两种改性磷矿粉的制备与表征

选用天然磷矿粉为原材料,通过硫酸酸化、有机无机活化剂活化分别制得酸化磷矿粉和活化磷矿粉。采用扫描电镜观察、X－射线衍射分析、激光粒度测试,证明了90%的酸化磷矿粉粒径为4.227 μm,90%的活化磷矿粉粒径达到220 nm。活化磷矿粉结晶度降低,比表面积增大,有利于磷素在土壤中的释放与吸附。此种制备方法开辟了磷肥生产新工艺。     

活化氧化竹基多孔活性炭理化结构与电容性能

针对当前生物质基多孔活性炭电极材料制备能耗高、性能调控难的瓶颈,提出活化氧化梯级热处理技术,以实现降本提质和探析多孔活性炭理化结构及其性能调控机制。该研究以废弃竹屑为原料,采用KHCO₃活化和低温空气氧化制备多孔活性炭,探讨不同活化氧化温度协同作用下多孔活性炭的理化结构和电化学性能。结果表明,相较于600 ℃活化的多孔活性炭（PAC-600）,增加了350 ℃低温空气氧化工艺后制备的多孔活性炭（PAC-600-350）的比表面积由154.361提升至264.235 m²/g。随着氧化温度由200升高到350 ℃,多孔活性炭氧元素含量增加、表面含氧基团（-C=O-O、-C-OH等）增多,其缺陷程度和润湿性增强。三电极测试中,相较于PAC-600多孔活性炭,经空气氧化的PAC-600-350在电流密度为1 A/g时的比电容为215.29 F/g,比电容提高至1.47倍。二电极测试中,在功率密度为215 W/kg时,PAC-600-350对称电容器的能量密度达到9.06 Wh/kg,且在5 A/g电流密度和5000次循环充放电后,PAC-600-350的电容保持率为86.59%,在超级电容器储能方面具备较大的应用潜力,该研究可为农林废弃物高值化利用提供参考。     

免耕和翻耕下典型棕壤花生铁营养特性差异

为了阐明免耕和常规翻耕20 cm下花生不同器官铁累积利用差异,在鲁东花生主产区3个典型棕壤试验点(望城、夏甸和齐山)系统研究了免耕和常规翻耕下花生铁营养特性变化。结果表明,相比免耕处理,常规翻耕20 cm增加了花生籽仁铁的累积,在望城点、夏甸点和齐山点分别增加了38.4%、20.2%和51.2%,且籽仁铁的累积与籽仁氮的累积及花生产量呈极显著正相关(P0.01)。免耕处理促进了花生茎、叶、果针和果壳等器官中铁的奢侈累积,在望城点、夏甸点和齐山点,这4个器官铁的累积量比常规翻耕处理分别提高了6.0%、32.1%和14.7%,同时花生累积带走的总铁量高于常规翻耕处理,从而造成土壤有效铁含量及土壤铁活化系数均比常规翻耕处理下降了15.1%~32.9%。综上,土壤翻耕措施能够有效增加花生籽仁铁的累积分配,降低茎、叶、果针和果壳等器官中铁的无效累积,从而提高花生铁的利用效率,该研究结果为花生田铁营养合理管理提供了理论依据。     

微晶化对钾长石粉钾素释放的影响

摘要: 利用微晶化设备对钾长石进行机械力活化处理,研究了不同处理时间对钾长石粉颗粒组成、 钾素释放量及生物有效性的影响。结果表明,钾长石经微晶化设备分别加工10 min、 40 min、 120 min和180 min后,微细颗粒（d10 m）组成比例分别达到51.69%、 65.44%、 85.34%和93.93%,比表面积明显增大,衍射峰强度显著减弱,同时钾素的释放量显著提高,其中微晶化处理180 min样品T3效果最好,2 mol/L HNO3和蒸馏水3次提取的钾总量分别为6118.8 mg/kg和2867.8 mg/kg; 4个处理（10 min、 40 min、 120 min和180 min）酸提钾总量分别是蒸馏水提钾总量的2.46、 1.81、 2.19和2.13倍,两种浸提剂提钾总量占钾长石全钾的0.50%~5.73%。微晶化以后钾长石粉中的绝大部分钾素仍以矿物态存在,但其生物有效性显著提高,促进了籽粒苋的生长和钾素积累。     

Effect of angiotensin-(1-7) on angiotensin II-induced rat renal interstitial fibroblast activation

AIM: To explore the influence of angiotensin-(1-7) on angiotension II (Ang II)-induced activation and extracellular matrix secretion in rat renal interstitial fibroblasts (NRK-49F cells). METHODS: The NRK-49F cells were maintained and sub-cultured, then the cells were divided into control group, Ang II group, Ang-(1-7) group and Ang II+Ang-(1-7) group. The expression of α-smooth muscle actin(α-SMA),transforming growth factor β₁ (TGF-β₁) and insulin-like growth factor I(IGF-I) was detected by the method of immunocytochemistry when the cells were cultured for 72 h. The content of TGF-β₁, IGF-I and collagen type I(Col I) in the cultured supernatants were measured by ELISA. RESULTS: In control group and Ang-(1-7) group, only basic expression of α-SMA and almost no expression of TGF-β₁, IGF-I and Col I were observed. Compared with control group, the expression of α-SMA, TGF-β₁, IGF-I and Col I was increased in Ang II group. Compared with Ang II group, the expression of α-SMA, TGF-β₁, IGF-I and Col I was significantly decreased in Ang II+Ang-(1-7) group.CONCLUSION: Ang-(1-7) inhibits the activation of renal interstitial fibroblasts and decreases the Ang II induced secretion of Col I by suppressing TGF-β₁ and IGF-I expression.     

