黄山松人工林球果生物量的测定

采取平均木法实测不同立地条件的 10年生黄山松球果生物量 ,阐明黄山松球果生物量与立地条件以及测树因子之间的相互关系。 10年生黄山松山脊球果生物量最高平均每株 0 5 8kg ,而山坡最低为 0 4kg。应用树高和胸径分别推导出预测黄山松球果生物量的回归方程。     

天然次生白桦林凋落物的分解及其生态效应

1988～1990年间以长白山支脉张广才岭帽儿山老爷岭生态站天然次生白桦林为研究对象,对林分凋落物的积累,组成与分解进行了定位观察研究。结果表明,38年生白桦林凋落物的现存量为13.644t/ha,其中叶为10.49t/ha,枝为2.58t/ha,树皮、种实、动物尸体及粪便等仅为0.57t/ha,年凋落盈为3.38t/ha,年分解量为0.633t/ha,年分解率为18.7％。     

白蜡虫优良种虫及种群性比组成的研究

白蜡虫(Ericerus pela Chavannes)是我国特产资源昆虫,国内产区很多。实验表明各产区繁育白蜡虫的产量与质量差异显著,其中以金沙江下游云、贵、川三省相接壤的白蜡虫产区,繁育的白蜡虫产卵数量多、雄卵比率高、产蜡时间长、产蜡量多,同时蜡虫的产量高,是我国白蜡虫的优良种虫。     

The effects of replacement of whole‐plant corn with oat and common vetch on the fermentation quality,chemical composition and aerobic stability of total mixed ration silage in Tibet

The objective of this experiment was to evaluate the effects of replacement of whole‐plant corn with oat and common vetch on the fermentation quality, chemical composition and aerobic stability of total mixed ration (TMR) silage in Tibet. Four TMR that varied in the forage sources on dry matter basis were used: (i) 52% whole‐plant corn (Control); (ii) 43% oat + 12% common vetch (OC3.6); (iii) 38% oat + 18% common vetch (OC2.2); and (iv) 33% oat + 23% common vetch (OC1.5). Silos were opened on day 45 and then subjected to an aerobic stability test for 12 days. The results showed that all silages were well preserved with low pH and NH₃‐N, and high lactic acid and V‐scores. With the increasing proportion of common vetch, crude protein, ether extract increased (P < 0.05), and neutral detergent fiber and acid detergent fiber decreased (P < 0.05). Under aerobic conditions, treated silages were more stable than the control silage as indicated by lower (P < 0.05) pH and yeast population. It was concluded that replacement of whole‐plant corn with oat and common vetch had no unfavorable effects on the fermentation quality and improved crude protein content and aerobic stability of TMR silage. OC2.2 silage was the best among three treated TMR silages.     

Synthesis, insecticidal activity, and QSAR of novel nitromethylene neonicotinoids with tetrahydropyridine fixed cis configuration and exo-ring ether modification

To keep the nitro group in the cis position, a series of nitromethylene neonicotinoids containing a tetrahydropyridine ring with exo-ring ether modifications were designed and synthesized. All of the compounds were characterized and confirmed by 1H NMR, high-resolution mass spectroscopy, elemental analysis, and IR. The bioassay tests showed that some of them exhibited good insecticidal activities against pea aphids. On the basis of 10 nitromethylene derivatives, the quantitative structure-bioactivity relationship (QSAR) was analyzed and established. The results suggested that AlogP98 and Dipole_Mopac might be the important parameters related with biological activities.     

Development of an enzyme-linked immunosorbent assay for the detection of pentachloronitrobenzene residues in environmental samples

A competitive enzyme-linked immunosorbent assay (ELISA) for pentachloronitrobenzene (PCNB), a fungicide and chemical intermediate, was developed using a polyclonal antiserum produced against a hapten-protein conjugate of pentachlorophenoxypropionic acid-bovine serum albumin (BSA). An indirect competitive ELISA of PCNB showed an IC50 of 37 ng/mL and a limit of detection (LOD) of 7 ng/mL. The ELISA can tolerate up to 10% (v/v) methanol, 5% (v/v) acetonitrile, or 5% (v/v) acetone without significant fluctuation of Amax and IC50. The assay sensitivity showed little change in a range of pH from 6 to 8 and concentrations of 0.05-0.2 M NaCl in the assay buffer. Very low cross-reactivities were observed for some structurally related compounds except for hexachlorobenzene (12%). The average recoveries of PCNB from fortified well water, river water, and soil samples were in ranges of 88-94, 80-91, and 70-81%, respectively. The correlations between the gas chromatographic and ELISA results were excellent (r 2 >or= 0.97, slopes from 0.86 to 1.10) for those fortified samples. The ELISA is a good alternative tool for monitoring PCNB residues in environmental samples.     

