期刊文献+
共找到184篇文章
< 1 2 10 >
每页显示 20 50 100
Effects of thrombopoietin pre-treatment on peri-liver transplantation thrombocytopenia in a mouse model of cirrhosis with hypersplenism 被引量:1
1
作者 Zi-Rong Liu Ya-Min Zhang +1 位作者 Zi-Lin Cui Wen Tong 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第10期2115-2122,共8页
BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resu... BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resulting in hypersplenism and excessive removal of platelets in the spleen,further reducing platelet count.When liver function is decompensated in cirrhotic patients,the decrease of thrombopoietin(TPO)synthesis is the main reason for the decrease of new platelet production.This change of TPO leads to thrombocytopenia and bleeding tendency in cirrhotic patients with hypersplenism.AIM To investigate the clinical efficacy of recombinant human TPO(rhTPO)in the treatment of perioperative thrombocytopenia during liver transplantation in cirrhotic mice with hypersplenism.METHODS C57BL/6J mice and TPO receptor-deficient mice were used to establish models of cirrhosis with hypersplenism.Subsequently,these mice underwent orthotopic liver transplantation(OLT).The mice in the experimental group were given rhTPO treatment for 3 consecutive days before surgery and 5 consecutive days after surgery,while the mice in the control group received the same dose of saline at the same frequency.Differences in liver function and platelet counts were determined between the experimental and control groups.Enzyme-linked immunosorbent assay was used to assess the expression of TPO and TPO receptor(c-Mpl)in the blood.RESULTS Preoperative administration of rhTPO significantly improved peri-OLT thrombocytopenia in mice with cirrhosis and hypersplenism.Blocking the expression of TPO receptors exacerbated peri-OLT thrombocytopenia.The concentration of TPO decreased while the concentration of c-Mpl increased in compensation in the mouse model of cirrhosis with hypersplenism.TPO pre-treatment significantly increased the postoperative TPO concentration in mice,which in turn led to a decrease in the c-Mpl concentration.TPO pre-treatment also significantly enhanced the Janus kinase(Jak)/signal transducers and activators of transcription pathway protein expressions in bone marrow stem cells of the C57BL/6J mice.Moreover,the administration of TPO,both before and after surgery,regulated the levels of biochemical indicators,such as alanine aminotransferase,alkaline phosphatase,and aspartate aminotransferase in the C57BL/6J mice.CONCLUSION Pre-treatment with TPO not only exhibited therapeutic effects on perioperative thrombocytopenia in the mice with cirrhosis and hypersplenism,who underwent liver transplantation but also significantly enhanced the perioperative liver function. 展开更多
关键词 Thrombopoietin pre-treatment CIRRHOSIS Liver transplantation Perioperative period PLATELET
下载PDF
Comparison of pre-treatment and post-treatment use of selenium in retinal ischemia reperfusion injury 被引量:3
2
作者 Alper Yazici Hasan Aksit +6 位作者 Esin Sogutlu Sari Arzu Yay Haydar Ali Erken Dilek Aksit Harun Cakmak Kamil Seyrek Sitki Samet Ermis 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第2期263-268,共6页
AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion(IR) model and compare pretreatment and post-treatment use.METHODS: Selenium pre-treatment group(n =8) was treated with intraperitoneal(i.... AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion(IR) model and compare pretreatment and post-treatment use.METHODS: Selenium pre-treatment group(n =8) was treated with intraperitoneal(i.p.) selenium 0.5 mg/kg for7 d and terminated 24 h after the IR injury. Selenium posttreatment group( n = 8) was treated with i. p. selenium0.5 mg/kg for 7d after the IR injury with termination at the end of the 7d period. Sham group(n =8) received i.p.saline injections identical to the selenium volume for 7d with termination 24 h after the IR injury. Control group(n =8) received no intervention. Main outcome measures were retina superoxide dismutase(SOD), glutathione(GSH),total antioxidant status(TAS), malondialdehyde(MDA),DNA fragmentation levels, and immunohistological apoptosis evaluation.RESULTS: Compared to the Sham group, selenium pre-treatment had a statistical difference in all parameters except SOD. Post-treatment selenium also resulted in statistical differences in all parameters except the MDA levels. When comparing selenium groups, the pre-treatment selenium group had a statistically higher success in reduction of markers of cell damage such as MDA and DNA fragmentation. In contrast, the post-selenium treatment group had resulted in statisticallyhigher levels of GSH. Histologically both selenium groups succeeded to limit retinal thickening and apoptosis. Pre-treatment use was statistically more successful in decreasing apoptosis in ganglion cell layer compared to post-treatment use.CONCLUSION: Selenium was successful in retinal protection in IR injuries. Pre-treatment efficacy was superior in terms of prevention of tissue damage and apoptosis. 展开更多
关键词 RETINA SELENIUM ISCHEMIA-REPERFUSION APOPTOSIS pre-treatment POST-TREATMENT oxidative stress
下载PDF
Effect of microwave pre-treatment on physical quality,bioactive compounds,safety risk factor,and storage stability of peanut butter 被引量:6
3
作者 Jefferson G.Degon Chang Zheng +3 位作者 Abdeen Elkhedir Bo Yang Qi Zhou Wenlin Li 《Oil Crop Science》 CSCD 2021年第3期137-144,共8页
Microwave,as a new heat treatment technology,has the characteristics of uniform and fast heating speed.It is an energy-saving technology known for improving oilseed product quality.Its efficiency mainly depends on the... Microwave,as a new heat treatment technology,has the characteristics of uniform and fast heating speed.It is an energy-saving technology known for improving oilseed product quality.Its efficiency mainly depends on the roasting power and time.However,the production of high-quality peanut butter using short-time roasting con-ditions are limited.Herein,we determined an appropriate microwave roasting power and time for peanuts and evaluated its impacts on the quality of peanut butter.Different roasting powers(400 W,800 W and 1200 W)and times(4,4.5,5,and 5.5 min)were preliminarily tested.Among them,800 W at 5 min was the most suitable.The roasting efficiency was further evaluated using color,sensory,bioactive compounds,storage stability,and safety risk factors of peanut butter produced from four peanut cultivars(Silihong,Baisha-1016,Yuanza-9102,and Yuhua-9414).The pre-treated butter obtained from three cultivars(Silihong,Yuanza-9102,and Yuhua-9414)with moisture content between 5%and 7.2%had a similar sensory score(6-7)as the commercial on a 9-point hedonic scale compare to the other.The color of the pre-treated peanut butter varies statistically with the commercial but remained in the recommended range of Hunter L*values of 51-52,respectively,for high initial moisture peanut cultivars.The total polyphenol(35.20-31.59±0.59μmol GAE/g)and tocopherol(19.05±0.35 mg/100 g)content in the butter obtained from three cultivars(Yuahua-9102,Yuhua,and Baisha-1016)and Silihong respectively,were significantly(P<0.05)higher than those in the commercial butter.The induction times of all pre-treated butter(19.80±0.99-7.84±0.07 h)were significantly(P<0.05)longer during storage at accelerated temperature than commercial samples.In addition,no benzo[a]pyrene was found in the pre-treated samples.Collectively,the microwave pretreated peanut butter was superior to the commercial one.These findings provided data support and a reference basis to promote microwave use for peanut butter production. 展开更多
