Interstellar Scattering of Pulsar Radiation and Its Effect on the Spectrum of NP0532

Angular scattering in the interstellar medium results in multipath dispersion which can amount to more than one pulse period for pulsars of short period and high dispersion measure. The dispersion, if operative, imposes on the pulsation flux a cutoff inversely proportional to the fourth power of the observing wavelength. The low-frequency pulse shape of pulsar NP0532 suggests that this pulsar is subject to such scattering and that the observed low-frequency cutoff in the apparent spectrum is not an intrinsic property of the pulsar. In fact, there is evidence that NP0532 may be identified as the compact, low-frequency source in the Crab Nebula and that the pulsar may radiate in accordance with its high-frequency spectrum down to frequencies as low as 10 megahertz, although the periodic time variations are suppressed by the scattering below 100 megahertz.     

Interstellar sulfur hydride: a search for the 111-megahertz lines

Similarities in the energy-level structure of the sulfur hydride radical and the hydroxyl radical suggest that sulfur hydride in the interstellar medium might be detectable because of a population inversion or anti-inversion similar to that of the hydroxyl radical. We have searched for the 111.54-megahertz transition [F (total angular momentum quantum number) = 2 --> 2] and for the 111.22-megahertz transition (F = 1 --> 1) in the galactic radio source W49, one of the brightest hydroxyl emission sources. No sulfur hydride emission lines with half-power widths of 130 hertz or greater were detected with the 1000-foot Arecibo antenna. The upper limits established with 100-hertz filters were 50 and 60 flux units (1 flux unit= 10(26) watt meter(-2) hertz(-1)), respectively, for the two lines.     

Volcanic Ash over Arizona in the Spring of 1982: Astronomical Observations

Astronomical observations in Arizona recorded the passage of one, and possibly more, volcanic dust clouds between January and June 1982. On 15 May the increase in extinction in visible wavelengths at Tucson was more than 40 percent or 0.4 in optical depth. At Flagstaff, 325 kilometers north, the increase in extinction on the same day was 25 percent. A detailed time history of atmospheric extinction plus evidence for nongray absorption from the cloud is presented.     

Radio Observations of Interstellar Hydroxyl Radicals: Have we discovered a gigantic maser, or could we be detecting interstellar communications?

The discovery of the radio frequency lines of OH gave the first positive evidence of the existence of OH in the interstellar medium. In the 3(1/2) years that have intervened, many observations have revealed totally unexpected anomalies in the radio-spectral properties of interstellar OH. As a result, no reliable astrophysical information has been derived from the OH observations, but a large body of information is waiting to be unraveled. The interpretations of the data which have been made, such as the values derived for OH/H abundance ratios or for the kinetic temperatures of interstellar gas clouds, must be viewed with caution. They may turn out to be drastically in error, once the origin of the OH emission and absorption is fully understood.     

A Search for the 110 larr 111 Transition of Interstellar Thioformaldehyde

A search has been made for the 1(10) <-- 1(11) transition of thioformaldehyde in interstellar clouds where formaldehyde is known to exist. Failure to detect this transition indicates that the ratio of thioformaldehyde abundance to that of formaldehyde is probably less than the abundance ratio of sulfur to oxygen.     

祖厉河水质状况及养殖潜力分析

[目的]研究祖厉河的水质特性,为开发利用祖厉河提供基础数据。[方法]水样取自甘肃省会宁县祖厉河中游河畔镇河段,水样的盐度和pH在采样点测定,其他水样处理后带回实验室测定,水样的处理和水质指标的测定按国家标准操作。[结果]祖厉河中游河畔镇河段河水的pH为8.15,盐度为10.00‰,Ca2+、Mg2+、氯化物、硫酸盐、CO32-碱度、HCO3-碱度、硝态氮化合物以及磷酸盐的含量分别为453.4、380.2、3 069.5、2 072.8、9.3、175.7、6.7 mg/L和52.9μg/L。[结论]祖厉河中游的水质接近海水水质,适宜养殖海水生物。     

Water Quality Characteristics in Znli River and Its Potential for Mariculture

[目的]研究祖厉河的水质特性,为开发利用祖厉河提供基础数据.[方法]水样取自甘肃省会宁县祖厉河中游河畔镇河段,水样的盐度和pH在采样点测定,其他水样处理后带回实验室测定,水样的处理和水质指标的测定按国家标准操作.[结果]祖厉河中游河畔镇河段河水的pH为8.15,盐度为10.00‰,Ca2+、Mg2+、氯化物、硫酸盐、CO32-碱度、HCO3-碱度、硝态氮化合物以及磷酸盐的含量分别为453.4、380.2、3069.5、2 072.8、9.3、175.7、6.7 mg/L和52.9μg/Lo[结论]祖厉河中游的水质接近海水水质,适宜养殖海水生物.     

