南方丘陵典型季节性干旱区节水稻作模式生态系统功能特征研究

运用生态经济学原理，采取实地凋查和田间试验方法，研究了南方丘陵典型季节性干旱区节水稻作模式生态系统的物流、能流、价值流及生态环境效应。结果表明，节水稻作模式的净初级生产力为309763×10^6～378094×10^6J／（hm^2·a），以化肥为主的辅助能投入为58607×10^6～97265×10^6J／（hm^2·a）．纯收入为3921～9426元／（hm^2·a）。不同节水稻作模式所表现出的变化特征为：采用节水灌溉双季稻模式，有利于减少系统化肥、农药、人工等能量投入．增加系统能量的输出．提高能量转换效率、光能利用效率和稻田的经济效益；采用水旱轮作双季稻节水稻作模式．有机肥的投入增加，能流循环指数提高．系统稳定性增强，但能量转换效率下降，稻田的经济效益有所降低;采用稻油轮作节水稻作模式，在减少系统化肥、农药、人工等能量投入同时．充分利用作物生长期间太阳辐射，光能利用效率提高，稻田的经济效益增加。与常规稻作模式相比，节水稻作横式的综合效益较高，具有较好的节水、省肥、省药效应以及控制农业面源污染效应。

不同节水稻作模式对土壤理化特性和土壤酶活性影响研究

针对南方丘陵区季节性干旱现状与目前稻田单一化的连作耕作制度对农田环境造成的不利影响因素,通过4a田间定位试验研究了节水稻作模式下土壤理化性状和土壤酶活性变化规律影响。结果表明,与该区常规稻作模式相比,在试验设计范围内,节水稻作模式下稻田的土壤理化性状明显改善,随着耕种年限增加,土壤容重下降,而孔隙度增加,土壤通透性增强,有效阻止土壤次生潜育化和土壤酸化,提高了土壤pH值;就土壤酶活性而言,节水稻作模式处理酶活性常规稻作模式相比,除转化酶外,其它酶活性均有不同程度的增加,尤其对磷酸酶与脲酶影响最大。

南方丘陵季节性干旱区节水稻作模式综合效益评价体系研究

针对南方丘陵区季节性干旱状况和稻作发展的基本特点,以节水稻作模式为研究对象,借鉴层次分析法(AHP)的基本原理,遵循科学、实用及简明的原则,构建南方丘陵区节水稻作模式综合效益评价模型,提出以经济效益、生态环境效益和社会效益3方面综合效益评价的16项评价指标.并以国家863"项目推广示范的节水灌溉双季稻模式、水旱轮作双季稻模式、稻油轮作模式3种节水稻作模式和当地常规双季稻模式为例,利用所建模型进行综合评价.结果表明,3种节水稻作模式的综合效益均优于该区常规稻作模式,以稻油轮作模式综合效益最高.因此,在南方丘陵季节性干旱双季稻区适当发展稻油轮作节水稻作模式具有良好的前景.该评价结果可为南方丘陵季节性干旱区水资源高效利用和稻作持续健康发展提供理论依据.

不同节水稻作模式对土壤微生物数量和微生物量碳氮的影响

针对南方丘陵区季节性干旱这一区域问题,以节水稻作模式为研究对象,以常规稻作模式为对照,通过田间定位试验,研究了稻基农田土壤微生物数量和土壤微生物量碳氮的变化规律。结果表明,与该区常规稻作模式相比,节水稻作模式的土壤微生物数量和土壤微生物量碳氮差异显著;节水稻作模式有利于土壤细菌和放线菌的增殖,但抑制了真菌的增殖;土壤微生物量碳和微生物量氮的显著增加,以水旱轮作双季稻模式最佳,说明采用节水稻作模式可有效提升土壤细菌数量、放线菌数量、微生物量碳和微生物量氮含量。因此,在南方丘陵季节性干旱区,采用节水稻作模式,可促进稻田生态系统健康持续发展。

多恩《夜祷,作于圣露西节》的形式主义解读

俄国形式主义认为作品的文学性在于文学的形式,即文学作品的语言、风格、结构。那么,文学创作的根本就在于艺术形式的表达。"陌生化"手段可以创造出新的艺术形式从而让人们重新感知原来的事物,激活艺术作品的生命力。在《夜祷,作于圣露西节》中,多恩运用非人化的情感表达方式,新奇的意象、隐喻、悖论、复义给读者带来了全新而独特的审美感受。

实用节水稻作技术(二)

水稻穴直播旱作技术 此项技术是水稻旱作技术之一,与条直播旱作技术最大的不同点即是由平条漫撒播种方式改为精量穴点播方式。

配套品种节水稻作

水稻虽具有水陆两生特性,但绝非所有水稻品种都适合于水稻旱作及湿润稻作等节水稻作栽培方式。因此,必须选择那些具有强耐旱性的适于节水稻作的旱作配套高产优质品种,且经过专门的技术处理,使其耐旱基因得以启动并充分表达,并严格按照各项技术规程进行操作,才能使得节水稻作获得成功。 目前,适合在吉林省节水稻作的专用配套品种有:丰优101。

实用节水稻作技术(一)

一、节水稻作概述 (一)水稻旱作的概念:水稻旱作是指在旱田条件下,选用耐旱性较强的适于旱作栽培的专用优质水稻品种,采取旱直播,全年旱管理的方式种植。全生育期以自然降水为主,稻田里不建立水层,在水稻生育的关键时期,遇旱适当补给一些水分,使水稻在土壤比较湿润的状态下,正常生长发育。 (二)水稻旱种的概念:水稻旱种是“水稻旱种、苗期旱长”,利用耐旱性较强的专用优质水稻品种旱直播,