关键词 Microwave pre-treatment Peanut butter SENSORY Storage stability:bioactive compounds
下载PDF
Tree-ring δ^(15)N of Qinghai spruce in the central Qilian Mountains of China:Is pre-treatment of wood samples necessary? 被引量:2
4
作者 WANG Ziyi LIU Xiaohong +5 位作者 WANG Keyi ZENG Xiaomin ZHANG Yu GE Wensen KANG Huhu LU Qiangqiang 《Journal of Arid Land》 SCIE CSCD 2022年第6期673-690,共18页
A knowledge of the tree-ring stable nitrogen isotope ratio(δ^(15)N)can deepen our understanding of forest ecosystem dynamics by indicating the long-term availability,cycling and sources of nitrogen(N).However,the rad... A knowledge of the tree-ring stable nitrogen isotope ratio(δ^(15)N)can deepen our understanding of forest ecosystem dynamics by indicating the long-term availability,cycling and sources of nitrogen(N).However,the radial mobility of N blurs the interannual variations in the long-term N records.Previous studies of the chemical extraction of tree rings before analysis had produced inconsistent results and it is still unclear whether it is necessary to pre-treat wood samples from specific tree species to remove soluble N compounds before determining theδ^(15)N values.We compared the effects of pre-treatment with organic solvents and hot ultrapure water on the N concentration andδ^(15)N of tree rings from endemic Qinghai spruce(Picea crassifolia)growing in the interior of the central Qilian Mountains,China,during the last 60 a.We assessed the effects of different preparation protocols on the removal of the labile N compounds and investigated the need to pre-treat wood samples before determining theδ^(15)N values of tree rings.Increasing trends of the tree-ring N concentration were consistently observed in both the extracted and unextracted wood samples.The total N removed by extraction with organic solvents was about 17.60%,with a significantly higher amount in the sapwood section(P<0.01).Theδ^(15)N values of tree rings decreased consistently from 1960 to 2019 in both the extracted and unextracted wood samples.Extraction with organic solvents increased theδ^(15)N values markedly by about 5.2‰and reduced the variations in theδ^(15)N series.However,extraction with hot ultrapure water had little effect,with only a slight decrease in theδ^(15)N values of about 0.5‰.Our results showed that the radial pattern in the inter-ring movement of N in Qinghai spruce was not minimized by extraction with either organic solvents or hot ultrapure water.It is unnecessary to conduct hot ultrapure water extraction for the wood samples from Qinghai spruce because of its negligible effect on the removal of the labile N.Theδ^(15)N variation trend of tree rings in the unextracted wood samples was not influenced by the heartwood-sapwood transition zone.We suggest that theδ^(15)N values of the unextracted wood samples of the climate-sensitive Qinghai spruce could be used to explore the ecophysiological dynamics while focusing on the long-term variations. 展开更多
关键词 tree rings stable nitrogen isotope ratio(δ^(15)N) nitrogen concentration solvent-extracted wood water-extracted wood wood pre-treatment Qinghai spruce Qilian Mountains
下载PDF
生物油/预处理废旧PE复合改性沥青研究
5
作者 冯新军 傅豪 《建筑材料学报》 EI CAS CSCD 北大核心 2024年第1期37-45,75,共10页
为了解决废旧塑料改性沥青储存稳定性和低温抗裂性差等问题,采用双螺杆挤出机对废旧聚乙烯(PE)进行预处理,并将其与生物油复合制得生物油/预处理废旧PE复合改性沥青.采用离析试验、流变性能试验、荧光显微镜试验和傅里叶变换红外光谱试... 为了解决废旧塑料改性沥青储存稳定性和低温抗裂性差等问题,采用双螺杆挤出机对废旧聚乙烯(PE)进行预处理,并将其与生物油复合制得生物油/预处理废旧PE复合改性沥青.采用离析试验、流变性能试验、荧光显微镜试验和傅里叶变换红外光谱试验分析了改性沥青的储存稳定性、低温抗裂性和高温稳定性.结果表明:经预处理后的PE密度与沥青密度相近,极性基团和C=C结构更多,化学活性增强,大大提高了废旧PE改性沥青的储存稳定性;生物油/预处理废旧PE复合改性沥青形成了连续的网状结构,进一步提高了废旧PE改性沥青的储存稳定性,并显著提升了其低温抗裂性,但降低了其高温稳定性. 展开更多
关键词 改性沥青 生物油 预处理废旧PE 储存稳定性 低温抗裂性
下载PDF
Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge 被引量:5
6
作者 Xinbo Tian Antoine Prandota Trzcinski +1 位作者 Li Leonard Lin Wun Jern Ng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第7期29-38,共10页