晾晒烟调制过程中酶促棕色化反应及调控方法

对晾晒烟叶在调制过程中酶促棕色化反应的过程、本质、反应发生的条件及影响因素进行了综述,探讨了晾晒烟叶调制过程中多酚氧化酶活性抑制剂、激活剂、环境温湿度条件、环境pH值和氧气浓度等对酶促棕色化反应的调控作用,并从基因调控多酚氧化酶(PPO)表达以及多酚氧化酶天然激活剂和抑制剂的应用角度提出了进一步发展的方向,旨在为晾晒烟调制过程中酶促棕色化反应的调控提供参考。     

孙中山农业思想在台湾现代农业发展中的实践与启示

孙中山是中国革命的伟大先行者,在领导中国民主革命的过程中,所形成的一系列思想对后来的社会经济发展都产生了重要的影响。农业问题是孙中山较为关心的领域,由此也形成了他较为完整的发展现代农业的思想。我国台湾现代农业发展所取得的成就离不开这一思想的指导。该文对孙中山农业思想的进行了梳理,分析了其思想我国台湾地区现代农业发展实践情况,并归纳其对大陆当前的现代农业发展战略的借鉴。     

能源植物资源及应用潜力概述

从不同的层面对能源植物的概念、研究历史、资源研究概况以及生物能源开发利用的可行性等进行了较为系统的分析和总结,对能源植物资源的进一步探索具有参考价值。     

Studies on the Mutagenicity and Teratogenicity of Kuianchun and Its Potential Carcinogenicity Prediction

Kuianchun is a newly synthesized antibacterial and growth-promoting drug. This paper selected a battery of three short-term tests, including Ames test, micronucleus test and sperm abnormality test, to detect the mutagenicity of Kuianchun. The carcinogenicity prediction and battery selection method (CPBS method) was used to determine the probability of carcinogenicity of Kuianchun based upon the results of shortterm tests mentioned above. In addition, traditional teratogenic test was selected to study teratogenicity of Kuianchun. In Ames test, Kuianchun showed mutagenic for Salmonella typhimurium strains TA98 and TA100 in the absence and presence of microsomal metabolic activation system (S9-mix). However, the mutagenicity was reduced by the addition of S9-mix. In micronucleus test, Kuianchun was administered intra-peritoneally to male mouse 30 hours and 6 hours before they were killed respectively. The result indicated that there was no significant difference on the number of micronucleated polychromatic erythrocytes (PCEs) in the mouse bone marrow induced by Kuianchun compared with the negative contrast (50% DMSO) (P ＞ 0.05). In sperm abnormality test, Kuianchun was administered through a gastric incubation to male mouse as a suspension in 2% Tween-80. The dosage levels were 450, 750, 1000 and 1500mg/kg per day for 5 days. The result indicated that the percentage of abnormal sperms induced by Kuianchun was not significant compared with the negative contrast (P＞0.05). In traditional teratogenic test, Kuianchun was given orally to pregnant mouse at 1/30,1/20 and 1/15 LDs0 during 6 - 15days of pregnancy period (the LD50 = 9000mg/kg). No toxicity was found either on mother and embryo in mouse, and teratogenic effects were also not observed at all tested dosages. The probability of carcinogenicity of Kuianchun is 23.8 % (θ = 0.238). The result demonstrated that Kuianchun is a non-carcinogen.     

新型饲料添加剂喹胺醇致突变性及其潜在致癌性预测

 选择Ａｍｅｓ试验、小鼠微核试验和精子畸形试验３种短期试验组合研究了喹胺醇的致突变性,并在获得各 单项试验结果的基础上,利用“致癌性预测和选择试验组合的方法”即 ＣＰＢＳ法对喹胺醇潜在致癌性进行预测。结果表 明：（１）Ａｍｅｓ试验喹胺醇标准掺入不论加与不加Ｓｇ－ｍｉｘ对鼠伤寒沙门氏菌 ＴＡ９８和ＴＡ１００两个标准株都有诱变性,并 有剂量－反应关系。加入 Ｓｇ－ｍｉｘ后,ＴＡ９８和 ＴＡ１００回复突变菌落数均明显下降。（２）小鼠处死前 ３０ｈ和 ６ｈ分别腹腔注 射哇胺醇３０,６０,１２０和２４０ｍｇ／ｋｇ,骨髓嗜多染红细胞（ＰＣＥ）微核率与阴性对照组（５０％ＤＭＳＯ）比较差异均不显著（Ｐ ＞０．０５）。（３）小鼠连续用哇胺醇４５０、７５０、１０００和１５００ ｍｇ／ｋｇ灌胃５ｄ（１次／ｄ）,于第３５天处死,精子畸形率与阴性对 照组（２％吐温－８０）比较差异均不显著（Ｐ＞０．０５）。（４）利用ＣＰＢＳ法预测,喹胺醇θ＝０．２３８,初步定为非致癌物,进一步 的结论还需增加试验组合进行确定。     

甘蓝型油菜自交不亲和保持系的选育及其利用潜力

选育自交不亲和系的保持系有望解决大量繁自交不亲和系的困难。通过对国外和国内50份材料对甘蓝型油菜自交不亲和系“271”,“SI1300”恢复性或保持性的研究。在中国甘蓝型油菜遗传资源中找到了SI系的保持系,并得到4个保持效果好的双低（低芥酸,低硫苷）材料,大部分材料能恢复自交不亲和特性,历而易于选育到优良杂交种,进一步的研究表明由保持系配制的单交和三交杂种都有一定的产量潜力,通过筛选适当的恢复系有望得到优良的自交不亲和杂种。     

