碳基材料的Z型和S型异质结光催化清洁能源综述

碳纳米管/纳米纤维、石墨烯、氧化石墨烯、还原氧化石墨烯、石墨炔、碳量子点和富勒烯等炭材料因具有高导电性、优异的稳定性和生物相容性等独特性能,近年来受到广泛关注。在炭材料中构建Z型和S型异质结已成为在能量转换应用中提高光催化效率的一种有效策略。本文综述了光催化制氢和CO_(2)还原等清洁能源的基本原理,阐述了它们各自的机理和优势。此外,还讨论了不同类型的炭材料以及其中Z型和S型异质结的合成和构建,强调了它们在促进电荷分离、减少光生载流子复合损失和扩大光谱响应范围方面的作用。以太阳能燃料生产为重点,讨论和总结了碳基Z型和S型异质结在光催化制氢和还原CO_(2)方面的最新进展。最后,讨论了目前碳基光催化剂领域的瓶颈和挑战,并对该领域的未来发展提出了有价值的见解。

石墨炔:一种用于合成水污染物有效吸附剂的新型炭材料

石墨炔(GDY)是一种新生的二维材料,其在去除水溶液中污染物的研究方面引起了广泛关注。GDY是sp和sp2杂化碳原子的框架,其在二维对称网络中存在苯环和二乙基键,因此具有优异的共轭性、独特的可调谐电子性能、以及优异的化学和热稳定性。GDY的分子中有C≡C键,且具有均匀分布的三角形孔,可提供更多的反应位点和多种反应路径。因而,GDY具有吸附性,其作为吸附剂时在去除污染水中的油、有机污染物、染料和金属方面表现优异。在已发表的文献中,GDY被用作吸附剂的报道十分有限。本文综述了GDY的合成方法、GDY作为吸附剂的应用以及GDY基吸附剂的表征,并展望了GDY在污染物修复中的应用前景。

Longitudinally extensive transverse myelitis associated with scrub typhus:A case report

Rationale:Longitudinally extensive transverse myelitis(LETM)is a rare inflammatory demyelinating disease predominantly associated with autoimmune and inflammatory disorders.Scrub typhus can cause a variety of neurological complications,which may result in poor recovery and long-term disability.This report reveals a rare linkage between LETM and scrub typhus.Patient concerns:A 24-year-old female presented with a history of fever for 10 days associated with progressive quadriparesis.Physical examination revealed bilateral lower limb weakness(grade 0/5)and bilateral upper limb weakness(grade 2/5)with reduced sensation below the T3 dermatome.Diagnosis:Scrub typhus presenting with longitudinally extensive transverse myelitis.Interventions:Steroid pulse therapy with antibiotics supported by early intensive rehabilitation.Outcomes:Complete recovery was achieved.Lessons:This case report highlights the importance of considering scrub typhus as a potential cause of LETM in endemic regions,particularly in patients presenting with febrile illness and neurological symptoms.

Clinical outcomes of triceps reflecting anconeus pedicle and olecranon osteotomy approach for distal humerus intercondylar fractures

BACKGROUND The preferred treatment for distal humeral intercondylar fractures is open reduction and internal fixation.While there is consensus about the posterior approach,several posterior approaches have been developed.It is debatable as to which approach is best.AIM To compare triceps reflecting anconeus pedicle(TRAP)and olecranon osteotomy approaches for internal fixation of distal humeral intercondylar fracture.METHODS In total,40 cases of Arbeitsgemeinschaft für Osteosynthesefragen/Association of the Study of Internal Fixation type C,closed,and Gustilo type I intercondylar humeral fractures were included.Patients ranged in age from 18 years to 70 years.The patients were randomized into two groups:TRAP group and olecranon osteotomy group,with 20 cases in each.All were followed up at 6 wk,3 months,6 months,and 12 months.Functional outcomes were measured in terms of flexion-extension arc,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score.RESULTS The mean age was 43.2 years in the TRAP group and 37.5 years in the olecranon osteotomy group.The mean operative time and mean duration of hospital stay in the TRAP group were significantly higher than in the olecranon osteotomy group(119.5 vs 111.5 min and 9.85 vs 5.45 d,respectively).The mean arc of flexion-extension,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score were comparable without any significant difference in the groups at the 12-month follow-up(107.0 vs 106.2,18.3 vs 15.7,and 84.2 vs 86.2,respectively).Ulnar paresthesia and superficial infections were comparable in both groups(2 cases vs 3 cases and 3 cases vs 2 cases,respectively).Hardware prominence was significantly higher in the olecranon osteotomy group,mostly due to tension band wiring.CONCLUSION Both approaches were equivalent,but there is a need for further study including higher numbers of subjects and longer study duration to prove the benefits of one approach over the other.