Impact of ultrasonication(ULS) and ultrasonication-ozonation(ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention tim... Impact of ultrasonication(ULS) and ultrasonication-ozonation(ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time(SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 m L biogas/g CODfedand the volatile solid(VS) removals were 35.6%, 38.3% and 42.1%, respectively at SRT of 10 days. At SRT of20 days, the biogas yields reached 313, 337 and 393 m L biogas/g CODfedand the VS removal rates were 37.3%, 40.9% and 45.3% in the control, ULS and ULS-Ozone reactors, respectively.ULS-Ozone pre-treatment increased the residual organic amount in the digested sludge.These soluble residual organics were found to contain macromolecules with molecular weights(MW) larger than 500 k Da and smaller polymeric products with MW around 19.4and 7.7 k Da. These compounds were further characterized to be humic acid-like substances with fluorescent spectroscopy analysis. 展开更多
关键词 Sewage sludge ULTRASOUND OZONE pre-treatment Molecular weight Anaerobic digestion
原文传递
Enhanced removal of organic matter and typical disinfection byproduct precursors in combined iron–carbon micro electrolysis-UBAF process for drinking water pre-treatment 被引量:4
7
作者 Yinghan Chen Tao Lin Wei Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第4期315-327,共13页
The organic matter and two types of disinfection byproduct(DBP) precursors in micropolluted source water were removed using an iron–carbon micro-electrolysis(ICME)combined with up-flow biological aerated filter(UBAF)... The organic matter and two types of disinfection byproduct(DBP) precursors in micropolluted source water were removed using an iron–carbon micro-electrolysis(ICME)combined with up-flow biological aerated filter(UBAF) process. Two pilot-scale experiments(ICME-UBAF and UBAF alone) were used to investigate the effect of the ICME system on the removal of organic matter and DBP precursors. The results showed that ICME pretreatment removed 15.6% of dissolved organic matter(DOM)and significantly improved the removal rate in the subsequent UBAF process. The ICME system removed 31% of trichloromethane(TCM) precursors and 20% of dichloroacetonitrile(DCAN) precursors. The results of measurements of the molecular weight distribution and hydrophilic fractions of DOM and DBP precursors showed that ICME pretreatment played a key role in breaking large-molecular-weight organic matter into low-molecular-weight components, and the hydrophobic fraction into hydrophilic compounds, which was favorable for subsequent biodegradation by UBAF.Three-dimensional fluorescence spectroscopy(3D-EEM) further indicated that the ICME system improved the removal of TCM and DCAN precursors. The biomass analysis indicated the presence of a larger and more diverse microbial community in the ICME-UBAF system than for the UBAF alone. The high-throughput sequencing results revealed that domination of the genera Sphingomonas, Brevundimonas and Sphingorhabdus contributed to the better removal of organic matter and two types of DBP precursors. Also, Nitrosomonas and Pseudomonas were beneficial for ammonia removal. 展开更多
关键词 DRINKING water pre-treatment MICRO-ELECTROLYSIS UP-FLOW biological aerated filter Organic matter DISINFECTION BY-PRODUCT precursors
原文传递
Optimized pre-treatment of high strength food waste digestate by high content aluminum-nanocluster based magnetic coagulation 被引量:5
8
作者 Tharindu Ritigala Hailu Demissie +9 位作者 Yanlin Chen Jiaxi Zheng Libing Zheng Jinxing Zhu Hua Fan Jiao Li Dongsheng Wang Sujithra KWeragoda Rohan Weerasooriya Yuansong Wei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第6期430-443,共14页
