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1.
在杂交水稻汕优63始稳期，用15mmol／LCa(2 =)喷施叶面，能增加抽穗结实期间主茎旗叶的叶绿素和可溶性蛋白质含量，提高超氧物歧化酶（SOD）的活性．降低丙二醛（MDA）含量．延缓叶片衰老；同时，Ca(2 )能增加主德的实位数、结实串和千粒重，从而提高谷产量． 相似文献
2.
李伯军 《内江师范学院学报》2007,22(4):78-82
杂种优势固定可通过无融合生殖、半配合生殖、染色体变异和组织培养等方法实现.在育种实践中,发现了杂种优势在F3代及以前不分离的现象,即早世代稳定,其遗传学机制包括有丝分裂重组机制、体细胞染色体消除机制、有丝分裂染色体分组机制和DNA片段杂交.研究发现,早世代稳定现象发生时存在一些共同的特征. 相似文献
3.
This paper proposes novel multi-layer neural networks based on Independent Component Analysis for feature extraction of fault
modes. By the use of ICA, invariable features embedded in multi-channel vibration measurements under different operating conditions
(rotating speed and/or load) can be captured together. Thus, stable MLP classifiers insensitive to the variation of operation
conditions are constructed. The successful results achieved by selected experiments indicate great potential of ICA in health
condition monitoring of rotating machines.
Project supported by the National Natural Science Foundation (No. 50205025) and the Natural Science Foundation of Zhejiang
Province (No. 5001004). 相似文献
4.
Remote sensing techniques have the potential to provide information on agricultural crops quantitatively, instantaneously
and above all nondestructively over large areas. Crop simulation models describe the relationship between physiological processes
in plants and environmental growing conditions. The integration between remote sensing data and crop growth simulation model
is an important trend for yield estimation and prediction, since remote sensing can provide information on the actual status
of the agricultural crop. In this study, a new model (Rice-SRS) was developed based mainly on ORYZA1 model and modified to
accept remote sensing data as input from different sources. The model can accept three kinds of NDVI data: NOAA AVHRR(LAC)-NDVI,
NOAA AVHRR(GAC)-NDVI and radiometric measurements-NDVI. The integration between NOAA AVHRR (LAC) data and simulation model
as applied to Rice-SRS resulted in accurate estimates for rice yield in the Shaoxing area, reduced the estimating error to
1.027%, 0.794% and (−0.787%) for early, single, and late season respectively. Utilizing NDVI data derived from NOAA AVHRR
(GAC) as input in Rice-SRS can yield good estimation for rice yield with the average error (−7.43%). Testing the new model
for radiometric measurements showed that the average estimation error for 10 varieties under early rice conditions was less
than 1%.
Project supported by the National Defense Scientific and Technological Committee of China(No. Y97#14-6-2) 相似文献
5.
Umezuruike Linus OPARA Dan JACOBSON Nadiya Abubakar AL-SAADY 《Journal of Zhejiang University. Science. B》2010,11(5):332-341
Banana is an important crop grown in Oman and there is a dearth of information on its genetic diversity to assist in crop breeding and improvement programs.This study employed amplified fragment length polymorphism(AFLP) to investigate the genetic variation in local banana cultivars from the southern region of Oman.Using 12 primer combinations,a total of 1094 bands were scored,of which 1012 were polymorphic.Eighty-two unique markers were identified,which revealed the distinct separation of the seven cultiva... 相似文献
6.