A three-dimensional numerical study on the effect of geometric asymmetry on arcjet thruster performance

In an arcjet thruster,the cathode and constrictor degrade with time,and the electrical arc discharge may become unsymmetrical.In this work,a three-dimensional numerical model of a hydrogen plasma arcjet is developed and validated to study the effect of unsymmetrical electric arc discharge on thruster performance.The unsymmetrical arc discharge is realized by introducing a radial shift of the cathode so that the cathode tip offset is 80μm(25%of the constrictor radius).Simulations are conducted for both axially centered cathode(coaxial)and off-centered cathode(non-coaxial)configurations with identical propellant flow rates and input current.Simulations show asymmetrical arc discharge in the non-coaxial cathode configuration,resulting in azimuthally asymmetric Joule heating,species concentrations,and velocity field.This asymmetry continues as the plasma expands in the divergent section of the nozzle.Temperature,species concentrations,and axial velocity exhibit asymmetric radial distribution at the nozzle exit.The computed Joule heating was found to reduce with cathode shift,and consequently,the thrust and specific impulse of the thruster was decreased by about 6.6%.In the case of the non-coaxial cathode,geometric asymmetry also induces a small side thrust.

Safety and efficacy of balloon angioplasty compared to stent-basedstrategies with pulmonary vein stenosis:A systematic review and meta-analysis

BACKGROUND Pulmonary vein stenosis(PVS)is an uncommon but known cause of morbidity and mortality in adults and children and can be managed with percutaneous revascularization strategies of pulmonary vein balloon angioplasty(PBA)or pulmonary vein stent implantation(PSI).AIM To study the safety and efficacy outcomes of PBA vs PSI in all patient categories with PVS.METHODS We performed a literature search of all studies comparing outcomes of patients evaluated by PBA vs PSI for PVS.We selected all published studies comparing PBA vs PSI for PVS with reported outcomes of restenosis and procedure-related complications in all patient categories.In adults,PVS following atrial fibrillation ablation and in children PVS related to congenital etiology or post-procedural PVS following total or partial anomalous pulmonary venous return repair were included.The patient-centered outcomes were risk of restenosis requiring re-intervention and procedural-related complications.The metaanalysis was performed by computing odds ratios(ORs)using the random effects model based on underlying statistical heterogeneity.RESULTS Eight observational studies treating 768 severe PVS in 487 patients met our inclusion criteria.The age range of patients was 6 months to 70 years and 67%were males.The primary outcome of the re-stenosis requiring re-intervention occurred in 196 of 325 veins in the PBA group and 111 of 443 veins in the PSI group.Compared to PSI,PBA was associated with a significantly increased risk of re-stenosis(OR 2.91,95%CI:1.15-7.37,P=0.025,I2=79.2%).Secondary outcomes of the procedurerelated complications occurred in 7 of 122 patients in the PBA group and 6 of 69 in the PSI group.There were no statistically significant differences in the safety outcomes between the two groups(OR:0.94,95%CI:0.23-3.76,P=0.929,I^(2)=0.0%).CONCLUSION Across all patient categories with PVS,PSI is associated with reduced risk of re-intervention and is as safe as PBA and should be considered first-line therapy for PVS.

Application of Nanotechnology in Soil Stabilization

Nano-technology is expanding its horizon in various science and technology fields.In civil engineering,soil is a complex material and used for various functions and applications.Meanwhile,sometimes an effective soil stabilization technique is needed to fulfil the site criteria and can be achieved by adopting various methods e.g.,physical,chemical,thermal or reinforcement using geotextiles and fabrics.The mechanism of soil stabilization using nanomaterials is still unexplored and open to prospective researchers.The present article attempts to touch and explore the possibilities of nano-technology in soil improvement and its applications in various civil engineering works.Microstructural analysis of the nanomaterials treated soils using the latest equipment has also been discussed.The study interprets that the use of nano materials is still limited,due to their high cost and sophisticated handling procedures.Though the use of nanoparticles in soil stabilization results in extraordinary improvements in various soil properties,the improved soil properties could be utilized for various geotechnical projects.The present study bridges the past findings to the present scenario of nanomaterials in soil improvement.

