谈高层建筑疏散楼梯设计中的常见错误

本文对高层建筑疏散楼梯在设计中的一些错误提出了自己的观点及解决办法;阐述了疏散楼梯在设计中的重要性,必须引起设计者的足够重视。     

The study on site quality evaluation for dahurian larch (Larix gmelinii Rupr.)

Site quality of larch (Larix gmelinii Rupr.) in Da Xingan Mountain in Inner Mongolia was studied systematically with about 1000 temporary plots and computer software. The nature of site class and site index curve was discussed in view of general mathematical model of height growth. The height growth of dominant tree of four divisions of forest stands were studied and site index tables were constructed respectively. In order to unify the comparing standard and convenience for management in this region, site index table was constucted too. Based on discussing the action and accuracy of forest type, a series of site quality evaluation (forest type-site index class-site index) was suggested. This subject of study is supported by the National Natural Scientific Fund (No. 39270549).     

谏壁发电厂泵站改造实践

为解决渣浆泵在运行时轴封水供应困难的问题，计算了谏壁发电厂松林山泵站的装置特必,天详细分析论证的基础上，确定了泵站的改造方案，进行了叶轮的优化设计。     

Effect of mate selection on fuzzy selective mating criteria in closed dairy multiple ovulation and embryo transfer nucleus programs

In order to control rates of response and inbreeding, mate selection using fuzzy selective mating criteria (FMC) was investigated in adult multiple ovulation and embryo transfer nucleus schemes for dairy cattle. Stochastic simulation was used to model the closed nucleus scheme. This mate selection was examined in four alternative mating and male selection schemes: (i) a hierarchical scheme; (ii) a hierarchical sibship scheme (two males per sibship); (iii) a factorial scheme (two sires per dam); and (iv) a factorial sibship scheme (two males per sibship and two sires per dam). Genetic response and inbreeding rate tended to be reduced by increasing the trade-off parameter of FMC between the expected breeding value and inbreeding of progeny. Inbreeding rates in all schemes were reduced by reducing the variance of family size through selection and the average coancestry of mating pairs through mate allocation.     

Utilization of Aromatic Rice in Improving Grain Quality of Hybrid Rice

ThesuccessfuldevelopmentandcommercialuseofhybridricehasgreatlyraisedriceyieldlevelinChina .However ,ithasbeenagreatchallengeforbreederstoim provethegrainqualityofhybridricewithoutsacrificeofitsyield ,i.e .,todevelophybridricecombinationswithgoodgrainqualityaswellashighyield .AromaticricelikeBasmatiinIndiaandPakistanandJasmineinThailand ,isfamousforitshighqualityandu niquepleasantflavorofaroma ,soitishighlyfavoredbyriceconsumersaroundtheworld .Itmightbeaneffectiveapproachtoimprovethegrainqual…     

Factors affecting agonistic interactions of pigs after regrouping in pens with a box

To determine the factors affecting agonistic interactions after regrouping, 24 pigs were allocated to six pens that each had a box. Half of the pigs were experienced in using the box. One castrated male and one female pig were transferred from each pen to another pen at random. The number of pigs attacked was particularly large for the pigs that had no experience in using the box and were transferred on the first day ( P <  0.05). The duration of access to the box was markedly longer for the pigs that had experience in using the box and were not transferred on the first day ( P <  0.05). The number and duration of attacks were significantly larger and longer toward unfamiliar individuals than toward familiar ones (both P < 0.01). The number of attacks toward the same sex was significantly larger than toward the opposite sex ( P <  0.01). A negative correlation was found between the number of agonistic interactions on the first day and the range of body weights in the pen mates ( r =  −0.78, P  = 0.07). In conclusion, regrouping with unfamiliar individuals should be avoided, but when unavoidable, the following methods are recommended to reduce agonistic interactions: (1) ensure the intruders are experienced in using a box, (2) move experienced intruders in with residents that have no experience in using a box, (3) mix different sexes, and (4) have wide variations in body weights in a pen.     

硝酸还原酶与氮素利用的关系及其在作物遗传育种中的应用(综述)

本文综述了硝酸还原酶与氮素利用的关系及其遗传特性和在作物育种中应用的某些最新进展。氮吸收、利用等性状的生理和遗传特性极其复杂,受环境影响很大,对其进行遗传改良需考虑多种指标。对硝酸还原酶活性(NRA)与品质性状和产量的关系的争论很多,有些研究表明 NRA 可作为品质、产量性状的选择指标,有些则相反。逆境条件下 NRA 的变化非常敏感,NRA 可能与抗逆性有关。     

国产MJ3210小型木工跑车带锯机锯解正交试验分析

采用正交试验设计法，对国产MJ3210小型木工跑车带锯机的锯解质量进行研究。通过实测马尾松锯材尺寸偏差、表面粗糙度等参数，得到其最佳的进料速度、锯解厚度和锯卡高度的组合方案。结果表明，该设备具有结构简单、出材率高、锯解精度高、质量好、成本低和生产效率高等优点。     

对引进草坪草在青海西宁地区的种植品质评价

通过对巴林、亨特、白宝、首相、百琪、百绿、凌志和维加斯8个引进草坪草品种的品质评价，研究了其在西宁地区的坪用性表现以及适应能力，选择出品质较优良的品种。测定了各品种的密度、盖度、质地、耐磨度、颜色、生育型和生长速度以及越冬力。结果表明，供试8个品种中的巴林、亨特、百琪、凌志和维加斯5个品种有较好的越冬能力(WH≥3)。而8个品种均表现出良好的坪用性(TPPl或TPP2≥3)，其中，巴林(Wh＝5，TPP1＝3．6，TPP2＝3.7)、亨特(Wh＝5，TPPl＝3.4，TPP2＝3.6)、百琪(Wh＝4，TPPl＝4.1，TPP2＝3．5)、凌志(Wh＝4，TPPl＝3.0，TPP2＝3．5)和百绿(Wh＝3，TPPl＝4.0，TPP2＝3.1)5个品种无论是越冬力还是坪用性均表现突出，可以作为当地品质较优良的草坪草。