谈节水稻作与节水灌溉技术

节水稻作是采取科学灌溉用水,提高水的利用效率。试验结果表明,在不影响水稻正常生长状态下,节水稻作可节约用水30%左右,减少了灌水作业次数,降低了成本。

3700mm筒节轧机工作辊热处理工艺

介绍了3700mm筒节轧机工作辊进行不透烧加热,且进行喷雾淬火的同时,对辊颈部位进行扣罩保护,淬火结束后马上装入回火炉进行回火的热处理工艺。

水田灌溉抗旱节水措施与办法的思考

受灌溉技术落后、管理水平低下、管理方法不合理等因素影响,我国多地长期存在水田灌溉效率低下问题,而受近年来多地干旱气候影响,这类问题的表现日渐严峻化,基于此,结合实际调研,分析水田灌溉抗旱节水的基本思路,提出合理选择节水灌溉制度、结合劳动人民经验、推广节水稻作生产体系三方面水田灌溉抗旱节水措施与办法,希望由此能够为相关农业人员带来一定启发。

Characteristics and Functions of Cooperative Economic Organizations for Water-saving Irrigation in Agricultural Development in Arid Areas

Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irrigation technologies.Currently,there are few researches on this cooperative economic organization.In this study,connotations of cooperative economic organizations for water-saving irrigation are specifically defined,and the characteristics and functions of this cooperative economic organization are analyzed.Based on that,several suggestions are proposed on the continuous development of cooperative economic organizations for water-saving irrigation.

吉林省旱稻发展的思路

从节水稻作的角度,概括了旱作技术和水资源的情况,根据旱稻的需水规律,提出旱稻栽培技术规程以及存在的问题,进一步探讨旱稻发展的潜力及其应用前景。

Dwarfing effects of plant growth regulators on narcissi

The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.

Neural mechanism of acupuncture-modulated gastric motility

AIM: To investigate the acupuncture-modulated gastric motility and its underlying neural mechanism.METHODS: Intragastric pressure and/or waves of gastric contraction in rats were recorded by intrapyloric balloon and changes of gastric motility induced by acupuncture stimulation were compared with the background activity before any stimulation. Gastro-vagal or splanchnic-sympathetic nerves were recorded or cut respectively for investigating the involvement of autonomic nerve pathways. Spinalization experiment was also performed.RESULTS: Acupuncture-stimulation by exciting Aδ and/or C afferent fibers, could only modulate gastric motility. Acupuncture-stimulation on fore- and hind-limbs evoked a moderate gastric motility followed by increased vagus discharges with unchanged sympathetic activity, while the same stimulus to the acupoints in abdomen resulted in reversed effects on gastric motility and autonomic nervous activities. The inhibitory gastric response was completely abolished by splanchnic denervation, but the facilitative gastric response to stimulation of acupoints in limbs was not influenced, which was opposite to the effect when vagotomy was performed. The similar depressive effects were produced by the stimulation at the acupoints homo-segmental to the gastric innervation in the animals with or without spinalization. However, the facilitation induced by the stimulation at the acupoints hetero-segmental to the gastric innervation was not observed in the spinalized animals.CONCLUSION: Facilitative effects of stimulating hetero-segmental acupoints are involved in the intact preparation of vagal nerves and spinal cord, while the inhibitory response induced by stimulating homo-segmental acupoints is involved in the intact preparation of sympathetic nerves. Only the acupuncture-stimulation with intensity over the threshold of Aδ and/or C afferent fibers can markedly modulate gastrointestinal motility.

Preliminary Investigation on Regulating Effects of Different TCM Treatments on Transcription of the Correlated Genes of Liver Cancer in Rats

The regulating effects of TCM treatments including clearing away heat and toxic materials,promoting blood circulation and removing blood stasis,and strengthening the spleen and regulating qi on the oncogene transcription were observed in the liver cancer model rats.The preliminary results indicated that the mRNA levels of H-ras N-ras and K-ras,and signal molecules correlated with the ras/MAPK signal transduction pathway were down-regulated by the different TCM treatments in varying degrees.Also,the regulating effects of the treatments on differently-displayed genes were discrepant.It is suggested that the molecular mechanisms of the TCM treatments for liver cancer was complex with different target genes.

Fine particle aggregating and flotation behavior induced by high intensity conditioning of a CO_2 saturation slurry

The influence on fine particle aggregation and flotation behavior induced by high intensity conditioning(HIC) from saturated of the slurry with CO2 saturation was investigated.Bubble size measurements were conducted.The effect of dissolved gas,xanthate addition and agitation speed on fine sphalerite particle aggregation-and flotation-behavior were studied.The results show that during HIC in air or CO2 saturated water xanthate acts as a frother.The dissolved gas content in the pulp and HIC play a synergistic role in promoting fine particle aggregation and hence flotation;a significantly enhanced aggregation of fine sphalerite particles in a CO2 saturated slurry by HIC is observed.The aggregate size increased when the agitation speed was increased from 700 r/min to 1500 r/min.Increasing the HIC speed to 1500 r/min caused a positive impact on flotation kinetics.Further increasing the speed to 2000 r/min resulted in an adverse effect on flotation kinetics.

Mechanisms mediating cholinergic antral circular smooth muscle contraction in rats

AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.