Effects of Ethanol Addition and Biological Pretreatment on Soda Pulping of Eulaliopsis binata

Morphological characteristics and proximate chemical analysis of E. binata showed it as a suitable raw material for writing and printing grade paper. Maximum pulp yield (43.58%) of kappa number 17.38 with 0.9% screening rejects was obtained at 12% of active alkali (as Na2O) pulping temperature 130&degC, cooking time 120 min and solid to liquor ratio 1:4. During bio-soda pulping of E. binata, pulp yield decreased slightly while pulp brightness, tensile index, burst index and double fold numbers were improved by 4.1%, 24.94%, 14.03% and 48.45% respectively compared to soda pulping. During ethanol-soda pulping of E. binata, pulp yield, pulp brightness, tensile index, burst index and double fold numbers were improved by 3.9%, 6.6%, 32.18%, 35.40% and 77.31% respectively compared to soda pulping.

Biotechnological Transformation of Lignocellulosic Biomass in to Industrial Products: An Overview

Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features of lignocellulosic biomass and composition of different lignocellulosic materials. This work is an overview about the conversion of lignocellulosic biomass into bio-energy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.

Differentiation of Sheeppox and Goatpox Viruses by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism

In the present study,the partial gene sequences of P32 protein,an immunogenic envelope protein of Capripoxviruses (CaPV),were analyzed to assess the genetic relationship among sheeppox and goatpox virus isolates,and restriction enzyme specific PCR-RFLP was developed to differentiate CaPV strains.A total of six goatpox virus (GTPV) and nine sheeppox virus (SPPV) isolates of Indian origin were included in the sequence analysis of the attachment gene.The sequence analysis revealed a high degree of sequence identity among all the Indian SPPV and GTPV isolates at both nucleotide and amino acid levels.Phylogenetic analysis showed three distinct clusters of SPPV,GTPV and Lumpy skin disease virus (LSDV) isolates.Further,multiple sequence alignment revealed a unique change at G120A in all GTPV isolates resulting in the formation of Dra I restriction site in lieu of EcoR I,which is present in SPPV isolates studied.This change was unique and exploited to develop restriction enzyme specific PCR-RFLP for detection and differentiation of SPPV and GTPV strains.The optimized PCR-RFLP was validated using a total of fourteen (n=14) cell culture isolates and twenty two (n=22) known clinical samples of CaPV.The Restriction Enzyme specific PCR-RFLP to differentiate both species will allow a rapid differential diagnosis during CaPV outbreaks particularly in mixed flocks of sheep and goats and could be an adjunct/supportive tool for complete gene or virus genome sequencing methods.

Reduced Model Based Control of Two Link Flexible Space Robot

Model based control schemes use the inverse dynamics of the robot arm to produce the main torque component necessary for trajectory tracking. For model-based controller one is required to know the model parameters accurately. This is a very difficult task especially if the manipulator is flexible. So a reduced model based controller has been developed, which requires only the information of space robot base velocity and link parameters. The flexible link is modeled as Euler Bernoulli beam. To simplify the analysis we have considered Jacobian of rigid manipulator. Bond graph modeling is used to model the dynamics of the system and to devise the control strategy. The scheme has been verified using simulation for two links flexible space manipulator.

Design of a USIM and ECC based handover authentication scheme for 5G-WLAN heterogeneous networks

A variety of wireless communication technologies have been developed to provide services to a large number of users.The future integrated 5G-WLAN wireless networks will support seamless and secure roaming,and various types of real-time applications and services,which will be the trend of next-generation computing paradigm.In this paper,we discuss the privacy and security problems in 5G-WLAN heterogeneous networks and present a logical 5G-WLAN integrated architecture.We also propose a novel USIM and ECC based design of handover authentication for next-generation 5G-WLAN heterogeneous networks that can provide secure and seamless Internet connectivity.Our scheme has the features of strong security and better performance in terms of computation cost,energy cost,and storage cost as compared with the state-of-the-art schemes.

