阿丁枫造林技术研究

本文阐述了高阿丁枫和蒙自阿丁枫驯化栽培的营林技术。１９８９年开始在普文试验林场进行造林试验，至１９９５年已造林１７２ｈｍ￣２。通过种子贮藏，两段式育苗、袋苗培育、整地方式、造林季节、造林密度、裸根苗和袋苗的造林对比、年度重复等的栽培试验研究，得出了高阿丁枫和蒙自阿丁枫适生区的造林配套技术。     

森林生态效益现实补偿费的计量--以川西九龙县为例

森林生态效益补偿实质上是消除生态效益"外部性",将"外部性""内部化"的一种手段.合理的补偿标准可以使资源配置最优,实现森林资源可持续发展.探讨现实补偿费的计量理论方法,指出合理补偿是以现阶段人们的支付意愿为标准.并以川西九龙县森林(公益林)为例,计算出2002年现实补偿费为31.589亿元,平均补偿1.745万元·hm2,不足理论补偿标准的1/3.     

木材干燥应力应变超微观模型的构筑

木材干燥应力应变研究不论在理论上探索还是用于指导生产实践,都具有重大的意义。然而木材干燥应力与应变的关系是非常复杂的,因为木材属于既有弹性又有塑性的材料———弹塑性材料。应变的大小受很多因素的影响,包括材料自身的因素,例如密度、管胞或纤维胞壁的微纤丝的角度以及恒定或变化的环境因素(如大气的温度、相对湿度)等。还有依从于时间的因素(申宗圻,1990)。正是由于木材本身的特殊结构及其在干燥过程中各参数变化的复杂性,建立一个精确性较高和适用性较广的干燥应力应变数学模型很困难。若不靠数学物理方法,单纯的试验很难重现实…     

Degradation and kinetic modeling of polyvinyl alcohol in aqueous solutions by a H<Subscript>2</Subscript>O<Subscript>2</Subscript>/Mn(II) system

This paper is about the degradation of polyvinyl alcohol (PVA) in aqueous solutions using a H2O2/Mn(II) system. Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were applied to analyze the degradation products of PVA, and the results revealed that the backbone chain of PVA could be effectively broken and oxidized. Several unsaturated degradation products, including carboxylic acids, ketones, aldehydes, olefins, and alkynes were also detected and identified by gas chromatography-mass spectrometry (GC-MS), which indicated that higher treatment temperatures would considerably promote the generation of lower molecular weight degradation products. According to the work presented in this paper, the degradation efficiency of PVA increased from 55 % at 60 oC to 99 % at 90 oC after treatment when the initial PVA concentration was 5 %, at pH=3 with a H2O2 and Mn(II) dose of 100 ml/l and 0.6 mol/l, respectively. In addition, kinetic modeling indicated that the experimental results were best fitted by the Page-modified model with an activation energy of 48.78 kJ/mol.     

Effects of dietary supplementation of Haematococcus pluvialis powder on gonadal development,coloration and antioxidant capacity of adult male Chinese mitten crab (Eriocheir sinensis)

The green algae Haematococcus pluvialis is an important source of natural astaxanthin as feed additive. This study was conducted to investigate the effects of dietary supplementation of H. pluvialis powder on gonadal development, coloration and antioxidant capacity of adult male Chinese mitten crab Eriocheir sinensis, and four experimental diets were formulated to contain 0, 0.2%, 0.4% and 0.6% of H. pluvialis powder. There were four treatments (defined as D1~D4) in this study and each treatment had three replicates. Dietary H. pluvialis contents had no significant effects on survival, body weight gain rate and gonadal development of male E. sinensis. For colour parameters, the total carotenoids content in carapace and hepatopancreas as well as hepatopancreatic lightness (L*) and carapace redness (a*) increased significantly with increasing dietary H. pluvialis (p < 0.05). For the antioxidant indices in the serum, D4 had the lowest activities of superoxide dismutase (SOD) and peroxidase (POD), but the highest glutathione peroxidase (GSH‐Px) and lactic dehydrogenase (LDH), while the malondialdehyde (MDA) in serum and hepatopancreas decreased significantly with the rising content of dietary H. pluvialis (p < 0.05); D1 had the highest levels of SOD, POD and GSH‐Px in hepatopancreas. For the non‐specific immune indices, the highest activities of acid phosphatase (ACP) and γ‐glutamyl transpeptidase (γ‐GT) were found on the serum of D3 and D4 (p < 0.05). D1 had the highest levels of ACP and alkaline phosphatase (ALP) in hepatopancreas, while D2 and D3 had the lowest levels of ALP and ACP respectively. These results suggested the optimal dietary natural astaxanthin level was around 40 mg/kg diets.     