Liu ZY Huang JF Shi JJ Tao RX Zhou W Zhang LL 《Journal of Zhejiang University. Science. B》2007,8(10):738-744
Detecting plant health conditions plays a key role in farm pest management and crop protection. In this study, measurement of hyperspectral leaf reflectance in rice crop (Oryzasativa L.) was conducted on groups of healthy and infected leaves by the fungus Bipolaris oryzae (Helminthosporium oryzae Breda. de Hann) through the wavelength range from 350 to 2 500 nm. The percentage of leaf surface lesions was estimated and defined as the disease severity. Statistical methods like multiple stepwise regression, principal component analysis and partial least-square regression were utilized to calculate and estimate the disease severity of rice brown spot at the leaf level. Our results revealed that multiple stepwise linear regressions could efficiently estimate disease severity with three wavebands in seven steps. The root mean square errors (RMSEs) for training (n=210) and testing (n=53) dataset were 6.5% and 5.8%, respectively. Principal component analysis showed that the first principal component could explain approximately 80% of the variance of the original hyperspectral reflectance. The regression model with the first two principal components predicted a disease severity with RMSEs of 16.3% and 13.9% for the training and testing dataset, respec-tively. Partial least-square regression with seven extracted factors could most effectively predict disease severity compared with other statistical methods with RMSEs of 4.1% and 2.0% for the training and testing dataset, respectively. Our research demon-strates that it is feasible to estimate the disease severity of rice brown spot using hyperspectral reflectance data at the leaf level. 相似文献
7.
INTRODUCTIONInthelastdecade,remotesensinghasbeenincreasinglyidentifiedasanobjective,standardized,possiblycheaperandfastermethodologyforcropproductionsurveysthanconventionalfieldinves-tigations(Bauman,1992).Muchprogresshasbeenmadethroughintensivestudiesoninventoryandproductionforecastingformajorcrops,suchaswheat,rice,cottonandmaize(Tennakoonetal.,1992;Rayetal.,1994;Fangetal.,1998).China,adevelopingcountrywith1.2billionpeople,hasbeenpayingcloseattentiontoitsex-istingandfuturefoodproduction… 相似文献
8.
The new Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite image offers a large choice of opportunities for operational applications. The 1-km Advanced Very High Resolution Radiometer (AVHRR) image is not suitable for retrieval of field level parameter and Landsat data are not frequent enough for monitoring changes in crop parameters during the critical crop growth periods. A methodology to map areas of paddy fields using MODIS, geographic information system (GIS) and global position system (GPS) is introduced in this paper. Training samples are selected and located with the help of GPS to provide maximal accuracy. A concept of assessing areas of potential cultivation of rice is suggested by means of GIS integration. By integration of MODIS with GIS and GPS technologies the actual areas of rice fields in 2002 have been mapped. The classification accuracy was 95.7% percent compared with the statistical data of the Agricultural Bureau of Zhejiang Province. 相似文献
9.
文章通过对项目教学法在《作物施肥原理与技术》课程中开展的可行性和必要性进行了分析,论证了在《作物施肥原理与技术》中应用项目教学法开展教学的优势,阐述了当前《作物施肥原理与技术》的教学现状及存在的问题,明晰了对《作物施肥原理与技术》实施项目教学法的具体过程和步骤,最后强调了项目教学法在该课程教学中的重要作用,并就课程教学中存在的系列问题提出了解决方案。 相似文献
10.
基于全寿命周期理论的工程项目健康检测体系构建 总被引：1，自引：0，他引：1
为了更有效地对工程项目的健康状态做出全面准确的评估,将全寿命期下工程项目所有监测指标按质量指标、费用指标、时间指标、各方面满意度和可持续发展指标等加以划分．并且基于该指标体系定性与定量指标相结合的特征,构建了PCA—PR分析模型．该模型先对全寿命期指标体系进行主成分分析（PCA）,从之前构建的全寿命期指标中甄选出一批可以作为工程项目健康检测分析的主要特征指标体系;再针对这些主要特征指标体系进行模式识别分析（PR）,即通过将工程项目即时可能状态划分为绿灯至红灯5种状态,利用模式识别模型和项目主要特征指标识别出项目任意时点的健康状态．最后结合实例进行相关分析,得出与实际情况较为吻合的分析结果,验证了该指标体系和模型的有效性． 相似文献
11.
根据1987年晚稻试验结果,对水稻穗部17个经济性状进行遗传相关和通径分析表明,16个经济性状对单株产量的直接效应大小不同,其中以一、二次枝梗的实粒数和粒重的直接效应最大,但这三者之间存在着互为负效应的矛盾关系(即负间接通径系统最大),并认为粒重不变的情况下,增加二次枝梗的实粒数,是提高单株产量的主要途径,还讨论了增加二次枝梗及其谷粒数的可行途径,提出了生理育种是今后水稻超高产育种的关键之一的论点。 相似文献
12.
