3 in the system, which is usually realized by the external circulation pump. In order to increase the concentration of circulating He-3, the still often take the orifice structure to limit the influence of the superfluid helium film, and this structure will also have a certain impact on the flow rate of He-3. This paper summarizes the flow rate models of each part of the orifice structure, and establishes a model related to the influence of pumping speed and the diameter of orifice on the flow rate of circulating He-3. The relationship between pumping speed and flow rate is developed and the relation is divided into three phases for detailed analysis. It is found that the flow rate and the concentration of circulating He-3 increase first and then decrease with the increasing diameter of orifice at a certain pumping speed, and the possible reasons for this phenomenon are analyzed. The results indicate that there is an optimal orifice diameter at a determined pumping speed. [ABSTRACT FROM AUTHOR]

Background: Despite the efficacy of absolute ethanol (EtOH), its radiolucency introduces several risks in interventional therapy for treating vascular malformations. This study aims to develop a novel radiopaque ethanol injection (REI) to address this issue. Methods: Iopromide is mixed with ethanol to achieve radiopacity and improve the physicochemical properties of the solution. Overall, 82 male New Zealand white rabbits are selected for in vivo radiopacity testing, peripheral vein sclerosis [animals were divided into the following 5 groups (n = 6): negative control (NC, saline, 0.250 ml/kg), positive control (EtOH, 0.250 ml/kg), low-dose REI (L-D REI, 0.125 ml/kg), moderate-dose REI (M-D REI, 0.250 ml/kg), and high-dose REI (H-D REI 0.375 ml/kg)], pharmacokinetic analyses (the blood sample was harvested before injection, 5 min, 10 min, 20 min, 40 min, 1 h, 2 h, 4 h, and 8 h after injection in peripheral vein sclerosis experiment), peripheral artery embolization [animals were divided into the following 5 groups (n = 3): NC (saline, 0.250 ml/kg), positive control (EtOH, 0.250 ml/kg), L-D REI (0.125 ml/kg), M-D REI (0.250 ml/kg), and H-D REI (0.375 ml/kg)], kidney transcatheter arterial embolization [animals were divided into the following 4 groups (n = 3): positive control (EtOH, 0.250 ml/kg), L-D REI (0.125 ml/kg), M-D REI (0.250 ml/kg), and H-D REI (0.375 ml/kg); each healthy kidney was injected with saline as negative control], and biosafety evaluations [animals were divided into the following 5 groups (n = 3): NC (0.250 ml/kg), high-dose EtOH (0.375 ml/kg), L-D REI (0.125 ml/kg), M-D REI (0.250 ml/kg), and H-D REI (0.375 ml/kg)]. Then, a prospective cohort study involving 6 patients with peripheral venous malformations (VMs) is performed to explore the clinical safety and effectiveness of REI. From Jun 1, 2023 to August 31, 2023, 6 patients [age: (33.3 ± 17.2) years] with lingual VMs received sclerotherapy of REI and 2-month follow-up. Adverse events and serious adverse events were evaluated, whereas the efficacy of REI was determined by both the traceability of the REI under DSA throughout the entire injection and the therapeutic effect 2 months after a single injection. Results: The REI contains 81.4% ethanol (v/v) and 111.3 mg/ml iodine, which can be traced throughout the injection in the animals and patients. The REI also exerts a similar effect as EtOH on peripheral venous sclerosis, peripheral arterial embolization, and renal embolization. Furthermore, the REI can be metabolized at a similar rate compared to EtOH and Ultravist® and did not cause injury to the animals' heart, liver, spleen, lungs, kidneys and brain. No REI-related adverse effects have occurred during sclerotherapy of VMs, and 4/6 patients (66.7%) have achieved complete response at follow-up. Conclusion: In conclusion, REI is safe, exerts therapeutic effects, and compensates for the radiolucency of EtOH in treating VMs. Trial registration: The clinical trial was registered as No. ChiCTR2300071751 on May 24 2023. [ABSTRACT FROM AUTHOR]

Coal spontaneous combustion (CSC) is one of the main disasters in the process of coal mining. In this paper, the important role of high-latent heat phase change material CH3COONa·3H2O (SAT) in controlling CSC was studied and compared with common inhibitors (NaCl, CaCl2, ascorbic acid (VC)). The thermal performance characteristics of SAT were revealed by the C80 micromanometer, and the effects of different inhibitors on the thermal behavior of Shengli lignite were analyzed and compared. Furthermore, the gas–solid coaxial fixed bed measurement system was used in conjunction with the Pfeiffer online mass spectrometer, to design the natural temperature rise experiment of coal after the heating interruption in the same programmed temperature rise interval, investigating the effects of different inhibitors on the temperature and gas production in the process of coal oxidation. The results show that the heat absorption effect of SAT is more significant than common inhibitors, which not only improves the heat absorption rate of the samples but also increases the total heat absorption of the sample by 236.6 J·g−1 compared with the raw coal. In the programmed temperature rise experiment, the maximum temperature point of the SAT-inhibited coal sample is reduced by 15.5% compared with raw coal, the time to reach the maximum temperature point is delayed by 20.5%, and the SAT inhibitor effectively inhibits the production of CO and CO2 gases. The method described in this paper provides a new idea for the prevention and control of CSC. [ABSTRACT FROM AUTHOR]