Coagulation-based pre-treatment efficiency of high strength digestate of food waste(HSDFW) anaerobic digestion is negated by organic ligand-catalyzed decomposition of coagulants. In this study, an efficient HSDFW pre-... Coagulation-based pre-treatment efficiency of high strength digestate of food waste(HSDFW) anaerobic digestion is negated by organic ligand-catalyzed decomposition of coagulants. In this study, an efficient HSDFW pre-treatment method, magnetic seeds(MS) coagulation, was employed by using highly stable Keggin Al_(30) nanocluster(PAC_(30)), MS and polyacrylamide(PAM), and its operation was optimized by evaluating the performance of removing turbidity, total suspended solids(TSS), chemical oxygen demand(COD), and total phosphorous(TP) phosphate. Results showed that at the optimum dosage of 4.82 g/L, PAC_(30) demonstrated excellent removals as high as 98.93% ± 0.1% of turbidity, 98.04% ± 0.1% of TSS, 58.28% ± 0.3% of total COD, 99.98% ± 0.01% of TP and 99.50% ± 0.01% of dissolved phosphate, respectively. Apparent molecular weight(AMW) and three-dimensional excitation-emission matrix(3 D-EEM) fluorescence spectroscopy analyses demonstrated more efficient removal of dissolved organic matter(DOM), particularly non-biodegradable and hydrophobic components by PAC_(30) than commercial coagulant. The sedimentation was much improved from 40 min by coagulation/flocculation to about 5 min settling by MS coagulation. The PAC_(30) based magnetic coagulation(MC) presents theoretical guidance on a cost-effective and much less footprint pre-treatment alternative for high strength wastewater. 展开更多
关键词 Magnetic coagulation Keggin nanocluster pre-treatment Removal mechanism Cost analysis
原文传递
Effect of pre-treatments on drying characteristics of Chinese jujube (Zizyphus jujuba Miller) 被引量:3
9
作者 Zhu Baomeng Wen Xuesen Wei Guodong 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2014年第1期94-102,共9页
Chinese jujube is delicious and nourishing fruit.However,fresh Chinese jujube is liable to rot and drying is a necessary process.Traditional drying is a time-consuming task due to the thick cuticle of Chinese jujube.T... Chinese jujube is delicious and nourishing fruit.However,fresh Chinese jujube is liable to rot and drying is a necessary process.Traditional drying is a time-consuming task due to the thick cuticle of Chinese jujube.To improve its drying efficiency,fresh Chinese jujube was pretreated with nine different methods prior to hot-air drying.Among these methods,dipping in 2%ethyl oleate plus 5%K_(2)CO_(3) for 10 min(alkaline emulsion of ethyl oleate,AEEO)was recommended for its time-saving effect,which was found more significant at lower drying temperatures.The beneficial effect was considered based on its cuticle destruction by AEEO pre-treatment.In the meantime,the drying process was divided into three stages;each of them obeyed the first order reaction kinetics.Activation energies for the first,second and third stages of control over jujube drying were 41.45 kJ/mol,35.24 kJ/mol and 49.52 kJ/mol,and reduced by 20.9%,22.1%and 29.0%,respectively,after AEEO pre-treatment,and the drying process was well predicted by Midilli et al.model.In view of browning during drying at higher temperatures,AEEO pretreated jujube was suggested to be dried at 60°C.This finding was considered to be helpful to the industrial drying of Chinese jujube. 展开更多
关键词 Zizyphus jujuba Chinese jujube pre-treatment hot-air drying activation energy mathematical modelling
原文传递
Influence of the initial transient state of plasma and hydrogen pre-treatment on the interface properties of a silicon heterojunction fabricated by PECVD 被引量:2
10
作者 武春波 周玉琴 +1 位作者 李国荣 刘丰珍 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2011年第9期147-150,共4页