Plant studies in the first Himalayan Biosphere Reserve: a review

Nanda Devi Biosphere Reserve(NDBR) was declared as the first Himalayan Biosphere Reserve owing to its unique biological and cultural wealth. Its core zones, Nanda Devi National Park and Valley of Flowers National Park, are a UNESCO World Natural Heritage Site. In spite of lying at a high altitude, interplay of factors such as unique geographical location, climate, topography and wide altitudinal variations have endowed NDBR with a rich and diverse flora. Proportionately high percentage of endemic and near endemic plants makes NDBR a very important protected area from conservation point of view. However, its floristic wealth is facing unprecedented threats in the form of climate change and growing anthropogenic pressure. Hence, a need was felt to assess the directionality, quality and sufficiency of past and ongoing research for the conservation of floral and ethnobotanical wealth of NDBR in the absence of any such previous attempt. Based on an extensive review of more than 150 plant studies on NDBR, this communication provides a detailed account of the current state of knowledge and information gaps on flora, vegetation ecology, rare, endangered, threatened(RET) and endemic plants and ethnobotany. Priority research areas and management measures are discussed for the conservation of its unique floral wealth. Incomplete floral inventorization, lack of biodiversity monitoring, meagre studies on lower plant groups, population status of medicinal plants, habitat assessment of threatened taxa and geo-spatial analysis of alpine vegetation were identified as areas of immediate concern.

Secondary Silicates as a Barrier to Carbon Capture and Storage in Deccan Basalt

Investigating the immobilization of CO2,previous basalt-water-CO2 interaction studies revealed the formation of carbonates over a short period,but with the extensive formation of secondary silicates(SS).The mechanisms involved in these processes remain unresolved,so the present study was undertaken to understand secondary mineral formation mechanisms.XRPD and Rietveld refinement data for neo-formed minerals show a drastic decrease in the Ca-O bond length,with the calcite structure degenerating after 80 h(hours).However,SEM images and EDS data revealed that a longer interaction time resulted in the formation of chlorite and smectite,adjacent to basalt grains which prevent basaltwater-CO2 interaction to form carbonates,thus restricting carbonate formation.As a result of this,the CO2 mineralization rate is initially high(till 80 h),but it later reduces drastically.It is evident that,for such temperature-controlled transformations,low temperature is conducive to minimizing SS surface coating at the time of mineral carbonation.

Species Diversity and Population Status of Threatened Plants in Different Landscape Elements of the Rohtang Pass,Western Himalaya

This paper highlights the quantitative estimates of plant species diversity and ecosystems of the Rohtang Pass,which is one of the most preferred visiting spots by tourists in Himachal Pradesh (H.P.),India. In spite of high pressure of anthropogenic activities,the Rohtang Pass still harbours a variety of flowering plants with economic value,including various medicinal herbs. In order to observe species diversity in different landscape elements (LSEs),ground surveys were conducted in nine unique LSEs within the elevation range between 3624 m and 4332 m. Plant community structure in each LSE was studied using stratified random sampling where a total 56 quadrats of 1 m2 in size for herbs and 7 quadrats of 25 m2 for shrubs were made. Of the total 50 plant species belonging to 15 families recorded in different random quadrats,24 species were found of medicinal value. Maximum species richness (18) and value of Shannon diversity (H'=2.2648) were observed on northeast-facing slope in Picrorhiza kurrooa dominated LSE in moist area,followed by Rheum emodi LSE (species richness = 17 and H' = 2.4141) distributed on south-facing slope. Maximum values of species richness and Shannon diversity in Rheum emodi LSE were observed between 8 ～ 12 and 1.4797 ～ 2.1911,respectively. Rhododendron anthopogon dominated LSE on northwest-facing slope was found least diverse in terms of species richness where the Simpson index of dominance (D) was 0.4205. The species were equal in abundance in P. kurrooa LSE on east-facing slope and Pleurospermum candollii LSE on north-facing slope,showing the maximum similarity in terms of species distribution between the two LSEs. Low turnover of species across common LSEs gives an idea regarding their limited distribution. Five species of threatened category according to the IUCN criteria were observed in seven LSEs. The largest population of threatened medicinal plants was recorded on northeast and northwest-facing slopes where population density of Bergenia stracheyi (29.25 individuals/m2),Picrorhiza kurrooa (19.83 individuals/m2) and Rhododendron anthopogon (26.23 individuals/25m2) was highest. Aconitum heterophyllum was recorded for the lowest density (1 individual/m2). It was observed that the distribution of medicinal plants was very habitat-specific. Lower soil pH in most of the LSEs reflected its acidic nature. A significant positive correlation of Shannon diversity was found with soil organic matter,carbon content available and total nitrogen. Considering the continuous pressure of anthropogenic activities,this paper suggests effective ecotourism planning and plant conservation mechanisms to protect valuable plant bioresource at the Rohtang Pass.