无柄灵芝菌LZ02高产漆酶条件及部分酶学性质分析

【目的】 从采自新疆天山的无柄灵芝菌(G.resinaceum)中筛选获得1株高产漆酶的LZ02菌株,对其产酶条件进行优化,研究部分酶学性质。【方法】 采用单因素实验,对其产酶条件优化并研究其酶学特性,采用双向电泳检测酶蛋白。【结果】 LZ02菌株产漆酶的最佳碳源为2.5%麦麸+1%葡萄糖,最佳氮源为干酪素; Cu²⁺、Mg²⁺、Fe²⁺、 Zn²⁺和Ca²⁺的添加对LZ02产漆酶有一定的促进作用,而Co²⁺具有明显的抑制作用;藜芦醇和愈创木酚抑制产酶并使产酶高峰由第3 d推后至第9 d,添加没食子酸和ABTS对产酶影响不大,单宁酸对产酶有抑制作用。LZ02菌漆酶最适反应温度为60℃,且在80℃仍具有漆酶活性;在40℃,pH 4.0~5.0,酶活性最稳定;最适反应pH为3.0,Mn²⁺ 、Zn²⁺、 Cu²⁺ 、Ba²⁺和K⁺对酶稳定性有一定的促进作用,Co²⁺、Cd²⁺、Cr²⁺和Pb²⁺对酶的稳定性具有明显的破坏作用;对菌体及发酵液进行了双向电泳检测,测定其等电点为4.1;获得了1个纯化酶蛋白质谱序列,该蛋白与Ganoderma Lucidum来源的Laccase高度同源。【结论】 无柄灵芝菌(G.resinaceum)漆酶的合成和分泌受到营养水平、培养条件、生长阶段以及培养基中诱导剂的严格调控,木质素或木质素相关的芳香类化合物、N源和C源也能调节漆酶的合成;漆酶活性对不同种类、不同浓度的金属离子以及诱导剂的响应不尽相同,其具有较复杂的生理功能及调控机制。     

毛竹和重组竹腐朽前后的表面颜色及耐腐性能

以毛竹和重组竹为研究对象,用绵腐卧孔菌(PV)、密粘褶菌(GT)两种褐腐菌和彩绒革盖菌(CV)、变色栓菌(TV)两种白腐菌进行腐朽试验,比较分析了毛竹和重组竹腐朽前后表面视觉性质及其质量损失差异。结果发现:毛竹和重组竹颜色均发生了显著变化,主要表现为明度(L~*)降低,色度值(C)、红绿轴色品指数(a~*)和黄蓝轴色品指数(b~*)显著增大,其中绵腐卧孔菌对毛竹及重组竹的色差影响最大。重组竹(耐绵腐卧孔菌)能达到Ⅰ级强耐腐水平;毛竹(耐绵腐卧孔菌)和重组竹(耐密粘褶菌和彩绒革盖菌)达到了Ⅱ级耐腐水平;毛竹(耐密粘褶菌、彩绒革盖菌和变色栓菌)和重组竹(耐彩绒革盖菌)为Ⅲ级稍耐腐水平。整体来看,重组竹对白腐菌和褐腐菌的耐腐效果好于毛竹。绵腐卧孔菌虽然对毛竹和重组竹的降解能力最弱,但对其颜色变化的影响却最大。扫描电镜可观察到彩绒革盖菌通过毛竹导管壁上的纹孔进入薄壁细胞、伴胞等,同时通过分泌木质素酶导致其细胞壁降解。     

Quantifying effect of tassels on near-ground maize canopy RGB images using deep learning segmentation algorithm

Precision Agriculture - Vegetation indexes (VIs) are a key variable for monitoring the crop growth and estimating crop productivity. The spectral traits of the tassels were significantly different...     

农户分化、公共服务设施对宅基地有偿使用意愿的影响研究——以伊宁市改革试点调研为例

【目的】 新疆伊宁市具有典型的自然条件,同时社会经济结构多样,各乡镇距离与伊宁市市区较近,研究宅基地有偿使用的影响因素极具可复制性和代表性,探析农户分化与农村公共服务设施建设供给对农户宅基地有偿使用意愿的影响因素,对深化伊宁市及不同区域宅基地制度改革和完善农村公共服务设施建设,规范农村土地管理、提高农户收入、促进乡村振兴等具有重要理论价值和现实意义。【方法】 基于农户视角下,文章通过对伊宁市各乡镇村实地抽样调查方式,构建农村公共服务设施指标体系,并通过熵权法测算农村公共服务设施指数;同时建立二元Logistics模型,运用实证检验来分析农村公共服务设施与农户分化对宅基地有偿使用意愿的影响。【结果】 农村公共服务设施越完善,农户宅基地有偿使用概率越大,且公共服务设施实证检验中医疗设施、交通设施、生产与生活设施对农户宅基地有偿使用意愿影响显著,而教育设施影响不显著;农户分化程度的大小,具有对农村公共服务设施影响农户宅基地有偿使用意愿起到调节作用,且农户分化程度越大越能促进农村宅基地生产经营规模多效利用,从而增强农村公共服务设施对农户宅基地有偿使用意愿的正向影响。【结论】 为促进宅基地制度改革和乡村振兴,集约节约使用农村土地,盘活利用宅基地,应该因地制宜,以经济手段与行政手段为主,法律手段为辅,加强公共服务设施建设和拓宽农户就业创业渠道,提升宅基地地价和价值辐射,提高农户宅基地有偿使用的意愿;并针对不同类型农户实施差别化宅基地有偿使用调控政策,防止宅基地违建和规范使用。