Amorphous/crystalline silicon heterojunctions(a-Si:H/c-Si SHJ) were prepared by plasma-enhanced chemical vapor deposition(PECVD).The influence of the initial transient state of the plasma and the hydrogen pre-tre... Amorphous/crystalline silicon heterojunctions(a-Si:H/c-Si SHJ) were prepared by plasma-enhanced chemical vapor deposition(PECVD).The influence of the initial transient state of the plasma and the hydrogen pre-treatment on the interfacial properties of the heteroj unctions was studied.Experimental results indicate that: (1) The instability of plasma in the initial stage will damage the surface of c-Si.Using a shutter to shield the substrate for 100 s from the starting discharge can prevent the influence of the instable plasma process on the Si surface and also the interface between a-Si and c-Si.(2) The effect of hydrogen pre-treatment on interfacial passivation is constrained by the extent of hydrogen plasma bombardment and the optimal time for hydrogen pre-treatment is about 60 s. 展开更多
关键词 silicon heterojunction PECVD interface properties initial transient state of plasma hydrogen plasma pre-treatment
原文传递
High-performance oxygen reduction catalysts in both alkaline and acidic fuel cells based on pre-treating carbon material and iron precursor 被引量:1
11
作者 Ping Song Heather M.Barkholtz +3 位作者 Ying Wang Weilin Xu Dijia Liu Lin Zhuang 《Science Bulletin》 SCIE EI CAS CSCD 2017年第23期1602-1608,共7页
We demonstrate a new and simple method for pre-treating the carbon material and iron precursor to prepare oxygen reduction reaction(ORR) catalysts, which can produce super-high performance and stability in alkaline so... We demonstrate a new and simple method for pre-treating the carbon material and iron precursor to prepare oxygen reduction reaction(ORR) catalysts, which can produce super-high performance and stability in alkaline solution, with high performance in acid solution. This strategy using cheap materials is simply controllable. Moreover, it has achieved smaller uniform nanoparticles to exhibit high stability, and the synergetic effect of Fe and N offered much higher performance in ORR than commercial Pt/C, with high maximum power density in alkaline and acid fuel cell test. So it can make this kind of catalysts be the most promising alternatives of Pt-based catalysts with best performance/price. 展开更多
关键词 pre-treatment Uniform nanoparticle Super-high performance High stability Fuel cell
原文传递
固废磷石膏基纤维增强水泥板制备及环保性能分析
12
作者 赵洲峰 裘吕超 +3 位作者 邹君文 付军 张澳 李锐杰 《建材世界》 2024年第2期26-29,共4页
研究旨在探讨利用预处理改性固废磷石膏(SWC)部分替代水泥,结合木质纤维、POM(Polyoxymethylene,聚甲醛)纤维、水泥和细砂,基于流浆法工艺制备固废磷石膏基纤维增强水泥板,进一步分析不同预处理改性磷石膏掺量(10%、20%、30%、40%)对纤... 研究旨在探讨利用预处理改性固废磷石膏(SWC)部分替代水泥,结合木质纤维、POM(Polyoxymethylene,聚甲醛)纤维、水泥和细砂,基于流浆法工艺制备固废磷石膏基纤维增强水泥板,进一步分析不同预处理改性磷石膏掺量(10%、20%、30%、40%)对纤维增强水泥板的物理、力学和环保性能的影响。实验结果表明,纤维增强水泥板的物理性能,如密度和吸水率,受到预处理改性磷石膏引入的影响较小。随着SWC掺量增加饱水抗折强度总体呈下降趋势,掺量在0~20%区间时影响并不明显,即便不掺入POM纤维,其3 d抗压强度仍可达到4.16MPa,满足A类和B类R1级纤维水泥板强度4 MPa的要求。加入适量POM纤维(1%)可以明显增加纤维增强水泥板强度。此外,制备过程中纤维增强水泥板CO_(2)排放量减少约20%,二氧化硫(SO_(2))和氮氧化物(NO_(x))等污染物的排放也显著减少,同时环境中可溶性磷酸盐和氟化物等污染物含量也间接降低。 展开更多
关键词 预处理改性磷石膏 纤维增强水泥板 环保性能
下载PDF
贵金属分析仪在合质金检测中的应用
13
作者 冯桂坤 路昊霖 +2 位作者 王耀杰 李香娟 王雷 《世界有色金属》 2024年第6期213-215,共3页
合质金使用火试金法测定前,需要先进行预测定,使用常规的重量法进行预测定,耗费时间长、成本高,且只能预测定出其中金和银含量,无法得到能影响检测结果的铜、铂、钯、铼、钨等元素的检测结果。使用贵金属分析仪对合质金进行预测定,可快... 合质金使用火试金法测定前,需要先进行预测定,使用常规的重量法进行预测定,耗费时间长、成本高,且只能预测定出其中金和银含量,无法得到能影响检测结果的铜、铂、钯、铼、钨等元素的检测结果。使用贵金属分析仪对合质金进行预测定,可快速测定出合质金中的金、银及杂质元素含量,根据预测定结果对样品进行预处理,确保杂质元素不对检测结果产生影响。该种预测定方式检测成本低、耗费的时间短,适合应用于合质金中金含量的预测定过程中。 展开更多
关键词 贵金属分析仪 预测定合质金中金属元素 预处理样品 消除对检测结果影响 适合应用推广
下载PDF
Nitrite pre-treatment of dewatered sludge for microbial fuel cell application
14
作者 Abdul Rasyid Ruslan Vel Murugan Vadivelu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第3期148-155,共8页