Hardware Chip Performance of CORDIC Based OFDM Transceiver for Wireless Communication

The fourth-generation(4G)and fifth-generation(5G)wireless communication systems use the orthogonal frequency division multiplexing(OFDM)modulation techniques and subcarrier allocations.The OFDM modulator and demodulator have inverse fast Fourier transform(IFFT)and fast Fourier transform(FFT)respectively.The biggest challenge in IFFT/FFT processor is the computation of imaginary and real values.CORDIC has been proved one of the best rotation algorithms for logarithmic,trigonometric,and complex calculations.The proposed work focuses on the OFDM transceiver hardware chip implementation,in which 8-point to 1024-point IFFT and FFT are used to compute the operations in transmitter and receiver respectively.The coordinate rotation digital computer(CORDIC)algorithm has read-only memory(ROM)-based architecture to store FFT twiddle factors and their angle generators.The address generation unit is required to fetch the data and write the results into the memory in the appropriate sequence.CORDIC provides low memory,delay,and optimized hardware on the field-programmable gate array(FPGA)in comparison to normal FFT architecture for the OFDM system.The comparative performance of the FFT and CORDICFFT based OFDM transceiver chip is estimated using FPGA parameters:slices,flip-flops,lookup table(LUTs),frequency,power,and delay.The design is developed using integrated synthesis environment(ISE)Xilinx version 14.7 software,synthesized using very-high-speed integrated circuit hardware description language(VHDL),and tested on Virtex-5 FPGA.

Influence of Binary Oxidant (FeCl₃:APS) Ratio on the Spectroscopic and Microscopic Properties of Poly(2,5-Dimethoxyaniline)

Poly(2,5-dimethoxyaniline) (PDMA) has been synthesized by chemical oxidative polymerization technique using varying ratio (wt/wt) of binary oxidants;ferric chloride (FeCl3) and ammonium persulfate (APS). Fourier transform infrared (FT-IR) and ultraviolet-visible (Uv-vis) spectroscopic investigations provide the evidence of the presence of both benzenoid and quinoid ring units. The thermal analysis and structural characterization data suggests that the oxidant ratio greatly controls the molecular ordering in PDMA. Surface morphology shows the existence of both amorphous and crystalline domains wherein the crystalline domain size depends on the oxidant ratio. The dc conductivity (σdc) of PDMA is also a function of binary oxidant ratio and at FeCl3:APS (50:50), it increases by two orders of magnitude. Films of PDMA synthesized using FeCl3:APS (50:50) binary oxidant exhibits a decrease in the surface current on exposure to ammonia gas.

沙棘油对犬科动物(狗)消炎能力的评估

用沙棘种子油对狗 (12只 ,性别随机 )的急性消炎能力进行了研究。急性炎症试验部位都选择在狗的背部。使用游标卡尺连续 7d测量皮肤上发炎部位的情况来检测沙棘种子油的消炎能力。结果说明沙棘种子油有抗炎的能力。同时使用棉球肉芽肿瘤测定法测定了沙棘种子油对狗 (12只 )皮肤的慢急性炎症的消炎能力。沙棘油对狗皮肤慢性炎症的抗感染能力太弱以致于无法检测到。

Plant studies in Himachal Pradesh,Western Himalaya: a systematic review

Owing to a predicted rise in temperature,increase in precipitation and the escalating anthropogenic stresses,the Himalayan ecosystems are the most threatened non-polar regions of the world.In the past,there have been racing extinctions and range shifts of several life forms in this region,particularly of the plant species.Therefore,consistent qualitative and quantitative records on botanical baseline data on a regular basis are indispensable.The current communication attempts to provide a detailed account on the current state of knowledge and research gaps in floristic studies of Himachal Pradesh,Western Himalaya.Based on an extensive review of more than 140 studies in the form of scientific peer reviewed literature on floristics,medicinal and aromatic plants(MAPs),rare,endangered,threatened and endemic species and ethno-botany,it is revealed that the number of floristic studies in Himachal Pradesh have surged in the past years but studies pertaining to the lower plants remain meagre.Unfortunately,the remote valleys including micro-watersheds lying in the coldarid regions are relatively less studied in terms of available growing stock and population status of MAPs.Depleting traditional ethno-botanical knowledge has been the major concern and,many threatened MAPs need to be accessed globally following IUCN standards.Thus,documentation of the conservation status of key MAPs,setting aside conservation areas around viable populations of threatened species,developing germplasm banks of the priority MAPs and monitoring the impacts of climate change has been suggested.