Comparison of an SMS text messaging and phone reminder to improve attendance at a health promotion center： A randomized controlled trial 总被引：2，自引：0，他引：2
Objective To compare the efficacy of a short messaging service (SMS) text messaging and phone reminder to improve attendance rates at a health promotion center. Methods A total of 1 859 participants who had scheduled appointments in the health promotion center of our hospital from April 2007 to May 2007 were enrolled in the study and randomly assigned into 3 groups control (no reminder) group, SMS text messaging reminder group and telephone reminder group. Attendance rates and costs of interventions were collected. Results A total of 1848 participants were eligible for analysis. Attendance rates of control,SMS and telephone groups were 80.5%, 87.5% and 88.3%, respectively. The attendance rates were significantly higher in SMS and telephone groups than that in the control group, with odds ratio 1.698, 95% confidence interval 1.224 to 2.316, P=0.001 in the SMS group, and odds ratio 1.829, 95% confidence interval 1.333 to 2.509, P＜0.001 in the telephone group. However, there was no difference between the SMS group and the telephone group (P=0.670). The cost effectiveness analysis showed that the cost per attendance for the SMS group (0.31 Yuan) was significantly lower than that for the telephone group (0.48 Yuan). ConclusionSMS and telephone are effective reminders for improving attendance rate at a health promotion center. SMS reminder may be more cost-effective compared with the telephone reminder. 相似文献
13.
Mental health problems are common in war-affected areas, but children have different levels of vulnerability. Based on ecological theory (Bronfenbrenner, 2005), this study analyses how factors related to the child (cognitive capacity), their family (parental depression and parenting styles), and their school (teachers’ practices and peer relations) mediate the association between traumatic stress (traumatic war experiences and stressful life-events) and child mental health (posttraumatic stress and psychological distress symptoms). The participants were 303 Palestinian children (51.2% girls) of 10–13 years (M = 10.94 ± 0.50) and their parents from the Gaza Strip. The children filled in questionnaires during school classes and the parents did so at their homes. The results of structural equation modeling substantiated the hypothesis that parental depression, poor parenting and low-quality peer relations mediated between traumatic stress and children’s mental health problems. Contrary to the hypothesis, child-related factors did not mediate that association. To conclude, parents and peers provide important age-salient social resources for children in war conditions, and psychosocial interventions should therefore enhance their beneficial functions. 相似文献
14.
本文采用二因素随机区组试验,探讨了不同NPK养分,不同磁化处理的磁性化肥对杂交水稻产量及产量构成因素的影响。统计结果表明:不同磁肥对水稻产量的影响差异达到了极显著水平,其中以N_3P_1K_1×磁化粉煤灰(2000GS磁化处理)的磁肥的效果最好。养分与磁处理间存在显著互作反应,不同磁肥对有效穗数,每穗实粒数的影响均极显著,但对千粒重的影响不显著,水稻产量与有效穗数的偏相关程度较大,水稻产量约70％可由每株有效穗数、每穗实粒数的变异决定,NPK养分是磁肥主成分,其效应大于磁效应,且磁效应与养分有关。 相似文献
15.