Sources and mechanisms of priming effect induced in two grassland soils amended with slurry and sugar

The mechanisms and specific sources of priming effects, i.e. short term changes of soil organic matter (SOM) decomposition after substance addition, are still not fully understood. These uncertainties are partly method related, i.e. until now only two C sources in released CO₂ could be identified. We used a novel approach separating three carbon (C) sources in CO₂ efflux from soil. The approach is based on combination of different substances originated from C₃ or C₄ plants in different treatments and identical transformation of substances like C₃ sugar (from sugar beet) and C₄ sugar (from sugar cane). We investigated the influence of the addition of two substances having different microbial utilizability, i.e. slurry and sugar on the SOM or/and slurry decomposition in two grassland soils with different levels of C_org (2.3 vs. 5.1% C). Application of slurry to the soil slightly accelerated the SOM decomposition. Addition of sugar lead to changes of SOM and slurry decomposition clearly characterized by two phases: immediately after sugar addition, the microorganisms switched from the decomposition of hardly utilizable SOM to the decomposition of easily utilizable sugar. This first phase was very short (2-3 days), hence was frequently missed in other experiments. The second phase showed a slightly increased slurry and SOM decomposition (compared to the soil without sugar). The separation of three sources in CO₂ efflux from grassland soils allowed us to conclude that the C will be utilized according to its utilizability: sugar>slurry>SOM. Additionally, decomposition of more inert C (here SOM) during the period of intensive sugar decomposition was strongly reduced (negative priming effect). We conclude that, priming effects involve a chain of mechanisms: (i) preferential substrate utilization, (ii) activation of microbial biomass by easily utilizable substrate (iii) subsequent increased utilization of following substrates according to their utilizability, and (iv) decline to initial state.     

机械活化玉米淀粉的微生物降解性能

为了提高玉米淀粉的微生物降解反应活性,采用搅拌球磨机对玉米淀粉进行机械活化,以活化时间为60 min的玉米淀粉和原淀粉为原料,酒曲为降解试剂进行微生物降解反应,并以降解产物的葡萄糖值（Dextrose Equivalent,DE）为评价指标,分别研究了糊化温度、pH值、淀粉浓度、降解时间、降解温度、酒曲培养液用量等因素对降解产物中葡萄糖值的影响,并采用扫描电镜对淀粉降解过程中的颗粒进行形貌观察。结果表明,机械活化预处理能提高玉米淀粉微生物降解反应液中葡萄糖的含量,且活化淀粉未经糊化就能直接被微生物降解,降解60 min时的DE值为36.76%,与原淀粉相比,提高了27.80个百分点。说明机械活化作用破坏玉米淀粉紧密的颗粒表面和结晶结构,有效地提高了微生物降解反应活性。     

不同种类小分子有机酸对砖红壤磷素形态转化的影响

【目的】明确有机酸的作用机制,为提高酸性红壤累积态磷素(P)可利用率提供科学依据。【方法】采用室内模拟试验研究了草酸、柠檬酸、苹果酸为代表的小分子有机酸对砖红壤磷素形态的影响。【结果】柠檬酸处理抑制了树脂交换P(P1)的解吸,而水(对照)、草酸和苹果酸处理促进了P1的解吸;在培养前期,3种有机酸抑制了NaHC_O3提取态无机P(P2)的活化,柠檬酸抑制作用最强,草酸抑制作用最弱;3种有机酸处理在整个培养时期均表现为活化NaHC_O3提取态有机P(P3)的作用,其中草酸活化能力最强;3种有机酸促进了NaOH提取态无机P(P4)的活化,其中草酸活化作用最强;3种有机酸抑制NaOH提取态有机P(P5)的活化;在整个培养时期,3种有机酸都表现为抑制稀盐酸提取态P(P6)、浓盐酸提取态无机P(P7)、浓盐酸提取态有机P(P8)和残留态P(P9)活化的作用。【结论】3种有机酸在不同培养时期对土壤磷形态的作用不同,草酸活化能力最强,其次是苹果酸,最后是柠檬酸。     

HCV p7下调基因p7TP2启动子序列的克隆及转录活性检测

【目的】克隆p7TP2基因的启动子区域,并检测HCV p7TP2启动子的转录活性。【方法】通过分析确定p7TP2基因翻译起始密码子ATG上游1 203 bp至下游147 bp的基因组DNA序列作为启动子,克隆启动子片段并构建载体pCAT3-p7TP2-p和pGLB-p7TP2-p,转染HepG2细胞,应用CAT表达系统和双荧光素酶系统检测启动子活性。【结果】克隆了预测具有启动子活性的片段,成功构建了pCAT3-p7TP2-p和pGLB-p7TP2-p载体,转染pCAT3-p7TP2-p的HepG2细胞,CAT表达活性是转染pCAT3-Basic细胞的5.98倍;转染pGLB-p7TP2-p的HepG2细胞,双荧光素酶表达活性是转染pGLB细胞的9.67倍。【结论】克隆的p7TP2启动子序列与预测的序列一致,并且具有启动子转录活性。     

采用碳酸钾活化法制备油茶壳活性炭

以油茶壳为原料,采用碳酸钾活化法制备活性炭.探讨了活化温度、浸渍比和保温时间对活性炭吸附性能的影响.结果表明,随着活化温度的提高和保温时间的延长,活性炭的得率不断下降,吸附性能呈先升后降的趋势.N2吸附-脱附等温线分析结果表明,活性炭具有发达的微孔结构,活化温度升高有利于中孔结构的发达.在较佳的实验条件下,活性炭的比表面积为1033.2 m2·g-1,总孔容积、微孔容积和中孔容积分别为0.662、0.500、0.162 cm3·g-1.