Introduction: Neutrophils are important participants in the innate immune response. They rapidly and efficiently identify and clear infectious agents by expressing large numbers of membrane receptors. Upon tissue injury or pathogen invasion, neutrophils are the first immune cells to reach the site of injury and participate in the inflammatory response. Materials and methods: A thorough search on PubMed related to neutrophil death or clearance pathways was performed. Conclusion: Inflammatory response and tissue damage can be aggravated when neutrophils are not removed rapidly from the site of injury. Recent studies have shown that neutrophils can be cleared through a variety of pathways, including non-inflammatory and inflammatory death, as well as reverse migration. Non-inflammatory death pathways include apoptosis and autophagy. Inflammatory death pathways include necroptosis, pyroptosis and NETosis. This review highlights the basic properties of neutrophils and the impact of their clearance pathways on the inflammatory response. [ABSTRACT FROM AUTHOR]

Background: Low temperatures during flowering severely affect crop growth and yield. Methods: This experiment was conducted under potted conditions with LXD 4 and TJH as test materials and pre-sprayed with exogenous ABA at a concentration of 20 mg·L-1 at flowering stage, respectively and then with an average of 15℃ condition for 5 days. Result: The results showed that foliar spraying exogenous ABA effectively inhibited the increase of MDA content and relatively significantly improved the photosynthetic parameters such as Gs and Tr and alleviated the loss of yield factors caused by chilling stress. Compared with spraying water, spraying exogenous ABA can significantly increase the yield per pot of LXD 4 by 6.72~17.77% and TJH by 6.41~37.04% under low temperature conditions. In summary, foliar spraying exogenous ABA ameliorated the effects of chilling stress on the physiological characteristics of adzuki bean leaves and improved yield as a result of improved antioxidant defense mechanisms which impeded lipid peroxidation. Thus, we conclude that foliar spraying exogenous ABA could decelerate the damages caused by chilling stress to some extent. [ABSTRACT FROM AUTHOR]

The traditional RFID reader module relies on a discrete original design. This design integrates a microcontroller, high-frequency RFID reader IC and other multiple chips onto a PCB board, leading to bottlenecks in cost, power consumption, stability and reliability. To align with the trend towards high integration, miniaturization and low power consumption in RFID reader, this paper introduces a fully integrated RFID Reader SoC. The SoC employs the open-source Cortex-M0 core to integrate the RF transceiver, analog circuits, baseband protocol processing, memory and interface circuits into one chip. It's compatible with ISO/IEC 14443 A-type and B-type and ISO/IEC 15693 transmission protocols and rates. Manufactured using a 0.18 μ m process, the chip is compatible with multiple standards. The optimized design of the digital baseband control circuit results in a chip area of only 11.95 mm 2 offering clear advantages in both area and integration compared to similar work. [ABSTRACT FROM AUTHOR]

Simple Summary: In 2019, Late Devonian Xinhang forest was reported from Anhui Province, China. It represents the earliest forest in Asia and China, and was regarded as monospecific with numerous small trees of the lycopsid. Recently, we found some other plants from the forest and now erect a new fern-like plant named Xinhangia. It is small with height of tens of centimeters, and usually has two orders of branches in alternate and sometimes triseriate pattern. Spines densely occur on the main axes and primary branches. Its leaf-like organs are very simple and dichotomize into recurved tips. Fertile organs are similar to the "leaves" but terminated in elongate and paired sporangia. Both the "leaves" and fertile organs are alternately arranged on secondary branches. In anatomy, the primary xylem is "8"-shaped and is surrounded by secondary xylem. With simple characters, Xinhangia represents a morphologically primitive plant and is of uncertain affinity at class or order level. As a component of Xinhang forest, Xinhangia will help understand the growth habit and habitat of fern-like plants, as well as the structure and ecology of ancient forests in the future. Palaeozoic fern-like plants show great diversity in their morphology and/or anatomy. Within this group, a novel taxon, Xinhangia spina gen. et sp. nov., is now reported from the Upper Devonian (Famennian) Wutong Formation of Anhui Province, China. The primary and secondary branches are borne alternately and sometimes in a triseriate pattern. Spines are evident on the main axes or stems and on the primary branches. Vegetative ultimate appendages with recurved tips are alternate, usually dichotomous 1–2 times, and sometimes as an aphlebia located at the base of primary or secondary branches. Fertile ultimate appendages are alternate, usually dichotomous 1–2 times, and terminate in elongated and paired sporangia. The stele has a clepsydroid-like primary xylem with each end bearing a protoxylem strand. The secondary xylem surrounding the primary xylem illustrates uniseriate rays. With rare divisions in both the vegetative and fertile ultimate appendages, Xinhangia represents a morphologically primitive plant. It is of uncertain affinity at the class or order level. The stelar architecture suggests that the clepsydroid stele may not be emphasized in discussing the relationship among fern-like plants such as rhacophytaleans. [ABSTRACT FROM AUTHOR]

