全文获取类型
收费全文 | 204篇 |
免费 | 90篇 |
国内免费 | 15篇 |
专业分类
综合类 | 17篇 |
化学工业 | 147篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 9篇 |
矿业工程 | 5篇 |
能源动力 | 36篇 |
轻工业 | 40篇 |
水利工程 | 7篇 |
石油天然气 | 6篇 |
无线电 | 2篇 |
一般工业技术 | 24篇 |
冶金工业 | 11篇 |
原子能技术 | 2篇 |
出版年
2024年 | 8篇 |
2023年 | 21篇 |
2022年 | 50篇 |
2021年 | 38篇 |
2020年 | 55篇 |
2019年 | 34篇 |
2018年 | 30篇 |
2017年 | 14篇 |
2016年 | 21篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 5篇 |
2012年 | 9篇 |
2011年 | 1篇 |
2010年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 0 毫秒
291.
生物质炭对植烟土壤质量及烤烟生长的影响 总被引:2,自引:0,他引:2
采用大田试验,在当地习惯施肥的基础上,添加不同比例的生物质炭(2.25、4.50 t/hm2),探讨了生物质炭对植烟土壤理化性质及烤烟生长的影响。结果表明,施加生物质炭影响了植烟土壤的理化性质,主要体现在0~10 cm土层。与对照相比,生物质炭处理提高了0~10 cm土层土壤田间持水量、总孔隙度、土壤pH、有机质和土壤CEC,同时还提高了土壤硝态氮、有效磷、速效钾的含量,降低了土壤容重及铵态氮的含量,且高施炭量的处理效果显著。生物质炭能促进烤烟生长过程中对钾元素的吸收,降低打顶后烤烟磷、氮元素的吸收及干物质的积累。与CK相比,移栽后90天,根干物质量在2.25和4.50 t/hm2水平下分别下降了5.58%和7.50%,茎和叶的干物质量虽有所下降,但各处理间差异不显著。 相似文献
292.
293.
以污水污泥、粉煤灰为原料,以质量分数为30%的氯化锌溶液为活化剂,在不同温度下煅烧制备污泥生物炭,用于处理含磷废水。通过单因素静态吸附实验探讨了污泥生物炭对磷的去除效果,并探究了其吸附机理。结果表明:300 ℃制备的污泥生物炭具有较好的除磷效果;扫描电镜(SEM)、比表面分析仪、傅里叶红外光谱仪(FT-IR)对原料和污泥生物炭表征结果显示,污泥生物炭煅烧前后的形貌及表面基团发生了显著改变,煅烧后样品的表面产生了较多微小空隙,比表面积增大,最高可达5.51 m2/g;在磷初始质量浓度为50 mg/L、吸附剂用量为16 g/L条件下,吸附在90 min达到平衡,磷的去除率高达93.73%;吸附过程符合准二级动力学方程及Freundlich等温吸附模型,最大饱和吸附量为9.615 mg/g;整个吸附过程ΔG0<0、ΔH0<0,是自发进行的放热过程;吸附过程除物理吸附外,同时涉及磷酸盐与吸附剂—OH或C—O共价键发生电子对配位作用,为物理-化学复合吸附;吸附剂第5次吸附为首次吸附量的85.74%,表现出较好的再生性能。 相似文献
294.
Yohanes Andre Situmorang Zhongkai Zhao Nichaboon Chaihad Chao Wang Aisikaer Anniwaer Yutaka Kasai Abuliti Abudula Guoqing Guan 《International Journal of Hydrogen Energy》2021,46(5):3640-3650
Co-pyrolysis of two different types of biomass among apple tree branch (ATB), knotweed stem (KWS), seaweed (SW) and rice straw (RSt) was conducted to obtain co-pyrolysis char (co-char), and then the steam gasification of those co-chars was compared with the steam co-gasification of the physically mixed individual biochars to investigate the synergetic effect resulted from alkali and alkali earth metal (AAEM) in each biomass involved. It is found that the silica species in the RSt had negative effect on the activity of co-char due to the formation of alkali silicate compounds. However, combination of RSt with some non-woody biomass such as SW also showed promoting effect. In particular, the gasification of the co-char from the combination of various biomass with low or no silica content showed improved gasification efficiencies due to the synergetic effect AAEM species in the co-char from the different biomass. Therefore, the biomass selection should play a significant role in the co-pyrolysis of different biomass in the two-stage gasification system. 相似文献
295.
Wenting An Xiaojie Sun Yong Jiao Paulo Srgio Barros Julio Wei Wang Songbai Wang Si‐Dian Li Shaomin Shuang 《国际能源研究杂志》2019,43(7):2514-2526
The pomelo peel char (PC) was prepared and used as fuel for solid oxide electrolyte direct carbon fuel cells with nickel‐yttrium stabilized zirconia anode, thin‐film YSZ electrolyte, and La0.8Sr0.2MnO3 cathode. The power densities of fuel cells operating on PC and catalyst‐loaded PC (PCC) fuels achieved 309 and 518 mW cm?2 at 850°C, respectively, which are among the highest power densities reported in the literature on DCFCs. The PC exhibited superior gasification reactivity than coal char due to its unique reticulated foam carbon structure with a homogeneously distributed inherent catalyst. The stability tests at a current density of 50 mA cm?2 and 825°C indicate that the cell using PC fuel operated in a more stable manner than that using PCC, and the fuel availabilities for PC and PCC were 47.25% and 34.71%, respectively. The results suggest that PC is a promising solid carbonaceous fuel for solid oxide electrolyte direct carbon fuel cells based on its adequate gasification reactivity and high compatibility with the fuel cells. 相似文献
296.