高产高效栽培下春玉米生育后期冠层结构及其光合特性的研究

以郑单958为供试品种，设高产高效栽培(GCGX)和农户传统栽培(CK)2个处理，于2012年和2013年连续2 a进行田间试验，测定春玉米生育后期冠层结构及其光合特性的变化规律。结果表明：吐丝期和乳熟期株高、穗位高产高效栽培略高于农户传统栽培。与农户传统栽培相比，高产高效栽培春玉米叶面积指数较大，在生育期上表现为吐丝之后更为明显，在叶位上表现为棒三叶以下叶片最为突出；不同叶位的叶倾角高产高效栽培显著小于农户传统栽培，而叶向值均显著大于农户传统栽培，在棒三叶表现最为明显；高产高效栽培生育后期净光合速率显著高于农户传统栽培，冠层光合能力极显著高于农户传统栽培。高产高效栽培下春玉米产量为14.009 t·hm^-2(2012)和13.255 t·hm^-2(2013)，均极显著高于农户传统栽培。     

Dietary Supplementation with Microencapsulated Lutein Improves Yolk Color and Lutein Content in Fresh and Cooked Eggs of Laying Hens

This study was conducted to compare the efficacy of diet supplemented with non-microencapsulated lutein (NL) and microencapsulated lutein (ML) in laying hens. A total of 270 Hy-line Brown laying hens (54 weeks old) were allocated to three groups with six replicates of 15 hens and were adapted to a wheat-soybean meal basal diet for two weeks. Next, the control birds were fed the basal diet, and the test birds were fed the basal diet supplemented with 600 mg/kg NL (12 mg/kg available lutein) or 90.1 mg/kg ML (10 mg/kg available lutein) for 35 days. Supplementation of lutein did not affect the productive performance of laying hens, but improved (P<0.05) the yolk color and red/green value (a*), with eggs from the ML group displaying improved color and a* values from the 15^th day of the experimental period. The blue/yellow value (b*) for the yolk showed an increase (P<0.05) through both NL and ML supplements. The yolk color of fried and boiled eggs and a* value of the yolk in fried eggs were improved (P<0.05) only through ML supplemented diet. Both NL and ML supplements resulted in lower (P<0.05) lightness and higher (P<0.05) a* values of yolk in boiled eggs, as well as higher (P<0.05) b* values in fried and boiled eggs. Yolk lutein content in fresh, fried, and boiled eggs was increased (P<0.05) in NL and ML groups with the latter being higher. In conclusion, ML improved yolk pigmentation and lutein retention in laying hens better than NL.     

Effect of EZH2 regulating Wnt/β-catenin signaling pathway on apoptosis of brain glioma cells

AIM: To investigate the effect of enhancer of zeste homolog 2 (EZH2) regulating Wnt/β-catenin signaling pathway on the apoptosis of brain glioma cell lines. METHODS: The expression level of EZH2 in glioma cell lines U87, H4 and U251 and normal human astrocytes (NHA) was detected by RT-qPCR and Western blot. The EZH2 siRNA and siRNA control were transfected into the H4 cells. The cell viability was measured by MTT assay. The apoptosis was analyzed by flow cytometry. Caspase-3 activity was detected by spectrophotometry. The expression levels of the key protein β-catenin of the Wnt/β-catenin signaling pathway and the downstream target molecule c-Myc were determined by Western blot. After the H4 cells transfected with EZH2 siRNA were treated with an activator of Wnt/β-catenin signaling pathway, the apoptosis rate was measured by flow cytometry, and the expression of β-catenin and c-Myc was determined by Western blot. RESULTS: The mRNA and protein expression levels of EZH2 in the glioma cell lines U87, H4 and U251 were significantly higher than those in NHA (P<0.05). The expression of EZH2 at mRNA and protein levels in the H4 cells was higher than that in U87 cells and U251 cells (P<0.05). EZH2 siRNA obviously inhibited the expression of EZH2 at mRNA and protein levels in the H4 cells. Knockdown of EZH2 expression decreased the viability of H4 cells, the apoptotic rate was significantly increased, and the activity of caspase-3 was significantly increased in the cells (P<0.05). Knockdown of EZH2 expression also inhibited the expression of β-catenin and c-Myc. The activator of Wnt/β-catenin signaling pathway reduced the apoptosis rate of H4 cells induced by down-regulation of EZH2, and reduced the activity of caspase-3 in the cells. CONCLUSION: EZH2 is over-expressed in glioma cells. Down-regulation of EZH2 expression induces apoptosis of glioma cells by inhibiting the activation of Wnt/β-catenin signaling pathway.     

川南地区1989—2019年农业干旱危险性特征分析

旨在研究川南地区近30年农业干旱危险性特征。基于川南地区（内江市、自贡市、宜宾市、泸州市）1989—2019年夏季（6—8月）降水数据,组成了降水距平百分率和农业干旱危险性等级之间的模糊隶属函数,通过引入区间平均隶属度,将信息扩散理论与之结合,研究了川南经济区的农业干旱危险性特征。结果显示：轻、中度农业干旱危险性水平最大的都是泸州市,危险性水平分别达21.47%、15.32%;重度农业干旱危险性水平最大的是自贡市,其危险性水平达7.58%;严重农业干旱危险性水平最大的是宜宾市,其危险性水平达7.47%。     

气相色谱-串联质谱法测定柑橘中5种杀螨剂残留

建立了气相色谱-串联质谱法(GC-MS/MS)检测柑橘中5种杀螨剂残留分析方法。样品经乙腈提取、氯化钠盐析后,取有机相用Qu EChERS方法净化,利用GC-MS/MS在多反应监测(MRM)模式下进行测定,外标法定量。5种杀螨剂在0.005~0.5mg/L浓度范围内呈现良好的线性关系,相关系数r^2均>0.996,方法定量限为0.005 mg/kg。在0.005、0.01和0.1mg/kg 3种添加水平下,加标回收率为70.6%~111.3%,相对标准偏差(RSD)为1.07%~14.64%。本方法简便、重现性良好,可用于柑橘类水果样品中杀螨剂的日常检测。