驳唐代进士难、明经易说

近几十年流行唐代进：仁难、明经易说,所持理由一是两科录取率相差悬殊,二是两科考试内容不同,难易有差。考察具体情况,不是这么回事。实际情况是,进士、明经,难易相当。     

First Trials to Set Up a Microwave Reflectometric Tool for the Survey of Historic Timber Structures

Timber structures can be degraded during their life both by structural problems and by biological degradation factors like fungi and insects. The occurrence of those biodegradation agents could lead to a loss of their structural integrity, in the absence of appropriate maintenance. An early assessment of the decay is even more important when the wooden structures are part of historical buildings, in the interest of conservation of cultural heritage.

This article presents an application of microwave reflectometry for the in situ evaluation of timber structures. The measurement system allows detecting anomalies inside the material in a non-destructive and non-invasive manner.

The reflection coefficient is measured by means of a vector network analyzer (VNA) using a double-ridge antenna which transmits the continuous-wave (CW) microwave signal and receives the signal reflected by the material under investigation.

Measurements on laboratory models demonstrated the feasibility of the method. Results obtained on timber beam sections, compared with the findings of traditional investigation methodologies, demonstrate the potentiality of microwave reflectometry, suggesting its possible usefulness during the diagnostic phase as a non-invasive tool for preliminary screening.     

浅谈随书光盘的管理与利用

该文通过对随书光盘管理中存在的问题的分析,结合实际,提出了提高随书光盘利用率的方法及建议。     

基于旅游生产线的景区容量算法

现行的风景区空间日容量的计算方法往往大大高估了景区容量。本文以游客在景区中的移动行为为出发点,将景区旅游线路类比为旅游生产线,其中游客为工件、景点为工序。利用旅游生产线的平行移动特征,推导出在景区日开放时间内能够完成景区游玩的游客批数。然后,以景区线路中的瓶颈景点容量为批量,该批量与批数相乘即得到了景区容量。旅游生产线理论填补了景区容量计算理论支撑的空白,并使景区容量计算真正的科学化、合理化。     

北京城市空间认知的影响因素分析

城市空间认知影响因素分析与认知空间格局研究具有同等的重要性。论文基于北京城市空间认知调查问卷数据,引入居民属性等16个变量,利用二值Logistic回归方法,提炼出23个认知地点整体以及交通节点、商场、休闲地三种类型地点的认知影响因素。发现:第一,不同类型地点的认知率影响因素存在异同,其中,存在职住变更是最为显著的共性因子。第二,各类地点中的显著影响因子对认知率的作用大小有明显差异,年龄46-55岁变量是23地点认知率的最重要影响因素,交通节点和商场认知率最重要的影响因素为就业内城四区,而就业地与休闲地距离小于等于6km变量对休闲地认知率的影响最大。第三,各类模型中的影响因素类型不同且影响程度有很大差异,故具有不同属性信息组合的居民认知率不同。     

Measuring use-related fracture velocity in lithic armatures to identify spears,javelins, darts,and arrows

This study employs a brittle fracture-mechanics-based approach to explore the relationship between lithic fracture velocity and precursory loading rate in fine-grained lithic armatures. The data demonstrate that only high-speed dart and arrow armatures are subject to dynamic loading events, whereas spear and javelin armatures are limited to rapid (and quasi-static) loading. The data presented were derived from controlled experiments employing spears, javelins, spearthrower darts, and arrows. Armatures associated with both bow and spearthrower technologies are reliably identified and distinguished from those of low-speed technologies such as spears and javelins. Javelin armatures may also sustain higher velocity fractures than spear armatures, thus permitting the further differentiation of these technologies. The methodology offers a quantitative, non-subjective means to identify the delivery technology associated with a lithic armature.     

辛亥革命元勋王天培将军遗文

辛亥革命元勋贵州籍将领王天培,一生追随孙中山先生革命,笃信三民主义,由于性情直率,胸怀坦荡,遭到蒋介石、何应钦等人嫉妒,以＂莫须有＂罪名陷害,英年早逝。从他撰写的一些对联、讲话、题词、诗歌、信函等遗文里,不难看出王天培聪颖的才华,直率的性格,忠诚的思想,坦荡的胸怀,以及坚定的信念和高尚的气节,不愧是贵州人民的好儿女。     

A Tale of Two Cities: A Decomposition of Recent Fertility Changes in Shanghai and Hong Kong

In the past 20 years, Hong Kong and Shanghai's total fertility rates (TFR) have undergone drastic changes: first declining and then rebounding. We use a decomposition method to assess changes in the TFRs of these two cities during the period 1990–2010. During the period of decline from 1990 to 2000, the decrease in marital fertility rate (MFR) was the major cause behind Shanghai's TFR decline; the decrease in nuptiality and MFR were equally responsible for the decline in Hong Kong's TFR. During the 2000–2010 period, although the decline in nuptiality exerted downward pressure on TFR, both cities experienced an increase in TFR mainly due to an increase in the MFR. Analysis of the difference in TFR between the two cities in 2010/2011, also reveals that Hong Kong's marriage delay has a negative impact on fertility and it is the higher MFR that leads to a higher TFR than Shanghai's TFR. It also shows that a reduction of first- and second-order births is equally responsible for Shanghai's lower MFR. Despite the one-child policy in Shanghai, some couples continue to postpone their first births, while others have even chosen to be childfree (a preferred term to ‘childless’). The tempo distortion is diminishing more prominently in Hong Kong, while the decline in fertility aspiration adds much uncertainty to future fertility trends in Shanghai.     

Estimating Historical Total Fertility Rates for Australia and Its States

Abstract.

Australian Bureau of Statistics Total Fertility Rate (TFR) statistics are available from 1921 for Australia, and for census years between 1947 and 1966 for the states, and then on an annual basis from 1971. Using historical, statistical publications, annual TFRs for Australia and the states dating back to federation in 1901 were calculated directly in years where data are available and estimated indirectly via the standardized fertility ratio in other years. For some periods where direct TFR estimation was applied, age-specific births used in the numerators of fertility rates must be estimated from partial data. Combined with Australian Bureau of Statistics data, the authors’ estimated TFRs contribute an uninterrupted time series of national and state TFRs for Australia from 1901 to 2011.     

The Author Responds

Abstract

Administrative practices, political initiatives, and budgetary concerns are eroding the ability of most universities to fulfill their mission as engines of meritocratic upward mobility. Colleges fulfilled this mission because they signaled that a student had acquired—or had always possessed—superior skills. Elite universities admit students who we know can succeed: Upward mobility occurred because other schools took chances on students whose backgrounds suggested that they might or might not succeed. Pushes to improve undergraduate retention and completion rates at these other universities result in a lowering of standards that threatens their signaling role, and with it, their ability to open doors for their students.