Tree lycopsids prospered in the Late Devonian and constituted a major part of the Late Paleozoic forest ecosystem that deeply impacted the Earth's climate. However, the fertile organs of these early tree lycopsids display low morphological disparity, which has hampered further knowledge about their ecological habit. Here, we report Omprelostrobus gigas gen. et sp. nov. from the Upper Devonian (Famennian) Wutong Formation at Changxing, Zhejiang, China. The collection includes aerial axes, strobili and associated roots. The strobili are the largest among coeval lycopsids to our knowledge, and are divided into proximal and distal portions by dimorphic sporophylls with differentiated laminae and probable strong photosynthetic capacity. The associated but not attached roots displaying multiple isotomous branches lack rootlets and typical rootlet scars. The varied strobili sizes of early tree lycopsids were relatively independent of their body plan, but the large strobili could suggest increased reproductive investment to overcome the disadvantages of the disturbed flooded habitat. A new species of Late Devonian fossil lycopsid with large strobili and differentiated sporophylls provides insight into reproductive investment of early tree lycopsids. [ABSTRACT FROM AUTHOR]

Arteriovenous malformation (AVM)-derived ophthalmic artery (OphA) branches are not common, and their management is very challenging. We evaluated the safety and efficacy of Trans OphA ethanol embolotherapy for these lesions. We retrospectively reviewed 26 patients with AVMs fed by OphA, who underwent transOphA embolization using ethanol from February, 2015 to December, 2019. Sixty-six transOphA embolotherapy procedures (range, 1–4 procedures; mean, 2.5 procedures) were performed. Devascularization degree, visual field, visual acuity, and quality-of-life outcomes were compared and analyzed at follow up (mean, 32.6 months; month range 10–60). Complications were recorded. Twenty-five of the 26 patients (96%) reported complete or > 90% AVM devascularization while one patient (4%) showed > 70% devascularization. Eleven patients (42%) presented with visual acuity impairments; among them, 6 had improvements while 4 were completely relieved. Eight patients (30.7%) presented visual field defects, 3 had improvements while 4 were completely relieved. Ten patients (38.4%) presented with diplopia and exophthalmos with 2 being completely relieved while 6 had major improvements. Bleeding was controlled in all cases (100%). All patients (100%) exhibited cosmetic deformities with 17 being completely relieved. Moreover, all patients (100%) exhibited impaired daily life, which was resolved in 21 patients with 5 patients reporting major improvements. After endovascular treatment, there was no vision loss, death, or permanent disability in any patient. TransOphA ethanol embolotherapy is efficacious and safe for symptomatic resolution or improvement of AVMs fed by OphA with acceptable complications without the risk of visual impairment. [ABSTRACT FROM AUTHOR]

Purpose: To summarize a 10-year, single-institution experience with ethanol embolization of nasal arteriovenous malformations (NAVMs) in 52 patients. Patients and methods: The present work was a retrospective study of 52 patients (aged between 1 and 67 years) with NAVMs who were treated with ethanol embolization between August 2009 and August 2019. The diagnosis of NAVMs was established based on clinical and imaging studies including ultrasound, computer tomography angiography, and digital subtract angiography. Embolization techniques used in the current study included transarterial, direct puncture, and a combination of both. The clinical and angiographic features, treatment methods, clinical outcomes, and complications were assessed within the mean period of 55.2 months (range, 1–119 months) after the last embolization. Results: The total number of embolization sessions (140 embolization procedures in 52 pts) included transarterial approach (1 pt), direct puncture (2 pt), and a combination of transarterial and direct puncture (49 pts). There was a positive correlation between nidus size and treatment sessions (r = 0.780, P = 0.0005) and the amount of ethanol injected (r = 0.840, P = 0.0004). Results of the current study showed that the therapeutic outcomes were complete response in two patients (3.8%) without recurrence throughout the follow-up period (range, 1–119 months; mean, 55.2 months), and partial response in 50 patients (96.2%). A total of seven patients (13.5%) experienced one or more complications, including skin necrosis in one patient (1.9%), transient hemoglobinuria in five patients (9.6%), and skin blister in five patients (9.6%). Conclusion: The reported single-institution experience evidently indicated that ethanol embolotherapy has the potential to successfully devascularize NAVMs and also significantly improve symptoms and signs. Further, it was evident that the use of a combination of transarterial and direct puncture techniques has the potential to increase the rate of therapeutic response in patients with NAVMs. [ABSTRACT FROM AUTHOR]

