小于

The aim of this paper is to construct a class of quasihereditary endomorphism algebras with global dimension ≤3 from the algebras of representation dimension at most three.

介绍了表示维数小于等于3的一类非常重要的代数，并从这类代数出发，构造了一类新的整体维数小于等于3的拟遗传自同态代数。

Fluosilicic acid,which is the byproduct from phosphate fertilizer factory,reacts with ammonium hydrocarbonate to obtain ammonium fluosilicate,then reacts with ammonium carbonate to form settled SiO 2,after filtration,water washing,drying and calcining,high purity SiO 2 with less than 10×10 -6 metal impurity and less than 10×10 -9 uranium and thorium respectively is made.

由磷肥厂副产氟硅酸同碳铵反应得氟硅酸铵，再和碳铵反应生成SiO2 沉淀，经过滤、水洗、干燥、煅烧得高纯SiO2 ，其金属杂质总含量小于 10× 10 -6，含放射性元素铀和钍各小于 10× 10 -9，通过实验获得了适宜的工艺条件，反应温度 70℃～ 80℃，反应时间 1 5h～ 2 0h ，配料比n(NH4HCO3 )∶n(NH4 2 SiF6 =4 4。

The results show that under the same condition, it's easiest at corn bottom fringe to thresh, the second is at top fringe and the last is middle fringe;the longitudinal bending force is the optimal forcing method for threshing.

结果表明：在同样试验条件下，玉米穗大端籽粒脱粒较容易，小端次之，中部较难；纵向弯曲力小于侧向弯曲力，侧向弯曲力小于压力；种子玉米脱粒时的最佳施力方式为纵向弯曲力。

Using the time-gain compensation technique to compensate for ultrasonic wave's weaking when transmitting in the air,and reduce the fluctuation of echo signal.The peak time detecting circuit which is composed of full-wave rectification circuit and differential circuit can detect the reach time of echo signal accurately.

和其他方法相比，如激光测距、微波测距等，由于声波在空气中传播速度远远小于光线和无线电波的传播速度，对于时间测量精度的要求远小于激光测距、微波测距等系统，因而超声波测距系统电路易实现、结构简单和造价低，且超声波在传播过程中不受烟雾、空气能见度等因素的影响，在各种场合均得到广泛应用。

These represent greater than, greater than or equal to, less than, and less than or equal to

这些即大于，大于或等于，小于，小于或等于

According to the Ministry of Agriculture Environmental Quality Supervision, Inspection and Testing Center of Jiayin County, three years of continuous monitoring results Jiayin County green soybean integrated regional soil pollution index is far less than O.7, grades are level, the atmospheric integrated index of less than O. 6, air quality level, without any pollution of water quality of water, soybean production in line with the green standards, the current has been made in A grade green food mark the right to use green food Jiayin County soybean acreage of 35 million mu, output reached 35,000 tons, including fat, high (22%), protein (42%) is the development of Jiayin County, the county economy's pillar industries.

根据农业部环境质量监督检验测试中心对嘉荫县三年的连续监测结果，嘉荫县绿色食品大豆种植区域土壤综合污染指标远远小于O.7，等级属于一级，大气综合指数小于O.6，大气质量为一级，水质属无任何污染的优质水，生产的大豆符合绿色标准，目前已经取得了A级绿色食品标志使用权，嘉荫县绿色食品大豆种植面积35万亩，产量达3.5万吨，含脂肪高（22％）、蛋白高（42％），是发展嘉荫县县域经济的支柱产业。

The power variation of the targeted harmonic signal and harmonic suppression ratio were calculated and evaluated. The theoretical caculations and simulated results suggest that power variation can be maintained within 1 dB with dc bias drift less than 5% and the harmonic suppression ratio is stable in the SSB RoF link.

理论计算和仿真结果表明，偏置漂移会使目标信号的功率抖动增大，但当偏置漂移量小于5％时，功率抖动小于1 dB，而谐波抑制比保持稳定；分析了与非理想光电调制器啁啾相关的有限消光比和双臂驱动不平衡度对RoF链路性能的影响，有限消光比会增加目标信号的功率抖动并降低谐波抑制比，而通过优化调制器的双臂驱动不平衡度可以提高单边带调制RoF链路性能。

The results showed that the constitutes of thin films by PLD consisted with the targets ,and realizing thin films deposited with same constitutes;All of the films were heteromorphism;It was revealed that the effect of the growth temperature was significant to the diffract peaks of the films and that of the substrate was negligible;the films had rather flatness surface and compact structure;the peak-to-tail roughness of PbSe thin films surfaces was less than 200nm and that of ZnO and Mn doped ZnO films surfaces was less than 100nm;Flat degree was improved with falling of growth temperature and laser energy .

测试结果表明：PLD法制备的薄膜的成分与靶材的基本一致，实现了同组分沉积；所有制备的薄膜都为多晶薄膜，发现薄膜生长温度是影响薄膜衍射峰的主要因素，基片类型对此影响不明显；所有薄膜表面比较平滑，结构比较致密；其中PbSe薄膜的表面不平整度小于200nm，ZnO和Mn离子掺杂ZnO薄膜的表面不平度小于100nm；生长温度和激光能量降低能提高薄膜表面的平整度。

XRD,X-ray EDS analysis,AFM and Fourier transform infrared spectroscopy were employed to characterize PbSe thin films. The results show that all of the films were heteromorphy and the growth temperature has effect to the diffract peaks of the films. The contents of PbSe thin films by PLD consisted with the targets,and realizing thin films deposited with same constitutes; the films had rather flatness surface and compact structure; the peak-to-tail roughness of PbSe thin films surfaces was less than 200nm;they had sensitivity to light of a specified wavelength and obvious absorption edge at 5μm corresponding to band-gap width of PbSe thin films;light of wavelength less than 5μm was strongly absorbed.

通过脉冲激光沉积法在Si(111)和SiO2玻璃基片上制备了PbSe薄膜。X射线衍射、X射线能谱、原子力显微镜、傅里叶变换红外光谱仪测试结果表明：所有制备的薄膜都为多晶薄膜，发现薄膜生长温度对薄膜衍射峰有一定影响；PLD法制备的薄膜的成分与靶材的基本一致，实现了同组分沉积；所有薄膜表面比较平滑，表面不平整度小于200nm，结构比较致密；PbSe薄膜对红外光具有敏感的响应特性；在波长为5μm处存在有明显的吸收边，此吸收边对应于直接带隙PbSe材料的禁带宽度；对应于波长小于5μm的红外光，PbSe薄膜存在有明显的强吸收。

We ascertain primary auditory cortex by recording the sound-induced reaction, then we stimulate white matter with electrode current, inducing and recording LTP in layer II /III.

结果发现：关键期给药组、成年给药组的LTP幅度增长百分数显著性小于正常组的LTP幅度增长百分数；关键期给药组LTP幅度增长百分数显著性小于成年给药组的LTP幅度增长百分数。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。