Huan Wang Dong-mei Liu Zhi-wei Zhao Fu-yi Cui Qi Zhu Tong-mian Liu 《浙江大学学报(A卷英文版)》2010,11(2):143-150
The formation of brominated trihalomethanes （THMs-Br） which is proved more carcinogenic than their chlorinated analogues reported was very different at various water qualities. This study was performed to assess the effects of water quality parameters （bromide concentration, pH value and ammonia concentration）, chlorination conditions （chlorine dose, reaction time） and ratios of Br^-/DOC and Br^-/Cl2 consumption on the formation and distribution of THMs-Br in chlorination. The results showed good correlation between the bromine incorporation factor （BIF） n（Br） and Br^-/Cl2 consumption ratio. The formation of total THM （TTHM） was found to＇ decrease with increasing ammonia concentration but to increase with bromide concentration and pH value. The n（Br） trends were significantly affected by the presence of bromide concentration. The effects on the molar yields of THMs were more strongly influenced by bromide concentration and dissolved organic carbon （DOC） concentration than pH value and natural organic matter （NOM） source. High Br^-/DOC and Br^-/Cl2 favor the formation of THMs-Br over chlorinated THMs （THMs-Cl）. The experimental data including the main parameters such as bromide, DOC, ammonia, pH and reaction time were used for developing the predictive model for THMs-Br. 相似文献
16.
ObjectiveAbusive head trauma is the leading cause of physical abuse deaths in children under the age of 5 and is associated with severe long-lasting health problems and developmental disabilities. This study evaluates the long-term impact of AHT and identifies factors associated with poor long-term outcomes (LTOs).MethodsWe used the Truven Health MarketScan Research Claims Database (2000–2015) to identify children diagnosed with AHT and follow them up until they turn 5. We identified the incidence of behavioral disorders, communication deficits, developmental delays, epilepsy, learning disorders, motor deficits, and visual impairment as our primary outcomes.ResultsThe incidence of any disability was 72% (676/940) at 5 years post-injury. The rate of developmental delays was 47%, followed by 42% learning disorders, and 36% epilepsy. Additional disabilities included motor deficits (34%), behavioral disorders (30%), visual impairment (30%), and communication deficits (11%). Children covered by Medicaid experienced significantly greater long-term disability than cases with private insurance. In a propensity-matched cohort that differ primarily by insurance, the risk of behavioral disorders (RD 36%), learning disorders (RD 30%), developmental delays (RD 30%), epilepsy (RD 18%), and visual impairment (RD 12%) was significantly higher in children with Medicaid than kids with private insurance.ConclusionAHT is associated with a significant long-term disability (72%). Children insured by Medicaid have a disproportionally higher risk of long-term disability. Efforts to identify and reduce barriers to health care access for children enrolled in Medicaid are critical for the improvement of outcomes and quality of life. 相似文献
17.
目的以衰老的自由基学说为依据,研究蚁皇浆口服液的抗衰老作用.方法52周龄小白鼠30只随机分为老龄实验组和老龄对照组,4周龄15只作为成年对照组,灌胃四周后分别取血测定SOD、CAT、Tch、TG和MDA等各项生化指标.结果老龄实验组SOD、CAT活性均明显升高(P＜0.01),MDA、Tch和TG含量明显降低(P＜0.01或P＜0.05).结论蚁皇浆口服液具有较强的抗氧化和抗衰老作用,是一种很有经济价值药食两用的保健品. 相似文献
18.
本文通过对水稻分蘖成穗与产量组成数量关系的分析表明：提高成穗率即可提高产量及其组成因子;群体穗数与产量多呈负相关,单株穗数与产量多呈正相关;群体的苗、茎（蘖）、穗与成穗率多呈负相关,单株的茎（蘖）、穗与成穗率多呈正相关。 相似文献
19.
Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes 总被引：2，自引：0，他引：2
INTRODUCTION Aluminum (Al) toxicity is one of the mostimportant yield-limiting factors for crop grown onacid upland and lowland acid sulphate soils (IRRI,1978). Al toxicity results in a reduced and damagedroot system, which in turn causes the affectedplants to be susceptible to drought stress and min-eral nutrient deficiencies (Foy, 1988). The physio-logical and biochemical mechanisms of the toxiceffect of Al on root elongation had been extensivelyinvestigated (Matsumoto, 2000). T… 相似文献
20.
Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an A1 sensitive lowland indica rice variety IR1552 and an Al tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for A1 tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1, 9, 12, respectively, and I QTL for root length under Al stress is identical on chromosome I after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for Al tolerance. This interval provides an important start point for isolating genes responsible for A1 tolerance and understanding the genetic nature of Al tolerance in rice. Four Al induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL. 相似文献