The earliest ovules in the Late Devonian (Famennian) are surrounded by a cupule that is involved in both protection and pollination, and generally have free integumentary lobes. Here we report a new taxon from the Famennian of China, Guazia dongzhiensis gen. et sp. nov. The terminally borne ovule is apparently acupulate (without cupule) and has four radially arranged wing-like integumentary lobes that are extensively fused, and folded lengthwise and inwards. Guazia provides evidence that not all Devonian seeds possess a cupule and it increases their diversity in integumentary lobes. This genus also suggests that the integuments develop new functions, probably including wind dispersal at the expense of the cupules. [ABSTRACT FROM AUTHOR]

With the expansion of the scale of coal mining, the safety problems caused by the reburning of coal are becoming more and more serious. In this paper, the pyrolysis characteristics of gas coal and the exothermic characteristics of reoxidation of residues were studied by using a synchronous thermal analyzer. The functional groups of pyrolysis residues were tested, and the group content and characteristic structural parameters were calculated based on quantum chemistry method. The results show that with the increase of pyrolysis temperature, Volatile maximum separation rate (Vmax) and the change in the residual weight of the coal sample (ΔWvp) increase. The increase of temperature will lead to the decrease of hydroxyl and aliphatic hydrocarbon content in coal, and the increase of aromatic hydrocarbon. With the deepening of pyrolysis, the ignition point temperature of coal samples decreases first and then rises, the combustion intensity and combustion concentration are strengthened. The pyrolysis results show that 462.8°C is the critical temperature for the transition during pyrolysis. The ignition point of the residue is less affected by the pyrolysis conditions, and the ignition temperature of the raw coal and the pyrolysis residue varies within 330.57°C–334.98°C. [ABSTRACT FROM AUTHOR]

Summary The three‐phase foam consisted of solid, liquid and gas is regarded as a highly effective measure for the underground mine fire prevention. In this study, the three‐phase foam technology is introduced and a visualization platform is established to exhibit the foam flow in a physical goaf. The diffusion rule and extinguishing performance for three‐phase foam are researched. Test results show that the three‐phase foam has a superior heat resistance than expansion foam in the top goaf. The coal heating rate is postponed after the three‐phase foam processing and the active functional groups are suppressed effectively. Increasing the foam expansion ratio is adverse to the three‐phase foam stability. The field application of three‐phase foam was evaluated via the practical extinguishment effect. The marked reduction in the sealed zone temperature and CO concentration proved that the proposed three‐phase foam technology was effective on controlling the concealed goaf fire. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a fully integrated high-frequency (HF) radio-frequency identification (RFID) tag chip based on the ISO/IEC 15693 and discusses a series of design techniques, including analog and digital control circuits. In order to get a more coupled power supply, an amplitude shift keying demodulator with very low modulation index is proposed. Moreover, modulator, limiter, and electrostatic discharge circuit are mentioned to make the tag IC work effectively and reliably. Besides, digital control circuit with 2-kbit EEPROM memory is designed to help the tag operate correctly under a very low magnetic field. The proposed RFID tag IC was fabricated using a 0.18-μm 2P6M CMOS technology with an area of 926 μm by 855 μm and a power consumption of less than 120 μA. Data rates of 6.62–52.97 kb/s are supported. The tag can operate under a minimum magnetic field of 0.12 A/m and a minimum modulation index of 2.33% which is far less than 10% required by the RFID standard. Compared with the prior references, the proposed tag IC has better performances especially in the aspect of low modulation index. [ABSTRACT FROM AUTHOR]

Foam is used as an efficient means of dust suppression in underground coal mines. The poor performance of conventional adding device of foaming agent restricts its wide application. The objective of this study is to propose and investigate a new parallel jet adding device (PJAD). Experimental results show that PJAD requires a greater water flow to produce negative pressure than the single stage jet adding device (SJAD) and is harder to generate cavitation. PJAD consumes a less pressure loss than SJAD and realizes any adding proportion below 1%, which is especially suitable for precision addition of foaming agent. A foaming system used for dust suppression is put forward with PJAD adding foaming agent. Field application indicates that foam achieves a far better dust suppression effect than the roadheader water spraying, and the foam cost is significantly reduced due to the low adding proportion of foaming agent. The marked dust suppression effect makes us believe that the proposed PJAD will greatly promote the large-scale application of foam technology used for dust suppression in underground coal mines. [ABSTRACT FROM AUTHOR]