海南南繁区水稻基因飘流的最大阈值距离及其时空分布特征

【目的】陵水、三亚、乐东三县（市）是各类水稻（包括转基因水稻）冬季南繁的主要基地或中心。计算并绘制海南南繁区乡镇尺度水稻基因飘流的最大阈值距离图,为南繁水稻育种设置合理的隔离距离提供参考。【方法】采用已建立的水稻基因飘流模型和阈值分析方法,依托南繁区自动气象站资料,计算了该区域乡、镇尺度向不育系和栽培稻基因飘流的最大阈值距离（the maximum threshold distances of gene flow,MTDs）,分析其时、空分布特征和影响因子。参照中国农业部有关水稻种子生产的质量标准,阈值分别设为1%和0.1%。【结果】南繁区向不育系的MTD_1%平均值为（110±31）m,最短为53 m,最长为195 m。向不育系的MTD_0.1%平均值为（169±44）m,最短为75 m,最长为271 m。向栽培稻的MTD_1%均小于1 m;MTD_0.1%平均值为（3.4±1.1）m,最短为0.6 m,最长为5.8 m。向不育系和栽培稻的MTD_0.1%两者相差近50倍。南繁区MTDs有2个高值区和4个高值点,3个低值区和5个低值点。以陵水、三亚、乐东为主体的南繁区,地处热带,三面临海,北面有五指山为屏障。冬季盛行东北季风,春季和初夏盛行南太平洋的东南季风和印度洋的西南季风。因此,南繁区的沿海陆地平原大都风速较大;沿海陆地与五指山区之间为中、低山丘陵地带,丘陵的走向和高度决定了该区的风向和风速;五指山南坡附近的丘陵地区,风速会因屏障效应而明显减小。【结论】地形特征和大气环流影响风向和风速,决定了南繁区MTDs空间分布的基本格局：高值区主要分布在该地区的东翼、西翼和南部沿海平原;低值区主要分布在五指山南麓的屏障区域。     

我国水产品加工业发展现状及潜力分析

通过论述中国水产品加工业发展的现状和特征。分析水产品加工业发展面临的问题和制约因素,提出中国水产品加工业未来发展的潜力在四个方面有待挖掘．即水产品加工业向精深加工发展,提高水产品加工品质、丰富加工种类;提高加工能力和技术装备水平,实现水产加工自动化和标准化;提高加工品质量安全水平,为消费者提供安全、方便的食品;积极开拓国内外消费市场,加工业与生产和消费紧密结合。和促进产业发展的政策建议。     

异丙威及其水解产物对DNA潜在损伤作用的研究

根据异丙威和DNA作用后形成加合物的过程可以从其吸收光谱和荧光光谱的变化反映出来,异丙威水解产物和DNA作用后会导致电化学峰正移以及电流减小的原理,用荧光光谱法、紫外吸收光谱法及电化学方法研究了异丙威及其水解产物与DNA的相互作用。结果表明,无论是异丙威还是其水解产物,都能与DNA发生嵌插作用并对其造成损伤。通过计算两者和DNA作用的结合常数,发现异丙威的水解产物与DNA的结合常数更大,即更易和DNA形成加合物而损伤DNA。     

江苏省农作物秸秆的生物天然气潜力及其温室气体减排估算

以适宜我国江苏省生物天然气生产的各类农作物秸秆的资源量为基础,以江苏省生物天然气的生产潜力为核心讨论其温室气体减排潜力.通过筛选的草谷比系数对江苏省秸秆资源进行全面系统的估算,并对江苏省秸秆资源量的区域分布规律进行探讨.研究结果显示,2012年江苏省理论秸秆资源量约4 840万t,其中水稻秸秆占秸秆资源总量的49％,小麦秸秆约占26％;可获得量约为3 934万t;秸秆的能源资源量为2 359万t.秸秆的生物天然气潜力为638 641万m3,其温室气体减排潜力为1 114.43万t.江苏省秸秆资源分布苏北地区最高,苏中地区其次,苏南地区最低.该研究结果可为江苏省秸秆资源利用提供参考依据.     

微生物群体感应及其在感染性疾病治疗新策略中的潜在应用

微生物抗药性突变株的出现,导致抗生素的治疗效果大幅降低,寻找新的感染性疾病防治策略迫在眉睫。病原菌的致病毒性受群体感应系统调控,因此,以群体感应为靶标,调控群体感应过程中的关键步骤可以达到治疗感染性疾病的目的。这种以阻断群体感应过程而非细胞生长为治疗策略的方式,不会引起抗药性突变株的出现,所开发的药物是抗病原性的,是继抗生素之后最具发展前景的新型抗感染药物之一。主要论述了有关群体感应作为新型药物靶标的可能性及相关研究的最新进展。