The effect of pre-treatment of dewatered sludge using different nitrite concentrations and p H for microbial fuel cell(MFC) application was investigated. The results show that the addition of nitrite was feasible to i... The effect of pre-treatment of dewatered sludge using different nitrite concentrations and p H for microbial fuel cell(MFC) application was investigated. The results show that the addition of nitrite was feasible to increase the solubilization rate of the sludge and may reduce mass transfer limitation at the anode. This helped the MFC to reach higher voltage and to generate more power. The higher free nitrous acid(FNA) concentration under the acidic condition helped to increase sludge solubilization. However, under an alkaline condition, during which the FNA concentration was relatively low, the solubilization of the sludge was higher. The highest voltage and power density produced was 390 mV and 153 mW/m^2, respectively, with the addition of nitrite at 100 mg-N/L and pH 9. Furthermore,it was found that elevated levels of FNA could inhibit electrogenic bacteria thus reducing power generation. 展开更多
关键词 Dewatered SLUDGE NITRITE pre-treatment Free nitrous ACID MICROBIAL FUEL cell ELECTRICITY generation
原文传递
Effect of Pre-treatment on the Bi-2223/Ag Tapes Fabricated with Different Powders
15
作者 Li Mingya1, Chen Xingpin2, Ye Chengli1, Yu Liang1, Zhu Xu1 1 Northeastern University at Qinhuangdao, Qinhuangdao 066004, China 2 Chongqing University, Chongqing 400044, China 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2011年第S3期325-328,共4页
Samples of Bi-2223/Ag tapes fabricated with powders contained different lead oxide compounds were annealed at a temperature lower than the formation temperature of Bi-2223 phase before traditional heat treatment, whic... Samples of Bi-2223/Ag tapes fabricated with powders contained different lead oxide compounds were annealed at a temperature lower than the formation temperature of Bi-2223 phase before traditional heat treatment, which was called pretreatment. In pre-treatment stage, samples were heat treated at 780 ℃ in 8.5% O2, and the dwelling time is different. Experimental results show that pre-treatment had different influence on the formation and size of the Bi-2223 grains for tapes fabricated with powders contained different lead oxide compounds. For tapes contained both Ca2PbO4 and the 3321 phase, the decomposition of the 3321 phase enhanced the growth of Bi-2212 grains during pre-treatment process, which promoted the formation of Bi-2223 phase and enhanced the superconducting properties of Bi-2223/Ag tapes. 展开更多
关键词 pre-treatment BI-2223/AG TAPES LEAD OXIDE COMPOUNDS critical current
原文传递
Potential role of Lycium barbarum polysaccharides in glaucoma management:evidence from preclinical in vivo studies 被引量:1
16
作者 Yamunadevi Lakshmanan Francisca Siu Yin Wong +1 位作者 Kwok-Fai So Henry Ho-Lung Chan 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第12期2623-2632,共10页
In recent years,the pharmacological benefits of herbal extracts have been revisited for their potential neuroprotective effects in glaucoma.The polysaccharides extracted from the fruits of Lycium barbarum L.,or Lycium... In recent years,the pharmacological benefits of herbal extracts have been revisited for their potential neuroprotective effects in glaucoma.The polysaccharides extracted from the fruits of Lycium barbarum L.,or Lycium barbarum polysaccharides,exert their anti-aging effect through reducing oxidative stress,modulating the immune response,enhancing neuronal responses,and promoting cytoprotection.The therapeutic efficacy of Lycium barbarum polysaccharides in preserving retinal ganglion cells and their functions was demonstrated in a range of experimental models of optic neuropathies.These include the acute and chronic ocular hypertension models,the partial optic nerve transection model,and the ischemic-reperfusion injuries model.Based on these findings,Lycium barbarum polysaccharides appear to be a good candidate to be developed as a neuroprotective agent for treating multifactorial diseases.This review aims to present a comprehensive review on the latest preclinical evidence on the pre-and post-treatment benefits of Lycium barbarum polysaccharides in retinal ganglion cell neuroprotection.The possible mechanisms of Lycium barbarum polysaccharides mediating retinal ganglion cell neuroprotection will also be described.Moreover,the potential research gaps in the effective translation of Lycium barbarum polysaccharides treatment into clinical glaucoma management will be discussed. 展开更多