Shougangia bellafrom the Late Devonian (Famennian) of South China is a fern-like plant known for its morphology and now provided with anatomy and a reconstruction. Its stems contain a dissected stele with a four-ribbed and an elongate-curved primary xylem segments changing to three elongate and slightly curved segments. Primary branches have a dissected stele with three similar primary xylem segments as in stems. The primary xylem of the stems and primary branches is mesarch, and individual primary xylem segments bear peripheral protoxylem strands and are surrounded by secondary xylem.Shougangiais anatomically compared with fern-like plants, zygopterid ferns and early seed plants, verifying its uncertain affinity at class and order levels as suggested by morphology, or representing a new order within the Cladoxylopsida. On the basis of anatomy and branching pattern, it is emphasized that most fern-like plants appear evolutionarily closely related to iridopteridaleans. Secondary xylem is involved not only in mechanical support, but also more likely in enhancing water supply for fern-like plants includingShougangia. By the Late Devonian, besides the abrupt drop of atmospheric CO2levels, the presence of secondary xylem may correlate well with the primary radiation of leaves (megaphylls) of euphyllophytes (e.g. fern-like plants, sphenopsids, progymnosperms and seed plants). [ABSTRACT FROM PUBLISHER]

Studying the effect of oxygen in coal oxidation is very important for understanding and controlling coal spontaneous combustion. However, the oxygen effect is not very easy to determine clearly due to the large effect of heat source on coal oxidation in temperature rising experiments. Here, focused on sub-bituminous coal, the oxygen effect was separated from coal oxidation by continuously measuring FTIR spectra of coal with respect to varying temperatures and under oxygen and nitrogen. The active groups’ real-time changes of coal oxidation, thermal treatment and oxygen effect were measured. The carboxylic ester and carboxyl units are the main functional groups that increase with temperatures increasing under oxygen and nitrogen, while the other functional groups decrease in quantity. The oxygen effect promoted the consumption of aliphatic hydrocarbons and hydroxyl groups and also promoted the formation of oxygen-containing groups (except hydroxyl). Four characteristic temperature stages involved in the oxygen effect and their key functional groups were identified. Simultaneously, the relationship of oxygen consumption and chemisorption in oxygen effect was analyzed. The starting temperature of oxygen chemisorption is between 50 and 60°C. The maximum contribution of oxygen effect was observed in methyl and methylene groups. These results are important for chemical control of coal spontaneous combustion. The oxidation of aliphatic hydrocarbon should be controlled before oxygen chemisorption. The value of oxygen consumption between 70 and 80°C can be measured accurately due to the constant chemisorption rate, which help to identify the tendency for spontaneous combustion. These results will help in better understanding of the reaction mechanism of coal oxidation, especially the oxygen effect. [ABSTRACT FROM AUTHOR]

A heterosporous lycopsid plant is described from the Upper Devonian (Famennian) Wutong Formation, Changxing County, northern Zhejiang Province, China. The plant is known for its terminal and many detached megasporangiate strobili, most of which do not have sporophylls preserved. Some megasporangiate strobili are closely associated with a vegetative axis bearing leaf cushions and with a mass of microspores. Because of the monosporangiate strobili, the present lycopsid belongs to the Dichostrobiles of the Isoёtales sensu lato. This lycopsid conforms to Changxingia in the vegetative leaves, leaf cushions (including leaf scar and ligule pit), some parts of the megasporophyll (pedicel, heel and lamina), the megasporangium and the megaspores, although the branching pattern of axes, the arrangement and other parts of megasporophyll are still unknown. The fossils are described as Changxingia sp., and this genus is expanded with character of microspore. Hence, the previous and present data indicate that the earliest lycopsids with monosporangiate strobili from the Upper Devonian of China are consistent in Lagenicula megaspores with gula and Lycospora microspores with equatorial cingulum. In contrast, the Carboniferous lycopsids with monosporangiate strobili in Euramerica and Cathaysia show great diversification of both megaspores and microspores. [ABSTRACT FROM AUTHOR]

Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and bilateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules. [ABSTRACT FROM AUTHOR]

To realize a stable addition of foaming agent used for foam technology, a new adding method using the jet cavitation was introduced, and its performance was investigated experimentally under different operating conditions. Experimental results show that the bubble region in the jet device has a constant vapor pressure, which creates a good condition for liquid absorption, while it shrinks with increasing outlet pressure. The liquid absorption amount keeps unchanged when the outlet pressure is lower than a critical value. The critical outlet pressure increases by 40% with decreasing cavitation absorption amount, which is especially suitable for mini-flow quantitative addition of foaming agent used for foam dust suppression. Its effectiveness on suppressing mine dust was evaluated in a heading face of underground coal mines. Field application indicates that the reliable and simple foaming system adopting the new adding method makes a marked dust suppression effect. The working environment of heading face is significantly improved, ensuring the safe tunneling and personal security. [ABSTRACT FROM AUTHOR]