Brian F. Snyder 《国际能源研究杂志》2019,43(3):1232-1244
Biomass pyrolysis is a promising method for the creation of biochar, a potentially long‐lived carbon sink, and renewable fuels. While a number of studies of the costs of pyrolysis exist, many fail to value the carbon storage benefit associated with biochar. Here, we evaluate the costs of three types of small‐scale pyrolysis systems (slow and fast, compared with gasification) in Costa Rica. We find that under many combinations of model parameters, fast and slow pyrolysis models are cost‐effective. Net present values are positive for slow pyrolysis at carbon prices above $7 t?1, indicating that a low carbon price is required to make slow pyrolysis cost‐effective. Likewise, fast pyrolysis is cost‐effective at any positive carbon price. Gasification is generally more costly than fast or slow pyrolysis, and the net present value of the gasification system is only positive at electricity prices over $0.15 kWh?1 or carbon prices over $150 t?1. Thus, both fast and slow pyrolysis models are promising methods for atmospheric CO2 reduction. 相似文献
297.
298.
以废白土与榴莲壳为原料制备了粘土生物炭吸附剂(spent bleaching earth biochar,SBEC)、以废白土为原料制备了粘土炭基吸附剂(spent bleaching earth,SBE)吸附废水中的Cr(VI)。用比表面积分析、SEM、XRD、FTIR对吸附剂进行了表征。考察了溶液初始pH、Cr(VI)溶液浓度、吸附剂投加量、吸附时间和吸附温度分别对吸附Cr(VI)的影响。25℃下pH为3时、SBEC 投加量为0.5g/L、Cr(VI)初始浓度为100mg/L、吸附时间120min,SBEC对Cr(VI)去除效率最高为86.1%,SBE则在pH为2去除效率最高为52.5%。SBEC、SBE对Cr(VI)的吸附过程符合准二级动力学模型,SBEC吸附过程符合Freundlich模型,SBE则与Langmuir吸附等温线模型较符合;吸附行为是自发吸热过程。经过5次吸附-脱附后,SBEC对Cr(VI)的去除率达58.8%。 相似文献
299.
为了寻求食用菌菌渣合理的资源化利用途径和开发绿色、高效的除磷吸附剂,以香菇菌渣(mushroom residue, MR)为原料,将其在800、900和1000℃下碳化制备生物炭后用于含磷废水的处理(MR-800C、MR-900C和MR-1000C)。理化特性分析显示,该生物炭富含K、Na、Ca和Mg等矿物质,尤其是Ca,其含量高达4328.43~4919.38 mmol/kg。Ca在生物炭中主要以CaCO3的形式存在,随着热解温度升高,部分被分解为CaO。另外,生物炭还具有较高的pHpzc(11.86~12.04)、发达的孔隙结构(比表面积为167.56~223.80 m2/g)和丰富的表面官能团(如C O、C C、C—O、Ca—O等)。在磷的吸附过程中,生物炭对磷的吸附量服从MR-800C< MR-900C< MR-1000C,且均可被Langmuir吸附等温线模型和准二级动力学模型很好拟合,即该吸附过程为化学作用主导的单层吸附。MR-800C、MR-900C和MR-1000C对磷的理论最大吸附量分别为104.17、121.95和128.21 mg/g。静电作用、孔填塞、配位作用及CaO所引起的沉淀作用[形成CaHPO4和Ca5(PO4)3(OH)]在该过程中起着重要作用。结果表明,食用菌菌渣可被开发作为低廉、高效的除磷吸附材料。 相似文献
300.
Rusen Zhou Xiaoxiang Wang Renwu Zhou Janith Weerasinghe Tianqi Zhang Yanbin Xin Hao Wang Patrick Cullen Hongxia Wang Kostya 《Frontiers of Chemical Science and Engineering》2022,16(4):475
Surface functionalization or modification to introduce more oxygen-containing functional groups to biochar is an effective strategy for tuning the physicochemical properties and promoting follow-up applications. In this study, non-thermal plasma was applied for biochar surface carving before being used in contaminant removal and energy storage applications. The results showed that even a low dose of plasma exposure could introduce a high number density of oxygen-functional groups and enhance the hydrophilicity and metal affinity of the pristine biochar. The plasma-treated biochar enabled a faster metal-adsorption rate and a 40% higher maximum adsorption capacity of heavy metal ion Pb2+. Moreover, to add more functionality to biochar surface, biochar with and without plasma pre-treatment was activated by KOH at a temperature of 800 °C. Using the same amount of KOH, the plasma treatment resulted in an activated carbon product with the larger BET surface area and pore volume. The performance of the treated activated carbon as a supercapacitor electrode was also substantially improved by>30%. This study may provide guidelines for enhancing the surface functionality and application performances of biochar using non-thermal-based techniques. 相似文献