关键词 animal model complementary and alternative medicine GLAUCOMA retinal ganglion cell Lycium barbarum polysaccharide NEUROPROTECTION neuro-rescue ocular hypertension POST-TREATMENT pre-treatment
下载PDF
Design and Research of High-throughput Automation System for Food Testing Laboratory
17
作者 Shuo YANG Lei WANG +3 位作者 Xuehua WANG Weian WANG Dawei WANG Ying WANG 《Agricultural Biotechnology》 CAS 2023年第3期116-118,共3页
In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection... In the process of food testing,human operation is an important variable affecting the experimental results.In order to reasonably avoid the influence of human subjective operation behavior on the accuracy of detection results,the laboratory information management system was used as the information platform to design a high-throughput laboratory automation pre-treatment system based on the deep integration of mechanical principles,visual analysis,high-speed conduction,intelligent storage and other technical systems.The experimental results showed that the system could shorten the sample circulation cycle,effectively improve the laboratory biosafety,and meet the requirements of high-throughput processing of samples. 展开更多
关键词 Food testing AUTOMATION pre-treatment system High throughput
下载PDF
Effect of Pre-Sowing Treatments on Mamalis (Pittosporum pentandrum Blanco Merr.) Seeds Germination under Nursery Condition
18
作者 Raffy L. Tano 《Open Journal of Ecology》 2023年第2期106-118,共13页
Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes,... Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes, hilar removal, and a control in which the seeds were sown without being treated. The experiment was laid out in the Completely Randomized Design (CRD) with four replicates and 60 seeds per treatment. Seeds were sown in an improvised Seedbox in October 2019. Germination was monitored daily for one month. The results showed that Mamalis seeds treated with lukewarm water have the earliest germination of twelve days, with a germination percentage of 66.67%. The germination rate of another treatment ranges from 0 - 44 percent, compared to 45 percent for the control treatment. It seems prudent to conclude that to enhance the vegetative propagation methods is to soaking in warm water at 37.5&#730;C for 2 hours could provide the best growth. 展开更多
关键词 Pittosporum pentandrum Seed Germination pre-treatments Sulfuric Acid Seed Dormancy
下载PDF
导电聚合物钽电容器浪涌稳定性研究 被引量:1
19
作者 田东斌 姚立国 余德艳 《电子元件与材料》 CAS 北大核心 2023年第11期1335-1339,共5页
导电聚合物钽电容器(PTCs)具有高体积效率、高可靠性、高稳定性、较宽的温度范围和良好的高频特性等特点,是高可靠功率电子电路中不可替代的关键电子元件。新一代电子电路的高电压、大电流和高频率作用于具有异常瞬变电流(ACC)特性的PT... 导电聚合物钽电容器(PTCs)具有高体积效率、高可靠性、高稳定性、较宽的温度范围和良好的高频特性等特点,是高可靠功率电子电路中不可替代的关键电子元件。新一代电子电路的高电压、大电流和高频率作用于具有异常瞬变电流(ACC)特性的PTCs,导致PTCs的浪涌失效几率增大,失效模式复杂。通过研究分析PTCs中漏电流的成因,影响浪涌失效的主要是位移电流和直流漏电流。采用聚合前、后处理技术,电介质-聚合物界面粘结强度增强,表面缺陷被屏蔽,电介质劣化引起的ACC和漏电流得到遏制。通过500000μF的储能电容器施加浪涌电流和1.5倍额定电压浪涌测试,PTCs漏电流的稳定性得到显著提高,耐受浪涌冲击的能力增强。该研究成果对电子装备系统的安全运行提供有力支撑。 展开更多
关键词 导电聚合物 钽电容器 前处理 浪涌测试 稳定性
下载PDF
硝基苯类废水的预处理技术研究 被引量:13
20
作者 樊金红 徐文英 +1 位作者 高廷耀 周荣丰 《环境污染与防治》 CAS CSCD 北大核心 2005年第1期8-11,共4页
   Fe(OH)2对硝基苯具有强烈的还原作用,短时间内可把硝基苯还原为苯胺。催化铁屑法处理硝基苯类废水,除了包括铁屑法处理废水的各种反应外,还能使硝基苯在其表面直接还原,且反应在弱碱性条件下效果较好。m(Fe)∶m(Cu)为10∶1,pH为9...    Fe(OH)2对硝基苯具有强烈的还原作用,短时间内可把硝基苯还原为苯胺。催化铁屑法处理硝基苯类废水,除了包括铁屑法处理废水的各种反应外,还能使硝基苯在其表面直接还原,且反应在弱碱性条件下效果较好。m(Fe)∶m(Cu)为10∶1,pH为9.5,废水硝基苯进水质量浓度为250 mg/L,反应时间为30 min,硝基苯的去除率达100%。 展开更多
关键词 硝基苯类废水 铁屑法 去除率 预处理技术 苯胺 弱碱性 水质量 反应时间 催化 还原
下载PDF
上一页 1 2 10 下一页 到第
使用帮助 返回顶部