Mine fires mainly arise from spontaneous combustion of coal seams and are a global issue that has attracted increasing public attention. Particularly in china, the closure of coal workfaces because of spontaneous combustion has contributed to substantial economic loss. To reduce the occurrence of mine fires, the spontaneous coal combustion underground needs to be studied. In this paper, a computational fluid dynamics (CFD) model was developed for coal spontaneous combustion under goaf gas drainage conditions. The CFD model was used to simulate the distribution of oxygen in the goaf at the workface in a fully mechanized cave mine. The goaf was treated as an anisotropic medium, and the effects of methane drainage and oxygen consumption on spontaneous combustion were considered. The simulation results matched observational data from a field study, which indicates CFD simulation is suitable for research on the distribution of oxygen in coalmines. The results also indicated that near the workface spontaneous combustion was more likely to take place in the upper part of the goaf than near the bottom, while further from workface the risk of spontaneous combustion was greater in the lower part of the goaf. These results can be used to develop firefighting approaches for coalmines. [ABSTRACT FROM AUTHOR]

Objective: Arteriovenous malformations (AVMs) involving the periorbital region are technically challenging clinical entities to manage. The purpose of the present study was to present our initial experience of ethanol embolization in a series of 16 patients with auricular AVMs and assess the outcomes of this treatment.Methods: Transcatheter arterial embolization and/or direct percutaneous puncture embolization were performed in the 16 patients. Pure or diluted ethanol was manually injected. The follow-up evaluations included physical examination and angiography at 1- to 6-month intervals.Results: During the 28 ethanol embolization sessions, the amount of ethanol used ranged from 2 to 65 mL. The obliteration of ulceration, hemorrhage, pain, infection, pulsation, and bruit in most of the patients was obtained. The reduction of redness, swelling, and warmth was achieved in all the 16 patients, with down-staging of the Schobinger status for each patient. AVMs were devascularized 100 % in 3 patients, 76-99 % in 7 patients, and 50-75 % in 6 patients, according to the angiographic findings. The most common complications were necrosis and reversible blister. No permanent visual abnormality was found in any of the cases.Conclusion: Ethanol embolization is efficacious and safe in the treatment of AVMs in the periorbital region and has the potential to be accepted as the primary mode of therapy in the management of these lesions. [ABSTRACT FROM AUTHOR]

Coal dust seriously threatens the safety and occupational health of coal mines. Numerical simulation research on the infrared radiation characteristics of diffused coal dust is carried out in fully mechanized working faces based on the optical monitoring problem of dust particles in mine atmospheric environments. The CFD method is applied to obtain the law of dust transport and distribution. Combined with Mie scattering model, the infrared radiation change characteristics and spectral selection of diffused coal dust particles are simulated and analyzed along the working face. The comparison results show the following: the attenuation and scattering characteristics of mine dust particles system are first enhanced, and then they weaken as the distance from dust source increases. The infrared attenuation of mine dust at the center of the vertical cross-section is generally greater than that at the roof and floor in the same location. The dispersion of mine dust directly determines the attenuation contribution of respirable dust to total dust. Moreover, the infrared absorption effect of functional groups in coal causes the infrared attenuation effect of coal dust to have obvious optical selectivity along the roadway, the existing optical “window.” [ABSTRACT FROM AUTHOR]

Late Devonian Minostrobus chaohuensis is one of the earliest monosporangiate-strobilate isoetaleans. Based on new material of this plant, the vegetative axis and microsporangiate strobilus are studied in detail, and the whole plant knowledge is summarized. The vegetative axis is isotomously branched. The stem is up to 55 mm in diameter with helically arranged leaf cushions. Stems and thick branches bear long fusiform leaf cushions and interareas with vertical linear ornamentations. A ligule pit, oblanceolate leaf scar, and vascular bundle scar appear on the leaf cushion. Distal axes have persistent lanceolate leaves and rhombic leaf bases. The microsporangiate strobilus is cylindrical in shape, possesses sporophyll with alate pedicel and long triangular lamina, uniseriate sporangial wall, subarchesporial pad inside the sporangium, and microspore with cingulum. Based on comparisons with other isoetaleans, the usage of the terms “leaf cushion” and “leaf base” is discussed, and Minostrobus chaohuensis is considered as a tree-like lycopsid. It suggests that arborescent isoetaleans with monosporangiate strobili had appeared and diversified in the Late Devonian. The multi-dichotomous branching system of Minostrobus provides new data on the evolution of growth architecture in rhizomorphic lycopsids. [ABSTRACT FROM AUTHOR]

The remarkable differences between the infrared spectra of oxygen adsorption and nitrogen desorption in coal have been experimentally and theoretically investigated. Density functional theory calculations were performed to better explain the mechanism of oxygen adsorption using six different molecular models of coal. In addition, the remarkable differences of infrared spectra between oxygen adsorption and nitrogen desorption was defined as the indexV, which was used to classify the spontaneous combustion tendency of coal. The experimental data indicated that the spectra in the 4000–2000 cm−1and 1250–1050 cm−1regions exhibited significant changes. These results suggest that the mechanism of oxygen adsorption is the alteration and transfer of charge density around the activated sites, which leads to the observed changes of the infrared spectra. TheV, which is related to the alteration of spectral intensity, is found to decrease with the increase of adiabatic oxidation time and the relative spontaneous combustion period of coal. This observation solidifies the connection between sample spectral intensity and oxygen chemisorption. These data suggest that the hydroxy in hydroxy and carboxyl groups on the surface of coal particles is the site of oxygen chemisorption, and theVcan be used to rapidly and accurately categorize the spontaneous combustion tendency of coal. [ABSTRACT FROM PUBLISHER]

A novel composite foam material for blocking air leakage in coal mine was developed. In order to examine the performance of the new composite foam, the foaming property, mechanical property, microstructure, thermal stability, and flame resistance of the composite foams, polyurethane foams, phenolic foams, and urea-formaldehyde foams were investigated. The results show that the composite foam had the biggest compressive strength, thermal stability, and flame resistance. Moreover, composite foam had the lowest foaming temperature and shrinkage, indicating that it had small risk in causing spontaneous combustion of coal, and it exhibited good air leakage blocking effect. Field application showed that composite foam could effectively block air leakage in goaf. Thus, composite foam materials were considered to be the potential candidates for blocking air leakage in coal mines to prevent spontaneous combustion of coal. [ABSTRACT FROM AUTHOR]

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Using expandable graphite (EG) and ammonium polyphosphate (APP) as flame retardants, we prepared two series of polyisocyanurate-polyurethane (PIR-PUR) foams (i.e., EG foams filled with different amounts of EG alone and APEG foams containing different amounts of expanded EG and APP) and evaluated the effect of the additives on the physical-mechanical property, fire behavior and thermal stability of the foams based on compressive strength test, limiting oxygen index (LOI), cone calorimeter test, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The addition of EG alone or both EG and APP into the foam greatly influences the physical-mechanical property. The compressive strength of APEG foams is closely related to the apparent density. The LOI value showed good improvement in both EG and APEG foams. The addition of APP in APEG foams gave better fire behavior than the EG foams with an obvious decrease in PHRR and increase in residue. In addition, the TGA curves illustrated that APP might be an effective charring agent to promote char formation. The SEM results showed that the incorporation of APP and EG allowed the formation of a cohesive and dense char layer, which inhibited the transfer of heat and combustible gas and increased the thermal stability of PIR-PUR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Moisture has a complex influence on the spontaneous combustion tendency of coal. The exothermicity of four different ranks of coal (lignite, gas coal, fat coal, and anthracite) with different total moisture contents during the oxidation process was tested by TA-DSC (Thermogravimetric Analysis- Differential Scanning Calorimetry). It was found that, for different ranks of coal, the effect of the moisture content can be quite different and for the same rank of coal, different moisture contents will affect the coal's exothermicity in very different ways. In addition, the critical moisture content at which the coal is most highly prone for spontaneous combustion was also obtained. It was found that different ranks of coal have different critical moisture contents. For lignite and anthracite, the critical moisture content was 25% and 20%, respectively. For the gas coal and fat coal, the lower the moisture content is, the greater the chance for the coal to have spontaneous combustion. [ABSTRACT FROM PUBLISHER]

A mild and efficient synthesis of N-substituted-3-aryl-3-(4-hydroxy-6-methyl-2-oxo-2 H-pyran-3-yl)propanamides via four-component reaction of an aldehyde, amine, Meldrum's acid, and 4-hydroxy-6-methyl-2 H-pyran-2-one in the presence of benzyltriethylammonium chloride (TEBAC) in aqueous medium is described. This method has the advantages of accessible starting materials, good yields, mild reaction conditions, and begin environmentally friendly. [ABSTRACT FROM AUTHOR]

Kunia venusta gen. et sp. nov. is reported from the late Middle Devonian (Givetian) Haikou Formation near Kunming City, Yunnan Province, China. This plant has three orders of naked axes that divide pseudomonopodially. The second- and third-order axes occur in a helix. Fertile appendages are distantly spaced and helically inserted to the third-order axis; they comprise equally dichotomous branches terminated by two clusters of paired and fusiform sporangia. Sterile appendages are dichotomous and distally recurved. A comparison is made with the basal euphyllophytes including the trimerophytes, cladoxylopsids, zygopterids, stauropterids, and some relevant genera of uncertain affinity. The new plant resembles them in dichotomous appendages with terminal elongated sporangia, but differs mainly in the three orders of pseudomonopodial axes bearing helical laterals. It is thus placed in the Euphyllophytina as incertae sedis. It is suggested that an evolutionary divergence in the branching pattern and appendage morphology might have occurred in the Middle Devonian euphyllophytes, that is, maintaining three dimensions versus yielding more or less planation. [ABSTRACT FROM AUTHOR]

Archaeopteris macilenta is one of the most widespread plants in the Late Devonian. Based on fossils from the Frasnian Huangjiadeng Formation, Yichang District of Hubei Province, for the first time we study in detail the anatomy of this progymnosperm plant in South China. Ultimate axes are protostelic with three xylem sympodia and lack secondary tissue. Penultimate axes are eustelic, bearing eight sympodia and a thin band of secondary xylem. Radially symmetrical sympodia of mesarch primary xylem produce traces of appendages in a spiral arrangement. Archaeopteris macilenta and A. halliana ( A. roemeriana) are dominant in the Frasnian and Famennian, respectively. Comparisons with these two species from other tectonic plates indicate consistent stelar architectures. Global spread, continuous occurrence, and identical anatomy during the Late Devonian indicate that Archaeopteris survived the Frasnian-Famennian extinction event. In this time, endemic genera and cosmopolitan taxa, including Archaeopteris, suggest the palaeogeographic isolation of South China and certain associations with other plates. [ABSTRACT FROM AUTHOR]

For calculating the stiffness function of a structure, the differential equation of the vibration of the structure was divided into the differential equation on the original stiffness function that was known, and Fredholm integral equation of the first kind on the undetermined stiffness function that was unknown. And the stable solutions of the integral equation, when the smooth factor was equal to zero, was solved by the extrapolation with p smooth factors. So the stiffness function of the structure is obtained. Applied examples show that the method is feasible and effective. [ABSTRACT FROM AUTHOR]

A new vascular plant, Hsüa deflexa sp. nov., is documented from the Lower Devonian ((upper) Pragian-lower Emsian) Xujiachong Formation, near Xujiachong village, Qujing District, eastern Yunnan, South China. In three dimensions, the branching system comprises a robust creeping main axis and comparatively slender erect lateral axes inserted oppositely or alternately. The lateral axes depart at right angles from the main axis. Towards the apex, the main axis is perhaps erect with the lateral axes attached at smaller angles. The lateral axes dichotomize equally one to three times in different planes and decrease in diameter and length acropetally. They bear sparse and irregular tiny spines. Apices of a pair of distal lateral axes curve in opposite directions and each terminates in a rounded to reniform sporangium. The sporangium dehisces into two equal valves along an indistinct convex marginal thickening. The xylem is possibly centrarch. This plant fits Hsüa in branching pattern, sporangial characters and xylem maturation.Hsüa deflexa sp. nov. differs mainly from the type speciesH. robusta in the presence of axial spines, perpendicular extension of lateral axes from the main axis and curving of distal lateral axes. Based on the possibly cen-trarch xylem and terminal sporangium, this plant relates to the rhyniophytes (sensu Banks, 1968). In view of the equal sporangial valves with marginal thickenings it resembles the zosterophyllophytes (sensu Banks, 1968).Hsüa is now treated asincertae sedis. [ABSTRACT FROM AUTHOR]

We describe the tracheid ultrastructure of Hsüa deflexa from the Lower Devonian (upper Pragian-lower Emsian) Xujiachong Formation, Qujing District, Yunnan Province, China. Scanning electron microscopy study of fusainized and permineralized tracheids shows that they are of G-type, bearing many irregularly distributed perforations. The cell wall consists of a decay-resistant inner part lining the cell lumen and a nonresistant outer part. The resistant inner part, i.e., the assumed heavily lignified secondary wall, is continuous over the poorly lignified outer part that comprises the primary wall and discontinuous secondary wall. It forms the annular thickening over the discontinuous secondary wall. The heavily lignified secondary wall may be divided into three layers. Minute perforations occur on the entire heavily lignified secondary wall, i.e., between and on the thickenings. Concerning the distribution, density, and diameter of perforations, G-type tracheids of H. deflexa share some characters of S-type tracheids. Based on observations of casts, cell wall perforation is cylindrical, with a smooth enclosing wall and two slightly enlarged ends. Lumen casts of tracheids have been formed in several stages. The tracheid ultrastructure of H. deflexa supports the theory of two depositional processes for the secondary cell wall. It indicates that at the genus level of Devonian plants, G-type tracheids differentiate in wall perforation characters; the chemical diversification of the secondary cell wall might have occurred by the Early Devonian. Moreover, this work adds to our knowledge about the evolution of tracheids and early land vascular plants. [ABSTRACT FROM AUTHOR]